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-Chain Selectively Influences the Development of the Common Mucosal Immune System Independent IgA-Producing B-1 Cell in Mucosa-Associated Tissues1
*
Department of Mucosal Immunology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan; and
Department of Immunology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
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Abstract |
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 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
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-chain (IL-5R-/-) selectively
influenced the mucosal IgA responses in vivo. While levels of IgA in
mucosal secretions were more reduced in IL-5R-/- mice
than in wild-type mice, the levels of IgA in serum were not changed.
The frequency of IgA-producing cells was reduced in mucosal effector
sites (e.g., intestinal lamina propria and nasal passage), but not in
inductive sites such as Payer’s patches and nasal-associated
lymphoreticular tissues in IL-5R-/- mice.
IgA-committed (surface IgA+; sIgA+) B-1 cells
mainly resided in mucosal effector tissues, while conventional
sIgA+ B (B-2) cells formed in mucosal inductive sites of
wild-type mice. In contrast, in the effector tissue of
IL-5R-/- mice, sIgA+ B-1 cells, but not
sIgA+ B-2 cells in the inductive site, were significantly
reduced. IL-5R was more expressed on sIgA+ B-1 cells
than was IL-6R, while both IL-5R and IL-6R were expressed on
sIgA+ B-2 cells in wild-type mice. sIgA+ B-1
cells produced high levels of IgA with rIL-5 rather than of rIL-6 in
vitro. Taken together, the findings suggest that the IL-5/IL-5R
signaling pathway is critically important for the development of common
mucosal immune system independent sIgA+ B-1 cell in mucosal
effector tissues in vivo. |
Introduction |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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- and ß-chains, each of which is a member of
cytokine receptor superfamily (4, 5). The binding of IL-5 occurs
through the IL-5R-chain, and the ß-chain forms a high affinity
with IL-5R for the intracellular signal-transduction pathway (4, 5).
IL-5 has been shown to be an important cytokine for the mucosal immune
system, possessing several unique immunologic features that distinguish
it from the systemic immune compartment (6). For example, IgA inductive
tissues, such as gut-associated lymphoreticular tissue
(GALT)3 or Peyer’s patches
(PP) containing a high frequency of IgA-committed B cells [surface
IgA+ (sIgA+) B cells] and Th1/Th2 cells, are
interconnected with IgA effector sites, including intestinal lamina
propria (i-LP) via the common mucosal immune system (CMIS) (7).
It has been shown that IL-5 is a major cytokine that induces
sIgA+ B cells to differentiate into IgA-producing plasma
cells utilizing mainly an in vitro system using PP and
mitogen-stimulated splenic B cells (6, 8, 9, 10, 11). Furthermore, IL-2 and
IL-6 have been demonstrated to be capable of enhancing IgA synthesis in
vitro (12, 13). A most IgA-enhancing effect was noted in LPS-treated
splenic B cell cultures containing IL-5, when compared with those
containing other Th1 and Th2 cytokines (9). When B cells isolated from
PP were separated into two fractions based on the expression of sIgA
and then cocultured with rIL-5, a major production of IgA Ab was noted
in the sIgA+ B cells with a cell-cycling stage (8). We are
fortunate to have at our disposal an IL-5R-chain-deficient mouse
model that allowed us to directly study the role of IL-5 and the IL-5R
signaling pathway in the induction of mucosal IgA Ab response in vivo,
a subject on which little information is currently available.
Recently, mice with a disrupted IL-5 (14) and IL-5R gene (15) were
constructed by homologous gene recombination. These mice have greatly
facilitated the study of the unique function of the IL-5/IL-5R
signaling pathway in vivo. For example, CD5+ B (B-1a) cells
in the peritoneal cavity (PEC) were reduced by about 50% in
IL-5-/- and IL-5R-/- mice (14, 15).
Unlike wild-type mice, IL-5-/- and
IL-5R-/- mice did not develop blood and tissue
eosinophilia when infected with worms (14, 15). In regard to Ab
production, IL-5R-/- mice showed lower serum
concentrations of IgM and IgG3 Abs than did normal mice. However, an
obvious alteration of serum Ab levels was not seen in
IL-5-/- mice when compared with wild-type mice (14).
