HLA A and B locus antigens in patients with unexplained hepatitis following halothane anaesthesia

HLA A and B locus antigens were determined in 17 patients who had recovered from unexplained hepatitis following halothane anaesthesia. The greatest deviations from expected frequencies were observed with A1, A11 and BW22, but these differences were not statistically significant when the P values were corrected for the number of antigens tested. Although a larger series might show such deviations to be significantly different, HLA typing is of no predictive value in determining those at risk to hepatitis following repeated halothane exposure.

Coxsackievirus B4 infection of the mouse pancreas: the role of natural killer cells in the control of virus replication and resistance to infection

The role of natural killer (NK) cells in the early immune response to a pancreatropic isolate of coxsackievirus B4 (CVB4) was investigated in a murine model of pancreatitis. Endogenous (background) NK cell activity in fresh spleen effector cells from eight mouse strains was compared with virus-augmented NK cell activity 4 days post-infection (p.i.). A significant virus-induced increase (P less than or equal to 0.003) in NK cell activity was seen in seven of eight infected mouse strains, when virus titres in the pancreas were beginning to fall. Lesions in the exocrine pancreas were least extensive in the three strains with the highest endogenous NK cell activity. In C3H/HeJ mice that had been depleted of NK cells prior to infection with a low virus concentration, resistance to infection of the pancreas was completely abolished; myocarditis was also observed in one of these animals. Thus, NK cells may limit virus replication in the pancreas and play a role in resistance in C3H/HeJ mice. Virus-specific neutralizing antibody was not detected in the serum until 5 to 6 days p.i. in most strains and did not appear to influence pancreatic virus titres. It may be significant that CVB4 infection did not induce the expression of major histocompatibility complex (MHC) class I molecules on target acinar cells. With certain tumour cells, an inverse relationship between MHC class I expression and susceptibility to NK cell-mediated lysis is well documented.

Is rheumatoid arthritis in Indians associated with HLA antigens sharing a DR beta 1 epitope?

HLA class II antigens were identified in a group of 44 patients with rheumatoid arthritis (RA) originating largely from the north or northeast of the Indian subcontinent and resident now in east London. Compared with 67 locally typed east London Asian controls, the prevalence of three HLA-DR antigens was raised in the patients: DR1 18.2% v 6.0% chi 2 = 3.99, DR4 20.5% v 11.9% chi 2 = 1.48, and DRw10 27.3% v 8.9% chi 2 = 6.56. These differences were also found when the patients with RA were compared with a larger control group of 110 northern Indians: DR1 18.2% v 7.2% chi 2 = 4.02, DR4 20.5% v 7.2% chi 2 = 5.56, and DRw10 27.3% v 8.1% chi 2 = 9.7. Twenty five (57%) of the patients expressed at least one of these antigens. All patients were also characterised for HLA-Dw types by mixed lymphocyte culture typing. The prevalence of the HLA-DR4 associated Dw types in the patients was: Dw4 2.3%, Dw10 0%, Dw14 11.4%, and Dw15 6.8%. The DR beta 1 chains of DR1 and DRw10 together with the Dw types of DR4 other than Dw10 share amino acid residues in a region of the third hypervariable region considered to be critical in antigen presentation. It is concluded that RA in Indians is associated with these HLA antigens, and data from this study support the hypothesis of a cross reactive epitope common to HLA specificities associated with RA.

Specificity of lymphocytotoxic autoantibodies (LCAbs) found in the serum of leprosy patients: class I MHC antigens

Lymphocytotoxic autoantibodies (LCAbs) of the IgM class have been identified in patients with borderline tuberculoid (BT) and borderline lepromatous (BL) leprosy with Type I reactions (I) as well as lepromatous leprosy (LL) patients with erythema nodosum leprosum reactions (ENL). The observation that lymphocytotoxic activity (LCA) was reduced in the presence of platelets led us to determine whether LCAbs had specificities for Class I Major Histocompatibility Complex (MHC) determinants. Absorption of LCA positive sera with platelets, classically used to deplete Class I specific lymphocytotoxic antibodies, reduced LCA towards autologous as well as allogeneic target cells. This was true for LCA positive sera from all patient classifications (group BT in the autologous system, p less than 0.01; in all other patient groups, p less than 0.001). Introducing B-2m to cytotoxicity assays only marginally reduced LCA when added at high concentrations (5 mg/ml). An anti-Class I MHC antiserum which blocked the lytic activity. The data indicate that LCAbs while absorbed by platelets, are not specific for the Class I MHC antigens. The autoantigen recognized by these autoantibodies therefore remains to be identified.

