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Evidence for the Extrathymic Origin of Intestinal TCR⁺ T Cells in Normal Rats and for an Impairment of This Differentiation Pathway in BB Rats¹

Arthritis and Immune Disorder Research Center, University Health Network, and Departments of Medicine and Immunology, University of Toronto, Toronto, Ontario, Canada

	Abstract

Top Abstract Introduction Materials and Methods Results and Discussion References

 
The BB rat lyp mutation, one of its diabetes susceptibility genes, is responsible for a 5-fold decrease in the number of peripheral TCR⁺ T cells. In this study we show that TCR⁺ T cells are virtually undetectable among splenic T cells and intestinal intraepithelial T lymphocytes (IEL) of BB rats, while they account for 3 and 30% of these two T cell populations, respectively, in normal animals. It has been shown that murine IEL expressing TCR develop extrathymically. We determined whether this is the case in rats. Athymic radiation chimeras reconstituted with normal hemopoietic precursors were devoid of donor-derived TCR⁺ T cells and TCR⁺ splenocytes but contained a normal number of TCR⁺ IEL, suggesting that in unmanipulated rats some of the TCR⁺ IEL may have an extrathymic origin. This was further supported by the observation that RAG1 transcripts are present in IEL of unmanipulated animals. No T cells developed in chimeras reconstituted with BB hemopoietic precursors, demonstrating that the BB rat lyp mutation inhibits both intrathymic and extrathymic development of TCR⁺ T cells.

	Introduction

Top Abstract Introduction Materials and Methods Results and Discussion References

 
The BB rat spontaneously develops an autoimmune, polygenic, diabetic syndrome (1). Several genes contribute to the susceptibility of this animal to type 1 diabetes; iddm2 maps to the class II region of the u haplotype of the major histocompatibility complex (RT1^u) on chromosome 20, while iddm1 maps to the lyp locus on chromosome 4 (2). The mutant allele of lyp carried by BB rats is responsible for an 5-fold decrease in the number of CD4⁺TCR⁺ and CD8⁺TCR⁺ T cells in secondary lymphoid organs (3).

The pathogenesis of this impaired development of thymus-derived TCR⁺ T cells has been well characterized at the cellular level. The analysis of hemopoietic radiation chimeras has demonstrated that this lymphopenia results from an intrinsic defect of T cell precursors (4), and there is evidence that the lymphopenic process is initiated at the latest stages of intrathymic T cell development. Specifically, two studies have reported a significant reduction in the number of single-positive mature CD4^-CD8⁺ thymocytes in BB rats (5, 6). Furthermore, it has been demonstrated that both the thymic output of T cells and the life span of recent thymic emigrants (RTE)³ are reduced in BB rats (7). This short life span of RTE explains why thymectomy of adult BB rats is followed by a rapid depletion of 75–80% of TCR⁺ T cells from secondary lymphoid organs (8). While the molecular basis of the BB rat lyp mutation has not been characterized yet, the resulting premature apoptosis of T cells is not due to a dysregulated expression of Bcl-2 or Bcl-x proteins or caspases (8) (S. Ramanathan and P. Poussier, unpublished observation).

Taken together, these results strongly suggest that the pool of recirculating lymphocytes of BB rats is devoid of long-lived naive T cells and that the continuous thymic output of T cells is crucial for maintaining a diverse T cell repertoire in this strain. Further, the inability to prime BB rat T cells 48 h after thymectomy shows that rescue of RTE from early apoptotic death through antigenic stimulation must occur within a few hours of thymic exit (8). Though the life span of activated T cells is also shortened in BB rats, long-term T cell memory can be maintained in these animals, possibly through an elevated turnover of these cells (8).

The effects of the BB rat lyp mutation on the development of TCR⁺ T cells have not been assessed. The distribution of TCR⁺ T cells among the various compartments of the immune system has been well characterized in normal rats and is very similar to what is observed in mice (9). Specifically, these T cells are present in very low numbers in the thymus and in secondary lymphoid organs but account for a large proportion of intraepithelial T cells (9). However, although it has been demonstrated that murine intraepithelial T cells can be of thymic or extrathymic origin depending on the epithelium where they reside (10, 11, 12), the origin of rat intraepithelial TCR⁺ T cells is unknown. It has been suggested that no extrathymic development of T cells occurs in the rat based on the absence of TCR⁺ and TCR⁺ intraepithelial lymphocytes (IEL) in nude rats (13). One could, however, argue that the abnormalities of the thymic and cutaneous epithelia observed in these mutant animals extend to the intestinal mucosa and compromise its capacity to support extrathymic T cell development (14).

