The JI PBL Intereron Source
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     
 

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Related articles in The JI
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Andrassy, J.
Right arrow Articles by Burlingham, W. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Andrassy, J.
Right arrow Articles by Burlingham, W. J.
The Journal of Immunology, 2003, 171: 5554-5561.
Copyright © 2003 by The American Association of Immunologists

Tolerance to Noninherited Maternal MHC Antigens in Mice 1

Joachim Andrassy2,*, Satoshi Kusaka2,*,{ddagger}, Ewa Jankowska-Gan*, Jose R. Torrealba{dagger}, Lynn D. Haynes*, Brodie R. Marthaler*, Robert C. Tam§,¶, Ben M.-W. Illigens§, Natalie Anosova§, Gilles Benichou§ and William J. Burlingham3,*

Departments of * Surgery and {dagger} Pathology and Laboratory Medicine, University of Wisconsin, Madison, WI 53792; {ddagger} Department of Gastroenterological Surgery, Transplant, and Surgical Oncology, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan; § Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114; and ICN Pharmaceuticals, Costa Mesa, CA 92626


   Abstract
Top
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 References
 
The phenomenon of tolerance to noninherited maternal Ags (NIMA) is poorly understood. To analyze the NIMA effect C57BL/6 (H-2b/b) males were mated with B6D2F1 (H-2b/d) females, whereby 50% of the offspring are H-2b/b mice that have been exposed to maternal H-2d alloantigens. Controls were H-2b/b offspring of C57BL/6 mothers, either inbred C57BL/6 mice or F1 backcross mice from breedings with H-2b/d fathers. We found that 57% of the H-2b/b offspring of semiallogeneic (H-2b/d) mothers accepted fully allogeneic DBA/2 (H-2d/d) heart grafts for >180 days, while similar transplants were all rejected by day 11 in controls (p < 0.0004). Foster nursing studies showed that both oral and in utero exposure to NIMA are required for this tolerogenic effect. An effect of NIMA was also found to extend the survival of skin grafts from a semiallogeneic donor (p < 0.02). Pretransplant analysis of splenocytes showed a 40–90% reduction of IL-2-, IL-5-, and IFN-{gamma}-producing T cells responding to H-2d-expressing APC in NIMAd-exposed vs control mice. Injection of pregnant BALB/c-dm2 (H-2Ld-negative) female mice i.v. with H-2Ld61–80 peptide profoundly suppressed the offspring’s indirect pathway alloreactive CD4+ T cell response to H-2Ld. These results suggest that the natural exposure of the fetus and newborn to maternal cells and/or soluble MHC Ags suppresses NIMA-allospecific T cells of the offspring, predisposing to organ transplant tolerance in adult mice.


   Introduction
Top
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 References
 
Despite advances in immunosuppressive therapy, immune-mediated rejection remains the leading cause of graft failure in patients. In addition, such treatment is nonspecific, and it is generally associated with increased risk of infection and neoplasia (1, 2, 3). It is therefore crucial to design more selective strategies to achieve donor-specific immune tolerance in recipients. Transplantation tolerance, defined broadly as long-term allograft survival in the absence of immunosuppressive treatment, is regularly achieved in nature during pregnancy. The fetus is separated from the mother by the placental barrier, a feature resembling that observed in immune-privileged sites (4, 5). This barrier is semipermeable, i.e., small numbers of fetal cells and soluble Ags can traffic from the fetus to the mother via the placenta and can persist in her body for extended periods of time (6, 7). A reciprocal process, the trafficking of maternal cells across the placenta, has also been documented (8) and can result in life-long microchimerism in the offspring (9). In addition, maternal cells and HLA proteins are ingested by the baby during nursing, possibly stimulating oral tolerance (10). Whether these processes can result in allo-tolerance has been the subject of debate. Evidence in favor of acquired tolerance to noninherited maternal Ags (NIMA) 4 includes the inhibition of humoral responses (11, 12), prolonged survival of kidney transplants from sibling (13) or cadaver (14) donors, and suppression of graft-vs-host responses after bone marrow transplantation (15). However, the NIMA effect has certain puzzling features. For example, renal allografts from maternal donors, while showing a significant graft survival benefit in infants (16), were not superior to paternal grafts after the second year of life and may indeed fare slightly worse in adult offspring (17) unless donor-specific transfusions are administered before transplant (18). Second, the improved long-term survival of renal allografts from NIMA+ sibling donors was associated with the rapid onset of an isolated acute rejection episode, suggesting sensitization to NIMA, rather than an acquired unresponsiveness (13). Third, there appears to be no acquired defect in primary CD8+ CTL responses to NIMA MHC class I alloantigens in adults (19, 20). Clearly, mechanistic analysis of the NIMA effect would greatly benefit from a reproducible animal model of NIMA-induced allo-tolerance.

In the present study we tested the hypothesis that maternal Ag exposure alone can induce tolerance to a primarily vascularized organ allograft in mice. Our results are consistent with this hypothesis and further suggest that a NIMA effect is due to a profound inhibition of allospecific T and B cell responses in the offspring rather than to immune deviation.


   Materials and Methods
Top
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 References
 
Source of mice and typing reagents

C57BL/6 (H-2b/b), DBA/2 (H-2d/d), and (C57BL/6 x DBA/2)F1 (B6D2F1; H-2b/d) mice were obtained from Harlan Sprague Dawley (Indianapolis, IN). BALB/c-dm2 mice breeding pairs were obtained from The Jackson Laboratory (Bar Harbor, ME). The care and breeding of animals was in accordance with institutional guidelines. Offspring of F1 backcross breeding pairs (NIMA and noninherited paternal Ag (NIPA) offspring) were nursed by the mother, weaned after 21 days, and typed for H-2 locus encoded Ags. To investigate the effect of oral vs in utero exposure to NIMA, offspring from NIMA and homozygous C57BL/6 breedings were exchanged for each other directly after birth and foster-nursed. Typing was performed either by flow cytometry using Abs specific for H-2KbDb (clone 5041.16.1; Cedarlane, Westbury, NY) and H-2Dd (clone 34-5-8S, Cederlane) or by a genomic DNA-based typing described previously (21). Offspring typed as positive for both b and d haplotype Ags were used as skin and organ donors of semiallogeneic (H-2b/d) grafts to H-2b/b homozygous recipients. Both donors and recipients were 6–12 wk old at the time of transplantation.

Skin grafting

Skin transplantation was performed using a modification of a technique described previously (22). Ear skin was harvested from a donor as well as the recipient mouse (autologous skin graft), and both were then placed in graft beds prepared on the back of the recipient. The grafts were secured using gauze and a bandage, which were removed for scoring purposes 7 days later. The allograft was considered fully rejected when it was >90% necrotic.

Heart transplantation and histopathologic analysis

Heterotopic vascularized heart transplantation was conducted using the intra-abdominal microsurgical technique described by Corry et al. (23). The grafts were monitored by daily palpation and graded from 4+ (strongest beat) to 0 (no beat). Graft rejection was determined by complete cessation of heartbeat (grade 0) and was confirmed by laparotomy. Histopathologic analysis was performed on paraffin-embedded sections of heart allografts removed at necropsy. Sections were stained with either H&E or Trichrome and were scored blindly according to the established clinical criteria for diagnosing heart transplant rejection (24).