Moreover, there was no significant difference between local Ab
responses, including IgA in lungs in IL-5-/- and in
wild-type mice following infection with influenza virus (14). Levels of
serum IgA in IL-5R-/- mice were comparable with those
of normal background mice (15). None of the IL-5-/- and
IL-5R-/- studies addressed the influence of specific gene
deletion on the mucosal IgA immune system despite accumulated in vitro
evidence suggesting that IL-5 and the IL-5R signaling pathway are
essential for the development of IgA B cells.
It is now well known that B cells can be separated into at least two subsets, B-1 and B-2, based on the expression of CD5 and CD45/B220 (16), the intensity of sIgM and sIgD (17), as well as the differences in anatomical localization and functional characteristics (18). An intriguing observation is that up to 40% of IgA-producing cells in the murine i-LP arise from a pool of B-1 precursors derived from the PEC (19). Peritoneal and lamina propria B-1 cells in mice have been shown to develop from a common pool and may represent a lineage separate from that of conventional PP B cells (20). Another study using transgenic mice has provided additional supportive evidence that intestinal IgA plasma cells are derived from B-1 cells (21). In addition, up to 50% of intestinal B cells are CD5+, a large number of which secrete IgA in humans (22). Taken together, these findings suggest that B-1 cells could be an important source for IgA- producing cells in mucosal tissues. Inasmuch as the reduction of B-1 cells was a common feature to both IL-5-/- and IL-5R-/- mice (14, 15), we focused our study on exploring the role of IL-5R and B-1 cells in the development of IgA-producing cells in mucosa-associated tissues using the latter gene-disrupted murine model together with the background wild-type mice.
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Materials and Methods |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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Mice with targeted disruption of the IL-5R-chain gene
(IL-5R-/-) were generated by homologous gene
recombination (15). IL-5R-/- and wild-type control
mice (IL-5R+/+) derived from F2 (C57BL/6 x 129 Sv)
were maintained and bred in barrier-protected animal facilities under
pathogen-free conditions using ventilated microisolater cages in the
experimental animal facility at the Research Institute for Microbial
Diseases, Osaka University (Osaka, Japan). All experiments were
conducted with sex-matched, 6- to 8-wk-old mice.
Cell preparations
Mononuclear cells from the nasal passage (NP), nasal-associated lymphoreticular tissues (NALT), PEC, spleen (SP), mesenteric lymph node (MLN), submandibular glands (SMG), PP, and i-LP were prepared as described previously (22, 23, 24, 25, 26, 27). Briefly, mononuclear cells from NALT, SP, and MLN were isolated by the mechanical method using gentle teasing through stainless steel screens. NP, SMG, and i-LP mononuclear cells were isolated by the enzymatic dissociation procedure with collagenase type IV (Sigma, St. Louis, MO).
Analysis for the isotype of Igs by ELISA
Levels of isotype-specific Ab in fecal extract, saliva, and
serum were determined by ELISA, as described previously (23, 28).
Briefly, 96-well plates (Nunc, Roshilde, Demmark) were coated with an
optimal concentration of goat anti-mouse Ig (100 µl of 2 µg/ml;
Southern Biotechnology, Birmingham, AL) in PBS. Wells were blocked with
200 µl of PBS containing 10% normal goat serum (Life Technologies,
Gaithersburg, MD) for 2 h at 37°C. After extensive washing,
serial dilutions of samples were added and incubated for 2 h at
37°C. After incubation and washing, the wells were treated first with
100 µl of a 1/1000 diluted biotinylated goat anti-mouse µ, 
,
or heavy chain-specific Ab (Southern Biotechnology), and then with
the detection solution containing a 1/2000 dilution of horseradish
peroxidase-conjugated streptavidin (Life Technologies). After washing,
color reaction was developed at room temperature with 50 µl of
tetramethylbenzidine reagent (Moss, Pasadena, MD). For the quantitation
of Igs, purified IgM, IgG, and IgA (Chemical International, Temecula,
CA) were used as standards. Reactions were terminated by the addition
of 50 µl of 0.5 M HCl after a 15-min incubation. The color reaction
was measured by an OD at 450 nm (OD450).
