Chlamydial antibody crossreactivity with peripheral blood mononuclear cells of patients with ankylosing spondylitis: the role of HLA B27.

We have previously reported the association of Chlamydia trachomatis with HLA B27+ related diseases. To investigate the possibility that chlamydial antibodies serve to localize the immune response in such diseases, we examined the crossreactivity of chlamydial antibodies (rabbit anti-D and anti-L2 serotypes) with peripheral blood mononuclear cells of patients with ankylosing spondylitis (AS) and anterior uveitis (AU) and with human and bovine ocular tissue and cells in culture. Our results indicate a significantly increased percentage binding of chlamydial antibody (D serotype) to the mononuclear cells of HLA B27+ patients with AS when compared with HLA B27- patients with AS (12.9% +/- 2.2 versus 5.4% +/- 2.2), B27+ controls (5.5% +/- 1.5) and B27- controls (6.1% +/- 1.0). There was no significant difference between controls and HLA B27+ patients with AU (6.6% +/- 1.9) and B27- patients with AU (8.7% +/- 1.1). This crossreactivity could not be blocked by monoclonal HLA B27 antibody. Chlamydial antibodies (D and L2) crossreact with human and bovine conjunctiva but not uvea, tissue culture derived iris fibroblasts or smooth muscle cells. Our results provide additional support for the concept of crossreactivity between antibodies to microbial agents and peripheral blood mononuclear cells of patients with HLA B27+ AS.     

Monoclonal antibody (B27M2) subdividing HLA-B27

Because HLA-B27 shows strong association with ankylosing spondylitis, it was of interest to produce murine monoclonal antibodies to study this antigen in detail. The first such anti-B27 antibody, anti-B27M1, reacted with 100% of B27 + cells and cross-reacted with homozygous B7 cells. In the present report a second monoclonal antibody, anti-B27M2, is described which subdivides HLA-B27 into two variants. Among healthy B27⁺ individuals, 87% were B27M1⁺ and B27M2⁺, and 13% were B27M1⁺ but B27M2⁺ by standard lymphocytotoxicity assays. The specificity of B27M2 antibody for the HLA-B27 molecule was confirmed with blocking studies using F(ab′)₂ fragments of HLA alloantibodies. Both the B27M2⁺ and B27M2 variants of HLA-B27 bred true in family studies. Unlike B27M1, B27M2 antibody did not react with B7 but did react with the rare Bw47 allele.For antibody binding studies Epstein-Barr virus-transformed B lymphoblastoid cell lines were derived from normal donors KCA (by lymphocytotoxicity shown to be B27⁺, B27M2⁺. VC (B27⁺, B27M1⁺, B27M2^?), and WH (B27^?, B27M1^?, B27M2^?). Each cell line bound equivalent amounts of W6/32 (monoclonal anti-HLA-ABC): KCA and VC bound similar amounts of anti-B27M1, but only KCA bound substantial anti-B27M2 antibody. These data are consistent with a model in which all B27 antigens possess a B27M1 epitope: whereas most, but not all, possess an additional and distinct epitope, B27M2. Although the relation of these genetic variants to disease susceptibility remains to be determined, the availability of epitope-specific monoclonal antibodies should help to refine our understanding of the structure and function of HLA molecules.     

采用 PCR-SSP法检测HLA-B27基因

目的：建立顺序特异引物聚合酶链反应（ＰＣＲ－ＳＳＰ）方法检测ＨＩＡ－Ｂ２７基因并与血清学方法比较。方法：设计合成Ｂ２７特异物３个和内源性阳性对照２个,建立ＰＣＲ－ＳＳＰ方法,用于Ｂ２７基因分型。血清学分型为一步法单克隆抗估方法。临床样本１００份,不源于可疑强直性脊柱炎患者。快速酚氯仿法提取模板ＤＮＡ。结果：１００例临床样本ＰＣＲ－ＳＳＰ行Ｂ２７基因分型均获成功。总耗时４ｈ。其中Ｂ２７阴性５８例,阳     

HLA-B27 PCR辅助诊断幼年强直性脊椎炎

目的：辅助诊断幼年强直性脊椎炎。方法：用ＰＣＲ技术对２４例临床表现为类风湿关节炎少关节型患儿的ＤＮＡ进行ＨＬＡ－Ｂ２７基因分析。结果：２４份标本中７例ＰＣＲ检测Ｂ２７基因阳性,占分析的２９．２％（７／２４）。７例Ｂ２７基因阳性病例中男５例,女２例,平均年龄１０．４岁。结论：Ｂ２７检测可作为诊断或鉴别诊断幼年强直性脊椎炎的重要指标,利于疾病病鉴别和预后估计。     

Molecular mimicry in Reiter's syndrome: cytotoxicity and ELISA studies of HLA-microbial relationships.