In the present study we have analyzed the development of TCR⁺ T cells in unmanipulated, diabetes-prone BB rats and in athymic radiation chimeras reconstituted with hemopoietic precursors derived from normal and BB donors. We show that TCR⁺ T cells are absent in adult unmanipulated BB rats but are present in normal numbers in the intestinal epithelium of athymic radiation chimeras reconstituted with normal hemopoietic precursors.

	Materials and Methods

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Animals

CD45 (RT7 in the rat) congenic, diabetes-prone BB.7^b rats have been developed in our animal facility and described previously (15). Diabetes-prone BB/W (RT7^a/a) and diabetes-resistant BB-DR/W (RT7^a/a) rats were purchased from Biomedical Research Models (Worcester, MA), while Wistar-Furth (WF; RT7^b/b) rats were purchased from Harlan Sprague-Dawley (Indianapolis, IN). All animals used in the present study were maintained under specific pathogen-free conditions.

The preparation of euthymic and athymic, hemopoietic radiation chimeras has been described previously (8). Briefly, recipients were thymectomized or sham-thymectomized at 4–5 wk, lethally irradiated (9 Gy) 2 wk later, and within 24 h reconstituted with 2–3 x 10⁷ T-depleted bone marrow cells or 4–5 x 10⁶ day 15 fetal liver cells. Donors and recipients of hemopoietic precursors differed at the RT7 locus. Depletion of T cells from the bone marrow inoculum was performed by negative selection using a rosetting procedure, as previously described (8). Hemopoietic reconstitution was assessed 10–12 wk after irradiation by multicolor cell surface immunofluorescence and FACS analysis of mononuclear cell (MNC) populations using mAbs specific for RT7^a, RT7^b, and various T, B, and NK cell-specific markers.

Isolation of IEL and LP lymphocytes

IEL and lamina propria (LP) lymphocytes were prepared as previously described with some modifications (16). Briefly, the small intestine was flushed with Ca²⁺- and Mg²⁺-free PBS and 2% FCS and opened longitudinally, and Peyer’s patches were removed. The intestine was cut into 5-mm pieces and incubated for 20 min with stirring in Ca²⁺- and Mg²⁺-free HBSS supplemented with 4 mM NaHCO₃, 2 mM DTT, and 5% FCS. The supernatant containing IEL and epithelial cells was collected, and the above procedure was repeated. After washing in HBSS and 5% FCS, rescued cells were fractionated by discontinuous Percoll (Amersham Pharmacia Biotech, Uppsala, Sweden) gradient centrifugation. Cells were resuspended in a = 1.062 Percoll solution, and the resulting cell suspension was underlayed with a = 1.109 Percoll solution. After centrifugation at 900 x g for 10 min, IEL were collected at the = 1.109/1.062 interface, washed, and analyzed.

After isolation of IEL, the resulting pieces of gut were incubated at room temperature with stirring in 25 ml of Ca²⁺- and Mg²⁺-free HBSS supplemented with 4 mM NaHCO₃ and 5 mM EDTA three times for 30 min each time, and the supernatant was discarded each time. The tissue was then incubated in RPMI 1640 and 5% FCS for 20 min. At the end of this incubation, the supernatant contained neither epithelial cells nor lymphocytes. The pieces of gut mucosa were then incubated at 37°C with stirring in 15 ml of RPMI 1640 and 5% FCS containing 90 U/ml collagenase (Roche, Mannheim, Germany) for 15 min, and the supernatant was collected in ice-cold medium. The above procedure was repeated twice. The resulting cell suspensions were washed, and the lymphocytes were isolated over a discontinuous Percoll gradient as described for IEL.