Enumeration of Ig-producing cells by ELISPOT
To determine the numbers of IgA-, IgG-, and IgM-producing cells
in mucosal inductive tissues (NALT and PP), effector tissues (NP, SMG,
and i-LP), MLN, SP, and PEC, the ELISPOT assay was used as previously
described (23, 26, 28). Briefly, 96-well filtration plates with a
nitrocellulose base (Millititer HA; Millipore, Bedford, MA) were coated
with 5 µg/ml affinity-purified goat anti-Ig (Southern
Biotechnology). The plates were blocked with complete medium containing
RPMI 1640 in the presence of 10% FBS, 50 µg/ml gentamicin, 50
µg/ml penicillin G, 50 U/ml streptomycin, and 10 mM HEPES. The
mononuclear cells in complete medium were added at varying
concentrations and were cultured at 37°C, in air with 5%
CO2 for 4 h. After the incubation, the plates were
washed thoroughly with PBS and then with PBS containing 0.05% Tween
solution. For the capture of Ab-producing cells, 1 µg/ml of
horseradish peroxidase-conjugated affinity-purified goat anti-mouse
µ-, -, or -specific Abs (Southern Biotechnology) was added.
After overnight incubation at 4°C, the spots were developed with
2-amino-9-ethylcarbazole (Polysciences, Warrington, PA) containing
hydrogen peroxide. Reddish-brown-colored spots were counted as
Ab-forming cells with the aid of a dissecting microscope. The data are
expressed as the mean number of AFC ± SE/105 cells,
after the triplicate determinations.
Confocal immunohistologic analysis
For the immunohistochemical analysis, a standard protocol was employed (29). After mice were sacrificed, mucosal-associated tissues (e.g., small intestine and SMG) were embedded in Tissue-Tek (Miles, Elkhart, IN), snap frozen in liquid nitrogen, and stored at -80°C until using. Cryostat sections (10 µm thick) on gelatin-covered slides were dried and fixed with acetone. Slides were dehydrated and preincubated for 20 min at room temperature in PBS containing 1% BSA and 0.05% NaN3. Sections were incubated with biotin-conjugated anti-mouse IgA Ab (R5-140; PharMingen, San Diego, CA) in a humidified chamber for 1 h at room temperature. After three washes in PBS, binding of biotinylated Abs was revealed with streptavidin-Cy5 (Amersham, Amersham, U.K.). After three final washes, the slides were mounted in PermaFluor (LIPSHAW, Pittsburgh, PA) and analyzed by confocal microscopy (Bio-Rad, Hercules, CA).
Analysis and purification of B cell subsets by flow cytometry
For analysis of B cell subsets to B-1a, B-1b, and B-2 cells,
lymphocytes were incubated with biotinylated anti-CD5 (53-7.3;
PharMingen), FITC-conjugated anti-IgD (11-26c.2a; PharMingen), and
PE-conjugated anti-IgM (IgH-6b) (AF6-78; PharMingen),
followed by streptavidin-conjugated PerCP (Becton Dickinson, Sunnyvale,
CA) (21, 30). Moreover, for the three-color staining analysis of
sIgA+ B-1a, B-1b, and B-2 cells, lymphocytes were incubated
with biotinylated anti-CD5 (53-7.3; PharMingen), FITC-conjugated
anti-IgA (R5-140; PharMingen), and PE-conjugated
anti-B220/CD45R (RA3-6B2; PharMingen), followed by
streptavidin-conjugated PerCP (Becton Dickinson, Palo Alto, CA) (22, 31). For analysis of cytokine receptor expression, biotinylated
anti-IL-2R-chain (7D4; PharMingen), anti-IL-5R-chain (32, 33), or anti-IL-6R (D7715A7; PharMingen) was used. These samples
were then subjected to flow cytometry analysis by using a FACS
Calibur (Becton Dickinson). Control cells were incubated with
individual isotype control Ab, and these cells were used to set the
lymphocyte gates. Each analysis was performed at least five times to
verify the results obtained, and the results were expressed as the
mean ± SEM. For the purification of different subsets of B
cells, a similar staining procedure was performed at 4°C and then
subjected to the flow cytometry sorting separation using FACS Vantage
(Becton Dickinson). This procedure yielded cells that were more than
99% pure.