The pathogenic links between HLA antigens, certain bacterial infections and arthritis have not yet been characterized. The hypothesis of cross-reactivity between HLA B27, the marker of disease susceptibility for these disorders, and the provocative microorganism has been suggested by studies of Klebsiella and ankylosing spondylitis. The present study examines the possibility of molecular mimicry between HLA B27 and two organisms implicated more directly in reactive arthritis, Yersinia enterocolitica and Chlamydia trachomatis. Antibodies against these organisms were obtained both from patients and from antisera raised in rabbits. Neither source of antibacterial antibody was specifically cytotoxic for HLA B27-positive lymphocytes, even when the target cells were derived from patients with recent infections due to these organisms. In addition, monoclonal antibodies against HLA B27 (M1 and M2) showed no reactivity with antigens from these organisms in an ELISA system. These data do not support the notion of molecular mimicry as being the basis of immunogenetic susceptibility to reactive arthritis and Reiter's syndrome following infections with Y. enterocolitica and C. trachomatis.     

Ankylosing spondylitis,HLA-B27 and Klebsiella. II. Cross-reactivity studies with human tissue typing sera.

Human monospecific HLA B27 typing sera have been shown to have increased binding activity for klebsiella extracts by haemagglutination (P less than 0.001), radiobinding assay (P less than 0.025) and radiolabelled antigen competition assay (P less than 0.02) when compared to non-B27 tissue typing sera. These observations are in agreement with those of studies using rabbit sera, suggesting that HLA B27 lymphocytes may exhibit partial cross-reactivity with bacterial antigens found in some Gram-negative microorganisms such as klebsiella. It is suggested ankylosing spondylitis may occur as a result of immunological damage following infection by Gram-negative bacteria carrying antigens having stereochemical similarity to self antigens.     

Complete coding sequence of HLA-B*2712: a serologic B27-negative antigen associated to Bw6

Abstract: We report the complete coding sequence of a new HLA-B27 subtype, B*2712, which was found in a Caucasian Spanish family within the chromosome A2-Cw2-B*2712-DR15-DQ6. B*2712 was first detected as a segregating B blank Bw6-associated antigen. Extensive serologic analysis demonstrated that this new B27 subtype was not recognised by any of the B27-monospecific antibodies, giving positive reactions only with some monoclonal reagents against B40 or B27,40. Sequencing analysis showed a high similarity with B*2708, only differing in three clustered amino acid residues at positions 69 to 71 located in the α helix of the α1 domain. Residues 69 and 71 point towards the T-cell receptor, while amino acid 70 points to the antigen binding site. Loss of the conserved structure of pocket B as well as the differentiated pocket F configuration suggests that B*2712 does not confer ankylosing spondylitis susceptibility, Misleading serologic definition supports the usefulness of DNA-typing methods to complement HLA class I typing.     

Routine HLA-B27 typing by flow cytometry: differentiation of the products of HLA-B*2702, B*2705 and B*2708

Patient HLA-B27 typing is widely performed as an aid to the diagnosis of several diseases, particularly ankylosing spondylitis. Typing by flow cytometry, using monoclonal antibodies, has been shown to be a potentially useful alternative to classical serology on account of its speed, simplicity and economy. However, we required a flow cytometry typing procedure that would accurately differentiate HLA-B27 (Bw4) from B2708 (Bw6) and not be confounded by other HLA-B7/B27 cross-reactive group antigens. Accordingly, we evaluated the simultaneous use of two monoclonal antibody preparations, ABC-m3-FITC (anti-B27 + weak B7)/BB7.1-PE (anti-B7) and FD705-FITC (anti-B27), by testing a highly selected panel of 62 reference lymphocytes containing examples of all HLA-B7/B27 cross-reactive group antigens, including: HLA-B42, B47, B48, B73, B703, B2702, B2705 and B2708. In addition, 268 whole blood samples from routine patient requests for B27-associated disease typing were tested in parallel with HLA-B typing using the standard complement-dependent microlymphocytoxicity test. The detailed specificity of the three monoclonal antibodies was established and the products of HLA-B*2702, B*2705 and B*2708 were found to be readily differentiated from each other and all other HLA-B7/B27 cross-reactive HLA-B antigens.     