mAbs, three-color immunofluorescence, and FACS analysis

The mAbs used in this study were affinity-purified from hybridoma culture supernatants on a Sepharose column coated with rat anti-mouse Ig or mouse anti-rat Ig, and then conjugated with FITC, biotin, allophycocyanin, or PE using standard procedures. These mAbs, which have been described previously (15), included anti-rat Ig (MARK1), anti-NKRP-1 (3.2.3.), anti-CD8 (MRC-OX8), anti-CD4 (W3/25), anti-CD45RC (OX22), and anti-CD5 (MRC-OX19), which were provided by Dr. A. A. Like (University of Massachusetts, Worcester, MA) with the permission of Dr. D. Mason (Sir William Dunn School of Pathology, Oxford, U.K.). R73, a hybridoma secreting an mAb specific for a nonpolymorphic determinant of rat TCR, and 341, a hybridoma secreting an mAb specific for rat CD8, were given by Dr. T. Hünig (University of Würzburg, Martinsried, Germany). The rat hybridomas 6A5 (anti-RT6^b) and NDS-58 (anti-RT7^a) were provided by Dr. D. Greiner (University of Massachusetts), and rat hybridoma 8G6.1 (anti-RT7^b) was provided by Dr. M. Newton (University of Oxford, Oxford, U.K.). G4.18, a mouse hybridoma secreting an mAb specific for rat CD3, was obtained from Dr. G. W. Butcher (Babraham Institute, Cambridge, U.K.) with the permission of Dr. B. M. Hall (University of New South Wales, Liverpool, Australia). The mAb V65 specific for a nonpolymorphic determinant of rat TCR, OX39 specific for CD25, and OX-49 specific for CD44 were purchased from BD PharMingen (Mississauga, Canada). Streptavidin-PE/Texas Red Tandem was purchased from Southern Biotechnology Associates (Birmingham, AL).

Suspensions of MNC were incubated with biotinylated mAb, followed by streptavidin-PE/Texas Red Tandem. PE-labeled, allophycocyanin-conjugated, and FITC-labeled mAbs were then added simultaneously. Viable cells were gated using forward and side angle scatter and were analyzed by flow cytometry with a FACSCalibur (BD Biosciences, San Jose, CA). At least 10⁴ cells/sample were acquired for analysis. The absolute number of cells within an MNC subset was calculated by multiplying the total number of MNC isolated by the proportion of cells accounted for by this subset. The total number of MNC from the intestinal epithelium and LP was determined before their purification by discontinuous Percoll gradient centrifugation.

IEL were depleted of B lymphocytes through incubation with a biotinylated goat antiserum specific for rat Igs (Bio/Can Scientific, Mississauga, Canada), followed by streptavidin microbeads (Miltenyi Biotec, Auburn, CA). B cells were then depleted by negative selection using MACS (Miltenyi Biotec) following the manufacturer’s instructions.

Analysis of RAG1 expression

Total RNA was isolated from thymocytes, B-depleted IEL, and kidneys of BB-DR/W rats using TRIzol (Invitrogen, Burlington, Canada) according to the manufacturer’s instructions. Total RNA (1 µg) was used for cDNA synthesis with Superscript (Invitrogen) and poly(dT)₁₅ (Invitrogen). Primers for the rat RAG1 gene were designed based on the sequence available at European Molecular Biology Laboratory gene bank (accession no. AJ006070) (17). The forward and reverse primers used were 5'-AAA AGG CAC CCG AAG AAG CAC AAA-3' and 5'-CAC GTC GAT CCG GGA AAA AAC TCT TGG-3'. The size of the PCR-amplified product was 370 bp. The forward and reverse primers for actin were 5'-CGA CGA GGC CCA GAG CAA GAG AGG-3' and 5'-CGT CAG GCA GCT CAT AGC TCT TCT CCA GGG-3'. The size of the PCR amplified actin product was 566 bp. PCR was performed with cDNA templates for 25 cycles consisting of 94°C for 30 s, 55°C for 60 s, and 72°C for 60 s, using a PTC-225 Peltier Thermal Cycler (MJ Research, Waltham, MA). The products were resolved in 1% agarose gels.