Effects of prepro-vasoactive intestinal peptide-derived peptides on the murine immune response

We have studied the effects of prepro-vasoactive intestinal polypeptide-derived peptides on lectin-induced lymphocyte proliferation and natural killer cell (NK) activity in cells from murine spleen, mesenteric lymph nodes, Peyer's patches, thymus and peripheral blood mononuclear lymphocytes (PBL). These peptides (vasoactive intestinal peptide (VIP), peptide histidine methionine (PHM-27) and peptide histidine valine (PHV-42)) showed differential effects in their immune response in a dose- and tissue-dependent manner. All peptides significantly decreased DNA synthesis in spleen (range: 45-30%), lymph nodes (range: 30-0%), Peyer's patches (range: 30-4%) and PBL (range: 30-16%). In these tissues there was no significant difference in their potency. In the thymus, however, PHM-27 (range: 27-15%) was significantly more potent (p less than 0.001) in inhibiting DNA synthesis than either VIP (range: 6-0%) or PHV-42 (range: 20-8%). The modulatory effects on NK activity by these peptides also showed an inhibitory effect. The order of potency was: VIP (range: 40-27%), PHV-42 (range: 22-11%) and PHM-27 (range: 20-8%). The presence of VIP inhibitor [( D-p-chloro-Phe6,Leu17]-VIP) at 10(-8) M in both functional assays caused a significant antagonism of the effects of VIP but not PHM-27 or PHV-42. Our results suggest the existence on lymphocytes of different receptors for prepro-VIP-derived peptides, and that they may be considered as important immunoregulatory molecules. Their mechanism of interaction, however, is not clearly understood.

T-cell receptor beta-subunit gene polymorphism and autoimmune disease

We have investigated the distribution of genotypes of a restriction fragment length polymorphism of the T-cell receptor beta-subunit gene in Caucasoid controls and patients with insulin-dependent diabetes mellitus, celiac disease, dermatitis herpetiformis, and idiopathic membranous nephropathy and also in South Indian controls and diabetics. We found no significant differences between the controls and patients with any disease in either ethnic group, a result which contrasts with previous reports of associations with both insulin-dependent diabetes mellitus and idiopathic membranous nephropathy. However, the most striking finding was a marked disparity between the genotype distribution in our Caucasoid control population and that previously reported by other investigators.

HLA DQ region gene polymorphism associated with primary IgA nephropathy

IgA nephropathy (IgAN) has been associated with HLA-DR4. We have recently described two non-allelic Taq I DQ beta gene-associated fragments sized 2.0 kb (T2) and 6.0 kb (T6), which strongly associate with DR4. T2 represents a polymorphism of the DQ beta gene and has been redesignated DQw8 (10th International HLA Workshop). The origin of the T6 fragment has not been determined, but probably represents a polymorphism of either the DQ beta or DX beta gene. When present together T2 and T6 define a subgroup of DR4 subjects at high risk of developing autoimmune disease. We have, therefore, studied DQ beta gene polymorphisms in IgAN. The DR antigen distribution was similar in IgAN and normal controls. The T2+/T6+ phenotype was present in 49% patients with IgAN compared to 15% of controls [P less than 0.0001, chi 2 = 32.8, Cramer's V = 0.41; relative risk = 5.5 (range, 2.8-11.0)]. Seventy-two percent of DR4+ IgAN patients and 29% of DR4+ controls were T2+/T6+ (P = 0.007, chi 2 = 17.0). These findings confirm the hypothesis that disease susceptibility genes are important in IgAN, and suggest that the putative gene(s) are located within or near to the DQ subregion. Moreover, similar DQ beta gene associations have been found in IDDM and pemphigus vulgaris, pointing to a common immunogenetic mechanism predisposing to several autoimmune diseases.

Major histocompatibility complex (MHC) protein analysis by optimised two-dimensional electrophoretic methods

Human histocompatibility molecules HLA-Class I and Class II (DR, DQ, DP) were analysed using three two-dimensional protocols: nonequilibrium pH gradient electrophoresis (NEPHGE), isoelectric focusing-acidic gradient (IEF-AG) and isoelectric focusing-basic gradient (IEF-BG). The three methods differ in their carrier ampholyte combinations and electrophoretic conditions. They provide different pH gradients and therefore different electrofocusing profiles. The NEPHGE protocol was adequate for separating proteins across a broad range of pI mobilities, i.e. 4.4 pH units between the acidic and the basic end. In contrast, the IEF-AG and the IEF-BG protocols gave a separation power across a narrow pH range, 1.9 and 1.7 pH units respectively. Thus, whereas the NEPHGE protocol provides a tool for a global major histocompatibility complex (MHC) antigen profile analysis, the IEF-AG and -BG allows one to investigate subcomponents of the individual MHC chains. For example, NEPHGE analysis of the HLA Class I heavy chain revealed a single spot. However, IEF-BG revealed the presence of six equidistantly spaced spots spanning a short pH gradient with identical molecular weight. Similar improved resolution was seen for the HLA-DR, DQ, and DP molecules. The IEF acidic gradient was adequate for separating the alpha chain; the IEF basic gradient gave better resolution of the beta chains. This data provides a baseline set of conditions for both analytical and preparative MHC protein studies prior to amino acid sequencing.

