Identification of a new epitope of human IRBP that induces autoimmune uveoretinitis in mice of the H-2b haplotype

PURPOSE: Experimental autoimmune uveoretinitis (EAU) is a T-cell-mediated disease induced by immunization with interphotoreceptor retinoid binding protein (IRBP). Major uveitogenic sites have been identified for mice of the H-2r and H-2k haplotypes but not for the H-2b haplotype. The present communication describes the characterization of an epitope contained in residues 1 to 20 of human IRBP that induces EAU in H-2b mice. METHODS: H-2b (C57BL/6, 129/J) and H-2r (BIO.RIII) mice were immunized with peptide 1-20 or with whole (bovine) IRBP. EAU (histopathology) and immunologic responses (delayed-type hypersensitivity [DTH], lymphocyte proliferation, and cytokine production) were assessed after 21 days. RESULTS: C57BL/6 mice, 129/J and (129/JxC57BL/6)F1 mice, immunized with 200 to 300 microg of peptide, developed DTH and EAU with scores comparable to those induced by 100 microg IRBP. Their lymphocytes proliferated to the peptide and produced interferon-gamma (but not interleukin-4) and transferred EAU to syngeneic recipients. Lymphocytes of IRBP-immunized mice also responded to the peptide. Peptide 1-20-immunized B1O.RIII mice failed to develop either disease or immunologic responses. CONCLUSIONS. Human IRBP peptide 1-20 contains a major epitope for the H-2b haplotype, which is apparently not presented by the H-2r haplotype.     

Residues 1-20 of IRBP and whole IRBP elicit different uveitogenic and immunological responses in interferon gamma deficient mice

Experimental autoimmune uveoretinitis (EAU) is a T-cell-mediated autoimmune disease induced by immunization with uveitogenic retinal antigens, or by the adoptive transfer of uveitogenic T-cells of the Th-1-like phenotype. We have previously shown that IFN-gamma-deficient mice (GKO) on the C57BL/6 background are equally susceptible to interphotoreceptor retinoid binding protein (IRBP)-induced EAU as the wild type (WT). In the present study, we evaluated EAU induction in GKO mice by the newly described H-2(b)epitope contained in residues 1-20 of human IRBP, and compared it to the response to the whole IRBP molecule. Similarly to previous observations with IRBP-induced EAU, delayed type hypersensitivity (DTH) and lymphocyte proliferation responses were elevated in GKO mice, as was production of IL-5 and TNF-alpha. However, unlike the responses induced by whole IRBP, there was no detectable IL-10 production to the peptide. Histopathology on day 21 after immunization, revealed that both GKO and WT mice developed retinal lesions, including damage to the photoreceptor cell layer, vasculitis and inflammatory cellular infiltration, but disease scores were significantly higher in GKO, and retinal detachment was observed only in GKO mice. In contrast to the wild type, the cellular infiltrate in eyes of GKO mice contained a prominent component of eosinophils, although of lower proportion in peptide-induced than in IRBP-induced EAU. We conclude that the cytokine and inflammatory responses to human peptide 1-20 differ perceptibly from the responses to whole bovine IRBP, and may explain the elevated EAU scores of GKO mice compared to wild type.     

Interphotoreceptor retinoid binding protein is a potent tolerogen in Lewis rat: suppression of experimental autoimmune uveoretinitis is retinal antigen specific