Cell culture conditions
Mouse sIgA+ B-1 and B-2 cells were isolated from i-LP lymphocytes by flow cytometry sorting, as described above. Purified B cells (1 x 104 cells) were cultured in 100 µl of complete RPMI 1640 medium containing 2 µg/ml LPS (Sigma) either in the presence or absence of rIL-5 (100 ng/ml; PharMingen) and/or rIL-6 (500 pg/ml; PharMingen) in U-bottom 96-well plates (Falcon, Lincoln Park, NJ). After 3 days of incubation, culture supernatants were harvested for the assessment of IgA production by isotype-specific ELISA, as described above.
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Results |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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-/- mice
In the initial experiment, the isotype-specific ELISA was used to
determine and compare the level of IgA, IgG, and IgM Abs in mucosal
secretions, including fecal extracts (feces) and saliva, and in serum
samples from IL-5R-/- and wild-type mice. The IgA
levels in mucosal secretions were reduced much more in
IL-5R-/- mice (
50%) than in wild-type mice (Fig. 1
). However, the levels of IgA and IgG
were not changed in serum, while the IgM levels were reduced by 60%
(Fig. 1). The latter finding was consistent with the previous results
(12). These results suggested that the removal of the IL-5R-specific
gene led to the selective impairment of IgA production at mucosal
compartments rather than at the systemic site.
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-/- mice
Mononuclear cells were isolated from different
mucosal-associated tissues to analyze whether the reduction of mucosal
IgA levels was caused by the decrease of IgA-producing cells in IgA
effector tissues of IL-5R-/- mice. The
isotype-specific ELISPOT assay was used to determine the frequency and
isotype of IgA-producing cells in IL-5R-/- and
wild-type mice. Numbers of IgM- or IgG-producing cells were seen
comparably low in mucosal tissues (e.g., i-LP, PP, MLN, NALT, SMG, and
NP) of both types of mice (Fig. 2,
A and B), while the levels of IgM-producing cells
in the PEC and SP were significantly lower in IL-5R-/-
mice than in wild-type mice (Fig. 2B). Interestingly, the
numbers of IgA-producing cells were decreased in mucosal effector
tissues, including i-LP, SMG, and NP, but not in inductive sites such
as PP and NALT (Fig. 2, A and B). The frequency
of IgA-containing cells was also evaluated in the tissue sections of
intestine and SMG by confocal imaging immunohistologic analysis.
Enumeration of the IgA-producing cells in SMG and i-LP (e.g., duodenum,
jejunum, and ileum) revealed that IgA plasma cells were more reduced in
IL-5R-/- than in wild-type mice (Fig. 3). This immunohistologic result further
confirmed the result obtained by isotype-specific Ab production
analysis by ELISA and ELISPOT assay, in which the partial impairment of
the IgA induction pathway was seen in the mucosal effector tissues
(e.g., i-LP, SMG, and NP) of IL-5R-/- mice.
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-/- mice
To determine the exact contribution of B-1 and B-2 cells in the
reduction of mucosal IgA in IL-5R-chain deficiency, our experiment
sought to elucidate the exact frequency of these different subsets of B
cells in mucosal inductive and effector tissues of normal background
mice. We found B-1 cells to be much more frequent in mucosal effector
tissues (e.g., i-LP, NP, and SMG) than in mucosal inductive tissues
(e.g., PP and NALT) (Table I), the latter
showing instead a predominance of B-2 cells. Mucosal B-1 cells can be
further classified into B-1a (IgMhigh, IgDlow,
CD5+) cells and B-1b (IgMhigh,
IgDlow, CD5-) cells based on the expression of
CD5. A high frequency of B-1a cells was more typical of SMG, while a
predominance of B-1b cells was characteristic of the i-LP and NP of
wild-type mice (Table I). B-1 cells were eroded, while B-2 cells were
not (Table I). These results demonstrate that IL-5R is essential for
the development of localized B-1a and B-1b cells in mucosal effector
sites, while GALT- and NALT-derived B-2 cells are exempted from IL-5R
dependency.