In vitro induction of immunological tolerance

IL-2 was previously shown to induce cytotoxic effectors with a broad spectrum of target specificities in thymus and spleen cell cultures. This study was designed to show whether T cells activated by H-2 allogeneic cells in MLC or by syngeneic tumor cells in MLTC are also potential targets for these cytotoxic effectors. We found that thymocytes activated in vitro for 5 days by rIL-2 were capable of killing tumor cells as well as activated T cells. Thymocytes activated by IL-2 were accordingly utilized as a means of effecting clonal deletion of T cells activated by H-2 allogeneic target cells in MLC. To establish whether the unresponsiveness is specific. IL-2-activated thymocytes were added as third party cells to MLC and MLTC. The results showed that both T cells, proliferating in response to H-2 allogeneic cells, and CTL, reactive against syngeneic tumors or H-2 allogeneic cells, are eliminated from the T cell pool. Only alloreactive T cells are specifically eliminated in MLC by IL-2-activated thymocytes, as the remaining T cells are capable of proliferating and generating CTL in response to antigenically unrelated third party allogeneic cells. The possibility that unresponsiveness might be due to soluble factors was ruled out by studies performed with a diffusable "chamber insert" culture system. The results provide evidence that IL-2-activated thymocytes induce in vitro T cell tolerance.

2'-5' oligoadenylate synthetase and its relationship to HLA and genetic markers of insulin-dependent diabetes mellitus

Cytokines and their related enzyme pathways may play a part in the development of insulin-dependent diabetes mellitus (IDDM). We have therefore studied the activity of the enzyme 2'-5' oligoadenylate synthetase (which is induced by both interferon and the tumour necrosis factors) in circulating mononuclear cells from 40 subjects with IDDM and 32 healthy control subjects. There was no difference in mean basal enzyme activity between the two groups. A polymorphism of the 2'-5' oligoadenylate synthetase gene, not previously described, was found using the restriction enzyme Bam HI. There was no association of 2'-5' oligoadenylate synthetase genotypes with IDDM, but there was a significant correlation between basal 2'-5' oligoadenylate synthetase activity and 2'-5' oligoadenylate synthetase genotypes. Significantly higher mean basal levels of 2'-5' oligoadenylate synthetase activity were associated with HLA-DQA 4.6 phenotype (determined using the restriction enzyme Taq 1 and a DQA probe) and HLA-DR3 (determined serologically), whereas significantly lower mean levels of enzyme activity were associated with HLA-DQA 5.5 and HLA-DR7, in both IDDM and control subjects. An analysis of variance confirmed that these associations were independent 2'-5' oligoadenylate synthetase genotype. Likewise, a significantly higher mean level of enzyme activity was associated with the heterozygous 1/3 insulin-related genotype in the IDDM subjects only. This study therefore suggests that the possession of certain HLA haplotypes might be associated with differing levels of basal 2'-5' oligoadenylate synthetase activity.

Biochemical analysis of a novel H-2 class I-like glycoprotein expressed in five AKR-(Gross virus) derived spontaneous T cell leukemias

The H-2 class I Ag profiles of five spontaneous AKR (H-2K) Gross virus leukemic cell lines were analyzed. A novel H-2 class I, "alloantigen"-like glycoprotein was immunoprecipitated and isolated from all the tumor cell lines using an H-2Dd-specific mAb 35-5-8. The novel Ag was also recognized in vitro by anti-H-2Dd-specific CTL. In addition, DNA from all the thymomas, but not the DNA from normal adult AKR thymic cells showed a transcribed gene detectable with an H-2Dd-specific oligonucleotide probe. The molecular profile of the novel antigen was further studied by two-dimensional gel electrophoresis and analyzed by a computer based image analyzer system and reverse-phase HPLC tryptic peptide mapping. Its molecular pattern was different from the syngeneic H-2Kk, H-2Dk, and the allogeneic H-2Dd gene products. The two-dimensional gel pattern of the novel H-2 class I molecule had a different overall structure reflected in isoelectric point, number, and distribution of polypeptide spots. The tryptic peptide map analysis showed six peaks exclusively identified with the novel Ag. The calculated degree of homology with the corresponding H-2Dd, H-Dk, and H-Kk peptides was 41, 56, and 51%, respectively. In addition, an unusual cell surface distribution of the novel Ag was observed in most of the leukemic lines. The removal of sialic acid residues by neuraminidase treatment facilitated the detection of the allodeterminants by anti-H-2Dd-specific mAb and CTL. Furthermore, we showed that in one AKR tumor line, 424, there is a close association of the novel Ag with the syngeneic class I molecules. Prior preclearance of the syngeneic class I molecules revealed the presence of the H-2Dd-like allospecificity. The genetic and molecular relationship between the expression of this novel class I-like glycoprotein and the recently sequenced Q5 gene is under current investigation.