AIMS—Administration of unfractionated retinal antigen(s) (retinal extract, RE) suppresses RE induced experimental autoimmune uveoretinitis (EAU) and offers a potential therapeutic alternative to non-specific immunosuppressive therapies for posterior uveitis and autoimmune diseases. S-Ag and interphotoreceptor retinoid binding protein (IRBP) are two major autoantigens within soluble RE. It was aimed to assess, firstly, as has previously been shown with S-Ag, if IRBP can induce intranasal tolerance and, secondly, the contribution of both these major autoantigens to tolerance induction by whole RE.
METHODS—Animals were tolerised by intranasal administration with S-Ag or IRBP, either alone or in combination, or RE before immunisation with either IRBP or RE. Control animals were administered nasally either PBS or MBP. Daily clinical responses were recorded biomicroscopically and histological grades were obtained using a semiquantitative scoring system. Weekly serum antibody levels to retinal antigens were measured by ELISA and delayed hypersensitivity responses (DTH) were assessed by skin reactivity to intradermal inoculation with retinal or non-specific antigens.
RESULTS—Microgram doses of IRBP successfully suppressed both clinically and histologically IRBP induced EAU. This suppression was accompanied by reduced antigen specific DTH reactivity but maintained T cell dependent (IgG2a) antibody responses. Furthermore, combined S-Ag and IRBP administration afforded equal suppression of RE induced EAU when compared with RE therapy alone. Suppression of RE induced EAU was not achieved with administration of a non-retinal specific autoantigen, MBP. Although individually, both S-Ag and IRBP suppressed RE induced EAU, whole RE was unable to protect against IRBP induced disease.
CONCLUSIONS—Intranasal administration of IRBP suppressed IRBP induced EAU in the Lewis rat. S-Ag and IRBP are the major contributors to the tolerogenicity within RE, despite the known uveogenicity of other retinal antigens within RE and induction of tolerance was retinal antigen specific. Furthermore, suppression induced by single antigen administration is antigen specific although concomitant bystander suppression may also play a role. RE was unable to protect against IRBP induced disease despite tolerogenic levels of antigen within RE. Although this may be due in part to a dose effect of either tolerising or immunising antigen, further investigation into the possible antigen dominance of IRBP or mucosal processing of combinations of antigens is necessary so that the full efficacy of mucosal tolerance therapy can be assessed.

     

Effects of monoclonal antibodies directed at cell surface molecules on murine experimental autoimmune uveoretinitis

· Background: To elucidate the immunopathogenic mechanism of endogenous uveitis, the effects of monoclonal antibodies to molecules involved in the immune response were studied in murine experimental autoimmune uveoretinitis (EAU). · Methods: Monoclonal antibodies to CD4, CD8, Ia^k, Ia^d, lymphocyte function-associated antigen-1 (LFA-1), and intercellular adhesion molecule-1 (ICAM-1) were used in this study. The monoclonal antibodies were added in the culture of lymph node cells from B10.BR mice(H-2^K) immunized with interphotoreceptor retinoid-binding protein (IRBP) and the inhibition of proliferative response was measured. In vivo, IRBP-immunized mice were treated with a high dose of the antibody, and the EAU induction was examined both clinically and pathologically. · Results: Proliferative response of IRBP-sensitized lymph node cells was inhibited strongly by anti-CD4 or anti-LFA-1 monoclonal antibody and moderately by anti-Ia^k or anti-ICAM-1 monoclonal antibody. In contrast, no inhibitory effect of anti-CD8 or anti-Ia^d monoclonal antibody was observed. In vivo treatment with anti-CD4 monoclonal antibody inhibited development of EAU in a dose-dependent manner, while in vivo treatment with other monoclonal antibodies did not cause significant suppression of EAU. · Conclusions: CD4, Ia, LFA-1, and ICAM-1 molecules play important roles in the antigen-specific immune response of lymphocytes. However, in in vivo treatment with monoclonal antibodies to these molecules, only anti-CD4 monoclonal antibody had a strong inhibitory effect on the development of EAU. Received: 4 January 1999 Revised version received: 1 March 1999 Accepted: 8 March 1999     

A new method for induction of experimental autoimmune uveoretinitis (EAU) in mice

Experimental autoimmune uveoretinitis (EAU) was induced in two strains of mice by repeated-immunization protocol. SMA mice (H-2 nondefined) and C57BL/6 mice (H-2b) were immunized with S-antigen mixed with Klebsiella 03 lipopolysaccharide (K03 LPS) repeatedly at intervals of 1 to 4 weeks. Following the tertiary immunization, the mice exhibited histopathological changes of EAU as well as significant immune responses to the antigen. The antigen doses required for successful EAU induction were 4 micrograms or more at each immunization time. The histopathology of EAU was characterized by mild infiltration of mononuclear cells in the retina and the choroid, particularly, at the retinal blood vessels and the photoreceptor cell layer. The anterior segment of the eye was not affected by inflammation, and therefore clinical signs of EAU were not detected even under an operating microscope. Since the mouse is a genetically and immunologically well-defined species, this model is useful for study of immunopathogenic mechanisms of EAU.     