Analysis of maternal cell microchimerism by nested PCR

Cells from spleens, lymph nodes, and thymuses were harvested, and genomic DNA was isolated using the Wizard Genomic DNA Purification Kit (Promega, Madison, WI). The purity and concentration of the DNA were analyzed by spectrophotometry, and 0.5 µg was used for nested PCR. A region of the MHC class II Eb gene nonspecific for the d haplotype was amplified for 30 cycles (75 s at 94°C, 60 s at 56°C, and 105 s at 72°C). This was followed by a second amplification of a d-specific region for 14 cycles (60 s at 94°C, 60 s at 56°C, and 60 s at 72°C). Primers for nonspecific amplification were: A, 5'-ACCCTGGCAACATTGAAGTC-3'; and B, 5'-TTCCTGGT-CATGTTGAGAAA-3'. Primers for d-specific amplification were: A, 5'-AGACTCTGTGAATGCCTGCCT-3'; and B, 5'-AGCTAGCGGCAGAGGCTACAGCA-3'.

Peptides

The peptides used in this study were synthesized at Norris Cancer Center Microchemistry Laboratory, University of Southern California, with a PE Applied Biosystems model 430A automated peptide synthesizer (Foster City, CA) using modified Merrifield chemistry and were purified by Sephadex Glo chromatography to a purity of >95%. Peptides were dissolved at a concentration of 1 mg/ml in PBS (10 mM phosphate and 150 mM NaCl, pH 7.2) and further diluted to appropriate concentrations with assay medium.

Preparation of responder cells

Spleen cells were used as a source of responder T cells. RBC were lysed for 2 min in Tris-NH4Cl solution. Spleen cells were washed twice in AIM-V (Life Technologies, Grand Island, NY) culture medium containing 0.5% FCS and resuspended at 107 cells/ml. In some experiments T cells were isolated from mouse spleen cells by negative selection using commercially available T cell purification columns according to the manufacturer’s instructions (Accurate Chemical & Scientific Corp., Westbury, NY; R&D Systems, Minneapolis, MN). Purified T cells were washed in HBSS and used at 5 x 105 cells/well in ELISPOT assays.

Preparation of APCs and donor cell sonicates

Splenocytes from donor and recipient naive mice were used as a source of allogeneic stimulator cells or syngeneic APCs, respectively. Single-cell suspensions of splenocytes devoid of RBC were prepared in culture medium and were gamma-irradiated (3000 rad). The irradiated cells were washed in HBSS, incubated for 10 min at 37°C, washed again, and finally resuspended in culture medium at 1–3 x 107 cells/ml. In some experiments allogeneic spleen cells were suspended at 3 x 107 cells/ml in culture medium and sonicated with 10 pulses of 1 s. The resulting suspension was frozen in a dry ice/ethanol bath, thawed at room temperature, centrifuged at 1200 rpm for 10 min to remove intact cells, and used to stimulate recipient splenocytes.

ELISPOT assay

ELISPOT assay was conducted as described previously (25), using either a 1:2 responder to donor stimulator cell ratio for mixed lymphocyte cultures or syngeneic APCs together with donor sonicate to detect a response to soluble alloantigens and allopeptides. Briefly, ELISPOT plates (Polyfiltronics, Rockland, MA) were coated with mAb in PBS overnight. Anti-IL-2, -IFN-{gamma}, -IL-4, and -IL-5 mAbs were used at 3, 4, 2, and 5 µg/ml (BD PharMingen, San Diego, CA). Plates were blocked with PBS containing 1% BSA for 1.5 h before cells were added and incubated at 37°C in 7% CO2 for different periods of time (20 h for IL-2, 42 h for IFN-{gamma} and IL-4, and 48 h for IL-5). After washing, biotinylated anti-lymphokine mAbs were added at 2 µg/ml (BD PharMingen) and incubated for 5 h at room temperature or overnight at 4°C. Plates were washed three times with PBS containing 0.025% Tween (PBST), and avidin-HRP (diluted 1/2000) was added for 1.5 h. Four washes with PBS were performed before spots were revealed by the addition of developing solution (800 µl of 3-amino-9-ethylcarbazole (Sigma-Aldrich, St. Louis, MO) in 24 ml of 0.1 M sodium acetate, pH 5.0, catalyzed by 12 µl H2O2).

Allopeptide-specific proliferation assay

Popliteal lymph node cells and splenocytes were obtained 10 days after s.c. immunization with Ld61–80 peptide and were used in Ag-induced proliferation assays. Cell suspensions were cultured in 0.2 ml of serum-free HL-1 medium (Ventrex, Portland, ME) containing 2 mM glutamine in 96-well plates for 4 days (5 x 105 cells/well). T cells were stimulated in vitro with Ld61–80 peptide or an irrelevant hen egg lysozyme peptide (HEL46–61; 5–20 µg/ml). Proliferation was assessed by the incorporation of 1 µCi of [3H]thymidine during the last 18 h of culture.

Ab detection

Serum samples were taken from the tail of tolerant NIMAd-exposed (H-2b/b) (>100 days post-transplant with a DBA/2 heart graft), B6 mice with a rejected DBA/2 heart graft and nontransplanted (naive) C57BL/6 mice. Varying concentrations of the serum samples were incubated with 2 x 105 thymocytes/tube from DBA/2 or C57BL/6 for 30 min. After washing, secondary Abs, anti-mouse IgG1-FITC or anti-mouse IgG2a-FITC (Southern Biotechnology Associates, Birmingham, AL) were added. After 30-min incubation, cells were washed, and propidium iodide (5 µg/ml) was added to exclude dead cells from analysis. The mean fluorescence intensity was determined by flow cytometry (Calibur; BD Biosciences, San Jose, CA).

Statistical analyses

Statistical analysis of ELISPOT and graft survival data was performed using Student’s t test and Wilcoxon’s log rank test, respectively.


   Results
Top
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 References
 
Influence of NIMA exposure on the survival of primarily vascularized heart allografts

As illustrated in Fig. 1, we used the F1 x P backcross breeding scheme of Zhang and Miller (26) to generate H-2b/b mice that had a B6D2F1 mother and thus were NIMA-H-2d exposed. In addition, we prepared an NIPA control consisting of F1 x P backcross breeding of a B6 female with a B6D2F1 father, generating H-2b/b offspring that had not been exposed to maternal H-2d-Ags during development, but had a similar genetic background. These F1 backcross NIPA mice were used along with inbred B6 mice as H-2b/b (nonexposed to H-2d) controls.



View larger version (27K):
[in this window]
[in a new window]
  		FIGURE 1. F1 backcross breeding scheme to create NIMAd-exposed and NIPAd control mice. Left, C57BL/6 males (H-2b/b) were mated with (B6 x DBA/2)F1 females (H-2b/d), thus exposing the H-2b/b offspring in utero and via breast feeding to the noninherited maternal d Ags (NIMAd; NIMAd exposure is shown by the outlined mouse). Right, (B6 x DBA/2)F1 males were mated with B6 females, creating H-2b/b F1 backcross offspring that had not been exposed to d. These are designated noninherited paternal Ag (NIPAd) controls. Haplotypes are color-coded: H-2b/b, gray; H-2b/d, gray and white.