Biochemical analysis of a novel H-2 class I-like glycoprotein expressed in five AKR-(Gross virus) derived spontaneous T cell leukemias

The H-2 class I Ag profiles of five spontaneous AKR (H-2K) Gross virus leukemic cell lines were analyzed. A novel H-2 class I, "alloantigen"-like glycoprotein was immunoprecipitated and isolated from all the tumor cell lines using an H-2Dd-specific mAb 35-5-8. The novel Ag was also recognized in vitro by anti-H-2Dd-specific CTL. In addition, DNA from all the thymomas, but not the DNA from normal adult AKR thymic cells showed a transcribed gene detectable with an H-2Dd-specific oligonucleotide probe. The molecular profile of the novel antigen was further studied by two-dimensional gel electrophoresis and analyzed by a computer based image analyzer system and reverse-phase HPLC tryptic peptide mapping. Its molecular pattern was different from the syngeneic H-2Kk, H-2Dk, and the allogeneic H-2Dd gene products. The two-dimensional gel pattern of the novel H-2 class I molecule had a different overall structure reflected in isoelectric point, number, and distribution of polypeptide spots. The tryptic peptide map analysis showed six peaks exclusively identified with the novel Ag. The calculated degree of homology with the corresponding H-2Dd, H-Dk, and H-Kk peptides was 41, 56, and 51%, respectively. In addition, an unusual cell surface distribution of the novel Ag was observed in most of the leukemic lines. The removal of sialic acid residues by neuraminidase treatment facilitated the detection of the allodeterminants by anti-H-2Dd-specific mAb and CTL. Furthermore, we showed that in one AKR tumor line, 424, there is a close association of the novel Ag with the syngeneic class I molecules. Prior preclearance of the syngeneic class I molecules revealed the presence of the H-2Dd-like allospecificity. The genetic and molecular relationship between the expression of this novel class I-like glycoprotein and the recently sequenced Q5 gene is under current investigation.

Functional studies of H-2k-like epitopes on DTIC treated and untreated L1210 (H-2d) clones

Following 'in vivo' treatment with 5-(3-3'-dimethyl-1-triazeno)imidazole-4-carboxamide (DTIC), murine leukemic cells acquire new antigenic specificities not detectable on parental cells and responsible for the rejection of the tumour by syngeneic hosts. 'In vivo' and 'in vitro' experiments pointed out an immunological cross reactivity between DTIC treated and untreated lines. Furthermore, specific CTLs raised against DTIC treated L1210 tumour cells (H-2d) were cytotoxic for H-2k target cells. The aim of this study is to investigate whether the H-2k cross reactivity displayed by L1210/DTIC is related to the drug treatment rather than due to an antigen already present in the parental line and maintained after treatment. Cloned cells from L1210, obtained by limiting dilution 'in vitro', were recloned 'in vivo' and then treated with DTIC. Syngeneic and allogeneic CTLs raised 'in vitro' against parental and treated clones showed lytic activity against H-2k target cells. Treated and untreated clones were then checked for the presence of H-2k-like determinants using monoclonal antibodies. One of these, HB-53 (IgG2bKkDk) was highly positive with all the clones tested in binding assay using iodinated Fab anti-mouse Ig, fluorescence and FACS analysis. Others displayed a low reactivity against both treated and untreated clones without significant differences. After neuraminidase treatment of two clones (D and D/DTIC), the H-100.5 (anti H-2Kk)-reactive epitope was dramatically exposed on the DTIC tumour cells but not on the parental clones. These data suggest that the H-2k cross reactivity is related to the presence of a TAA that is maintained after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological significance of beta hCG, HLA and other membrane antigen expression on bladder tumours and their relationship to tumour infiltrating lymphocytes (TIL)

Expression of beta human chorionic gonadotropin (beta hCG) by bladder tumours has been shown to be associated with increased metastases and resistance to treatment with radiotherapy and chemotherapy. Preliminary results from typing frozen tumours using monoclonal antibodies against HLA determinants show reduced or lost expression of one or more antigens in two thirds of patients studied with a trend for more malignant behaviour and inability to generate tumour infiltrating lymphocyte expression using Interleukin-2 in those patients whose tumours demonstrate loss. In this series beta hCG expression was only seen in a subgroup of those demonstrating loss of HLA antigen expression. Studies of beta hCG secreting bladder cancer cell lines showed that it was possible to induce class II HLA antigen expression with gamma Interferon, and that this treatment but not alpha Interferon reduced beta hCG production by the cell line.

Are certain HLA haplotypes responsible for low testosterone levels in males?

The level of testosterone on 138 HLA typed healthy males and 71 male rheumatoid arthritis patients were analysed. HLA-B15 was associated with a lower mean serum testosterone level in males than any other tissue type. This was observed in both the normal and RA groups.

Analysis of HLA antigens on germ cells in human semen

Nucleated cells other than sperm (NCOS) were isolated from human semen by centrifugation on a Ficoll density gradient. Using tissue-specific monoclonal antibodies (mAb) greater than 99% of the NCOS were found to be sperm cell precursors (SpP). These cells were tested for the expression of class I and II (DR, DP and DQ) HLA antigens by using specific mAb. The anti-HLA class I and II and anti-beta 2-microglobulin mAb reacted with less than 1% of the NCOS. This was demonstrated by indirect immunofluorescence microscopy and fluorescence-activated cell sorter analysis. These results were similar to those obtained from testing germ cells in frozen sections of normal adult testis using the same panel of mAb. In mixed lymphocyte-NCOS cultures, the SpP failed to stimulate allogeneic lymphocytes even when different concentrations of cells were used. These results indicate little or no expression of HLA class I and II including the HLA-D (T cell-defined) determinant on the SpP, a phenomenon which could be of biological importance.