Homocysteine modification of HLA antigens and its immunological consequences

Homocysteine-treated cells can be specifically lysed by cytotoxic T lymphocytes (CTL) identifiable in patients with ankylosing spondylitis and reactive arthritis. Sensitization of target cells involves disulfide bonding and the interaction between homocysteine and HLA antigens occurs in a pre-Golgi compartment in the cells. Salmonella-infected B cells are also lysed by homocysteine-specific CTL, suggesting that intracellular invading microorganisms may provide homocysteine which would gain access to the newly synthesized intracellular HLA molecules and modify them inside the cells. Two different mechanisms for homocysteine modification of HLA antigens are proposed: homocysteine could bind directly to the unpaired cysteine residues in HLA antigens, or it could bind indirectly to HLA antigens through cysteine-containing peptides bound to them. Thus, HLA antigens containing unpaired cysteine residues (e.g. HLA B27) could be modified by homocysteine directly or indirectly, while HLA antigens without unpaired cysteine residues (e.g. HLA A68) could only be modified indirectly. The results are discussed in relation to the potential involvement of homocysteine-specific CTL in ankylosing spondylitis and reactive arthritis, both of which are related to bacterial infections, associated with HLA B27, and considered to be autoimmune diseases.     

中国人HLA-B27、B7、B13和B40的检测及其相互杂合与交叉的分析

目的　检测 1194例初诊怀疑患强直性脊柱炎 (AS)和其它关节性疾病患者的HLA B2 7、B7、B13和B40位点抗原的分布 ,并分析这些位点的相互杂合和其抗原的交叉反应性。方法　微量细胞毒反应法 ,在同一块反应盘上同时检测。结果　 1.在 1194例患者中 ,HLA B2 7抗原阳性率达38 6 % ;B7的抗原阳性率为 7 4% ;B13为 14 6 % ;B40为 13 4%。2 .在HLA B2 7阳性人群中 ,B7抗原的阳性率为 14 3% ,明显升高 ,而在HLA B2 7阴性人群中 ,B7的阳性率仅为 3 2 % ,明显降低 ;3.在44 7例HLA B2 7阳性人群中 ,未检测到HLA B2 7、B7、B13三种抗原皆为阳性者 ,说明B7和B13之间没有交叉 ;4.据此 ,在HLA B2 7阴性人群中 ,查到的HLA B7/B13阳性率 0 5 4%应代表这两个位点的杂合 ;5 .无论在HLA B2 7阳性还是阴性人群中 ,HLA B13/B40的抗原阳性率远高于HLA B7/B40的阳性率 ,说明B13和B40位点的杂合或交叉 ,远大于B7与B40之间的杂合或交叉。结论　检测HLA B2 7及其相关B位点抗原的频度有助于分析这些位点的杂合及其抗原的交叉反应性的特点     

Immune function in ankylosing spondylitics and their relatives: influence of disease and HLA B27.

So as to distinguish the separate influences of ankylosing spondylitis (AS) and possible HLA B27 associated immune response genes on immune response patterns, a battery of immunological tests were performed on fourteen patients with AS and their first-degree relatives. Previously unrecognized AS was detected by clinical and radiological means. Individuals with ankylosing spondylitis had significantly higher serum IgG and IgA concentrations than both their B27 positive and B27 negative relatives. B27 positive relatives had significantly lower phytohaemagglutinin (PHA) lymphocyte transformations than B27 negative relatives (P less than 0.01), while there was no difference between the ankylosing spondylitic and B27 positive groups. Antibody titres to Streptokinase/Streptodornase were significantly higher in the B27 positive individuals, with or without AS, than their B27 negative relatives (P less than 0.005 and P less than 0.02 respectively). These results show that serum immunoglobulin differences were associated with disease, while differences in PHA stimulation and varidase antibody titres were associated with the B27 antigen. These findings may indicate the presence of HLA associated immune response genes including those involved with reactions to a particular antigenic component of Streptokinase/Streptodornase.     

