DQ beta restriction fragment length polymorphism and its relationship to insulin dependent diabetes mellitus

HLA Class II serological and DQ beta restriction fragment length polymorphisms (RFLPs) were compared in 69 patients with insulin-dependent diabetes mellitus (IDDM) and 81 healthy British Caucasoid controls. The backbone of the analysis was formed by two Taq 1 RFLPs of the DQ beta region designated T2 omega and T6. The two are not allelic and can be inherited individually, together on one, or separately on both, parental haplotypes, the latter almost invariably in association with DR4. In our study the frequency in IDDM patients of both T2 omega and T6 together (relative risk for IDDM = 6.4) is similar to that of DR3/DR4 (relative risk for IDDM = 5.4) with an even higher relative risk for IDDM when they are combined, (relative risk = 18 with 95 per cent confidence limits between 14 and 22). We have thus defined DQ beta RFLPs which tightly associate with IDDM individuals with DR4.

Molecular dissection of human testicular germ cell differentiation with monoclonal antibodies

Monoclonal antibodies (MoAbs) were raised by immunising mice with nucleated cells other than sperm (NCOS) obtained from semen of an oligospermic donor. These MoAbs recognised different germ cell differentiation antigens (GDA) which appear at various stages of spermatogenesis and/or spermiogenesis. The GDA were found to be differentially expressed on spermatocytes, spermatids and on the various sub-regions of human spermatozoe. Some of the MoAbs also recognised changes in the antigenic structure of the sperm during their post-testicular maturation. Using solubilised sperm products, MoAb GDA-J/F1 reacted with a 92 kDa band in Western immunoblotting. The importance of these antibodies in the study of germ cell differentiation together with their potential clinical uses in the investigation of infertility, autoimmunity and immunological contraception are discussed.

Analytical studies of the binding parameters describing the interaction of HLA-DR epitopes with a specific monomorphic monoclonal antibody

In this paper we present an analytical study of the binding parameters related to the interactions of the HLA-DR-specific monoclonal antibody (L243) and its reacting epitope as expressed on the cell surface of seven Epstein-Barr virus-transformed B cell lines. Scatchard, Sips and Langmuir equations were used to plot and analyse the data obtained from each reaction. A single affinity constant (K) value was derived at low and high concentrations of free antibody for each antibody-cell interaction tested and was of the order of 10(7) M-1. Similar heterogeneity indices (a) (close to 1.0) and K values were obtained for most of the cells. These results suggest that the reacting HLA-DR epitopes are homogeneously distributed and equally accessible to the antibody on all the cells tested. The average number of epitopes per cell was 3.4 X 10(6), SD 0.5 X 10(6) and were similar for all the cell lines. The analytical and experimental model presented here can be useful for studying quantitative and qualitative variations in the expression of MHC epitopes in oncogenesis and disease associations.

HLA associations with multiple sclerosis in Sicily and Malta

The islands of Sicily and Malta have very different prevalence rates for multiple sclerosis (MS): at least 44 per 100,000 in Sicily and only 4 per 100,000 in Malta. In Northern Europe, MS is associated with HLA-DR2/Dw2. The other components of the commonest DR2-containing haplotype of this region, HLA-A3-B7-DR2-Dw2, also tend to be present at higher frequency in MS patients. HLA Class I and II antigen frequencies and associations in controls and MS patients from Sicily and Malta were studied to discover whether they might account for the difference in MS prevalence. In Sicilian MS patients, DR2 is increased in frequency compared with controls and four out of five DR2-positive patients also type as Dw2. In the Maltese population, DR2 is present at high frequency but approximately half of the DR2 positive individuals do not type as Dw2 so that DR2 is probably most commonly present as part of Class II haplotypes other than those commonly associated with MS. Additional differences in HLA profile of the Sicilian and Maltese populations were found when HLA-A, -B, and B-DR antigen associations were examined. Therefore, some of the difference in MS prevalence might be explained by genetic factors.