 
Heterotopic heart transplants were performed in NIMAd-exposed mice and control H-2b/b recipients, using either fully allogeneic DBA/2 (H-2d/d) or third-party (H-2k/k) mice as donors. When fully allogeneic DBA/2 (H-2d/d) heart grafts were transplanted, NIPA control mice uniformly rejected their grafts by day 11 after transplantation, similar to the graft survival time in B6 recipients (Fig. 2). In contrast, only a minority (9 of 21, or 43%) of NIMAd-exposed mice receiving DBA/2 heart allografts rejected their allografts, mostly in delayed fashion (median, 20 days). The other 57% (12 of 21) of NIMA recipients retained their allografts throughout the period of investigation (>180 days; Fig. 2). All DBA/2 hearts in NIMAd-exposed recipients showed some graft swelling and weakening of the heart beat between 7 and 14 days after transplantation, indicative of an acute rejection episode. The heartbeat score of most long-surviving grafts remained low (1+ to 2+), while in others it regained strength up to a 3+ level (data not shown). The tolerance induced by NIMA exposure was specific for H-2d alloantigens, in that third-party C3H heart allografts were all rejected within 9 days after transplantation (Fig. 2A). When NIMA and B6 offspring were exchanged for each other directly after birth, resulting in either oral or in utero exposure alone, a prolongation of fully allogeneic grafts from DBA/2 could no longer be observed (Fig. 2B). As controls, offspring from NIMA breedings (H-2b/b) were transferred and nursed by foster B6D2F1 mothers. When these mice were transplanted with heart allografts from DBA/2, the long term graft survival rate was similar to that seen in NIMAd-exposed offspring nursed by their own mothers (compare Fig. 2, A and B). This suggests that the loss of the NIMA effect when pups were nursed by B6 mothers was not due to separation from the natural mother itself.



View larger version (23K):
[in this window]
[in a new window]
  		FIGURE 2. A, Influence of NIMA exposure on the survival of primary vascularized, fully allogeneic heart grafts. NIMA mice (H-2b/b, exposed to maternal d Ags) were transplanted with DBA/2 hearts ({blacksquare}; n = 21). As controls, NIPA backcross (H-2b/b; {diamond}; n = 5) and C57BL/6 mice ({circ}; n = 7) were also transplanted with DBA/2 hearts. As a third-party control ({diamondsuit}; n = 5) NIMAd-exposed, F1 backcross (H-2b/b) were transplanted with C3H hearts (H-2k/k). *, p < 0.003 vs NIPA, p < 0.0004 vs B6, p < 0.0009 vs C3H. B, Importance of oral vs in utero exposure to NIMA on the survival of primary vascularized, fully allogeneic heart grafts. NIMA offspring (H-2b/b) was transferred and nursed by either a foster B6D2F1 (H-2b/d) mother ({blacksquare}; n = 9) or a B6 mother ({diamond}; n = 9), resulting in oral and in utero exposure to NIMA or in utero exposure alone. For oral exposure alone, B6 offspring (H-2b/b) were foster-nursed by a B6D2F1 mother ({circ}; n = 10). All mice received a DBA/2 heart allograft at maturity. *, p < 0.02 vs in utero exposure, p < 0.02 vs oral exposure. C, Maternal cell microchimerism. A nested PCR was performed on DBA/2 (pos. control), B6 (neg. control), and mixtures of DBA/2 and B6 cells (1/104 to 1/2 x 105) as shown. Fully exposed NIMA animals (lanes 1–3) had positive signals of varying intensity for MHC class II Ebd-specific DNA. In utero only exposure resulted in either low (lane 4) or undetectable (lane 5) levels of microchimerism. No d-specific cells were detected in NIPA animals (lanes 6 and 7).

 
Maternal cell microchimerism may be critical for the induction and maintenance of tolerance. Therefore, we analyzed levels of maternal cell microchimerism in fully (oral plus in utero) and partially (in utero only) exposed NIMA animals as well as in NIPA and B6 controls. As shown in Fig. 2C, all fully exposed NIMA animals (lanes 1–3) showed a positive signal with varying intensity. Partially exposed NIMA animals either showed low levels (lane 4) or levels that remained below the level of detection (lane 5). No d-positive cells were detected in NIPA controls (lanes 6 and 7).

Histopathological analysis of no longer functional DBA/2 heart grafts transplanted into NIMAd-exposed animals (Fig. 3B, 24 days post-transplant) showed a less severe acute rejection pattern compared with the NIPA control (Fig. 3A, 8 days post-transplant). DBA/2 grafts from tolerant NIMA animals (Fig. 3, C and D, 293 and 338 days post-transplant) showed only mild leukocyte infiltrates and well preserved myocytes. A series of five tolerant animals (not shown) had varying degrees of acute rejection grades from IA to IIIA. The rejection grades were inversely correlated with the strength of the heart beat (1+ to 3+; see also Fig. 3, C–F).



View larger version (161K):
[in this window]
[in a new window]
  		FIGURE 3. Histology of transplanted DBA/2 heart allografts. A, Graft from a NIPA control (H-2b/b) mouse undergoing acute rejection grade IV on day 8 post-transplant (magnification, x200). There is a severe lymphocytic infiltration with myocyte damage (black arrow) and large foci of necrosis (white arrow) with myocyte destruction and cell debris (inset; magnification, x600). B, Graft from NIMAd-exposed F1 backcross (H-2b/b) undergoing delayed rejection on day 24 post-transplant (magnification, x200). Sections show acute rejection grade IIIA with pronounced perivascular (black arrow) and multifocal interstitial lymphocytic infiltrates with foci of myocyte damage. Note that changes were moderate compared with the NIPA control (A), still showing viable tissue (white arrow and inset; magnification, x600). C and E, Graft from tolerant NIMAd-exposed F1 backcross (H-2b/b). The animal was sacrificed on day 293 post-transplant with good graft function (heart beat, 2+). H&E staining (C; magnification, x200) shows acute rejection grade II with mild perivascular and interstitial infiltrates (white arrow). Importantly, vessels (black arrow and inset; magnification, x600) have no significant intimal thickening, a feature characteristic of chronic rejection. Staining with Trichrome (E; magnification, x400) reveals mild perivascular and interstitial fibrosis (in blue). The vessel (black arrow) located directly underneath the epicardium (white arrow) shows no intimal thickening and a widely patent lumen. D and F, Graft from tolerant NIMAd-exposed F1 backcross (H-2b/b). The animal was sacrificed on day 338 post-transplant and had maintained excellent graft function (heart beat, 3+). H&E staining (D; magnification, x200) shows acute rejection grade IA with mild focal interstitial lymphocytic infiltrates and no myocyte damage (white arrow). Vessels show no significant intimal thickening (inset; magnification, x600). Trichrome staining (F; magnification, x400) reveals mild perivascular and focal interstitial fibrosis (in blue), but no fibrointimal proliferation of the vessels (arrow).

 
Additionally, trichrome stains were performed for more in-depth analysis of chronic changes. Here, a mild degree of interstitial and perivascular fibrosis was seen (Fig. 3E, 293 days post-transplant, and Fig. 3F, 338 days post-transplant). This was expected in part due to the severe hypotrophic changes (heterotopically transplanted hearts receive no influx from the lungs, and thus pump considerably smaller volumes). The coronary arteries, however, had patent lumina with no intimal thickening, a key diagnostic criterion for chronic rejection.