An evaluation of Com‐B27, a fluorescein‐conjugated mouse anti‐HLA‐B27 reagent

We evaluated the HLA‐B27 typing reagent Com‐B27, which is claimed to show minimal cross‐reactivity with HLA‐B7, for use in flow cytometry‐based typing. This combination reagent consists of the fluorescein‐conjugated HLA‐B27 mouse monoclonal antibody ABC‐m3 and a non‐conjugated HLA‐B7 monoclonal antibody that is claimed to block the reactivity of ABC‐m3 to B7 without affecting its reactivity to B27. It reacted well with B27 (B*2702, B*2705) and B2708 [mean median channel fluorescence intensity (MCFI) 8.40] and weakly with B7 (including cells from homozygous B*07 donors), B42/B73 and B22/B37/B44 reference cells (mean MCFI 2.05, 3.09 and 1.10, respectively). It showed a uniform discrimination between B7 and B27/B2708 with no ‘overlap’ in MCFI values, which was seen with the standard ABC‐m3 antibody. There was complete agreement when our standard three‐antibody‐based B27/B2708 flow cytometry assay and the Com‐B27 reagent alone were used to independently assign B27/B2708 status to 651 random patients. Thus, the Com‐B27 reagent provided improved discrimination between B7 and B27/B2708 over the ABC‐m3 antibody, and its B27/B2708 assignments were comparable with our standard flow cytometry assay. However, for consistently reliable B27/B2708 typing we continue to recommend the use of a minimum of two B27 reagents in a protocol that includes DNA‐based testing of ‘equivocal’ B27/B2708 assignments.     

Evidence to show MHC-linked factors other than HLA-B27 governing susceptibility to spondylo-arthropathies in Asian Indians

The HLA antigen profile of 129 North Indian patients with ankylosing spondylitis, 66 patients with Reiter's syndrome and 57 patients with 'unclassifiable' arthritis was compared with 380 normal, healthy controls. Besides B27 which appeared with a significantly increased frequency in the three patient groups, other HLA antigens, viz. A2 and B35, showed deviated frequencies. The HLA supratype A2, B27 was found to be at an elevated frequency in patients with ankylosing spondylitis and unclassifiable arthritis whereas the B35, B27 combination showed a decreased frequency in our Reiter's syndrome sample. These data suggest that besides B27, other HLA-linked factors influence susceptibility to spondylitic disorders and might act as 'modifier' genes for the type and severity of spondylo-arthropathy in a B27-positive individual.     

Histocompatibility typing and the counseling of families with ankylosing spondylitis

White individuals who are HLA B27-positive have an increased risk of developing ankylosing spondylitis or related diseases. HLA typing can be used in counseling relatives of persons with spondylitis, if the limitations of presently available data are recognized.     

Natural cytotoxic function and ankylosing spondylitis

Natural Killer (NK) cell function was evaluated in 28 ankylosing spondylitis (AS) patients (21 B27 positive), at one hand by the use of a Leu7 (HNK-1) monoclonal antibody, at the other hand by spontaneous cytotoxicity against a K562 cell line (preincubated with a fluorogenic substrate) evaluated by a flow cytometric assay. There is no difference in NK cell activity neither between AS patients and controls nor between B27 positive and negative AS. The study brings no evidence for a NK function control by the B27 gene. There is no correlation between NK activity and each of the other parameters investigated (ESR, B2m, IgA, Leu7, T4/T8). At the opposite, NK activity is significantly decreased (p = 0,006) in AS patients under NSAIDs treatment compared with non treated patients. NSAIDs rather enhance NK activity, the decrease observed in the present study could be due to evolution of the disease itself, and may be a pathogenetic factor contributing to remaining of bacterial antigens according to the current hypothesis of the disease's aetiology.     

HLA-B67: A member of the HLA-B16 family that expresses the ME1 epitope

Abstract: HLA-B67 is an uncommon antigen that has been defined by serological crossreactivity with the HLA-B7 and HLA-B16 (B38 and B39) antigens. It is found at highest frequency in certain Oriental populations and has been best defined in the Japanese. Nucleotide sequencing of cDNA encoding B67 reveals the B*6701 allele to be a subtype of B39 which differs from B*39011 by substitution at residues 67–71 of the α₁ helix. In the region of difference B*6701 is identical in sequence to B7, B22, B27 and related molecules that express the epitope recognized by the ME1 monoclonal antibody. That the HLA-B67 molecule binds strongly to the ME1 antibody was demonstrated by immunoprecipitation and cell surface binding assays. Identical B*6701 nucleotide sequences were obtained for the B67 alleles isolated from 2 unrelated Japanese and 1 North American caucasoid.     

