Polymorphic restriction endonuclease sites linked to the HLA-DR alpha gene: localization and use as genetic markers of insulin-dependent diabetes

Polymorphic restriction endonuclease sites within the HLA-DR alpha gene have been defined, localized, and used as genetic markers in the analysis of susceptibility to insulin-dependent diabetes mellitus (IDDM). Hybridization of Bgl II-digested human genomic DNA with a cDNA clone for the HLA-DR alpha chain (pDR alpha-1) has revealed three allelic restriction fragment lengths: 3.8 kilobase pairs (kb), 4.2 kb, and 4.5 kb. Hybridization of EcoRV-digested human genomic DNA with the same probe has revealed two allelic polymorphic restriction fragment lengths: 9.2 kb and 13.0 kb. By analysis of double digests of genomic DNA from individuals homozygous for each of the allelic variants, the polymorphic restriction sites were found to be clustered near the 3' end of the HLA-DR alpha gene. The observed correlations of DR alpha Bgl II restriction site variants with serologically determined DR specificities suggest linkage disequilibrium between the DR alpha and DR beta loci. The 3.8-kb fragment is correlated with the DR1 type (Pc = 4.4 X 10(-4)); and the 4.2-kb fragment, with a subset (B8,DR3) of the DR3 type (Pc = 5.1 X 10(-4)) and with the DR6 type. The segregation pattern of HLA-DR alpha polymorphic Bgl II restriction fragments was analyzed in six IDDM families. The observed association of IDDM with the Bgl II 4.2-kb DR alpha restriction variant is higher than with existing serological markers and supports the utility of this approach in elucidating IDDM inheritance.

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.

A new approach to the diagnosis of active Rh0(D) immunization in passively immunized pregnant women

An assay has been developed to distinguish active from passive Rh0(D) immunization in a patient who had recently received hyperimmune anti-Rh0(D) immunoglobulin therapy. Isolated peripheral B lymphocytes from a pregnant woman at 32 weeks gestation were co-cultured with Epstein-Barr virus in a liquid growth medium. After 7 days, anti-Rh0(D) antibodies produced in vitro by the transformed lymphocytes were detected in culture supernatants, thereby proving active immunization and indicating the potential of hemolytic disease of the newborn in the current pregnancy. This assay was also performed with peripheral B lymphocytes from three groups of individuals: mothers known to be Rh0(D) immunized and who recently delivered Rh-positive infants, women with longstanding Rh0(D) immunization, and women who were treated with anti-Rh0(D) globulin. In the first group, anti-Rh0(D) antibodies were again detected after in vitro viral stimulation. In the latter two groups, essentially no anti-Rh0(D) activity was detected.

Molecular variants of the HLA-B27 antigen in healthy individuals and patients with spondylarthropathies

Despite major advances in genetic and structural studies of the HLA-B27 antigen, the underlying mechanism responsible for the remarkable association between this antigen and spondylarthropathies remains unknown. At a molecular level, the use of B27M1 and B27M2 monoclonal antibodies has permitted the identification of distinct allospecific epitopes on the B27 molecule. One of these epitopes, B27M2, is polymorphic and has allowed us to define B27 variants: B27M2[+], B27M2[-], and B27M2[int]. The heterogeneity of the B27 antigen correlates well with biochemical and cytotoxic evidence of genetic heterogeneity. These variants exhibit ethnic variation and also appear to correlate, in preliminary studies, with disease susceptibility, especially among Orientals. HLA gene probing is potentially an even more precise tool than monoclonal antibodies for the study of MHC-related disease susceptibilities. Initial work in our laboratory has resulted in the production of probes with specificity for HLA-B locus genes and current efforts are directed toward the derivation of B27 allele-specific probes. It seems likely that, when such probes are applied to B27-positive individuals, complexity in addition to the B27M2 variants will be revealed. Yet to be defined is the mechanism behind the association between B27 and AS. Is the association causal for disease, or is B27 indeed just a marker for other pathogenic factors somehow linked to it? Available evidence points to both causal and linked roles for B27 in ankylosing spondylitis. Products of both HLA and non-HLA gene families may interact with infectious disease pathogens in susceptible individuals to produce a disorder which may not be specific in its association with any one pathogenic factor.

Human monoclonal antibodies neutralizing varicella-zoster virus

Hybridomas secreting human monoclonal antibodies to varicella-zoster virus were produced by fusing B cells of a patient recovering from acute varicella infection with a human-mouse cell line. Two hybrid lines have continued to secrete IgG1, one with kappa and the other with lambda chains, for at least 12 months. Each antibody neutralizes virus infectivity between 1-5 micrograms of partially purified immunoglobulin/ml, each shows a different pattern of immunofluorescent staining of virus-infected cells, and one identifies three viral proteins with molecular weights of 60,000, 95,000, and 97,000.