Adoptive transfer of experimental autoimmune uveoretinitis induced by interphotoreceptor retinoid-binding protein

The immunopathogenic mechanisms of experimental autoimmune uveoretinitis (EAU) induced by interphotoreceptor retinoid-binding protein (IRBP) were studied. Lymph node (LN) cells or spleen cells were collected from donor rats 14 days after the immunization with IRBP. After the 3-day pre-incubation of these cells with either IRBP or Concanavalin A (Con A), the cells were transferred to naive syngeneic rats intraperitoneally. EAU was successfully transferred by LN cells pre-cultured with IRBP, while EAU was poorly transferred by LN cells pre-cultured with Con A. On the other hand, spleen cells pre-cultured with either IRBP or Con A were quite potent to transfer EAU. In addition, the enriched helper/inducer T-cells repeatedly transferred EAU, while the enriched suppressor/cytotoxic T-cells did not. There also existed the simultaneous involvement of pinealitis. The histopathological features of EAU and pinealitis were generally similar to those in actively immunized rats. The immune responses to IRBP in recipients with EAU were mostly cellular (delayed hypersensitivity type skin response and proliferative responses of lymphocytes), while humoral responses (Arthus type skin response and antibody activities) were quite weak in most of the recipients. Thus, it was confirmed that cellular immunity plays a major role in the adoptive transfer of EAU by IRBP as in S-antigen-induced EAU.     

实验性自身免疫性葡萄膜视网膜炎大鼠T细胞受体Vβ8.3基因的表达

目的 探讨实验性自身免疫性葡萄膜视网膜炎(EAU)大鼠CD4⁺T细胞抗原受体(TCR)Vβ8.3基因的表达。 方法 Lewis大鼠18只分为EAU、Freund完全佐剂及空白对照组。用Fmoc 化学合成法合成光感受器间维生素A类结合蛋白（IRBP）R16多肽片段，以诱导EAU动物模型。利用磁吸附细胞分选法(MACS)分离大鼠脾脏CD4⁺T细胞，流式细胞术检测MACS分选前后CD4⁺T细胞比例，监测细胞分选效果。通过荧光定量-聚合酶链反应法检测大鼠脾脏CD4⁺T细胞的TCR Vβ8.3基因片段的表达。 结果 IRBP R16 免疫Lewis大鼠稳定地诱导出EAU动物模型；MACS分选CD4⁺T细胞的纯度较分选前明显增高 （P＜0.001）；IRBP R16 诱导的EAU大鼠CD4⁺T细胞受体Vβ8.3基因的表达显著高于空白对照组（P＜0.05）。 结论 在IRBP R16 诱导的EAU中存在着抗原特异性T细胞受体Vβ8.3基因的优势利用，为EAU的免疫治疗提供了新的思路。 （中华眼底病杂志，2004，20：167-167）     

“High endothelial venules”: expression kinetic in IRBP-induced EAU

Summary Experimental autoimmune uveitis (EAU) is a T-cell-mediated disease expressing high endothelial venules (HEVs) in the retina. HEVs could be responsable for the absorption of activated T-cells. The purpose of this study was to investigate the kinetics of HEV expression in the murine IRBP (interphotoreceptor retinoid binding protein) induced EAU. Methods: B10.A mice were immunized subcutanously with IRBP. The eyes were analysed on days 10, 18, 24 and 28 (n = 5 for each time point). While HEVs were identified with the mAb MECA 325, the control mAb MECA 20 stained all endothelial cells. Results: HEVs were detectable in the intact retina from day 10. Presence of HEVs peaked on day 18 and decreased by day 28, when maximal inflammation and retinal destruction was detectable. Conclusion: HEV expression could play a central role in the onset of EAU, allowing homing and migration of inflammatory cells into the eye.      