Passive vaccination with a human monoclonal antibody: generation of antibodies and studies for efficacy in Bacillus anthracis infections

A major difficulty in creating human monoclonal antibodies is the lack of a suitable myeloma cell line to be used for fusion experiments. In order to create fully human monoclonal antibodies for passive immunization, the human mouse heteromyeloma cell line CB-F7 was evaluated. Using this cell line, we generated human monoclonal antibodies against Bacillus anthracis toxin components. Antibodies against protective antigen (PA) and against lethal factor (LF) were obtained using peripheral blood lymphocytes (PBLs) from persons vaccinated with the UK anthrax vaccine. PBL were fused with the cell line CB-F7. We obtained several clones producing PA specific Ig and one clone (hLF1-SAN) producing a monoclonal antibody (hLF1) directed against LF. The LF binding antibody was able to neutralize Anthrax toxin activity in an in vitro neutralization assay, and preliminary in vivo studies in mice also indicated a trend towards protection. We mapped the epitope of the antibody binding to LF by dot blot analysis and ELIFA using 80 synthetic LF peptides of 20 amino acid lengths with an overlapping range of 10 amino acids. Our results suggest the binding of the monoclonal antibody to the peptide regions 121-150 or 451-470 of LF. The Fab-fragment of the antibody hLF1 was cloned in Escherichia coli and could be useful as part of a fully human monoclonal antibody for the treatment of Anthrax infections. In general, our studies show the applicability of the CB-F7 line to create fully human monoclonal antibodies for vaccination.     

Complete heart block — another HLA B27 associated disease manifestation

An increased prevalence of ankylosing spondylitis and other HLA B27-associated rheumatic diseases has recently been demonstrated in a group of men with permanent pacemaker-treatment. The purpose of the present study was to find out if HLA B27 was associated with severe bradyarrhythmias also in the absence of rheumatic disease.
The frequency of B27 was determined in 83 permanently paced men with complete heart block, in whom presence of radiological or clinical signs of a B27-associated rheumatic disease had been excluded. Eighty-four healthy subjects were HLA typed for comparison.
HLA B27 was found in 17% of the patients and in 6% of the controls, a significant difference with P = 0.017 (Fisher's exact test). The present study suggests that, in a subgroup of patients with complete heart block, the development of heart block is B27-associated, and that the pathophysiological mechanism is similar to that leading to ankylosing spondylitis.
Another B27-associated disease manifestation has been demonstrated.     

HLA-B27等位基因和亚型与强直性脊柱炎关系研究进展

大量的研究证明,强直性脊柱炎(AS)是与人类白细胞抗原(HLA)相关性最强的疾病。AS的发病与HLA-B27阳性密切相关,并与B7、B13、B40等几个等位基因有一定关系。HLA-B位点有42个等位基因,其中HLA-B27具有高度多态性,含有22个以上的亚型,不同亚型的碱基序列间只有个别差异。B27亚型在AS患者中的分布因地区和种族上的差别而不同,在中国主要以B2704和B2705为主,但以B2705分布最广。这几年大量的人B27转基因鼠实验证明AS与B27的关联性。     

HLA antigens, psoriasis and acute anterior uveitis in Bechterew's syndrome (ankylosing spondylitis)

One hundred and twenty-two consecutively hospitalized patients with ankylosing spondylitis (AS) were reexamined. Ninety-two per cent were HLA B27 positive. Of the HLA B27 negative patients, 60% were found to have psoriasis, as opposed to 11 % of the HLA B27 positive patients. Acute anterior uveitis (AAU) was found only in HLA B27 positive patients, and more frequently in males than in females. The genetic and clinical heterogeneity of AS, together with the overlapping clinical criteria for AS and psoriatic spondylitis, may make the term "Bechterew's syndrome" preferable. Based on these findings and previous reports, we conclude that (i) AAU is a manifestation of Bechterew's syndrome in HLA B27 positive patients, (ii) HLA B27 negative patients without any obvious accompanying manifestations may suffer from psoriatic spondylitis, and (iii) genetic predisposition to psoriasis in persons who are HLA B13, B17 and B37 negative, may interact with the genetic predisposition to Bechterew's syndrome in HLA B27 positive persons and produce Bechterew's syndrome with psoriasis or psoriasis-like skin eruptions.