	Results and Discussion

Top Abstract Introduction Materials and Methods Results and Discussion References

 
The BB rat lyp mutation compromises the development of TCR⁺ T cells

The number of TCR⁺ T cells was assessed in different lymphoid organs of 8- to 10-wk-old BB/W and BB-DR/W rats by three-color immunofluorescence and FACS analysis. It has been previously reported that in normal rats TCR⁺ cells are found mostly in the spleen and epithelia (9). Accordingly, the spleen of BB-DR/W animals contained 3.4 ± 0.3 x 10⁶ TCR⁺ T cells, while 3.3 ± 0.1 x 10⁶ IEL-expressing TCR⁺ T cells were isolated from the intestinal mucosa of these animals (Table I). In contrast, TCR⁺ T cells were virtually undetectable in the same lymphoid compartments of age-matched BB/W rats. This absence of peripheral TCR⁺ T cells in BB/W rats was also observed in younger animals (Table II) and was confirmed by immunohistochemistry (data not shown). It has previously been shown that the BB/W rat lyp mutation severely compromises the development of CD4^-8⁺TCR⁺ T cells (18). Our results demonstrate that the effects of the lyp mutation on the differentiation of TCR⁺ T cells are as severe as those observed in peripheral CD4^-8⁺TCR⁺ T cells (Tables I and II). Because TCR⁺ thymocytes were virtually undetectable in BB/W and BB-DR/W rats by both immunohistochemistry and flow cytometry (data not shown), it is difficult to ascertain the developmental stage of TCR⁺ T cells affected by the BB/W rat lyp mutation.

There is evidence in mice that CD4^-8^+-TCR⁺ IEL are of extrathymic origin, contain high proportions of cells expressing high-affinity, self-specific TCR, fail to proliferate in response to Ag, and, for some of them, recognize nonclassical MHC class I molecules (11, 19, 20). Assuming that the development and selection of rat CD4^-8^+-TCR⁺ IEL are not totally dissimilar to those of their murine counterparts, it is not implausible that these peculiarities protect this T cell subset from the deleterious effects of the BB/W rat lyp mutation observed in other CD4^-8⁺TCR⁺ T cell subsets.

The near-normal numbers of CD4⁺8^-TCR⁺ T cells in the intestinal mucosa of BB/W rats could reflect a preferential migration of CD4⁺8^-TCR⁺ recent emigrants to that site, where subsequent activation by luminal Ags would rescue them from premature apoptotic death. Alternatively, and assuming that the rat intestinal mucosa is a site of extrathymic T lymphopoiesis, as is its murine counterpart, another nonexclusive explanation for the relatively high number of intraintestinal CD4⁺8^-TCR⁺ T cells could be that these cells are continuously generated in situ (11, 12).

It has been demonstrated that RTEs of BB/W rats die prematurely unless they encounter and respond to their specific Ags (8). Consequently, thymectomy of adult BB/W rats is followed by the rapid disappearance of naive T cells, which in this animal account for the majority of peripheral T cells (8). We reasoned that thymectomy should also affect a preferential migration of RTEs to the intestinal mucosa, while it would be of little consequence on T cells generated extrathymically and/or activated by luminal Ags. As illustrated in Table II and as expected, thymectomy of 4- to 5-wk-old BB/W rats was followed by a >80% drop in the number of TCR⁺ T cells in secondary lymphoid organs compared with an 10% decrease in BB-DR/W rats in 2 wk. In contrast, thymectomy had no effect on the number of T cells present in the intestinal mucosa of both BB/W and BB-DR rats. This observation strongly suggested that there is no preferential migration of naive T cells to the intestinal mucosa in BB/W rats.

This interpretation was further supported by the phenotypic characterization of these intraintestinal CD4⁺8^-TCR⁺ T cells. As illustrated in Fig. 1, most of the CD4⁺8^-TCR⁺ IEL of both BB-DR/W and BB/W rats express a surface phenotype of mature and activated T cells. In the rat species, surface expression of CD90 is restricted to thymocytes and recent (<1-wk-old) thymic emigrants, while it is lost in mature T cells (21). Only 5–10% of CD4⁺8^-TCR⁺ IEL expressed CD90 on their surface (Fig. 1A) in BB-DR/W and BB/W rats, and, moreover, the level of CD90 expression was low, indicating that these T cells are not RTEs. Furthermore, the majority of CD4⁺8^-TCR⁺ IEL expressed the activation markers CD25 and CD44 (Fig. 1, B–D). Interestingly, both the proportion of CD4⁺8^-TCR⁺ IEL expressing CD25 and the level of expression of this marker were consistently higher in BB/W rats than in BB-DR/W animals.

View larger version (27K): [in this window] [in a new window]   FIGURE 1. Phenotypic analysis of CD4+8-TCR+ IEL in BB-DR/W and BB/W rats. Cells were isolated and stained as described in Materials and Methods. A, Differential expression of CD4 and TCR on the surface of unfractionated IEL. B–D, Differential expression of CD45RC and CD90 (B), CD25 (C), and CD44 (D) on the surface of CD4+8-TCR+ TCR IEL.