HLA class III haplotypes in multicase rheumatoid arthritis families

The class III complement proteins (C2, BF, C4A, and C4B) were studied in 57 multicase rheumatoid arthritis (RA) families. When the gene frequencies for RA probands were compared to a normal control panel (162 haplotypes), a significantly higher frequency of the rare variant C4B*3 was observed (p less than 0.05). No significant differences were seen for the other C2, BF, C4A, or C4B alleles. The most common haplotype found in the probands was HLA-Cw5,B44,C2*C,BF*S,C4A*3,C4B*3,DR4, occurring with a frequency of 0.088. Haplotypes containing HLA-DR4 and Bw62 were found to carry either C4A*3,C4B*3; C4A*3,C4B*1; or C4A*4,C4B*2. When only haplotypes containing DR4 were compared between probands and controls, the frequency of the C4B*3-bearing haplotype remained higher in the probands. It is concluded that Bw62,C4A*3,C4B*3DR4 is a haplotype which is especially associated with RA. The low frequency in the RA population of this haplotype indicates that C4B*3 has a minor role in overall RA susceptibility.

Serum lymphocytotoxic activity in leprosy

Sera from 167 patients across the spectrum of leprosy and 46 endemic controls were screened for lymphocytotoxic activity (LCA). The Terasaki microdroplet lymphocytotoxicity assay was performed at 37 degrees C and 15 degrees C to test sera for LCA against a panel of lymphocytes from 50 donors which represented most known HLA-ABC antigens. Raised complement-dependent LCA at 15 degrees C was seen in leprosy patients with histories of erythema nodosum leprosum (ENL) or reversal/Type I (I) reactions. Eighty-six per cent of lepromatous (LL) patients with a history of ENL (n = 21, P less than 0.001), 83% of borderline lepromatous (BL) and 88% of borderline tuberculoid patients (BT) with a history of Type I reactions (n = 12, P less than 0.01 and n = 24, P less than 0.001 respectively) had LCA compared to 39% of endemic controls (n = 46). LCA was attributed to IgM on the basis of reduced activity when serum was treated with both dithiothreitol or absorbed with antiserum for IgM. Removal of immune complexes and rheumatoid factor did not influence LCA. LCA-positive sera reacted similarly with allogeneic lymphocytes from either healthy donors or leprosy patients. Moreover LCA-positive sera reacted with autologous lymphocytes. Specificities for HLA-ABC antigens were not identified. The potential role of these autoantibodies, manifested in leprosy patients with hypersensitivity reactions remains speculative.

Tumour necrosis factor-alpha enhances the cytolytic and cytostatic capacity of interleukin-2 activated killer cells

The cytotoxic and cytostatic responses of peripheral blood lymphocytes from eight cancer patients and splenocytes from four patients activated with rIL2 and a combination of rIL2 and rTNF-alpha were tested against two tumour cell lines. The cytotoxic response of rIL2-activated lymphocytes did not exceed the natural killer cytotoxicity values in all patients tested. In fact the killing capacity of some PBL deteriorated after rIL2 activation. The combined use of rIL2 and rTNF-alpha reversed this detrimental effect and enhanced the cytotoxic capacity of all PBL tested. In instances where high levels of killing were already achieved by rIL2 alone additional rTNF-alpha did not induce a significant change. This indicates that the role of rTNF-alpha may be to promote the response to rIL2 of PBL which react suboptimally to this lymphokine. rTNF-alpha did not only enhance cytotoxic capacity but also conferred cytostatic capacity to rIL2-activated LAK cells which were cytotoxic but unable to inhibit the growth of the surviving target cells. Natural killer cell selected K562 target cells which were less susceptible to killing by untreated lymphocytes than the parent K562 tumour cell line were killed more aggressively by rIL2 + rTNF-alpha LAK cells than by rIL2-LAK cells. No phenotypic differences were detected in these two cultures of LAK cells which indicates that the increased cytotoxic and cytostatic capacity of rIL2 + rTNF-alpha-LAK cells may be due to a higher state of activation of these cells or due to their capacity to recognise a broader spectrum of targets than rIL2-LAK cells.

HLA antigen and haplotype frequencies in Greeks

A random panel of 189 healthy Greek subjects was HLA typed for A, B and DR antigens. The alleles of these loci were found to be in Hardy-Weinberg equilibrium. Compared with other European Caucasoid populations, the frequencies of A9, B5, B18, B35, DR2 and DR5 were raised and that of B8 lowered. Significant linkage disequilibrium was found between a number of A/B, B/DR and A/DR antigen combinations. Some of the antigen associations usually seen in Caucasoid populations were also present in this sample (A1-B8-DR3, B14-DR1, B15-DR4) although others were missing (A3-B7-DR2, B35-DR1, B44-DR4). In addition, some antigen combinations have not been previously described. The most frequent two locus haplotypes in the Greek population are B8-DR3 and B18-DR5.