Immunological and morphological characterisation of nucleated cells other than sperm in semen of oligospermic donors

Nucleated cells other than sperm (NCOS) were obtained from semen samples of oligospermic donors. The cells, after separation from sperm, were studied by immunological and morphological techniques including electron microscopy (EM). Using an indirect immunofluorescence (IIF) test, more than 95% of the NCOS reacted with xenoantisera specific for human sperm and germ cells but showed less than 5% reactivity with monoclonal antibodies (MoAbs) directed against surface markers of different leucocyte subsets or cytokeratin. This indicated that the majority of NCOS were germ cells in origin. These results were concordant to those obtained by EM which showed the presence of germ cells at various stages of differentiation. Our data therefore show that the application of immunological techniques could help and may replace laborious EM in the identification of the different cell types among NCOS. Also, the results emphasize that germ cells and not leucocytes appear to be the major cell type among NCOS, a concept which could have therapeutic and biological implications.

HLA expression on human germinal cells

Ejaculated human seminal plasma cells obtained from 46 healthy men and 48 infertile patients were tested for expression of HLA class I and II antigens by complement-mediated cytotoxicity, cell-binding radioimmunoassay (CB-RIA), and an ELISA involving monoclonal antibodies (mAbs). In a group of healthy men tested for HLA expression on human spermatozoa, 4 of 46 were positive for class I and II HLA antigens. However, the results were negative in a second examination of the same donors, possibly on account of alterations with time in the expression of various subpopulations of cells which are antigen positive or antigen negative. In a group of infertile patients, we found positive expression of HLA class I and II antigens in 7 of 48 men. The samples contained immature and mature sperm but no contaminating leucocytes or epithelial cells.

HLA class II alpha chain gene polymorphisms in patients with insulin-dependent diabetes mellitus, dermatitis herpetiformis, and celiac disease

We have investigated DNA polymorphism of the class II alpha chain genes in HLA typed patients with insulin dependent diabetes mellitus (IDDM; n = 79), celiac disease (CD; n = 46), dermatitis herpetiformis (DH; n = 53), and controls (n = 86). Preferential allelic associations of HLA genes and gene products have thus been constructed for susceptibility to these diseases. DR alpha and DQ alpha gene polymorphisms indicated heterogeneity of HLA DR3, DRw6, and DR7, and HLA DR2 and DRw6, respectively. In DR7 positive CD patients a 3.8-kilobase (kb) DR alpha fragment, which correlated with DQw3, was found in only 11% of patients compared with 45% of corresponding controls (P less than 0.05). An increased frequency of a DX alpha genotype UU in all three diseases was found (IDDM 59%, DH 45%, CD 48%, compared to 21% in controls, P less than 0.001), which is not explained solely by the increased frequencies of DR3-DX alpha U. We therefore conclude part of the genetic susceptibility for these three conditions is encoded by genes within the DQ-DX subregion.

Genetic markers in late paraphrenia: a study of HLA antigens

Patients with late paraphrenia were typed for HLA-A, -B and -C. Increased frequencies of BW55 (P = 0.036), B37 (P = 0.008) and CW6 (P = 0.056) were found relative to controls. Unlike findings in paranoid schizophrenia, there was no HLA-A9 association, suggesting that paraphrenics may be genetically distinct from schizophrenics. The primary association seems to be with B37, which has the lowest corrected P value and highest relative risk; if this were replicated, it would make possession of this antigen a strong risk factor for developing the disorder.

Frequency and associations of HLA-DR and HLA-DQ antigens in a British Caucasoid panel

The frequencies of the HLA-DR and -DQ antigens, including those of the new specificities "DRBr" and TA10, were established in a random panel of 286 British Caucasoids. The most frequent DR antigens were DR2, DR4 and DR7. The DR-DQ antigen associations were examined and the only heterogeneity found was with DR7 which was found to be associated predominantly with DQw2 but also with DQw3. The DR4's were subdivided into those positive and those negative for TA10 and DR4-TA10 was found to be associated with HLA-B44.