Evidence for extrathymic development of TCR⁺ T cells in rats

The extrathymic development of TCR⁺ and TCR⁺ T cells has been studied in several species. We and others have demonstrated that both T cell lineages can develop in normal numbers in athymic mice (10, 12, 22). Specifically, athymic radiation chimeras reconstituted with T-depleted bone marrow or day 12 fetal liver cells are devoid of donor-derived T cells in secondary lymphoid organs, but contain normal numbers of donor-derived TCR⁺ and TCR⁺ IEL (12). In contrast, it was shown that all T cells present in birds and sheep are thymus derived (23, 24). One study has analyzed the development of IEL in athymic nude rats and could not detect lymphocytes expressing CD3 on their surface or containing transcripts for TCR and TCR in the intestinal mucosa of these animals (13). This lack of intestinal intraepithelial T cells was interpreted as evidence for the thymic origin of these cells in normal rats. However, the abnormalities of the thymic and cutaneous epithelia observed in nude animals could extend to the intestinal mucosa and compromise the T lymphopoietic capacity of this organ (14).

To determine whether intraintestinal T cells are of thymic or extrathymic origin in rats, we prepared athymic bone marrow and day 15 fetal liver radiation chimeras using RT7^a/a BB/W rats as recipients and RT7^b/b BB/W and WF as donors of hemopoietic precursors. There were two reasons for choosing BB/W rats as recipients. These animals are T lymphopenic and very sensitive to gamma radiation (our unpublished observation). We therefore reasoned that very few T cells of recipient origin would survive a lethal irradiation, and, consequently, the potential expansion of donor-derived T cells would be uncompromised.

The presence of donor-derived T cells in the various lymphoid compartments of these chimeras was evaluated 10–12 wk after reconstitution. As expected, there were virtually no recipient-derived MNC in any lymphoid compartment as determined by cell surface immunofluorescence and flow cytometry using RT7^a- and RT7^b-specific mAbs (data not shown). As illustrated in Table III, no donor-derived T cells expressing TCR could be detected in the spleen, lymph nodes, intestinal epithelium, and LP of these chimeras independent of the source of hemopoietic precursors, strongly suggesting that these T cells are of thymic origin in unmanipulated animals.

In contrast to TCR⁺ T cells, TCR⁺ T cells developed in athymic radiation chimeras reconstituted with hemopoietic precursors of WF origin. Specifically, the intestinal epithelium of these chimeras contained a normal number of donor-derived TCR⁺ T cells (Table III). As illustrated in Fig. 2, the phenotype of donor-derived TCR⁺ IEL was similar to that of TCR⁺ IEL isolated from unmanipulated rats. Specifically, the majority of donor-derived TCR⁺ IEL express CD8 and RT6 but do not express CD8 and CD45RC on their surface.

View larger version (31K): [in this window] [in a new window]   FIGURE 2. Phenotypic analysis of TCR+ IEL isolated from an unmanipulated WF rat (A) and an adult thymectomized, lethally irradiated BB/W rat reconstituted with day 15 fetal liver cells of WF origin (B). Cells were isolated and stained as described in Materials and Methods. Differential expression of CD8 and CD8 (upper panels) and CD45RC and RT6.2 (lower panels) on the surface of TCR+ IEL is shown.

It is important to note that the presence of TCR⁺ T cell was restricted to the intestinal epithelium of these chimeras. This observation indicates that TCR⁺ IEL of extrathymic origin do not recirculate and suggests that these cells developed in situ in these chimeras. Furthermore, the full reconstitution of the pool of TCR⁺ IEL in athymic radiation chimeras raises the question of whether some of the TCR⁺ IEL present in unmanipulated rats are of extrathymic origin and develop in the intestinal epithelium.