Prolongation of skin graft survival in NIMA-exposed offspring

Control B6 mice failed to reject semiallogeneic (H-2b/d) heart allografts (data not shown). However, they did reject semiallogeneic skin grafts, making it possible to compare the DBA/2 and B6D2F1 as donors in the same allograft system. NIMAd-exposed mice as well as NIPA and B6 controls were transplanted with semiallogeneic (H-2b/d) skin. All skin allografts were rejected. We observed a 3-day prolongation in median survival time of semiallogeneic (H-2b/d) skin grafts in NIMAd-exposed mice that was statistically significant compared with either NIPA (p < 0.01) or B6 (p < 0.02) control mice (Table I) and was consistent with a previous report (26). There was a slight increase in the mean graft survival time of fully allogeneic DBA/2 skin allografts in NIMAd mice compared with B6 control mice (p < 0.01; Table I); however, this was not significant when compared with NIPA controls (p = NS).


View this table:
[in this window]
[in a new window]
  		Table I. Skin graft prolongation in NIMAd exposed mice

 
Influence of fetal/neonatal exposure to NIMA on the response of alloreactive T cells

To study the immunologic mechanism of the tolerogenic NIMA effect on heart allograft survival in vitro, we examined the frequency of cytokine-producing alloreactive T cells from nongrafted mice. As shown in Table II, we detected a potent primary response of IFN-{gamma}-, IL-2-, and IL-5-producing T cells from B6 control mice to both DBA/2 and B6D2F1 stimulator cells, the response to fully allogeneic APC being ~2- to 3-fold higher. Strikingly, all NIMAd-exposed F1 backcross mice (H-2b/b) displayed markedly lower cytokine responses; the frequency of cytokine-producing T cells responding to semiallogeneic splenocytes in NIMAd-exposed mice was reduced by 68–85%, while the average number of T cells responding to fully allogeneic DBA/2 stimulators was reduced by 36–75% relative to B6 controls (Table II).


View this table:
[in this window]
[in a new window]
  		Table II. Pre-transplant frequency of alloreactive T cells in NIMA-exposed and control micea

 
Although the effect on type 2 (IL-5-producing) responder T cells (30–70% reduction; p < 0.05) was not as pronounced as the effect on type 1 (IFN-{gamma}- and IL-2-producing) cells (78–85%-reduction; p < 0.01; Table II), we found no evidence for Th1 to Th2 immune deviation as a result of exposure to maternal alloantigens.

Influence of NIMA exposure on alloreactive T cell responses after skin graft challenge

The influence of the semiallogeneic mother on the developing immune system of the NIMA offspring, while sufficient to overcome a full major plus minor histocompatibility barrier in the DBA/2 to B6 heart transplant model, was not able to induce tolerance to skin allografts. Nonetheless, the profound (68–85%) reduction in the pretransplant frequency of cytokine-responsive anti-F1 T cells relative to controls as well as the F1 skin graft prolongation data hinted that the NIMA effect in mice, as in humans (13), may, in fact, be strongest in the recipient of a semiallogeneic (partially MHC-matched) allograft. To verify this, we transplanted NIMAd-exposed and control B6 mice with skin allografts from either fully (H-2d/d) or semiallogeneic (H-2b/d) donors. Ten days later we measured the frequency of IFN-{gamma}-, IL-2-, IL-5-, and IL-4-producing T cells, the latter as an additional marker of Th2 cells. As shown in Fig. 4, left panel, the frequencies of both IL-2- and IFN-{gamma}-producing T cells from NIMA animals responding to the semiallogeneic donor APC were significantly reduced (p < 0.01) relative to those of skin-grafted B6 controls to levels comparable to those observed in nongrafted mice (Table II). Interestingly, no significant differences in type 2 cytokine (IL-4, IL-5)-producing T cells between control and NIMA mice were seen.



View larger version (17K):
[in this window]
[in a new window]
  		FIGURE 4. Influence of NIMA exposure on the frequency of alloreactive T cells producing type 1 and 2 cytokines in skin-grafted mice. NIMAd-exposed F1 backcross (H-2b/b) or B6 control mice were engrafted with semiallogeneic skin from B6D2F1 (left panel) or fully allogeneic skin from DBA/2 donors (right panel). The frequency of type 1 (IL-2, IFN-{gamma}) and type 2 (IL-4, IL-5) cytokine-producing T cells was evaluated using ELISPOT. The results represent the mean number of spots ± SE obtained in six mice tested individually. *, p < 0.01; **, p < 0.001. {blacksquare}, Response to donor APCs by skin grafted C57BL/6 (positive control); , response to donor APCs by skin grafted NIMAd-exposed F1 backcross mice; {square}, response to B6 APCs by skin grafted NIMAd-exposed F1 backcross mice (negative control).

 
As shown in Fig. 4, right panel, T cells obtained after challenge of control mice with DBA/2 skin grafts and restimulation with donor (DBA/2) cells in vitro showed profoundly increased (>2000 spots/106) IL-2 and IFN-{gamma} cytokine responses compared with naive B6 controls (Table II). While there was a highly significant (p < 0.001) reduction in IL-2-producing cells relative to the controls in NIMAd-exposed mice, the same mice showed no deficit in IFN-{gamma} response to a fully allogeneic DBA/2 skin challenge.

Influence of maternal injection with allopeptide on indirect pathway alloresponses in offspring

In the setting of fetal-maternal microchimerism as well as in transplantation of bone marrow or organ allografts containing passenger leukocytes (27), APCs from both host and donor are available to the host T cells. This unique situation is the basis for the duality of indirect (host APC-dependent) (28) and direct (donor APC-dependent) (29, 30) allorecognition pathways. While the use of F1 stimulator cells may partly detect the response of allopeptide-specific, self MHC-restricted T cells (31), we could not assess the NIMA effect on purely indirect pathway Th1 or Th2 cells in the C57BL/6-anti-DBA/2 model, since the frequency of T cells responding via an indirect pathway to DBA/2 spleen cell sonicates and autologous APC was extremely low (<15 spots/106 cells; data not shown). We therefore used the well-characterized indirect pathway response of CD4+ T cells from H-2Ld-negative BALB/c-dm2 mice to the Ld61–80 peptide (32). This immunodominant peptide or saline alone was injected i.v. into pregnant BALB/c-dm2 mice. Two weeks after weaning, offspring were primed s.c. with either Ld61–80 peptide or HEL46–61, an irrelevant third-party peptide, also recognized in the context of IAd. Responder spleen cells from all mice were restimulated in vitro with the same peptide used for s.c. priming. T cells from control offspring of saline-treated mothers showed a normal dose-dependent response to the Ld61–80 peptide (Fig. 5). T cells from offspring of Ld peptide-treated mothers, however, failed to react to the Ld61–80 peptide, but responded normally to HEL46–61 (Fig. 5). This result indicates that exposure to a maternally derived soluble MHC allopeptide Ag in utero can lead to a specific reduction of alloreactivity mediated via the indirect pathway.