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-/- mice
To further specify IL-5-dependent IgA B cells, the frequency of
sIgA+ B cells in B-1a, B-1b, and B-2 cell subsets was
measured in mononuclear cells isolated from mucosal effector tissues of
IL-5R-/- and control background mice. The numbers of
sIgA+ B-2 cells were similar in both groups of mice (Figs. 4 and 5),
while the frequency of sIgA+ B-1a and B-1b cell fractions
was reduced significantly in IL-5R-/- mice (Figs. 4 and 5). This reduction affected predominantly B-1a cells in SMG and
B-1b cells in i-LP (Fig. 4), suggesting that the IL-5/IL-5R signaling
pathway is essential for the development of these cells at these
effector sites.
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, IL-5R, and IL-6R)
expressions on sIgA+ B cells
When the expression of cytokine receptor for the known
IgA-enhancing factors (e.g., IL-2, IL-5, and IL-6) (2, 8, 9) was
examined in the different subsets of sIgA+ B cells in
wild-type mice, the levels of IL-5R (36%) were found to be much
higher than those of IL-6R (8%) in sIgA+ B-1 cells (Fig. 6). On the other hand, IL-6R (56%)
was more prevalent rather than IL-5R (31%) on sIgA+
B-2 cells (Fig. 6). Both sIgA+ B-1 and B-2 cells
expressed IL-2R, the latter subset containing higher numbers of
positive cells (27%) than did B-1 cells (16%). In
IL-5R-/- mice, the expression of IL-6R on
sIgA+ B-1 and B-2 cells was comparable with that of the
wild-type group. However, IL-2R expression was reduced significantly
on sIgA+ B-1, but not B-2 cells of
IL-5R-/- mice (Fig. 6). These results suggest that the
development of sIgA+ B-1 cells requires a cytokine signal
provided via the IL-5/IL-5R pathway. In contrast, sIgA+ B-2
cells might be stimulated to develop via a signal provided via IL-6R
even in the absence of the IL-5/IL-5R signaling pathway since B-2 cells
express both IL-5R and IL-6R.
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In our final experiment for this study, sIgA+ B-1 or
B-2 cells were isolated from i-LP of IL-5R-/- and
wild-type mice and then cocultured with or without IL-5 and/or IL-6 to
enhance IgA production in LPS-stimulated in vitro system. When
sIgA+ B-1 cells from wild-type mice were incubated with
IL-5, but not IL-6, high levels of IgA synthesis were induced. In
contrast, B-2 cells produced IgA in the presence of IL-5 and/or IL-6
(Fig. 7). In the case of
IL-5R-/- mice, the level of IgA production was not
changed when B-1 cells were cultured with IL-5 and/or IL-6 in
comparison with the control wells (without the cytokine) (Fig. 7). On
the other hand, B-2 cells from IL-5R-/- mice
produced high levels of IgA in the presence of IL-6 (Fig. 7). These
findings indicate that the IL-5/IL-5R signaling pathway is essential
for the differentiation of sIgA+ B-1 cells into
IgA-producing plasma cells, but may be compensated for in
sIgA+ B-2 cell differentiation by the signal provided by
the IL-6/IL-6R pathway in the situation of IL-5R gene deletion.
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Discussion |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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-deficient mice. The
discrepant results obtained by these two gene-deleted mice could be
explained by the redundancy of the cytokine network. IL-3 and
granulocyte-macrophage CSF have been shown to share some IL-5-like
activity due to the common usage of the ß-chain receptor (35). Thus,
it is possible that some of these redundant cytokines may provide
compensatory signals for the induction of IgA B cell responses in
IL-5-/- mice.
An important aspect of this study is a new finding that IL-5R-chain
gene deletion affected IgA B cell development in the mucosal but not
the systemic compartment. Thus, while IgA-producing cells were reduced
in mucosal effector tissues of IL-5R-/- mice, leading
to decreased levels of IgA Ab in mucosal secretions, the level of serum
IgA remained the same as that seen in normal mice. It is interesting to
postulate that the development of IgA-producing B cells in
mucosa-associated tissue requires a stimulation signal provided via
IL-5R. In contrast, a cytokine cascade of IL-5/IL-5R may not be
essential for the induction of serum IgA responses. This observation
further emphasizes that the mucosal IgA system possesses an independent
regulatory mechanism that distinguishes it from the systemic immune
system. To this end, it has been shown that mucosal IgA in humans
differs from that of human serum IgA in molecular size and in subclass
distribution. For example, mucosal IgA is dimeric and/or polymeric,
while serum IgA is generally monomeric (36). Comparison of the IgA
subclass distribution in the two sites revealed that equal levels of
IgA1 and IgA2 Abs were generally found in secretions, while predominant
IgA1 Abs were seen in serum (36).