Epstein-Barr virus-associated B-cell proliferations of diverse clonal origins after bone marrow transplantation in a 12-year-old patient with severe combined immunodeficiency

A 12-year-old boy with severe combined immunodeficiency who had been kept in a gnotobiotic environment since birth received bone marrow from a histoincompatible sibling in an attempt to reconstitute immunologic function. To prevent graft versus host disease, the donor's marrow was treated in vitro with monoclonal antibody and complement to remove alloreactive T cells. Eighty days after transplantation, the patient had a systemic illness characterized by fever, thrombocytopenia, gastrointestinal pain, and bleeding; he died on the 124th post-transplantation day. Postmortem examination revealed multiple tumor-like B-cell proliferations, recipient in origin, in numerous organs. Epstein-Barr virus (EBV) was isolated from the patient's pharyngeal secretions; EBV nuclear antigen was found in spontaneously transformed peripheral-blood lymphocytes, inflammatory cells from peritoneal fluid, and bone marrow cells; and EBV genomes were discovered in all tumor tissues. The donor's serum showed evidence of past EBV infection. Analysis of cellular immunoglobulin and immunoglobulin gene DNA from the tumors indicated both monoclonal and oligoclonal B-cell proliferations. These findings provide evidence for the evolution of EBV-induced polyclonal activation of B cells to oligoclonal B-cell proliferation and finally to monoclonal B-cell lymphoma.

Transfusion-acquired cytomegalovirus infection in cardiac surgery patients

The incidence of transfusion-acquired primary cytomegalovirus (CMV) infection was studied in 483 cardiac surgery patients. Ninety-six patients (20%) were found to lack antibody to CMV [CMV Ab(-)] as measured by radioimmunoassay. Sixty-eight CMV Ab(-) were followed by viral culture and/or serology from eight weeks to one year after transfusion. Transfusion requirements in CMV Ab(-) patients were as follows: whole blood/packed red blood cells, mean 4.7 +/- 2.6 units; platelets (20 patients), 6.9 +/- 3.8 units; fresh frozen plasma (25 patients), mean 3.3 +/- 1.6 units. Forty-nine percent of 235 donor units tested had antibody to CMV. One donor unit (0.4%) had CMV-specific IgM. This was not associated with CMV infection in the recipient. One patient (1.5%) demonstrated evidence of seroconversion to CMV during the follow-up period. This is significantly less than reported in previously published studies (P less than .01). Serological methods used, the age of the transfused blood, the immune status of the transfusion recipient, and the administration of passive antibody in fresh frozen plasma are factors that may be responsible for the low incidence observed.

HLA loss variants of a B27+ lymphoblastoid cell line: genetic and cellular characterization

Variants of a lymphoblastoid cell line, LCL 526 (SB3 MB1 DR1 B44 C5 A2/SB4 MT4 DR4 B27 C2 A24), which lost various HLA specificities were selected with monoclonal antibodies and complement using a method developed by Kavathas et al. (PNAS 77:4251, 1980). Using alpha B27 monoclonals, 8 B27 only loss mutants and 4 B27 haplotype multiple loss mutants were generated. The parental LCL 526 and two of the B27- mutants were used to select alpha B27 CTLs. The selection of six A2 loss, one A2-C5 loss, and 14 A2 haplotype multiple loss variants as well as secondary selection on haplotype loss variants to obtain A null, B null, DR null, and total A, B, C, null variants is also described. The usefulness of these mutants for the study of the relationship between B27 and disease and as two new haplotypes for immunologic, genetic, and molecular research is discussed. These mutants are available to other researchers.

A cytolytic human T lymphocyte clone differentially recognizing HLA-B27 subtypes

A cytolytic human T cell (CTL) clone, designated F/M-F159, has been produced, the lytic specificity of which distinguishes subtypes of HLA-B27. This was demonstrated in cell-mediated lympholysis (CML) assays of: 1) a panel of target cells from unrelated donors, 75 B27 + and 36 B27-; 2) six families, including 20 B27 + and 14 B27- individuals; and 3) B27 + and B27- variants of a B27+ lymphoblastoid cell line (LCL). Specificity of F/M-F159 for HLA-B27 was confirmed by blocking studies with monoclonal antibodies. Lysis of B27 + targets reactive with the anti-B27 monoclonal antibody B27M2 was 30-104%, while lysis of B27 +, B27M2- targets was 4-22%. Lysis of B27- targets expressing HLA-Bw47, known to be cross-reactive with the B27M2 antibody, was 10 to 19%, while lysis of all other B27- targets was less than or equal to 10%. Clone F/M-F159 lysed B27 + targets, and failed to lyse B27- targets, irrespective of the clinical status of the cell donors. It is concluded that F/M-F159 recognizes an epitope present on the majority of serologically identified HLA-B27 molecules and that this epitope is closely related to, but not identical with, the epitope recognized by the antibody B27M2. These findings are interpreted as supporting a direct role for HLA-B27 in disease pathogenesis.