View larger version (22K):
[in this window]
[in a new window]
  		FIGURE 5. Influence of injection of mothers with Ld61–80 peptide on the indirect alloresponse in offspring. BALB/c-dm2 pregnant female mice, which are lacking Ld MHC class I gene expression, were injected i.v. with saline ({square}) or Ld61–80 allopeptide (• and {triangleup}). Offspring (when 6–8 wk old) were primed with Ld61–80 allopeptide (•) or HEL46–61 peptide ({triangleup}). The spleen cells from offspring were harvested and restimulated with the priming peptide. Offspring from saline-treated females ({square}) were primed and boosted with Ld61–80 peptide and served as positive controls. The results of proliferation in response to varying concentrations of Ld61–80 ({square} and •) or HEL46–61 ({triangleup}) are representative of four mice tested individually.

 
IgG Ab responses to heart allografts in NIMA-exposed vs control mice

A sensitive indicator of the indirect pathway response to alloantigens is the ability of the host to mount Th-dependent IgG responses to donor MHC Ags (33). We therefore compared the IgG1 and IgG2a Ab responses of tolerant NIMAd-exposed and control C57BL/6 mice (rejectors), both >100 days post-transplant with DBA/2 heart grafts. As shown in Fig. 6, rejectors produced significantly higher levels of Th2-dependent IgG1 (p < 0.05) and Th1-dependent IgG2a (p < 0.05) Abs compared with the tolerant NIMA animals. No autoantibodies could be detected when serum was incubated with C57BL/6 cells (data not shown).



View larger version (18K):
[in this window]
[in a new window]
  		FIGURE 6. Influence of NIMA exposure on the production of alloantibodies. Serum titrations (y-axis) to reach a mean fluorescence intensity (MFI) of 20 using anti-mouse IgG1 ({blacksquare}) and anti-mouse IgG2a-FITC () Abs in NIMA-tolerant animals, transplanted with a fully allogeneic heart from DBA/2 (>100 days post-transplant; n = 5), C57BL/6 mice with a rejected heart graft from DBA/2 (>100 days post-transplant; n = 2), and naive (nontransplanted) C57BL/6 (n = 3). *, p < 0.05.

 

   Discussion
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
References
 
Until now the primary evidence favoring in utero and neonatally acquired tolerance to noninherited maternal Ags has come from human studies (12, 13, 15, 34). We report here the remarkable finding that 57% of DBA/2 (H-2d/d) heart allografts were accepted without any additional drug or conditioning treatment in NIMAd-exposed F1 backcross (H-2b/b) mice. Furthermore, the long-surviving (>200 days) allografts lacked vascular intimal hyperplasia associated with chronic rejection and common to models of heart allograft acceptance induced in adult inbred rodents (35, 36). Several possible mechanisms may contribute to the tolerogenic effects exerted by the mother on the developing immune system of the offspring. One is the idea suggested by a retrospective human study that the NIMA effect is in part a manifestation of donor-specific oral tolerance through milk feeding (10). While this previous study could not distinguish the in utero from oral tolerance effects of NIMA exposure, we show clearly that both are required for the NIMA effect in a highly immunogenic heart allograft model (Fig. 2B).

Maternal cells and soluble MHC Ags may cause clonal deletion of fetal/neonatal T cells responding to NIMA via the direct and indirect allorecognition pathways. Maternal cell microchimerism in the thymus of both mouse (37) and human (38) newborns has been reported, and this could cause deletion of newly arising donor-reactive T cells (39, 40). The abrogation of allopeptide-specific proliferative responses in offspring of mothers injected with allopeptide during pregnancy (Fig. 5) and the pronounced decrease in direct pathway T cell responses to H-2d-positive APC in NIMAd-exposed offspring (Table II) are also consistent with this possibility. However, while the numbers of IFN-{gamma}-producing T cells responding to DBA/2 stimulator cells was suppressed pretransplant (Table II), a donor DBA/2 skin allograft challenge restored this response in NIMAd-exposed mice to a level indistinguishable from that in skin-grafted control B6 mice (Fig. 4). Since the IFN-{gamma}-producing T cells responding to skin allograft challenge are mainly CD8+, while the IL-2 responders are mainly CD4+ (41), the low IL-2, but high IFN-{gamma}, response to DBA/2 skin graft challenge (Fig. 4) suggests a more profound inhibitory effect of NIMA exposure on allo-specific CD4+ than on CD8+ T cells. While skin transplants seem to be rejected by both the CD4+ and CD8+ T cell compartments (25), with a stronger contribution by the latter (42), heart transplant rejection appears to be more dependent on a functioning CD4+ alloresponse (43, 44). Thus, if the mother’s tolerogenic effect in the heart transplant model is deletional, it is not uniformly so, but rather seems biased toward CD4+, MHC class II-restricted T cells. These could very well include CD4+ T cells specific for allopeptides presented by host MHC class II+ APC, as suggested by the profound inhibition of proliferative CD4 T cell response to Ld61–80 in offspring of mothers injected with this allopeptide during pregnancy (Fig. 5). However, this experiment is open to an alternative interpretation, that the mother’s T cells impose a regulated state of unresponsiveness in the offspring, since she herself lacks the alloantigen Ld. For this reason we have conducted preliminary experiments in the NIMAd F1 backcross model, using the E{alpha}52–67 peptide derived from the d haplotype (45, 46). We found a 27–32% reduction of IFN-{gamma} and IL-2 ELISPOT responses to E{alpha}52–67 in NIMAd-exposed animals compared with B6 controls (J. Andrassy, G. Thomas, and W. J. Burlingham, unpublished observation).

An alternative to the idea of central deletion is the induction of anergy in NIMA-reactive T cells due to maternal microchimerism in peripheral lymphoid tissues. The anergy hypothesis predicts that the NIMA-specific T cells will not proliferate when they encounter NIMA+ APC soon after allograft challenge due to maternal inactivation, but will still persist and retain certain functions (47). Zhang and Miller (26) reported higher levels of donor T cells (microchimerism) in NIMA-exposed, long-term skin graft acceptors compared with NIMA-exposed F1 backcross mice that rapidly rejected NIMA+ skin and suggested that anergy due to a veto effect (48) might be responsible. We found varying degrees of maternal cell microchimerism in nongrafted NIMAd-exposed animals. The results indicated higher levels of d-positive cells in oral plus in utero exposed NIMA animals compared with only in utero exposed NIMAd mice and NIPA controls. We have shown in a previous human study that rare maternal cells in a patient accepting a maternal renal allograft without immunosuppression could specifically inhibit anti-donor CTL activity in vitro, accounting for a state of functional unresponsiveness (anergy) of these CTL in vivo (49).

A third possible mechanism for the specific tolerance to NIMA+ heart transplants and prolongation of NIMA+ semiallogeneic skin allografts involves active immune regulation, a common feature of organ allograft acceptance in mice and humans (50, 51). This seems likely in view of the importance of oral exposure to the maternal d Ags, since oral tolerance is known to depend upon TGF-{beta} production by Th3 or T regulatory cells (52, 53). While the ELISPOT data tend to rule out Th1 to Th2 immune deviation induced by neonatal T cell priming (54, 55), inhibition of both Th1 and Th2 responses by a T regulatory cell is a distinct possibility (56, 57). Since maternal APC encountered during development are semiallogeneic, they may carry allopeptides naturally processed and presented via the shared class II allorecognition pathway (32) and thus provide the first stimulus for development of NIMA allopeptide-specific T regulatory cells. Maternal induction of a metastable balance between primed effector and regulatory T cells might explain the paradox of the early rejection crises at a time when levels of donor APC (58) and chemokines (59) are highest in the NIMAd-exposed host. The observation of an early diminution of heartbeat in NIMAd-exposed mouse allograft recipients is consistent with the increased incidence of early acute rejection episodes in patients receiving a NIMA+ kidney transplant from a sibling donor and who go on to accept their grafts long term (13).