ORIGINAL ARTICLE,The Immunomodulator Vasoactive Intestinal Peptide (VIP) Does Not Affect Experimental Autoimmune Uveitis (EAU) in B10.RIII Mice

Purpose: Vasoactive intestinal peptide (VIP) exhibits immunomodulatory activities both in vivo and in vitro, including efficient inhibition of murine experimental arthritis. In this study, we investigated the effects of VIP treatment on the induction of experimental autoimmune uveoretinitis (EAU). Methods: EAU was induced in B10.RIII mice by immunization with interphotoreceptor retinoid-binding protein (IRBP) using routine methods, but without treatment with pertussis toxin (PTX). VIP was injected i.p. at different doses into mice on alternate days. Mice were tested by conventional methods for ocular inflammation, antibody levels, lymphocyte proliferation, and cytokine release by cultured lymphocytes. Results: Treatment with VIP, at different doses, had essentially no effect on the development of EAU or antibody production in the B10.RIII mice. The treatment did have variable effects on the low interferon-γ production by lymphocytes of these mice. Conclusion: Unlike its inhibitory effect in the experimental arthritis system, VIP did not modulate the development of EAU in B10.RIII mice.     

实验性自身免疫性葡萄膜视网膜炎中浸润细胞的表型及其凋亡的研究

目的探讨实验性自身免疫性葡萄膜视网膜炎(experimental autoimmune uveoretinitis,EAU)中参与的细胞表型及其凋亡。方法用光感受器间维生素A类结合蛋白(interphotoreceptor retinoid-binding protein,IRBP)免疫16只Lewis鼠后，于眼组织切片和平片上进行免疫组织化学染色和原位 凋亡染色，所用抗体为抗单核细胞、巨噬细胞(EDI)、MHC-II类抗原(OX6)、T淋巴细胞(R73)的单克隆抗体，所用原位凋亡试剂盒为TACS1 Klenow。结果用IRBP免疫Lewis鼠后，16只鼠中12只发生了临床可见的葡萄膜炎，炎症平均得分为1.29±0.7级；免疫组织化学染色发现葡萄膜和视网膜中有大量的单核细胞、淋巴细胞及MHC-II⁺细胞浸润，这些组织中均可见浸润细胞的凋亡，虹膜睫状体中凋亡细胞明显多于脉络膜和视网膜中的凋亡细胞。结论单核巨噬细胞、淋巴细胞和MHC-II⁺细胞均参与了EAU的形成，在EAU早期即有浸润细胞发生凋亡，此可能是导致这种炎症迅速消退的重要机制。（中华眼底病杂志，2000，16：1-70）     

IRBPR16多肽的合成及其致葡萄膜视网膜炎活性的探讨

目的 探讨光感受器间维生素A类结合蛋白（IRBP）的R16多肽片段的致葡萄膜视网膜炎活性。设计实验研究。研究对象36只Lewis大鼠。方法应用Fmoc法合成并纯化牛IRBPR16多肽片段,以诱导实验性自身免疫性葡萄膜视网膜炎（EAU）模型,并对该模型进行临床观察和组织学检查。培养EAU大鼠的引流淋巴结细胞,测定淋巴细胞增殖反应。各实验同时建立单纯弗式完全佐剂（CFA）免疫组和空白对照组。主要指标多肽分析,视网膜形态学,淋巴细胞增殖反应。结果合成的IRBPR16多肽片段纯度为95．6％。应用IRBPR16多肽片段作为抗原免疫Lewis大鼠,可成功诱导出EAU模型。EAU的临床分级为（3．33±0．52）级,病理分级为（3．67±0．92）级;CFA组和空白对照组大鼠眼部均无异常改变。EAU组大鼠引流淋巴结中抗原特异性淋巴细胞增殖反应增强,为（33．27±7．24）×10^cpm,显著高于CFA组[（1．91±1．16）×10^3cpm]和空白对照组[（1．23±0．51）×10^3cpm]（P〈0．05）。结论IRBPR16多肽片段具有较强的致葡萄膜视网膜炎活性,引流淋巴结抗原特异性淋巴细胞增殖反应增强。IRBPR16多肽诱导的EAU为研究人类葡萄膜视网膜炎提供了一个重要的动物模型。     

Differentiation of Th1 and Th2 cells in lymph nodes and spleens of mice during experimental autoimmune uveoretinitis