Human cytotoxic T-cells against measles virus-infected and myelin basic protein-coated targets are cross-reactive

Cytotoxic T lymphocytes (CTL) which recognized measles virus antigens were generated by in vitro sensitization of peripheral blood lymphocytes from normal volunteers against autologous measles virus-infected lymphocytes. Cytotoxicity of measles virus-infected targets by these effectors was considerably enhanced when the effector-target cell mixtures were incubated in presence of 10 or 100 ng myelin basic protein (MBP) for the 3-hour duration of the 51Cr release assay. In most experiments, specific release of radioisotope was doubled or tripled. Bovine serum albumin caused only slight increases in cytotoxicity. The killing of allogeneic target cells by alloimmune CTL was not affected by either of these reagents. Measles-specific CTL were also able to kill target cells that were cultured overnight in presence of MBP but washed prior to the assay. Conversely, CTL generated by culturing lymphocytes in presence of MBP for 6 days were able to kill MBP-coated and measles virus-infected target cells. The implications of these findings in the pathogenesis of multiple sclerosis are discussed.

HLA antigens in palindromic rheumatism and palindromic onset rheumatoid arthritis

Fifty patients who presented with typical palindromic rheumatism of at least 6 months' duration were tissue-typed for HLA A, B, C antigens. DR typing was also performed but was not possible for technical reasons in three patients. Twenty-three patients who had progressed to definite or classical rheumatoid arthritis (RA) after a mean interval of 5 years were compared with 20 patients whose palindromic attacks had persisted over a similar period. Both groups showed a significantly higher frequency of DR4 antigen than a control population. The RA group also showed an increased frequency of DR1. There was no significant difference in the frequency of DR4 or any other DR antigen between the two patient groups. The frequency of B27 antigen was significantly higher in the palindromic group compared with the controls. It is suggested that although DR4 may be associated with a tendency to inflammatory joint problems, environmental or other unrelated genetic factors may be more important in determining the progression of palindromic rheumatism to RA.

Abrogation of lethal graft-versus-host reaction directed against non-H-2 antigens: role of Mlsa and K/I region antigens in the induction of unresponsiveness by alloimmunization

A graft-versus-host reaction (GVHR) directed against DBA/2 non-H-2 antigens alone can be induced by grafting B10.D2 bone marrow and spleen cells intravenously to heavily irradiated, H-2d compatible (DBA/2 X B10.D2)F1 adult mice. Under the experimental conditions used, only 0-10% of recipients survive, but the survival is greatly increased by donor alloimmunization, a few days prior to grafting, against host-specific (DBA/2) non-H-2 antigens and non-specific (foreign) H-2 antigens. The increased survival is mediated by alloimmunization-activated suppressor cells which can decrease the intensity of the immune reaction developed by normal B10.D2 cells both in vivo (GVHR) and in vitro (proliferative response measured in mixed lymphocyte culture, MLC). The present experiments were designed to explore the antigenic requirements for inducing suppression. The results showed that in GVHR the protective effect induced by donor alloimmunization against the specific non-H-2 antigens, which leads to 70-80% survival, is due primarily, if not entirely, to immunization against Mlsa antigens. Results of MLC experiments confirmed this conclusion, showing that immunization against Mlsa antigens is sufficient to account for the suppressive effect induced by the specific immunization. In addition, they indicated that the non-specific protective effect induced by donor alloimmunization against foreign H-2 antigens, which leads to 20-30% survival, is due to immunization against antigens encoded by the K and/or I region(s) of the H-2 complex; immunization against D region encoded antigens alone has no effect.

The expression of murine Qa region gene product(s) in L cell transformants

The cosmid H3.5, containing genes mapping to the murine H-2 Qa region, was used to transfect L cells by the calcium phosphate co-precipitation method. The resultant transfected cells expressed a Qa-like determinant as detected by an immune serum raised against the transfectant cells and Qa specific monoclonal antibodies. Two-dimensional gel analysis revealed the expression of a class I-like heavy chain with a similar molecular mass to the Qa2 antigens of the positive strain B10 and B10.A but with a different isoelectric point. The cosmid H3.5 spans 40 kb of DNA and contains at least one complete Qa region gene which encodes the Qa-like determinant detected in this study.