Lastly, the alloantibody response is known to be a risk factor for the development of chronic heart allograft rejection, particularly complement-fixing Ig isotypes (60). Fetal and neonatal exposure to NIMA may directly inhibit the alloreactive B cells of the offspring (12). Our data suggest that NIMAd exposure both inhibits the development of Th1 responses to H-2d both before and after transplant. This along with direct effects on developing B cells may account for the marked reduction of Th1-dependent, complement-fixing IgG2a Abs after transplant and may contribute to the absence of chronic vascular changes in the long-surviving hearts.

In conclusion, we have found a powerful NIMA effect, promoting tolerance to a primarily vascularized organ allograft in mice. The mechanism of this effect, which closely parallels the NIMA effect seen in human renal and bone marrow transplantation, involves profound suppression of Th indirect and direct pathway responses following fetal/neonatal exposure to maternal cells and alloantigens.

Note added in proof.

Recent ELISPOT analysis of NIPA pre-transplant controls indicate a reduced Th-1 response relative to B6 controls; however, NIMA Th-1 responses are consistently lower.


   Acknowledgments
 
We acknowledge Dr. Tom Warner for assistance with histopathology analysis, Gregory Scott Thomas for assistance with peptide studies, Cheryl Naffz for secretarial assistance, and Dr. Jon van Rood for critical comments on the manuscript.


   Footnotes
 
1 This work was supported by National Institute of Health Grants R01AI44077 and K02AI01452 (to W.J.B.), and RO1EY13310 and AI33704 (to G.B.), and Deutsche Forschungsgemeinschaft AN391/1-1 (to J.A.). Back

2 J. A. and S. K. contributed equally to this work. Back

3 Address correspondence and reprint requests to Dr. William J. Burlingham, Department of Surgery, Room G4/702 CSC, University of Wisconsin, Madison, WI 53792. E-mail address: burlingham{at}surgery.wisc.edu Back

4 Abbreviations used in this paper: NIMA, noninherited maternal Ag; HEL, hen egg lysozyme; NIPA, noninherited paternal Ag. Back

Received for publication April 28, 2003. Accepted for publication September 2, 2003.