PURPOSE: Experimental autoimmune uveoretinitis (EAU) is a T-cell-mediated autoimmune disease that can be elicited in susceptible rodent strains by immunization with a retinal autoantigen, such as interphotoreceptor retinoid-binding protein (IRBP). In this study, we investigated whether there is a correlation between inflammation in the eye and T-helper (Th)1- and Th2-type responses in the lymph nodes and the spleen after immunization of B10.A mice with IRBP. METHODS: B10.A mice were immunized with IRBP emulsified with complete Freund's adjuvant (CFA), and eyes were then enucleated for histological examination of EAU at 1, 2, 4, 6, or 8 weeks after immunization. In addition, lymph node cells and spleen cells were collected, and cultured with IRBP to measure T-cell proliferation responses and Th1-type (interleukin [IL]-2, interferon [IFN]-gamma), Th2-type (IL-4, IL-10) cytokine production. RESULTS: Pathologically, severe ocular inflammation occurred 2 weeks after IRBP immunization, persisted for 2 weeks, and then gradually resolved. Interleukin-2 and IFN-gamma production were observed in draining lymph node cells at 1 and 2 weeks after IRBP immunization. Those responses then diminished, whereas IFN-gamma production by spleen cells was observed from week 1, peaked at week 4, and gradually decreased. Alternatively, significant production of IL-4 or IL-10 by draining lymph node cells was not detected at any time point. Both IL-4 and IL-10 production by spleen cells was observed at week 6. CONCLUSIONS: Th1-type responses were observed early in draining lymph nodes, then in the spleen after IRBP immunization. The levels of IFN-gamma production by spleen cells reflected the severity of EAU, confirming their pathogenic role in this disease. Th2-type responses were generated in the spleen only as the disease receded, suggesting a role for Th2 cells in the spontaneous termination of EAU.     

过继转发IRBP致敏脾细胞诱发EAU、EAP的实验研究

将光感受器间维生素A类结合蛋白(IRBP)免疫鼠的脾细胞单独或与IRBP一起培养后注射至6只Lewis鼠的腹腔内(每鼠3×10⁷个细胞),发现经IRBP刺激的脾细胞既可转移特异性免疫反应，又可使受鼠发生实验性自身免疫性葡萄膜视网膜(EAU)、实验性自身免疫性松果体炎(EAP)；而未用IRBP刺激的脾细胞则不能诱发EAU、EAP和特异性免疫反应。此结果表明细胞免疫在EAU、EAP发生中起决定性作用，并证明过继转移前用特异性抗原刺激是不可缺少的。 （中华眼底病杂志，1993，9：210-213）     

The onset mechanism of experimental autoimmune uveoretinitis induced by interphotoreceptor retinoid-binding protein]

In order to analyze the onset mechanism of experimental autoimmune uveoretinitis (EAU), two experimental models were used; one was EAU induced by one injection of purified bovine interphotoreceptor retinoid-binding protein (IRBP) with complete Freund's adjuvant in Lewis rat, and the other was an IRBP-induced autoimmune uveoretinitis that occurred spontaneously in nude (nu/nu) mice at 4 weeks of age reconstituted by the grafting of rat embryonic thymus (TG nude mouse). EAU develops when the IRBP-reactive lymphocytes in the regional lymph-nodes are activated. Activation begins when the T lymphocyte recognizes the peptide for the epitope bound to a major histocompatibility complex (MHC) molecule in the antigen-presenting cell by way of the T-cell receptor (TCR). In EAU, ten peptide residues p1182-1191 of the IRBP amino acid sequence, were revealed to be sufficiently capable of lymphocyte activation for EAU, and it was also shown that amino acid positions 1182W (tryptophane), 1185G (glycine), 1186V (valine) and 1188P (proline) of IRBP play important roles as the epitopes or agretopes in developing EAU. On the other hand, two amino acids of IRBP, amino acid positions 1182W (tryptophane) and 1194P (proline) were shown to be the agretopes inducing autoimmune uveoretinitis in the TG nude mouse. A study of the variable region of the TCR with a residual p1182-1194 specific T-cell line from the TG nude mouse revealed that as many as 96% utilized the T-cell receptor V beta 6 gene and that the peptide-MHC molecule complex was recognized by restricted receptors. Adhesion molecules such as ICAM-1 and LFA-1 were also found to play an important role as cofactors in activation of lymphocytes in the antigen-recognition process of EAU. Uveoretinitis seemed to result from an immune reaction in the eye occurring when the T lymphocyte arrives there, activating the immunological process. ICAM-1 and LFA-1 were also found to be involved in the infiltration process of inflammatory cells: our immunohistological examination revealed that ICAM-1 was present in the retinal pigment epithelium and epithelium of the ciliary body composing the blood-ocular barrier. In contrast, LFA-1 was expressed in the infiltrating cells. Finally, the tolerance of IRBP was discussed and it was experimentally demonstrated that the absence of IRBP-induced uveoretinitis in human beings and certain experimental animals resulted from endogenous IRBP serving as a tolerogen; we assumed that the breakdown of this self-tolerance would induce EAU due to thymic dysfunction or IRBP antigen injection.     