HLA-D region heterogeneity in a Nigerian population

HLA class II antigens were studied in a panel of 130 Nigerians. Complex patterns of associations were seen between HLA-Dw, -DR and -DQ specificities, differing widely from those reported for other populations. A number of Dw types were associated with the same DR antigen: Dw'1N' and Dw'BERN' with DR1, Dw2 and Dw'2N' with DR2, Dw5 and Dw'5N' (Dw5 + Dw'F5') with DRw11. It was also observed that a Dw type associated with more than one DR antigen: HLA-Dw3 was assigned to individuals who were DR3 negative and similarly Dw10, Dw13 and Dw14 to individuals negative for DR4. HLA-DRw8 and Dw8 were completely dissociated in Nigerians, and Dw8 did not show a preferential DR association. These results demonstrate that DR and DQ identity between HTC stimulator and responder cell is not necessarily a prerequisite for Dw to be assigned. Preliminary studies show that subtypes of HLA-Dw1 and Dw8 detected by HTC typing correlate with restriction fragment length polymorphisms (RFLPs) detected with a combination of Bgl II enzyme and DRA/DRB cDNA probes. HLA-DP antigen frequencies differed between Nigerians and British Caucasoids. The most common DP antigen in Nigerians was DPw1, compared with DPw4 in Caucasoids. HLA-DPw6 appeared to be absent or rare in both Nigerians and British Caucasoids. Only five out of 68 Nigerians tested were assigned two DP specificities. The association between HLA-DR3 and DPw1 reported in Caucasoid panels was absent in Nigerians.

HLA-DR4 associated Dw types in rheumatoid arthritis

Frequencies of HLA-DR4 and its related Dw types were compared between randomly selected normal controls and the index cases of multiplex rheumatoid arthritis (RA) families. A DR4 frequency of 68.3% was observed in index cases (n = 57) compared to 31.2% in normal controls (n = 96). Cellular typing with homozygous typing cells (HTCs) revealed significant increases of Dw4 (49.1% vs 22.9% RR = 3.2 p less than 0.001) and Dw14 (22.8% vs 2.1% RR = 13.9 p less than 0.001) in the index cases. A non-significant increase was seen for Dw13 (8.8% vs 4.1%). When DR4 positive patients and controls were compared, a significant increase was seen only for Dw14 (34.2% vs 6.6% RR = 7.3 p less than 0.01). Data from HLA genotyped RA and normal families allowed an examination of haplotype combinations of HLA-B antigens and DR4/Dw types to be made. HLA-Dw4 was predominantly found with B44 and Bw62 with nearly all DR4/Bw62 haplotypes being Dw4 positive. HLA-Dw13 was associated with B44 and Dw14 with Bw60, B44 and B27. Based on HTC and normal family data. Dw10 was found to be strongly associated with B38 containing haplotypes. Analysis of 69 C4A, C4B complement typed DR4 haplotypes failed to show any statistically significant association between Dw type and "complotype". However, there was a suggestion of C4A3. BQO being associated with Dw4 (34.2% vs 16.1% X2 = 2.9 p = ns) and C4A3, B1 with Dw14 (45.5% vs 27.6% X2 = 2.1 p = ns).(ABSTRACT TRUNCATED AT 250 WORDS)

Persistence of donor-specific class II antigens in allografted human heart two years after transplantation

It has been suggested that one of the mechanisms of action of cyclosporin is by abrogation of major histocompatibility complex class II expression. We have tested this hypothesis by following the expression of DR7, a polymorphic determinant of the class II DR locus in cardiac biopsies from 12 heart or heart-lung recipients who were themselves DR7 negative but whose donors were DR7 positive. All patients received cyclosporine and azathioprine immunosuppression. Immunoperoxidase and immunofluorescent techniques were used. The DR7 determinant was found on interstitial structures on donor heart at all times studied, including at 2 years after transplantation. Double immunofluorescent labeling of donor heart before transplantation revealed that more than 60% of the DR7 was on endothelial cells. At later times the proportion of DR7 on endothelial cells increased, but even at 1 year some DR7 was found on interstitial structures not of endothelial origin. The significance of these findings to mechanisms of long-term immunosuppression is discussed.

Solubilisation effect of Nonidet P-40, triton X-100 and CHAPS in the detection of MHC-like glycoproteins

We have analysed the differential solubilisation effect of three detergents on cell-membrane histocompatibility glycoproteins. Two nonionic detergents (Nonidet P-40 and Triton X-100) which are extensively used in the extraction of MHC proteins and a zwitterionic detergent (CHAPS) which is sulphobetaine derivative of cholic acid were used. An AKR (H-2k) derived spontaneous leukaemic cell line--424--was used as the experimental model. In this tumour cell line a class I-like antigen is expressed but not directly detected by cell-binding radioimmunoassay or immunoprecipitation from NP-40 or Triton X-100 solubilised glycoproteins. However, 46 kDa and 12 kDa bands consistent with the classical H-2 class I pattern were seen by SDS-PAGE after immunoprecipitation with the 34.5.8 anti-H-2Dd MoAb using CHAPS solubilised 424 glycoproteins. The H-2Dd-reactive molecule appears to be associated with at least one of the syngeneic class I specificities (H-2Kk, H-2Dk) and not accessible to react with the specific anti H-2Dd MoAb. The detergents NP-40 and Triton X-100 appear to be less efficient than CHAPS in breaking protein-protein interactions. This property of CHAPS permitted the adequate solubilisation of the novel antigen and its direct detection. The results of this study suggest that the alternative use of a non-denaturing zwitterionic detergent may contribute to the detection and characterisation of MHC-related, membrane-bound proteins of tumours and normal cells.