Serological biochemical and functional characterisation of three different HLA-DR monoclonal antibodies derived from C57BL6 mice

C57BL6 mice which do not express I-E gene products were immunised with EBV transformed human B cell lines to generate MoAbs. Three hybridoma supernatants which initially reacted with the immunising donor cell but not a T cell line lacking Class II antigens were further investigated. I-D SDS-PAGE patterns of molecules precipitated by the three supernatants from a cell membrane lysate were characteristic of HLA-Class II alpha and beta chains. Two-dimensional analysis established the specificity of the supernatants as HLA-DR specific. This was confirmed by the reaction patterns with Class II mutant deletant cell lines. In both ELISA and cytotoxicity one reacted with all lymphoblastoid cell lines tested, one reacted with all except two that were DR7 homozygous and the third reacted strongly only with cells that were DR3. All three antibodies were cytotoxic to both peripheral blood lymphocytes and EBV transformed B cell lines. The DR3 specific MoAb (IgG2a) was suitable as a typing reagent. The DR3 reactive MoAb specifically inhibited stimulation by a Dw3 HTC and the other two MoAbs inhibited all HTCs tested. These findings are consistent with the view that certain determinants responsible for the Dw specificities are carried on the DR molecules.

New HLA DNA polymorphisms associated with autoimmune diseases

Certain class II determinants of the human histocompatibility locus antigens (HLA) have been implicated in the aetiology of several autoimmune diseases, including rheumatoid arthritis (RA) and insulin-dependent diabetes mellitus (IDDM). HLA-Dw4 was the first HLA determinant found to be significantly increased in RA patients compared with controls, while Dw4 and Dw3 were found to be significantly increased in IDDM patients. When the HLA-DR system was defined, RA patients were found to have an increased frequency of DR4 and IDDM patients an increased incidence of both DR4 and DR3 compared with controls. As the HLA-Dw specificities are narrower than the serologically defined DR specificities, it was of specific interest to the present study that Dw4, Dw10, Dw13, Dw14, Dw15 and DKT2 are included in DR4. We describe here new restriction fragment length polymorphisms (RFLPs) and, together with the newly described serologically defined DQ specificity TA10, test their prevalence and associations in controls and diseased patients. We find that the newly characterized DNA bands are present at a much higher frequency in RA and IDDM patients than in controls. These findings may lead to a greater understanding of the pathogenesis of such diseases.

HLA-Dw specificity assignments are independent of HLA-DQ, HLA-DR, and other class II specificities and define a biologically important segregant series which strongly activates a functionally distinct T cell subset

Several lines of evidence indicate that HLA-Dw, as defined by HTC typing, is not the result of the combined stimulatory effect of HLA-DR and DQ. Therefore, responder cells do not have to share HLA-DQ antigens with the stimulator HTCs to give a typing response. The common HLA-DR-DQ associations observed in HTCs correspond to different patterns of linkage disequilibrium in different populations. HLA-DQ and HLA-Dw are functionally heterogeneous. Although HLA-DQ molecules may play a role in primary stimulation, this role is distinct from that of Dw determinants which have strong lymphocyte activating properties. The role of the HLA-DQ determinants on the other hand, is one of modulating the total T cell response by controlling the proliferation of suppressor and cytotoxic cells. The primary MLC response is the result of the proliferative effect of HLA-Dw, DR, DP, and other associated determinants, in conjunction with a modulatory effect of DQ molecules. However, HLA-Dw (as detected by HTC typing) are DR associated determinants which are immunodominant in primary MLR. The genes of the HLA-DR subregion have been named DR by the WHO nomenclature committee. This subregion encodes the HLA-DR specificities and the DRw52 and DRw53 determinants. Unfortunately this nomenclature does not take into account the need to define the genetic basis of the HLA-Dw determinants--whether they are encoded by separate genes within the HLA-DR subregion or whether they are encoded by as yet unspecified genes in the HLA class II region in linkage disequilibrium with HLA-DR DRw52/53. There are at least three and possibly four beta chain genes in the HLA-DR subregion, all in strong linkage disequilibrium with each other. Some of these are expressed in most haplotypes while others are not; some behave as pseudogenes in some haplotypes and in others, all the genes are expressed. All the genes of the class II region have not been fully characterized. HLA-Dw determinants may be specified by one or more of these genes. When more information becomes available, the genetic and molecular basis of the HLA-Dw series as well as the functional heterogeneity and antigenic strength of the various class II determinants will be better understood.