B cells can be classified into B-1 cells and conventional B (B-2) cells
(16, 17, 18, 37). B-1 cells were largely lacking in the IgA inductive
tissues such as PP and NALT, in which B-2 cells are shown to be
predominant in normal mice (Table I
and Fig. 5). However, B-1 cells
constituted a major fraction of the B cells in mucosal effector
tissues, including i-LP, NP, and SMG (Table I and Fig. 4). Thus, only
B-1 cells were reduced in the mucosal IgA effector site in
IL-5R-/- mice (Table I). Furthermore, our result
directly demonstrated that a population of sIgA+ B-1 cells
was deleted in the effector tissue of IL-5R-/- mice
(Figs. 4 and 5). The lack of sIgA+ B-1 cells in mucosal
effector tissue contributed to the low levels of mucosal IgA Abs in
IL-5R-/- mice. These findings show that the B-1
lineage of B cells is an important source of IgA-committed B cells for
the induction of mucosal Ab production, a response that is totally
regulated by the IL-5/IL-5R signaling cascade. In vivo and in vitro
studies provide support to this view by suggesting that B-1 cells could
be a major supplier for IgA plasma cells in the mucosal effector
tissues (19, 21, 38).
Taken together, our current results and those of previous studies (15)
make clear that two distinct lineages of IgA B cells developed from B-1
and B-2 cells are involved in the formation of the mucosal barrier
provided by secretory IgA. Furthermore, an interesting
possibility would be that sIgA+ B-2 cells contribute
mucosal IgA responses via the CMIS (e.g., migration pathway from PP and
NALT to the effector sites), while B-1 lineage sIgA+ B
cells act independently of it. In this regard, it has been shown that
IgA plasma cells in mucosal effector tissues (e.g., gut and salivary
gland) were derived from GALT- or PP-containing sIgA+ B
cells via the CMIS (6, 7). Our finding suggests that these
sIgA+ B cells in the mucosal inductive tissues (e.g., PP
and NALT) belong to the B-2 family (Table I). Thus, PP and NALT of
normal mice contain only sIgA+ B cells with B-2 lineage
(Figs. 4 and 5). The frequency of these sIgA+ B-2 cells was
the same in IL-5R-/- mice as in normal mice. Although
the numbers of IgA-producing cells in mucosal effector tissues and the
levels of secretory IgA Ab in external secretions were decreased in
IL-5R-/- mice, degree of IgA production was maintained
due to the B-2 cell-derived, IgA-producing cells. Thus, the numbers of
sIgA+ B-2 cells, presumably originating at an IgA inductive
site and subsequently differentiating into plasma cells, were found to
be similar in the mucosal effector tissues of both
IL-5R-/- and wild mice (Fig. 2).
The CMIS-independent sIgA+ B cells are derived from
B-1 cells since the partial reduction of IgA synthesis was noted in
IL-5R-/- mice that lack the development pathway for
B-1 cells. Further evidence for the presence of this CMIS-independent
IgA pathway was provided by a previous experiment in which surgical
removal of PP and cannulation of the thoracic duct did not result in
the complete deletion of mucosal IgA responses (39). Analysis of PP and
NALT cells from normal wild-type mice revealed the absence of B-1 cells
(Table I). Furthermore, it was shown that intestinal B-1 cells
originated in the PEC (16, 20). Not only the PEC, but mucosal effector
tissues such as i-LP and NP may contain unidentified and localized
sites that may serve as an alternative source for the development of
B-1 cells. For example, the intestinal tract has been found to possess
a high concentration of thymic-independent T cells (40). Furthermore,
intestinal crypt patches have been identified and suggested as a
potential thymic-independent site for the development of subpopulations
of mucosal T cells (41). Thus, it is possible to suggest that the
CMIS-independent sIgA+ B-1 cells may arise from localized
and specialized nests in the intestinal tract and NP in addition to the
PEC.