DTIC xenogenized lines obtained from an L1210 clone: clonal analysis of cytotoxic T lymphocyte reactivity

Antineoplastic compounds can induce on tumour cells new antigens that undetectable on parental cells and which are transmissible as a genetic character. In this study mouse leukaemia L1210 was cloned in vitro by limiting dilution and one cloned line was recloned in vivo. Four subcloned tumour cell lines (A,D,R,S) were xenogenized in vivo by DTIC treatment (A/DTIC, D/DTIC, R/DTIC, S/DTIC) following a schedule previously described. Up to 10(7) cells of these xenogenized subclones, injected i.p., were rejected by syngeneic hosts, although they grew in immunosuppressed hosts. The DTIC treated subclones were lysed by in vivo-primed, in vitro-restimulated (with the relevant subclone) lymphocytes. The cytotoxic lymphocyte activity was not strictly specific since parental, DTIC-untreated cells were also lysed, although less efficiently. CTL directed against the D/DTIC subclone were cloned by limiting dilution. Ninety-four CTL clones were assayed against L1210 subcloned cells, DTIC-treated and untreated, and against different murine tumours (syngeneic or allogenic). Three specific antigens could be identified in the 51Cr release assay. The DTIC subclones expressed one antigen that was specifically recognized by a set of CTL clones. A number of CTL clones were able to lyse the L1210 subcloned cell exclusively, targetting a tumour-associated antigen that did not appear to be modified in the DTIC-treated subclones. A third antigen was demonstrated in the parental and DTIC treated D subclone. On the basis of these results it was postulated that there was at least one common DTIC-inducible antigen specific and reproducible within an identical cell population. Moreover, DTIC treatment did not modify histocompatibility antigens or TAA pre-existing in L1210 cells. The findings discussed here provide new information about permanent xenogenization of tumour cells, which might be exploited for experimental chemo-immunotherapy of cancer.

Modulatory anti-T antibody on mature human lymphocytes

A monoclonal antibody developed in our laboratory, designated AN1, was investigated using in vitro cellular techniques. We found that this antibody modulates cell activation depending on the stimulatory signal used. Autologous and allogeneic MLR or MNC activated by mitogens like PHA and antigen like PPD, are all inhibited by the antibody. The inhibition takes place at an early stage of the cell activation pathway and cannot be reversed by exogenously added IL-2. The MNC activated with phorbol esters like TPA, on the other hand, showed enhancement in response to this antibody, whereas OKT3-activated cells are unaffected. This antibody is also found to inhibit specific CTL but has no affects on NK activity. The tissue distribution of the antigen(s) detected by our antibody showed that it is specific for mature unactivated human T cells and furthermore the target antigen(s) disappeared as a result of cell activation. The implications of these findings are discussed.

Characterization of two monoclonal antibodies raised against human testicular cells

Human testicular cells isolated from biopsy tissue were used for generation of monoclonal antibodies. Two hybridoma supernatants C3 and D4 were selected according to their reaction with sperm-precursor cells (immature sperms) in an enzyme-linked immunosorbent assay (ELISA). C3 reacted with testicular but no other tissue. D4 did not reveal any pattern of testicular staining in spite of its similarity to C3 in binding to sperm-precursor cells in ELISA and microcytotoxicity test.

Novel HLA class II-associated structural patterns in coeliac disease and type I diabetes

Cell membrane antigens were precipitated from EBV transformed cell lines by a monomorphic DR monoclonal antibody. Three mutually exclusive patterns with two glycoproteins (g25 and g28) that had not been previously identified, were observed. The first, g25+/g28- was found in all cell lines from 40 healthy individuals; a second, g25-/g28- was found in 4/7 coeliac and 2/4 IDDM patients and a third, g25+/g28+ was found in 3/7 coeliac and 1/4 IDDM patients. RFLP analysis with Class II alpha and beta chain probes and several restriction enzymes did not correlate with either of the disease associated patterns. Several possibilities regarding the identity and mode of action of the two polypeptides are described.

A comparative serological and molecular study of linear IgA disease and dermatitis herpetiformis

The class I and class II HLA serologically defined antigens and DQ alpha and DX alpha restriction fragment length polymorphism (RFLP) in 23 patients with linear IgA disease (LAD) were determined and their frequencies compared with those in a group of patients with dermatitis herpetiformis (DH) and healthy controls. In LAD there was a significant increase in HLA-B8 and DR3 and a larger increase in the DQw1-DR2/DRw6 related DQ alpha 6.2 kb and 6.8 kb RFLP. In DH there was a significantly increased frequency of HLA-A1, B8, DR3, and DQw2 with a concomitant increase in the DR3-DQw2 related DQ alpha 4.6 kb RFLP. The difference in DR3 frequencies and the increased frequency of DQw1 rather than DQw2 in LAD indicates that different susceptibility genes operate in the two diseases.