To determine whether T cell development occurs in the intestinal epithelium of unmanipulated rats, we looked for evidence for TCR rearrangement in the rat IEL compartment. Specifically, we looked for the presence of RAG1 transcripts in these cells by RT-PCR. As illustrated in Fig. 3, such transcripts were easily detected in B cell-depleted IEL from young, adult, and unmanipulated rats. Depletion of the few B cells present in the IEL compartment was performed before RNA extraction to rule out the potential contamination of our samples by some immature, peripheral B cells that have not yet extinguished RAG1 expression (28). The presence of donor-derived TCR⁺ IEL in athymic radiation chimeras as well as the detection of RAG1 transcripts in the IEL compartment of unmanipulated rats provide strong evidence in support of extrathymic origin and intraintestinal maturation of some of the TCR⁺ IEL present in normal animals.

View larger version (33K): [in this window] [in a new window]   FIGURE 3. Detection of actin (top) and RAG1 transcripts (bottom) in B cell-depleted IEL from a BB-DR/W rat by RT-PCR. Extraction of total RNA from the indicated organs, cDNA synthesis, and RT-PCR were performed as described in Materials and Methods.

It has been demonstrated that the precursors of murine intraintestinal T cells expressing TCR and TCR are located in small cellular aggregates appended to the intestinal crypts, called cryptopatches (31, 32). We examined sections of the rat intestine to determine whether cryptopatches are also present in this species, but failed to detect them (P. Poussier, unpublished observation).

Donor-derived TCR⁺ T cells could not be detected in the various lymphoid compartments of athymic radiation chimeras reconstituted with hemopoietic precursors of BB/W origin. This result combined with our analysis of TCR⁺ T cells in unmanipulated BB/W rats demonstrates that the lyp mutation of this strain compromises both intrathymic and extrathymic development of TCR⁺ T cells (Table III). Importantly, injection of athymic radiation chimeras with bone marrow- and fetal liver-derived precursors from BB/W donors was followed by the full reconstitution of other hemopoietic, non-T cell lineages (Table III), confirming that the lyp mutation only affects T cell precursors. Of note, the absence of extrathymic development of TCR⁺ T cells following hemopoietic reconstitution of athymic recipients strongly suggests that the CD4⁺8^-TCR⁺ T cells present in near-normal numbers in the intestinal mucosa of unmanipulated BB/W rats are thymus-derived and have been rescued from premature apoptotic death by Ag activation at that site.

The antigenic specificity and the role of TCR⁺ T cells remain poorly understood. Their preferential localization at epithelial surfaces and the demonstration that following activation these T cells secrete keratinocyte growth factor suggest that these cells could regulate the homeostasis of epithelial tissues (33). This is supported by the demonstration that chronic administration of exogenous keratinocyte growth factor to normal rats alters the proliferation of enterocytes (34). It is not implausible that the lack of TCR⁺ IEL in BB rats contributes to the increased permeability of the intestinal mucosa of these animals (35).

	Footnotes

 
¹ This work was supported by a research grant (MOP-37882) from the Canadian Institutes for Health Research. L.M. was supported by a postdoctoral fellowship from the government of Iran.

² Address correspondence and reprint requests to Dr. Philippe Poussier at the current address: Sunnybrook and Women’s College Health Sciences Center, 2075 Bayview Avenue, Room A-338, Toronto, Ontario, Canada M4N 3M5. E-mail address: ppoussie{at}sten.sunnybrook.utoronto.ca

³ Abbreviations used in this paper: RTE, recent thymic emigrant; IEL, intraepithelial lymphocyte; LP, lamina propria; MNC, mononuclear cell; WF, Wistar-Furth.

Received for publication August 20, 2001. Accepted for publication December 19, 2001.

	References

Top Abstract Introduction Materials and Methods Results and Discussion References

 

