Abnormal anti-viral immune response in mice is corrected in HLA-B27.2-transgenic mice.

In contrast to the strong Sendai virus-specific cytotoxic T-lymphocyte (CTL) responses in C57BL/6 mice. H-2Kb mutant bm1 mice are nonresponders to Sendai virus. By appropriate crossings between HLA-B27 double-transgenic mice and Kb mutant bm1 mice, and after subsequent selection, H-2bm1 homozygous mice were produced expressing the human HLA-B27.2 and beta 2-microglobulin genes. Here we show that the introduction of a human HLA class I gene into the genome of the H-2bm1 Sendai virus-nonresponder mutant mice resulted in good responsiveness to Sendai virus, and in normal levels of Sendai virus-specific CTL precursors. The CTL response in the HLA-B27.2 double-transgenic H-2bm1 mice against Sendai virus was restricted by the HLA-B27.2 molecule. These results show the direct involvement of HLA class I molecules in regulation of the anti-viral CTL repertoire and represent for the first time a correction of abnormal anti-viral immunity in mice by incorporation of a human MHC class I (HLA-B27.2) gene.     

Experimental autoimmune uveitis in HLA-B27 transgenic mice

The major histocompatibility complex (MHC) gene, HLA-B27 is strongly associated with autoimmune uveitis and spondyloarthropathies in humans. Experimental mouse models of autoimmune uveitis involve systemic immunization with the retinal autoantigen interphotoreceptor retinoid binding protein (IRBP). To assess possible roles of HLA-B27 in autoimmune uveitis, as well as to investigate a possible new animal model of human uveitis, inbred strains of C57BL/6 and C57BL/6 possessing the human HLA-B27 or HLA-A2 transgene were immunized with IRBP emulsified in complete Freund's adjuvant (CFA). Dilated eye examinations were performed to assess the timing and clinical course of any ensuing uveitis. Mice were sacrificed 3 to 4 weeks postinjection and the eyes submitted for histopathologic analysis.

CFA alone did not produce any clinical uveitis. Fifty percent of eyes from the background C57BL/6 strain developed uveitis as early as 10 days postinjection. Of the eyes demonstrating uveitis, an average clinical score of 2.5 was present. Pathologically, a moderate scleritis and anterior uveitis was present. Fifty percent of A2 transgenic eyes developed uveitis as early as 14 days postinjection with an average clinical score of 2.0. Pathologically, a mild vitriitis was present. Uveitis developed in only 20% of B27 transgenic mice and reached a peak on day 28. The average EAU score in diseased animals was 4.5. A dense retinitis and panuveitis was associated with severe vitritis. We conclude that the presence of the B27 gene is associated with a decreased incidence and slower rate of onset of EAU following immunization with IRBP; however, EAU may be more severe in the HLA-B27 expressing animals who do develop disease.     

HLA class II and HLA-B27 oligotyping in two Siberian native population groups

Abstract: It was the purpose of this study to better define the frequency of HLA-B27 subtypes and HLA class II alleles among indigenous populations from the eastern tip of the Chukotka Peninsula of Siberia, Russia, which have higher frequencies of HLA-B27 (40%) and spondyloarthropathies (2%) than Caucasian populations and test the hypothesis that these populations are more closely related to Orientals. Siberian Eskimos and Chukchi residing in four coastal villages on the Chukotka Peninsula inhabited by Siberian Eskimos and Chukchi people were examined using oligotyping of the polymerase-chain reaction-amplified second and third exons of the HLA-B27 gene. HLA-class II alleles (DRB1, DQA1 and DQB1) were similarly determined. Of 88 HLA-B27 positive individuals from these villages, all had HLA-B*2705, including the four patients with Reiter's syndrome and the five ankylosing spondylitis, except one Eskimo control who had HLA-B*2702. None had HLA-B*2704, a frequent subtype in Orientals. HLA-class II typing in 70 Siberian Eskimos and 71 Siberian coastal Chukchi revealed HLA-DRB1*0401, DRB1*0802, *0901 and *1402 to account for nearly all the DRB1 alleles found in this population, similar to what has been described in Eskimos in Alaska, but different from Chinese or native Americans in the U.S. The overwhelming majority of the individuals examined had HLA-DQB1*0301, similar to what has been observed in Native Americans. The Siberian Eskimos differed from the coastal Chukchi only in the occurrence of HLA-DRB1*0701, DQA1*0201, DQB1*0201 alleles, which occurred only in the former group. These data suggest that the Chukotka population is genetically more closely related to Caucasians and native Americans and less to other Oriental populations.     