   References
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

  1. Rubin, R. H., J. S. Wolfson, A. B. Cosimi, N. E. Tolkoff-Rubin. 1981. Infection in the renal transplant recipient. Am. J. Med. 70:405.[Medline]
  2. Penn, I.. 1998. Occurrence of cancers in immunosuppressed organ transplant recipients. Clin. Transplant. :147.
  3. Hirsch, H. H., W. Knowles, M. Dickenmann, J. Passweg, T. Klimkait, M. J. Mihatsch, J. Steiger. 2002. Prospective study of polyomavirus type BK replication and nephropathy in renal-transplant recipients. N. Engl. J. Med. 347:488.[Abstract/Free Full Text]
  4. Niederkorn, J. Y., J. W. Streilein. 1983. Alloantigens placed into the anterior chamber of the eye induce specific suppression of delayed-type hypersensitivity but normal cytotoxic T lymphocyte and helper T lymphocyte responses. J. Immunol. 131:2670.[Abstract]
  5. Ksander, B. R., M. M. Mammolenti, J. W. Streilein. 1991. Termination of immune privilege in the anterior chamber of the eye when tumor-infiltrating lymphocytes acquire cytolytic function. Transplantation 52:128.[Medline]
  6. Bianchi, D. W., G. K. Zickwolf, G. J. Weil, S. Sylvester, M. A. DeMaria. 1996. Male fetal progenitor cells persist in maternal blood for as long as 27 years postpartum. Proc. Natl. Acad. Sci. USA 93:705.[Abstract/Free Full Text]
  7. Nelson, J. L., D. E. Furst, S. Maloney, T. Gooley, P. C. Evans, A. Smith, M. A. Bean, C. Ober, D. W. Bianchi. 1998. Microchimerism and HLA-compatible relationships of pregnancy in scleroderma. Lancet 351:559.[Medline]
  8. Hall, J. M., P. Lingenfelter, S. L. Adams, D. Lasser, J. A. Hansen, M. A. Bean. 1995. Detection of maternal cells in human umbilical cord blood using fluorescence in situ hybridization. Blood 86:2829.[Abstract/Free Full Text]
  9. Maloney, S., A. Smith, D. E. Furst, D. Myerson, K. Rupert, P. C. Evans, J. L. Nelson. 1999. Microchimerism of maternal origin persists into adult life. J. Clin. Invest. 104:41.[Medline]
  10. Campbell, D. A., Jr, M. I. Lorber, J. C. Sweeton, J. G. Turcotte, J. E. Niederhuber, A. E. Beer. 1984. Breast feeding and maternal-donor renal allografts: possibly the original donor-specific transfusion. Transplantation 37:340.[Medline]
  11. Owen, R. D.. 1945. Immunogenetic consequences of vascular anastomoses between bovine twins. Science 102:400.[Free Full Text]
  12. Claas, F. H., Y. Gijbels, J. van der Velden-de Munck, J. J. van Rood. 1988. Induction of B cell unresponsiveness to noninherited maternal HLA antigens during fetal life. Science 241:1815.[Abstract/Free Full Text]
  13. Burlingham, W. J., A. P. Grailer, D. M. Heisey, F. H. Claas, D. Norman, T. Mohanakumar, D. C. Brennan, H. de Fijter, T. van Gelder, J. D. Pirsch, et al 1998. The effect of tolerance to noninherited maternal HLA antigens on the survival of renal transplants from sibling donors. N. Engl. J. Med. 339:1657.[Abstract/Free Full Text]
  14. Smits, J. M., F. H. Claas, H. C. van Houwelingen, G. G. Persijn. 1998. Do noninherited maternal antigens (NIMA) enhance renal graft survival?. Transplant. Int. 11:82.[Medline]
  15. van Rood, J. J., F. R. Loberiza, Jr, M. J. Zhang, M. Oudshoorn, F. Claas, M. S. Cairo, R. E. Champlin, R. P. Gale, O. Ringden, J. M. Hows, et al 2002. Effect of tolerance to noninherited maternal antigens on the occurrence of graft-versus-host disease after bone marrow transplantation from a parent or an HLA-haploidentical sibling. Blood 99:1572.[Abstract/Free Full Text]
  16. Cecka, J. M., D. W. Gjertson, P. I. Terasaki. 1997. Pediatric renal transplantation: a review of the UNOS data: United Network for Organ Sharing. Pediatr. Transplant. 1:55.[Medline]
  17. Opelz, G.. 1990. Analysis of the "NIMA effect" in renal transplantation: Collaborative Transplant Study. Clin. Transplant. :63.
  18. Burlingham, W. J.. 2000. The blood transfusion effect. S. A. W. Thiru, Jr, ed. Immunology and Pathology of Transplantation 92. Blackwell, Oxford.
  19. Hadley, G. A., N. Kenyon, C. B. Anderson, T. Mohanakumar. 1990. Downregulation of antidonor cytotoxic lymphocyte responses in recipients of donor-specific transfusions. Transplantation 50:1064.[Medline]
  20. Roelen, D. L., F. P. van Bree, E. van Beelen, J. J. van Rood, F. H. Claas. 1995. No evidence of an influence of the noninherited maternal HLA antigens on the alloreactive T cell repertoire in healthy individuals. Transplantation 59:1728.[Medline]
  21. Saha, B. K., J. J. Shields, R. D. Miller, T. H. Hansen, D. C. Shreffler. 1993. A highly polymorphic microsatellite in the class II Eb gene allows tracing of major histocompatibility complex evolution in mouse. Proc. Natl. Acad. Sci. USA 90:5312.[Abstract/Free Full Text]
  22. Kawamura, T., T. Niguma, J. H. Fechner, Jr, R. Wolber, M. A. Beeskau, D. A. Hullett, H. W. Sollinger, W. J. Burlingham. 1992. Chronic human skin graft rejection in severe combined immunodeficient mice engrafted with human PBL from an HLA-presensitized donor. Transplantation 53:659.[Medline]
  23. Corry, R. J., H. J. Winn, P. S. Russell. 1973. Primarily vascularized allografts of hearts in mice: the role of H-2D, H-2K, and non-H-2 antigens in rejection. Transplantation 16:343.[Medline]
  24. Billingham, M. E., N. R. Cary, M. E. Hammond, J. Kemnitz, C. Marboe, H. A. McCallister, D. C. Snovar, G. L. Winters, A. Zerbe. 1990. A working formulation for the standardization of nomenclature in the diagnosis of heart and lung rejection: Heart Rejection Study Group: The International Society for Heart Transplantation. J. Heart Transplant. 9:587.[Medline]
  25. Illigens, B. M., A. Yamada, E. V. Fedoseyeva, N. Anosova, F. Boisgerault, A. Valujskikh, P. S. Heeger, M. H. Sayegh, B. Boehm, G. Benichou. 2002. The relative contribution of direct and indirect antigen recognition pathways to the alloresponse and graft rejection depends upon the nature of the transplant. Hum. Immunol. 63:912.[Medline]
  26. Zhang, L., R. G. Miller. 1993. The correlation of prolonged survival of maternal skin grafts with the presence of naturally transferred maternal T cells. Transplantation 56:918.[Medline]
  27. Steinmueller, D.. 1967. Immunization with skin isografts taken from tolerant mice. Science 158:127.[Abstract/Free Full Text]
  28. Benichou, G., P. A. Takizawa, C. A. Olson, M. McMillan, E. E. Sercarz. 1992. Donor major histocompatibility complex (MHC) peptides are presented by recipient MHC molecules during graft rejection. J. Exp. Med. 175:305.[Abstract/Free Full Text]
  29. Benichou, G., A. Valujskikh, P. S. Heeger. 1999. Contributions of direct and indirect T cell alloreactivity during allograft rejection in mice. J. Immunol. 162:352.[Abstract/Free Full Text]
  30. Lechler, R. I., G. Lombardi, J. R. Batchelor, N. Reinsmoen, F. H. Bach. 1990. The molecular basis of alloreactivity. Immunol. Today 11:83.[Medline]
  31. Weber, D. A., N. K. Terrell, Y. Zhang, G. Strindberg, J. Martin, A. Rudensky, N. S. Braunstein. 1995. Requirement for peptide in alloreactive CD4+ T cell recognition of class II MHC molecules. J. Immunol. 154:5153.[Abstract]
  32. Fedoseyeva, E. V., R. C. Tam, P. L. Orr, M. R. Garovoy, G. Benichou. 1995. Presentation of a self-peptide for in vivo tolerance induction of CD4+ T cells is governed by a processing factor that maps to the class II region of the major histocompatibility complex locus. J. Exp. Med. 182:1481.[Abstract/Free Full Text]
  33. Steele, D. J., T. M. Laufer, S. T. Smiley, Y. Ando, M. J. Grusby, L. H. Glimcher, H. Auchincloss, Jr. 1996. Two levels of help for B cell alloantibody production. J. Exp. Med. 183:699.[Abstract/Free Full Text]
  34. Owen, R. D., H. R. Wood., A. G. Foord, P. Sturgeon, L. G. Baldwin. 1954. Evidence for actively acquired tolerance to Rh antigens. Proc. Natl. Acad. Sci. USA 40:420.[Free Full Text]
  35. Subramanian, S. V., R. J. Kelm, J. A. Polikandriotis, C. G. Orosz, A. R. Strauch. 2002. Reprogramming of vascular smooth muscle {alpha}-actin gene expression as an early indicator of dysfunctional remodeling following heart transplant. Cardiovasc Res. 54:539.[Abstract/Free Full Text]
  36. Demetris, A. J., N. Murase, Q. Ye, F. H. Galvao, C. Richert, R. Saad, S. Pham, R. J. Duquesnoy, A. Zeevi, J. J. Fung, et al 1997. Analysis of chronic rejection and obliterative arteriopathy: possible contributions of donor antigen-presenting cells and lymphatic disruption. Am. J. Pathol. 150:563.[Abstract]
  37. Piotrowski, P., B. A. Croy. 1996. Maternal cells are widely distributed in murine fetuses in utero. Biol. Reprod. 54:1103.[Abstract]
  38. Stevens, A., H. Hermes, T. Tylee, J. L. Nelson. 2002. Maternal microchimerism in human thymus. Clin. Immunol. 103:S16.
  39. Sharabi, Y., V. S. Abraham, M. Sykes, D. H. Sachs. 1992. Mixed allogeneic chimeras prepared by a non-myeloablative regimen: requirement for chimerism to maintain tolerance. Bone Marrow Transplant. 9:191.[Medline]
  40. Lubaroff, D. M., W. K. Silvers. 1970. The abolition of tolerance of skin homografts in rats with isoantiserums. J. Immunol. 104:1236.[Abstract/Free Full Text]
  41. Boisgerault, F., Y. Liu, N. Anosova, E. Ehrlich, M. R. Dana, G. Benichou. 2001. Role of CD4+ and CD8+ T cells in allorecognition: lessons from corneal transplantation. J. Immunol. 167:1891.[Abstract/Free Full Text]
  42. Auchincloss, H., Jr, R. R. Ghobrial, P. S. Russell, H. J. Winn. 1988. Prevention of alloantibody formation after skin grafting without prolongation of graft survival by anti-L3T4 in vivo. Transplantation 45:1118.[Medline]
  43. Madsen, J. C., W. N. Peugh, K. J. Wood, P. J. Morris. 1987. The effect of anti-L3T4 monoclonal antibody treatment on first-set rejection of murine cardiac allografts. Transplantation 44:849.[Medline]
  44. Yamada, A., T. M. Laufer, A. J. Gerth, C. M. Chase, R. B. Colvin, P. S. Russell, M. H. Sayegh, H. Auchincloss, Jr. 2003. Further analysis of the T-cell subsets and pathways of murine cardiac allograft rejection. Am. J. Transplant. 3:23.[Medline]
  45. Murphy, D. B., S. Rath, E. Pizzo, A. Y. Rudensky, A. George, J. K. Larson, C. A. Janeway, Jr. 1992. Monoclonal antibody detection of a major self peptide. MHC class II complex. J. Immunol. 148:3483.[Abstract]
  46. Quezada, S. A., B. Fuller, L. Z. Jarvinen, M. Gonzalez, B. R. Blazar, A. Y. Rudensky, T. B. Strom, R. J. Noelle. 2003. Mechanisms of donor specific transfusion tolerance: pre-emptive induction of clonal T cell exhaustion via indirect presentation. Blood 102:1920.[Abstract/Free Full Text]
  47. Malvey, E. N., M. K. Jenkins, D. L. Mueller. 1998. Peripheral immune tolerance blocks clonal expansion but fails to prevent the differentiation of Th1 cells. J. Immunol. 161:2168.[Abstract/Free Full Text]
  48. Fink, P. J., R. P. Shimonkevitz, M. J. Bevan. 1988. Veto cells. Annu. Rev. Immunol. 6:115.[Medline]
  49. Burlingham, W. J., A. P. Grailer, J. H. Fechner, Jr, S. Kusaka, M. Trucco, M. Kocova, F. O. Belzer, H. W. Sollinger. 1995. Microchimerism linked to cytotoxic T lymphocyte functional unresponsiveness (clonal anergy) in a tolerant renal transplant recipient. Transplantation 59:1147.[Medline]
  50. VanBuskirk, A. M., M. E. Wakely, J. H. Sirak, C. G. Orosz. 1998. Patterns of allosensitization in allograft recipients: long-term cardiac allograft acceptance is associated with active alloantibody production in conjunction with active inhibition of alloreactive delayed-type hypersensitivity. Transplantation 65:1115.[Medline]
  51. VanBuskirk, A. M., W. J. Burlingham, E. Jankowska-Gan, T. Chin, S. Kusaka, F. Geissler, R. P. Pelletier, C. G. Orosz. 2000. Human allograft acceptance is associated with immune regulation. J. Clin. Invest. 106:145.[Medline]
  52. Marth, T., W. Strober, B. L. Kelsall. 1996. High dose oral tolerance in ovalbumin TCR-transgenic mice: systemic neutralization of IL-12 augments TGF-beta secretion and T cell apoptosis. J. Immunol. 157:2348.[Abstract]
  53. Gonnella, P. A., D. Kodali, H. L. Weiner. 2003. Induction of low dose oral tolerance in monocyte chemoattractant protein-1- and CCR2-deficient mice. J. Immunol. 170:2316.[Abstract/Free Full Text]
  54. Forsthuber, T., H. C. Yip, P. V. Lehmann. 1996. Induction of TH1 and TH2 immunity in neonatal mice. Science 271:1728.[Abstract]
  55. Singh, R. R., B. H. Hahn, E. E. Sercarz. 1996. Neonatal peptide exposure can prime T cells and, upon subsequent immunization, induce their immune deviation: implications for antibody vs. T cell-mediated autoimmunity. J. Exp. Med. 183:1613.[Abstract/Free Full Text]
  56. Hara, M., C. I. Kingsley, M. Niimi, S. Read, S. E. Turvey, A. R. Bushell, P. J. Morris, F. Powrie, K. J. Wood. 2001. IL-10 is required for regulatory T cells to mediate tolerance to alloantigens in vivo. J. Immunol. 166:3789.[Abstract/Free Full Text]
  57. Katagiri, K., J. Zhang-Hoover, J. S. Mo, J. Stein-Streilein, J. W. Streilein. 2002. Using tolerance induced via the anterior chamber of the eye to inhibit Th2-dependent pulmonary pathology. J. Immunol. 169:84.[Abstract/Free Full Text]
  58. Larsen, C. P., P. J. Morris, J. M. Austyn. 1990. Migration of dendritic leukocytes from cardiac allografts into host spleens: a novel pathway for initiation of rejection. J. Exp. Med. 171:307.[Abstract/Free Full Text]
  59. el-Sawy, T., N. M. Fahmy, R. L. Fairchild. 2002. Chemokines: directing leukocyte infiltration into allografts. Curr. Opin. Immunol. 14:562.[Medline]
  60. Russell, P. S., C. M. Chase, H. J. Winn, R. B. Colvin. 1994. Coronary atherosclerosis in transplanted mouse hearts. II. Importance of humoral immunity. J. Immunol. 152:5135.[Abstract]