Experimental autoimmune uveoretinitis in brown Norway rats induced by bovine interphotoreceptor retinoid-binding protein and renal cryosurgery

In Brown Norway (BN) rats, it is known to be difficult to induce experimental autoimmune uveoretinitis (EAU) by the injection of retinal S-antigen (S-Ag) or interphotoreceptor retinoid-binding protein (IRBP) together with complete Freund's adjuvant (CFA), unless intravenous Bordetella Pertussis is used as an additional adjuvant. In the present study it was found that the rate of onset of EAU could be increased in BN rats immunized with IRBP and CFA by simultaneous cryosurgery to the renal cortex. There was no evidence of retinal vasculitis, pinealitis or nephritis in the rats with EAU except for renal inflammatory infiltrates as a reaction to the cryosurgery. Affected eyes eventually showed destruction of most retinal components and prominent infiltration of the retina by macrophages, with the changes being more severe than those previously reported in Lewis rats with EAU induced by IRBP. Data suggesting the existence of an antibody that cross-reacts with the proximal renal tubules and the retinal pigment epithelium were also obtained.     

S-nitrosoglutathione prevents interphotoreceptor retinoid-binding protein (IRBP(161-180))-induced experimental autoimmune uveitis.

PURPOSE: Experimental autoimmune uveitis (EAU), an animal model of human uveitis, is an organ-specific autoimmune disease mediated by various inflammatory cytokines. In particular, tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and interferon (IFN)-gamma are known to play a role in its pathogenesis. S-nitrosothiol S-nitrosoglutathione (GSNO), a slow nitric oxide (NO) donor, was reported to have beneficial effects in inflammatory disease in ischemia-reperfusion injury. The efficacy of GSNO treatment on interphotoreceptor retinoid-binding protein (IRBP)-induced EAU was investigated, using functional, histologic, and immunologic readouts. METHODS: Mice were immunized with a single injection of IRBP(161180) peptide to induce EAU, followed by a daily treatment with GSNO (1 mg/kg). Electroretinogram (ERG) analysis, histopathology, and immunologic responses to IRBP were analyzed. The effects of GSNO treatment on the antigen-specific T-cell recall responses and their cytokine production were determined. RESULTS: A single immunization of IRBP(161180) peptide led to significant structural damage of the retina and concomitant elimination of ERGs. Daily oral GSNO treatment from days 1-14 following immunization was found to be effective against IRBP-induced EAU. Histopathologic and ERG analysis both demonstrated significant retinal protection in GSNO-treated mice. The GSNO treatment of EAU animals significantly attenuated the levels of TNF-alpha, IL-1beta, IFN-gamma, and IL-10 in retinas, as measured by quantitative real-time polymerase chain reaction analysis. The splenocytes isolated from EAU- and GSNO-treated mice had lower antigen-specific T-cell proliferation in response to IRBP protein, and their cytokine production was inhibited. CONCLUSIONS: The oral administration of GSNO significantly suppressed the levels of inflammatory mediators in the retinas of EAU mice. This suppression was associated with the maintenance of normal retinal histology and function. These results clearly demonstrated the therapeutic potential of GSNO in EAU, and provide new insights for the treatment of human uveitis.     