A novel HLA class II molecule

Molecular evidence has been obtained for a novel monomorphic HLA class II molecule distinct from HLA-DP/DQ/DR using a panel of lymphoblastoid cells which include HLA-loss mutants. The expression of this molecule was investigated using monomorphic affinity-purified mouse monoclonal antibodies (mAbs), including one of the IgG2a subclass designated EDU-1. This antibody reacts strongly in a cell-binding radioimmunoassay with HLA-DR and -DQ loss mutants derived from a lymphoblastoid parental cell. The EDU-1 mAb also reacted with a local panel of homozygous Epstein-Barr virus-transformed cell lines. The reactive molecules were further detected on allostimulated T-cell clones and various leukemic cells including those of myeloid origin which lack surface expression of HLA-DQ molecules. Thus the class II molecule described in this study corresponds to a monomorphic HLA class II determinant expressed on a variety of cells of different origin and HLA phenotypes. Moreover, this antigen structure is distinct from that of HLA-DP/DQ/DR as shown by direct immunoprecipitation, serial immunodepletion experiments, and two-dimensional gel electrophoresis. The molecule could be specified by new class II genes between DP and DQ. An alternative explanation for the genetic basis of the novel molecule is the existence of isotypic associations between alpha and beta chains of various class II molecules (DP, DX, DZ, and DO) but not DR and DQ as the mutant cells tested lack the latter genes.

T-cell receptor V beta use predicts reactivity and tolerance to Mlsa-encoded antigens

T lymphocytes reactive with the product of the Mlsa-allele of the minor lymphocyte stimulating (Mls) locus use a predominant T-cell receptor beta-chain variable gene segment (V beta 6). Such V beta 6-bearing T cells are selectively eliminated in the thymus of Mlsa-bearing mice, consistent with a model in which tolerance to self antigens is achieved by clonal deletion.

T cells define new alloantigens controlled by a gene(s) in the M1s region on mouse chromosome 1

Two different types of T cell clones which recognize Mlsb haplotype gene products were established by using mice congenic at the Mls locus. The antigens defined by these T cells showed differences not only in strain distribution but also in the restriction element for antigen recognition by T cells (i.e. Kd or Dd). The antigens appear to be expressed on various types of lymphocytes.

DY determinants, possibly associated with novel class II molecules, stimulate autoreactive CD4+ T cells with suppressive activity

A set of T cell clones (TCC) isolated from HLA-DR-, Dw-, DQ-matched allogeneic MLCs was found to proliferate autonomously when stimulated with cells carrying a wide range of class I or II specificities. This apparently unrestricted proliferation was relatively weak, and only low levels of IL-2 were present in the supernatants of stimulated cells. Autologous as well as allogeneic PBMC and B lymphoblastoid cell lines (B-LCL) were capable of stimulating such clones, which were also restimulated by suppressive, but not by helper, TCC. Moreover, such clones displayed the unusual property of autostimulation. mAb inhibition experiments suggested that class II- or class II-restricted antigens were involved in stimulation. Thus, certain "broad" mAbs (TU39, SG520) reacting with multiple locus products inhibited activation of these reagents, but none of those reacting more specifically with DR (TU34, TU37, L243, Q2/70, SG157), DQ (TU22, SPV-L3, Leu 10), or DP (B7/21), or mixtures of these mAbs, were able to do so. Evidence from sequential immunoprecipitation experiments suggested that mAb TU39 bound class II-like molecules other than DR, DQ, and DP on TCC and B-LCL, and it is therefore proposed that such putative novel class II-like molecules may carry the stimulating determinants for these autoreactive clones. DY-reactive clones lacked helper activity for B cells but mediated potent suppressive activity on T cell proliferative responses that was not restricted by the HLA type of the responding cells. Suppressive activity was induced in normal PBMC by such clones, as well as by independent suppressive clones, which was also inhibited only by mAb TU39. These findings lead to the proposal that DY-reactive autostimulatory cells may constitute a self-maintaining suppressive circuit, the level of activity of which would be regulated primarily by the availability of IL-2 in the microenvironment.

HLA-DR alpha, -DX alpha, and DR beta III gene association studies in DR3 individuals

In this study we have examined the results of probing with synthetic oligomers at the DR beta III locus, together with restriction fragment length polymorphisms defined by BglII digestion and a cDNA DR alpha probe, and Taq 1 digestion and a genomic DQ alpha probe. We have demonstrated heterogeneity of the human leukocyte antigen DR3 and close association of the DR alpha, DR beta III, and DX alpha genes. Two DR3-related preferential allelic associations have been identified, which may prove useful in family analysis as well as for investigations of DR3-related diseases.