Organization, sequence and expression of the HLA-B27 gene: a molecular approach to analyze HLA and disease associations

Among the numerous autoimmune diseases associated with various HLA alleles, the one with the highest relative risk so far reported has been ankylosing spondylitis with HLA-B27. To examine this relationship more directly, we have cloned the gene encoding the HLA-B27 antigen and determined its complete DNA sequence. Comparison of the HLA-B27 sequence with that of the allelic HLA-B27 shows a high level of homology. Mutations are distributed evenly between exons and introns. Exon 1 and intron 1 are the most divergent ones, and the degree of divergence distinctly declines towards the 3' end. The HLA-B57 gene when transfected into murine L cells is expressed on the cell surface and reacts with a panel of monoclonal antibodies directed against monomorphic and polymorphic determinants associated with HLA-B27 antigen. The isolation of this gene allows for the first time a search for structural features which make the HLA-B27 antigen a high risk genetic factor for a group of rheumatoid disorders, in particular ankylosing spondylitis.     

强直性脊柱炎患者HLA-B27位点等位基因相关抗原的表达

目的：探讨强直性脊柱炎（AS）患者HLA-B27位点等位基因相关抗原的表达。方法：采用补体依赖性微量淋巴细胞毒法检测418例脊柱关节炎（SpAS）患者和30例正常对照HLA-B27相关抗原。结果：418例SpAS患者73例被确诊为AS,Bw6、B27（47）、B27和B7/B27/B73/B81抗原阳性率分别为31%、28%、25%和22%。在AS中,B27阳性组与B27阴性组间有不同分布,两组B27（47）、B27、B7三种等位基因有统计学意义（P〈0.01）。在66例B27阳性组中,除B13与Bw6成负相关外,Bw4与B27（47）、B7与B27之间等均成明显的正相关。结论：在AS患者中,B13与Bw6、B60/61/47/48/81（13）,B7与B27,Bw4与B27（47）,Cw1与B42B45表达联锁失衡,B27并不是AS易感的唯一因素,其他基因位点可能起增强（如Cw1及Cw2）或抑制（如B13）AS发生的作用。     

Susceptibility of HLA-B27 transgenic mice to Yersinia enterocolitica infection

The majority of patients with reactive arthritis have the major histocompatibility complex class I gene HLA-B27. The development of arthritis in these patients often occurs following infection with one of several enteric bacteria, including Yersinia enterocolitica. In this study, transgenic mice expressing HLA-B27 and their negative full sibs were infected intravenously with Yersinia enterocolitica 0:8 WA in an attempt to develop an experimental model of reactive arthritis. To date, no reactive arthritis has been observed; however, a significantly higher incidence of paralysis was observed in the HLA-B27⁺ transgenic mice. Injection of 10⁵ organisms induced hind limb paralysis in 8 out of 30 of the HLA-B27 transgenic mice (27%) and in only 1 of the 24 negative siblings (4%). Paralysis occurred in 14 out of 30 HLA-B27⁺ mice (47%) at a dose of 10⁴ organisms. Only 2 of the 25 negative siblings (8%) were affected at this dose. Paraspinal abscesses were found in all of the paralyzed animals. At the 10⁴ dose most of the HLA-B27⁺ mice (70%) succumbled to the disease within 4 weeks, while the mortality in their B27⁻ full sibs was less than 10%. Thus, HLA-B27 transgenic mice have higher mortality and morbidity from infection with Y. enterocolitica 0:8 WA than corresponding HLA-B27⁻ littermates.     

HLA-B27 and HLA-A2 subtypes: structure, evolution and function

Beyond the resolution of tissue typing serology, HLA class I antigens display a certain level of structural microheterogeneity, that allows their subdivision into subtypes. The structure of these subtypes shows that multiple mechanisms operate in the generation of HLA polymorphism and suggests possible evolutionary pathways for subtype diversification. In addition, subtype polymorphism critically affects cellular allorecognition and antigen presentation to self-restricted T cells. These properties are used to define the structure and diversity of T-cell epitopes. In this review, José López de Castro discusses the nature and evolution of this polymorphism and its modulation of antigen recognition by cytolytic T lymphocytes.     

HLA-B27 in Rheumatoid Arthritis and Amyloidosis

To study the role of genetically determined immune responsiveness in the pathogenesis of systemic amyloidosis complicating rheumatoid arthritis the HLA antigens were identified in 26 patients with rheumatoid arthritis complicated by secondary amyloidosis, in 44 patients with rheumatoid arthritis, and in 11 patients with secondary amyloidosis of non-rheumatoid origin. Subjects with ankylosing spondylitis, sacroiliitis without peripheral polyarthritis, Reiter's disease, reactive arthritis, erosive osteoarthritis, psoriatic arthropathy, systemic lupus erythematosus or arthritis associated with a gastrointestinal involvement were excluded from the study. Patients with amyloidosis secondary to rheumatoid arthritis had a high frequency of the HLA specificity B27 and of the haplotype likely to bear A2, B27. The association with B27 was closest in the group of male patients with amyloidosis whose rheumatoid arthritis had begun at an early age and who lacked demonstrable rheumatoid factor in serum. These patients may represent a genetically determined subentity of rheumatoid arthritis.     