实验性自身免疫性葡萄膜炎小鼠T细胞变化的动态研究

目的：了解实验性自身免疫性葡萄膜炎(experimental autoimmune uveitis, EAU)不同进展阶段小鼠T细胞动态变化,对葡萄膜炎治疗方案的优化及疗效评价提供指导。

方法：用CFA+PTX+IRBP对6～10周龄雌性C57BL/6小鼠后肢及尾部皮下进行三点免疫建立EAU模型,于免疫3,7,14,21,28d取外周血行流式细胞术检测。

结果：用特异性抗原IRBP免疫后,EAU疾病在第14d左右产生,在第21d达最高峰,以后开始逐渐缓解。随着EAU疾病的发生,CD4⁺CD25⁺调节性T细胞、CD4⁺CD3⁺辅助T细胞数量均有增加,CD4⁺CD25⁺调节性T细胞增加更为明显,CD4⁺CD25⁺Foxp3⁺调节性T细胞数量第21d达到高峰,第28d开始下降,CD4⁺CD25⁺Foxp3⁺/CD4⁺CD25^-Foxp3⁺比值从第3d开始逐渐增加,到第21d达到高峰,从第28d开始下降。

结论：EAU疾病的发生和转归与CD4⁺CD25^+/-Foxp3⁺Treg细胞密切相关,CD4⁺CD25^+/-Foxp3⁺Treg细胞为阐明EAU的缓解机制、预防和治疗人类葡萄膜炎提供了新思路。     

The requirement for pertussis to induce EAU is strain-dependent: B10.RIII, but not B10.A mice, develop EAU and Th1 responses to IRBP without pertussis treatment.

PURPOSE: Experimental autoimmune uveoretinitis (EAU) in mice is an important model for elucidating basic mechanisms in autoimmune eye disease. The need for pertussis toxin (PTX) as an additional adjuvant to elicit EAU has limited the usefulness of this model in some types of studies by introducing a pleiotropic factor with confounding effects on the immune response. METHODS: In the present study the authors examined the ability of B10.RIII mice, the most susceptible strain known so far, to develop EAU in response to the retinal antigen, interphotoreceptor retinoid-binding protein (IRBP), and to a major uveitogenic epitope of IRBP, peptide (p)161-180, in the absence of PTX treatment. RESULTS: The data indicate that high disease scores in response to IRBP and p161-180 were found in B10.RIII mice, without the need for PTX as part of the immunization protocol. Unlike the B10.A strain in which appreciable disease did not develop without PTX, B10.RIII mice mounted a high IFN-gamma response to IRBP in the absence of PTX treatment. Interestingly, and unlike the effect with IRBP, in vitro recall response to p161-180 was low in IFN-gamma, despite good EAU scores. CONCLUSIONS: The data indicate that an important mechanism through which PTX facilitates induction of cell-mediated autoimmunity is by promoting a Th1 polarization of the immune response. The propensity of B10.RIII mice to mount a more polarized Th1 response to IRBP than other strains may contribute to their ability to develop EAU without pertussis adjuvant. Nevertheless, the induction of EAU by p161-180 in the context of a relatively limited IFN-gamma production indicates that non-Th1- and Th-related mechanisms are likely to act in concert to determine the outcome of disease.     

IRBP免疫鼠血清特异性抗体的测定及动态变化

我们首次在国内提纯了光感受器间维生素 A类结合蛋白(interphotoreceptor retinoid-binding protein,IRBP),将其免疫 Lewis 大鼠后动态测定了鼠血清抗IRBP 抗体和抗视网膜 S 抗原抗体.发现抗 IRBP 抗体于免疫后第7天出现,以后逐渐上升,于第26天达高峰,未测出抗 S 抗原抗体.根据特异性抗体与实验性自身免疫性葡萄膜视网膜炎(experimental autoimmune uveoretinitis,EAU)之间的关系,讨论了特异性体液免疫反应在 EAU发生中的作用.     

The purification of bovine IRBP and its uveitogenic action]

The interphotoreceptor retinoid-binding protein, IRBP, shuttles the retinoid between photoreceptor cells and the pigment epithelium. It also induces experimental autoimmune uveoretinitis (EAU). The authors first purified IRBP in China by Con A Sepharose affinity chromatography in conjunction with the purification of bovine retinal S-antigen by ion-exchange chromatography. EAU was successfully induced by injection of emulsified IRBP 50 micrograms with Freund's complete adjuvant into the footpad of Lewis rats. It was characterized by panophthalmia with severe damage to the posterior retina, and lymphocytes predominated the inflammatory infiltration that included mononuclear and polymorphonuclear cells.