A group of Th2 cytokines has been shown to be essential in the
triggering of sIgA+ B cells to mature into IgA-secreting
plasma cells. For example, the induction of differentiation of
sIgA+ B cells and subsequent IgA synthesis were enhanced in
vitro by the presence of IL-5, IL-6, and/or IL-10 (6, 8, 9, 10, 11, 12). Our
results suggest that the differentiation of B-1 cells into IgA
plasma-producing cells may involve a cytokine pathway distinct from
that required for B-2 cell differentiation. Analysis of
cytokine-specific receptors revealed that IL-5R was more dominantly
expressed than IL-6R on sIgA+ B-1 cells (Fig. 6). In
contrast, the level of IL-5R expression was similar to that of IL-6R on
B-2 cells in the i-LP. The production of IgA Ab was enhanced by IL-5
rather than by IL-6 in an in vitro culture containing sIgA+
B-1 cells, while both cytokines were effective for the induction of IgA
Ab in B-2 cells (Fig. 7). Furthermore, it was demonstrated that
PEC-originated CD5+ B cells require IL-5 for the
differentiation to IgA plasma cells (42). Most recent study showed that
IgA-committed IL-5-dependent CD5+ B cells were deleted in
IL-5-/- mice (43). Taken together, these results
suggested that a cytokine pathway of IL-5/IL-5R is key to the
differentiation of CMIS-independent sIgA+ B-1 cells into
plasma cells for mucosal IgA production. This pathway cannot be
compensated by the IL-6/IL-6R signaling cascade. In contrast,
CMIS-dependent B-2 cells originating from the IgA inductive tissue
(e.g., PP) can respond to stimulation signals provided by both
IL-5/IL-5R and IL-6/IL-6R cascades to become IgA-producing cells. It
was also shown that IL-6 is an effective IgA-enhancing cytokine for B
cells originating from PP, but not those derived from the PEC (44).
Because of the capability of dual expression of IL-5R and IL-6R on B-2
cells, IL-6 provided a compensatory up-regulatory signal for mucosal
sIgA+ B-2 cells, resulting in the maintenance of some
degree of IgA response in IL-5R-/- mice.
In summary, our study provides new evidence that IL-5R is a critically important cytokine-specific receptor for the differentiation of sIgA+ B-1 cells, but not B-2 cells, into plasma and for subsequent IgA production in mucosal effector tissues. Furthermore, it was suggested that sIgA+ B-1 cells arise from CMIS-independent pathway, while sIgA+ B-2 cells are generated by the CMIS, using cytokine stimulation signals transduced via IL-5R and/or IL-6R. Since the distribution of B-1a, B-1b, and B-2 cells differed in several mucosa-associated tissues, it would be interesting and important to examine in a future study the contribution of these different sources of sIgA+ B cells for the induction of Ag-specific mucosal immune responses against thymus-dependent, thymus-independent-1, and thymus-independent-2 Ags and their specific requirements for Th1 and Th2 cytokines.
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Acknowledgments |
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Footnotes |
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2 Address correspondence and reprint requests to Dr. Hiroshi Kiyono, Department of Mucosal Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, 565-0781, Japan. E-mail address:
3 Abbreviations used in this paper: GALT, gut-associated lymphoreticular tissues; CMIS, common mucosal immune system; ELISPOT, enzyme-linked immunospot; i-LP, intestinal lamina propria; MLN, mesenteric lymph node; NALT, nasal-associated lymphoreticular tissues; NP, nasal passage; PE, phycoerythrin; PEC, peritoneal cavity; PerCP, Peridinia chlorophyll protein; PP, Peyer’s patches; sIgA, surface IgA; SMG, submandibular gland; SP, spleen.
Received for publication June 8, 1998. Accepted for publication September 24, 1998.
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-deficient mice. Immunity 4:483.[Medline]
transgenic mice are derived from B-1 (Ly-1 B) cells. Int. Immunol. 5:1317./
T cell-deficient mice have impaired mucosal immunoglobulin A responses. J. Exp. Med. 183:1929.-producing T cells, TCR expression and IgA plasma cells from mouse salivary gland associated tissues. J. Immunol. 148:2030.[Abstract]
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)
and wild-type (IL-5R
) mice were analyzed by
ELISA. Results represent the values (mean ± SEM) from five
experiments (five mice per group).