HLA-B27 subtypes in the spondarthropathies

The spondartliropathy (Sp)-associated HLA-B27 antigen includes al least seven subtypes. B*2701–07, of which 01, 02, 05 and 07 occur in Caucasians. This study examined the B27 subtype distribution in British patients with Sp. The 133 HLA-B27⁺ subjecis comprised 94 European Caucasian Sp (58 ankylosing spondylitis (AS), 22 reactive arlhrilis (ReA: 11 sexually acquired (SARA). 11 enteric (EReA)). eight undifferentiated Sp (USp). and six pauciarticular juvenile-onset chronic arthritis (pJCA)) patients, antl 34 healthy Caucasian controls, together with four Asian Indian and one Chinese. ³⁵S-labelled B27 was immunoprecipitated with anti-B27 MoAbs. and subtyped according to isoelectric point (pi) following isoelectric focussing. The use of B27 MoAb permitted subtype assignment without full class 1 HLA lyping. The vast majority (95%) were B*27O5 (Caucasian controls 31/34; AS 55/58; ReA 21/22; USp 8/8. and pJCA 6/6; Indian control 1/1 and AS 2/3: Chinese pJCA I/I), and the remainder B*2702. No B*270l or 07 subjects were identified. AS occurs in both B*2702 and 05 subjects, and we extend this observation to small numbers of ReA and of Indian AS subjects. This implicates molecular features shared between B27 subtypes, rather than subtype-determining regions of the antigen, in Sp palhogenesis.     

HLA-B27 antigen and rheumatoid arthritis

The influence of HLA-B27 antigen on clinical, radiological and laboratory features of rheumatoid arthritis (RA) was studied. The group with B27 antigen comprised: 4 males and 20 females aged 28 to 71 and a group of patients free from B27 antigen consisted of 2 males and 21 females aged 26 to 69. RA patients possessing the B27 antigen did not differ regarding the age of the onset of disease, the distribution of affected joints during the follow-up (3-10 years), the development stages of the disease and the presence of rheumatoid factor when compared with B27 negative RA patients. The arthritis of the radiocarpal joints (p less than 0.01) was significantly more often the first sign of the disease in patients with B27 antigen. In these patients low back pain and morning stiffness in the low back were twice as frequent as they were in patients not possessing this antigen. The clinical pattern of the affected spine was also found more frequently in B27 carriers (p less than 0.05). B27 positive RA patients showed also the clinical pattern of sacroiliitis (SI) (p less than 0.05) and x-ray SI (p less than 0.01) significantly more often than the patients free from this antigen. In addition, symmetric arthritis of the peripheral joints was more often diagnosed in patients free from B27 antigen.     

HLA-B27 misfolding and ankylosing spondylitis

Understanding how HLA-B27 contributes to the pathogenesis of spondyloarthritis continues to be an important goal. Current efforts are aimed largely on three areas of investigation; peptide presentation to CD8T cells, abnormal forms of the HLA-B27 heavy chain and their recognition by leukocyte immunoglobulin-like receptors on immune effector cells, and HLA-B27 heavy chain misfolding and intrinsic biological effects on affected cells. In this chapter we review our current understanding of the causes and consequences of HLA-B27 misfolding, which can be defined biochemically as a propensity to oligomerize and form complexes in the endoplasmic reticulum (ER) with the chaperone BiP (HSPA5/GRP78). HLA-B27 misfolding is linked to an unusual combination of polymorphisms that identify this allele, and cause the heavy chain to fold and load peptides inefficiently. Misfolding can result in ER-associated degradation (ERAD) of heavy chains, which is mediated in part by the E3 ubiquitin ligase HRD1 (SYVN1), and the ubiquitin conjugating enzyme UBE2JL. Upregulation of HLA-B27 and accumulation of misfolded heavy chains can activate ER stress signaling pathways that orchestrate the unfolded protein response. In transgenic rats where HLA-B27 is overexpressed, UPR activation is prominent. However, it is specific for heavy chain misfolding, since overexpression of HLA-B7, an allele that does not misfold, fails to generate ER stress. UPR activation has been linked to cytokine dysregulation, promoting lL-23, IFNβ, and lL-1α production, and may activate the IL-23/IL-17 axis in these rats. IL-1α and IFNβ are pro- and anti-osteoclastogenic cytokines, respectively, that modulate osteoclast development in HLA-B27-expressing transgenic rat monocytes. Translational studies of patient derived cells expressing HLA-B27 at physiologic levels have provided evidence that ER stress and UPR activation can occur in peripheral blood, but this has not been reported to date in isolated macrophages. Inflamed gastrointestinal tissue reveals evidence for HLA-B27 misfolding, ERAD, and autophagy, without acute UPR activation. A more complete picture of conditions that impact HLA-B27 folding and misfolding, the full spectrum and time course of consequences of ER stress, and critical cell types involved is needed to understand the role of HLA-B27 misfolding in spondyloarthritis pathogenesis.     