1. Colle, E., R. D. Guttmann, T. Seemayer. 1981. Spontaneous diabetes mellitus syndrome in the rat. I. Association with the major histocompatibility complex. J. Exp. Med. 154:1237.[Abstract/Free Full Text]
2. Jacob, H. J., A. Pettersson, D. Wilson, Y. Mao, A. Lernmark, and E. S. Lander. 1992. Genetic dissection of autoimmune type I diabetes in the BB rat. [Published erratum appears in 1994 Nat. Genet. 7:215.] Nat. Genet. 2:56.
3. Woda, B. A., A. A. Like, C. Padden, M. L. McFadden. 1986. Deficiency of phenotypic cytotoxic-suppressor T lymphocytes in the BB/W rat. J. Immunol. 136:856.[Abstract]
4. Francfort, J. W., A. Naji, W. K. Silvers, C. F. Barker. 1985. The influence of T-lymphocyte precursor cells and thymus grafts on the cellular immunodeficiencies of the BB rat. Diabetes 34:1134.[Abstract]
5. Groen, H., F. A. Klatter, N. H. Brons, G. Mesander, P. Nieuwenhuis, J. Kampinga. 1996. Abnormal thymocyte subset distribution and differential reduction of CD4⁺ and CD8⁺ T cell subsets during peripheral maturation in diabetes-prone BioBreeding rats. J. Immunol. 156:1269.[Abstract]
6. Plamondon, C., V. Kottis, C. Brideau, D. M. Metroz, P. Poussier. 1990. Abnormal thymocyte maturation in spontaneously diabetic BB rats involves the deletion of CD4^-8⁺ cells. J. Immunol. 144:923.[Abstract]
7. Zadeh, H. H., D. L. Greiner, D. Y. Wu, F. Tausche, I. Goldschneider. 1996. Abnormalities in the export and fate of recent thymic emigrants in diabetes-prone BB/W rats. Autoimmunity 24:35.[Medline]
8. Ramanathan, S., K. Norwich, P. Poussier. 1998. Antigen activation rescues recent thymic emigrants from programmed cell death in the BB rat. J. Immunol. 160:5757.[Abstract/Free Full Text]
9. Kuhnlein, P., J. H. Park, T. Herrmann, A. Elbe, T. Hunig. 1994. Identification and characterization of rat / T lymphocytes in peripheral lymphoid organs, small intestine, and skin with a monoclonal antibody to a constant determinant of the / T cell receptor. J. Immunol. 153:979.[Abstract]
10. Mosley, R. L., D. Styre, J. R. Klein. 1990. Differentiation and functional maturation of bone marrow-derived intestinal epithelial T cells expressing membrane T cell receptor in athymic radiation chimeras. J. Immunol. 145:1369.[Abstract]
11. Poussier, P., H. S. Teh, M. Julius. 1993. Thymus-independent positive and negative selection of T cells expressing a major histocompatibility complex class I restricted transgenic T cell receptor / in the intestinal epithelium. J. Exp. Med. 178:1947.[Abstract/Free Full Text]
12. Poussier, P., P. Edouard, C. Lee, M. Binnie, M. Julius. 1992. Thymus-independent development and negative selection of T cells expressing T cell receptor / in the intestinal epithelium: evidence for distinct circulation patterns of gut- and thymus-derived T lymphocytes. J. Exp. Med. 176:187.[Abstract/Free Full Text]
13. Vaage, J. T., E. Dissen, A. Ager, I. Roberts, S. Fossum, B. Rolstad. 1990. T cell receptor-bearing cells among rat intestinal intraepithelial lymphocytes are mainly /⁺ and are thymus dependent. Eur. J. Immunol. 20:1193.[Medline]
14. Lefrancois, L., L. Puddington. 1995. Extrathymic intestinal T-cell development: virtual reality?. Immunol. Today 16:16.[Medline]
15. Ramanathan, S., P. Poussier. 1999. T cell reconstitution of BB/W rats after the initiation of insulitis precipitates the onset of diabetes. J. Immunol. 162:5134.[Abstract/Free Full Text]
16. Poussier, P., M. H. Julius. 1997. Preparation of mononuclear cells from the gut-associated immune system. I. Lefkovits, ed. In Immunology Methods Manual Vol. 3:1509. Academic, New York.
17. Bischof, A., J. H. Park, T. Huenig. 1999. Expression of T cell receptor chain mRNA and protein in / T cells from euthymic and athymic rats: implications for T cell lineage divergence. Dev. Immunol. 36:1.
18. Elder, M. E., N. K. Maclaren. 1983. Identification of profound peripheral T lymphocyte immunodeficiencies in the spontaneously diabetic BB rat. J. Immunol. 130:1723.[Abstract]