Related articles in The JI:

IN THIS ISSUE

The JI 2003 171: 4957-4958. [Full Text]  



This article has been cited by other articles:


Home page
 BloodHome page
S. J. Opiela, R. B. Levy, and B. Adkins
Murine neonates develop vigorous in vivo cytotoxic and Th1/Th2 responses upon exposure to low doses of NIMA-like alloantigens
Blood, August 15, 2008; 112(4): 1530 - 1538.
[Abstract] [Full Text] [PDF]

Home page
 Biol. Reprod.Home page
M.-C. Maurel and C. Kanellopoulos-Langevin
Heredity--Venturing Beyond Genetics
Biol Reprod, July 1, 2008; 79(1): 2 - 8.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
A. L. Feitsma, J. Worthington, A. H. M. van der Helm-van Mil, D. Plant, W. Thomson, J. Ursum, D. van Schaardenburg, I. E. van der Horst-Bruinsma, J. J. van Rood, T. W. J. Huizinga, et al.
Protective effect of noninherited maternal HLA-DR antigens on rheumatoid arthritis development
PNAS, December 11, 2007; 104(50): 19966 - 19970.
[Abstract] [Full Text] [PDF]

Home page
 BloodHome page
K.-i. Matsuoka, T. Ichinohe, D. Hashimoto, S. Asakura, M. Tanimoto, and T. Teshima
Fetal tolerance to maternal antigens improves the outcome of allogeneic bone marrow transplantation by a CD4+CD25+ T-cell-dependent mechanism
Blood, January 1, 2006; 107(1): 404 - 409.
[Abstract] [Full Text] [PDF]

Home page
 J. Immunol.Home page
J. Kaplan and S. Land
Influence of Maternal-Fetal Histocompatibility and MHC Zygosity on Maternal Microchimerism
J. Immunol., June 1, 2005; 174(11): 7123 - 7128.
[Abstract] [Full Text] [PDF]

Home page
 Biol. Reprod.Home page
C. Vernochet, S. M. Caucheteux, M.-C. Gendron, J. Wantyghem, and C. Kanellopoulos-Langevin
Affinity-Dependent Alterations of Mouse B Cell Development by Noninherited Maternal Antigen
Biol Reprod, February 1, 2005; 72(2): 460 - 469.
[Abstract] [Full Text] [PDF]

Home page
 BloodHome page
T. Ichinohe, T. Uchiyama, C. Shimazaki, K. Matsuo, S. Tamaki, M. Hino, A. Watanabe, M. Hamaguchi, S. Adachi, H. Gondo, et al.
Feasibility of HLA-haploidentical hematopoietic stem cell transplantation between noninherited maternal antigen (NIMA)-mismatched family members linked with long-term fetomaternal microchimerism
Blood, December 1, 2004; 104(12): 3821 - 3828.
[Abstract] [Full Text] [PDF]