Development of lymphocytes in interleukin 7-transgenic mice

We have developed and established mouse transgenic lines in which the mouse interleukin 7 gene was targeted for expression in the lymphoid cell compartment. Northern blot analysis indicate that the transgene is expressed in bone marrow (BM), spleen and thymus, but not in kidney, liver, brain or heart. Both the frequency and absolute numbers of B cell precursors and mature B lymphocytes are increased in the BM and spleen of the transgenic mice. Although there is no expansion of the pro-T lymphocyte population in the BM, the number of all major subsets of thymocytes and peripheral T lymphocytes is increased in the majority of the transgenic mice analyzed. The B and T cell lymphocytes in the transgenic mice are functionally competent. In contrast, the number of granulocytes and macrophages in the BM of transgenic mice is similar to that in control non-transgenic littermates. Our results indicate that interleukin 7 plays an important role in vivo in the development of B and T lymphocytes.     

HLA-B27 polymorphism in the Malays

The frequency of HLA-B27 and its subtypes was determined in 878 Malay subjects. Thirty-five of the subjects typed for HLA-A, -B and -DR were found to be positive for HLA-B27. The frequency of this allele in the Malay population was found to be 3.99%. The subtypes observed and their frequencies are: HLA-B*2704 (19.4%), HLA-B*2705 (5.6%), HLA-B*2706 (72.2%) and HLA-B*2707 (2.8%).     

Susceptibility and HLA-B27 in post-dysenteric arthropathies.

A recent outbreak of bacillary dysentery in The Netherlands revealed that, despite the close association of HLA-B27 with post-dysenteric or reactive arthritis (ReA), not even in one family did all HLA-B27 positive patients infected by an arthritogenic bacterium, develop ReA. This dissociation shows that additional factors beside B27 may determine susceptibility to ReA.     

CCL27-transgenic mice show enhanced contact hypersensitivity to Th2, but not Th1 stimuli

CCL27 is one of the CC chemokines produced by epidermal keratinocytes and is suggested to be involved in the pathogenesis of inflammatory skin diseases. To clarify the contribution of CCL27 in skin inflammation, we created transgenic C57BL/6 mice that constitutively produce CCL27 in epidermal keratinocytes. These mice had high serum CCL27 levels and did not show any phenotypical change. Thus we stimulated these mice with various reagents by single and repeated application. Interestingly, only contact hypersensitivity to repeated application with fluorescein isothiocyanate was significantly enhanced in transgenic mice compared to non-transgenic mice. Under this condition, the numbers of inflammatory cells, CCR10-positive cells, CCR4-positive cells and cutaneous lymphocyte-associated antigen-positive cells were increased, and IL-4 mRNA expression was higher in the lesional skin of transgenic mice. Increased number of mast cells and higher serum IgE levels, which were similar to atopic dermatitis, were also observed. These results indicated that CCL27 modified inflammation by attracting CCR10-positive and CCR4-positive cells into the lesional skin, and may participate in the pathogenesis of Th2-shifted skin diseases such as atopic dermatitis.     

Mitigating selection in HLA-B27 not confirmed

The existence of a small, discrete group of HLA-B27 promoters, potentially able to mitigate the deleterious effect of this allele, has not been confirmed.     

Inflammatory disease in HLA-B27 transgenic rats

Summary: A spontaneous inflammatory disease in rats transgenic for HLAB27 resembles the B27-associated human spondyloarthropathies, Colitis and arthritis, the two most important features, require T cells, gut bacteria, and high expression of B27 in bone marrow-derived cells, Control rats with HLA-B7 remain healthy. Most rats with HLA-Cw6 (associated with psoriasis vulgaris) remain healthy; a minority develop mild and transient disease. Rats with a mutant B27 with a Cys67←Ser substitution resemble wild-type B27 transgenics, but with a lower prevalence of arthritis. A similar phenotype is seen in B2 7 rats co-expressing a viral peptide that binds B27. Disease-prone LEW but not F344 B27 rats develop high serum IgA levels concurrent with disease progression. Colitis is associated with high interferon-y, arthritis with high interleukin-6. Disease is similar in B27 LEW, F344, and PVG rats, but the DA background is protective. Conclusions: The spondyloarthropathy-like disease in rats is specific for HLA-B27 but does not require Cys67. Arthritis but not colitis is particularly sensitive to B27 peptide-binding specificity. Genetic background exerts a strong influence, but some phenotypic differences exist between permissive strains that do not influence disease susceptibility The data favor a role for B27 peptide presentation in arthritis, but other mechanisms to explain the role of B27 have not been excluded.