Identification of HLA-B27M1 and -M2 cross-reactive antigens in Klebsiella, Shigella and Yersinia

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Rescue of human monoclonal antibody production from an EBV-transformed B cell line by fusion to a human-mouse hybridoma

A human-mouse cell line that is hypoxanthine-aminopterin-thymidine sensitive and ouabain resistant was derived from a fusion between human B lymphocytes and a mouse myeloma line. This new mutant, when fused to a relatively unstable EBV-transformed B cell secreting a human monoclonal anti-A (red blood cell antigen) antibody, resulted in stable hybridomas capable of long term production of the specific human monoclonal antibody. Furthermore, some of the hybrid clones secreted antibody in far greater titer than the original EBV cell line. We conclude that fusion to this human-mouse line is an efficient approach to the production of human monoclonal alloantibodies and an effective method of 'rescuing' secretion of desired antibody from EBV cell lines.

Immunologic responsiveness and safety associated with the Coccidioides immitis spherule vaccine in volunteers of white, black, and Filipino ancestry

A trial of the killed Coccidioides immitis spherule vaccine was undertaken with 151 healthy skin test negative adult volunteers and controls to evaluate the safety of selected regimens, the induction of humoral and cell-mediated immune responses, and to determine if there were immunogenetic differences in these responses. The vaccine was given as three intra-deltoid doses over 8 weeks. No severe systemic symptoms were noted, although 3% of 3.5 mg doses (but no 1.75 mg doses) were associated with severe local reactions. Half the vaccinees had skin test conversions, which generally persisted greater than or equal to 6 months, two-thirds showed boosting of lymphocyte transformation in vitro, and 16% given three 3.5 mg doses developed antibody. There was an association between degree of local adverse vaccine reaction and immunostimulation, and a trend to immune response in persons of O blood type and with some HLA phenotypes. There was no evidence of deficient response to vaccination in subpopulations known to respond to coccidioidal infection poorly. A regimen of three 1.75 mg doses appears to be safe and without reduced immunogenicity, and there is no evidence dosage modification for certain subpopulations would be necessary in efficacy studies.

Identification of several functional subgroups of HLA-B27 by restriction of the activity of antiviral T killer lymphocytes

Anti-Epstein-Barr virus and antiinfluenza A cytotoxic T lymphocytes (CTL) have been used to study the restriction of human antiviral responses by HLA-B27 antigens. Three functional subgroups of HLA-B27 have been clearly distinguished by this "restriction-typing assay". No cross-reaction could be detected between the three subgroups either at the CTL level or at the level of antigen-presenting cells. The cells of subgroup 1 are always positive [M2(+)] when tested in immunofluorescence with a monoclonal B27-specific antibody which divides HLA-B27 into a major M2(+) and a minor M2(-) subgroup. These M2(+) group 1 cells are apparently also HLA-B27W as previously shown by Ivanyi and co-workers using anti-HLA-CTL. Subgroup 2 includes only M2(-) cells. A comparison between this group and the previously described HLA-B27K is not fully conclusive, since two typing cells which were clearly HLA-B27K apparently did not belong to group 2. Only two donors, both of Oriental origin, have been included in subgroup 3. Both of them were "M2 intermediate". These results demonstrate (1) the existence of several functional subgroups of HLA-B27 with an interesting correlation with the M2(+), M2(-), or M2 intermediate phenotypes, and (2) the possibility of using the restriction-typing assay to define such functional subgroups not detected by classical allosera.

An HLA-B locus probe clarifies endonuclease polymorphism of major histocompatibility complex class I genes

A DNA probe specific for the HLA-B locus has been isolated from a broadly cross-reactive HLA class I genomic clone. Locus specificity of the probe appears to be derived primarily from a stretch of approximately 180 nucleotides comprising the last (7th) intron of the original B7 gene. Use of the probe to analyze Southern blots of genomic DNA from unrelated individuals provides the first direct demonstration of intragenic localization of an HLA allele-specific restriction endonuclease site. Availability of this probe should make practicable the study of HLA-B locus restriction fragment length polymorphism as genetic markers of disease susceptibility, and should provide a model for developing probes specific for other HLA class I loci.