19. Cruz, D., B. C. Sydora, K. Hetzel, G. Yakoub, M. Kronenberg, H. Cheroutre. 1998. An opposite pattern of selection of a single T cell antigen receptor in the thymus and among intraepithelial lymphocytes. J. Exp. Med. 188:255.[Abstract/Free Full Text]
20. Das, G., D. S. Gould, M. M. Augustine, G. Fragoso, E. Sciutto, I. Stroynowski, L. Van Kaer, D. J. Schust, H. Ploegh, Jr C. A. Janeway, et al 2000. Qa-2-dependent selection of CD8/ T cell receptor /⁺ cells in murine intestinal intraepithelial lymphocytes. J. Exp. Med. 192:1521.[Abstract/Free Full Text]
21. Hosseinzadeh, H., I. Goldschneider. 1993. Recent thymic emigrants in the rat express a unique antigenic phenotype and undergo post-thymic maturation in peripheral lymphoid tissues. J. Immunol. 150:1670.[Abstract]
22. Rocha, B., P. Vassalli, D. Guy-Grand. 1994. Thymic and extrathymic origins of gut intraepithelial lymphocyte populations in mice. J. Exp. Med. 180:681.[Abstract/Free Full Text]
23. Dunon, D., M. D. Cooper, B. A. Imhof. 1993. Thymic origin of embryonic intestinal / T cells. J. Exp. Med. 177:257.[Abstract/Free Full Text]
24. Hein, W. R., L. Dudler, B. Morris. 1990. Differential peripheral expansion and in vivo antigen reactivity of / and / T cells emigrating from the early fetal lamb thymus. Eur. J. Immunol. 20:1805.[Medline]
25. Lin, T., G. Matsuzaki, H. Kenai, T. Nakamura, K. Nomoto. 1993. Thymus influences the development of extrathymically derived intestinal intraepithelial lymphocytes. Eur. J. Immunol. 23:1968.[Medline]
26. Lin, T., G. Matsuzaki, H. Kenai, K. Nomoto. 1994. Progenies of fetal thymocytes are the major source of CD4^-CD8⁺ intestinal intraepithelial lymphocytes early in ontogeny. Eur. J. Immunol. 24:1785.[Medline]
27. Wang, J., J. R. Klein. 1994. Thymus-neuroendocrine interactions in extrathymic T cell development. Science 265:1860.[Abstract/Free Full Text]
28. Yu, W., H. Nagaoka, M. Jankovic, Z. Misulovin, H. Suh, A. Rolink, F. Melchers, E. Meffre, M. C. Nussenzweig. 1999. Continued RAG expression in late stages of B cell development and no apparent re-induction after immunization. Nature 400:682.[Medline]
29. Imaoka, A., S. Matsumoto, H. Setoyama, Y. Okada, Y. Umesaki. 1996. Proliferative recruitment of intestinal intraepithelial lymphocytes after microbial colonization of germ-free mice. Eur. J. Immunol. 26:945.[Medline]
30. Bandeira, A., T. Mota-Santos, S. Itohara, S. Degermann, C. Heusser, S. Tonegawa, A. Coutinho. 1990. Localization of / T cells to the intestinal epithelium is independent of normal microbial colonization. J. Exp. Med. 172:239.[Abstract/Free Full Text]
31. Kanamori, Y., K. Ishimaru, M. Nanno, K. Maki, K. Ikuta, H. Nariuchi, H. Ishikawa. 1996. Identification of novel lymphoid tissues in murine intestinal mucosa where clusters of c-kit⁺ IL-7R⁺ Thy1⁺ lympho-hemopoietic progenitors develop. J. Exp. Med. 184:1449.[Abstract/Free Full Text]
32. Saito, H., Y. Kanamori, T. Takemori, H. Nariuchi, E. Kubota, H. Takahashi-Iwanaga, T. Iwanaga, H. Ishikawa. 1998. Generation of intestinal T cells from progenitors residing in gut cryptopatches. Science 280:275.[Abstract/Free Full Text]
33. Boismenu, R., W. L. Havran. 1994. Modulation of epithelial cell growth by intraepithelial T cells. Science 266:1253.[Abstract/Free Full Text]
34. Housley, R. M., C. F. Morris, W. Boyle, B. Ring, R. Biltz, J. E. Tarpley, S. L. Aukerman, P. L. Devine, R. H. Whitehead, G. F. Pierce. 1994. Keratinocyte growth factor induces proliferation of hepatocytes and epithelial cells throughout the rat gastrointestinal tract. J. Clin. Invest. 94:1764.
35. Meddings, J. B., J. Jarand, S. J. Urbanski, J. Hardin, D. G. Gall. 1999. Increased gastrointestinal permeability is an early lesion in the spontaneously diabetic BB rat. Am. J. Physiol. 276:G951.[Abstract/Free Full Text]

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