Detection of platelet antibodies by anti-kappa light chain facilitation of C-FDA (KC-FDA) thrombocytotoxicity

Sensitivity of the carboxyfluorescein diacetate (C-FDA) thrombocytotoxicity technique for the detection of antiplatelet antibodies has been enhanced by the addition of an anti-Kappa light chain antibody facilitation step. This new technique, KC-FDA, was compared with the platelet suspension immunofluorescence test (PSIFT) by titering platelet-reactive allo-anti-PlAl and anti-HLA antibodies. The results show that compared to PSIFT, KC-FDA is more sensitive for detecting platelet specific antibodies (PlAl), is more or equally sensitive for detecting other antibodies (HLA), and is significantly faster and easier to perform.

Analysis of HLA-B27 antigen with monoclonal antibodies

To explore the possibility that the HLA-B27 antigen may exist in more than one form, murine monoclonal antibodies were produced to B27 molecules. The first such antibody, anti-B27M1, reacts with 100% of B27 + cells and, therefore, does not distinguish B27 + healthy individuals from those with spondyloarthropathies. A second antibody, anti-B27M2, recognizes a variant of the B27 molecule that is present in most but not all Caucasian B27 + individuals. The frequency of B27M2(+) variants also appears to differ among different ethnic groups. Preliminary studies suggest that B27 + patients with ankylosing spondylitis are less likely than B27 + healthy individuals to express the B27M2 variant.

Monoclonal antibodies to HLA-B27

Because HLA-B27 is such an important genetic marker for susceptibility to spondyloarthropathies and other related diseases, study of this alloantigen was undertaken using murine monoclonal antibodies. The first monoclonal anti-B27 antibody, B27M1, is an IgG2a lymphocytotoxic antibody that reacts with all B27 antigens and cross-reacts to a lesser degree with the B7 antigen. Cross-reactivity with B7 is attributed to a B27-like epitope on the B7 antigen but which, as determined by cytotoxicity blocking studies, is distinct from the B7 allospecific epitope itself. The second B27 monoclonal antibody, B27M2, is a lymphocytotoxic IgM antibody reacting with most (greater than 85%) but not all of B27 antigens tested and having no cross-reactivity with B7. As determined by cytotoxicity blocking studies, the B27M2 epitope appears near the allospecific B27 epitope and the B27M1 epitope on the B27 antigen molecule. Immunochemical studies reveal isoelectric point and size differences between the B27M2+ and the B27M2- variants of HLA-B27. Based on these data, a model is proposed for the B27 antigen in which a B27M1 epitope is constant but the B27M2 epitope is present on the B27 antigen of some individuals and absent from that of others. B27M1 antibody reactivity does not appear to be associated with unusual disease susceptibility but preliminary data suggest the B27M2- variant of B27 may be more strongly associated with ankylosing spondylitis.

Hodgkin's disease susceptibility: linkage to the HLA locus demonstrated by a new concordance method

The role of genetic susceptibility in the pathogenesis of Hodgkin's Disease has been considered relatively minor because of the rarity of familial disease, the absence of an identified pattern of inheritance, and the weakness of HLA associations in population studies. The availability of four prospectively ascertained HD families permitted reappraisal of the cosegregation of HLA and HD susceptibility by a new extended concordance analysis method. HLA haplotype concordance among patients was greater than that expected by chance alone for our four families (P less than 0.022) and also for these in combination with twelve informative families in the literature (P less than 0.0015). This study thus provides a new method, based on genotype concordance of affected relatives, for assessing linkage of HLA and disease susceptibility, and new evidence for the genetic control of susceptibility to HD. The model presented, as well as alternative and more complex models, points to the existence of an HD susceptibility gene in or near the HLA region, which, in the presence of a suitable etiologic agent or additional genetic susceptibility, leads to the induction of HD.

Immunochemical variants of HLA-B27

Detailed study of HLA-B27 was prompted by the extremely strong associations between this antigen and spondyloarthropathies. Despite the relative homogeneity of this antigen when defined by alloantisera, B27 reactivity with the monoclonal antibody B27M2 suggests previously unrecognized heterogeneity. To define and confirm this heterogeneity on a molecular level, detergent extracts were prepared from B cell lines derived from individuals reactive (+) or unreactive (-) with the B27M2 antibody. Extracts were immunoprecipitated by specific allogeneic or monoclonal antibodies and analyzed by two-dimensional polyacrylamide gel electrophoresis. By this method the B27M2+ and B27M2- variants of HLA-B27 had different isoelectric points (pl) and could be distinguished from each other and from a different (Bw44) control alloantigen. Blockade of glycosylation by pretreatment of cells with tunicamycin did not alter pl but did reduce HLA antigens by approximately 3000 daltons. These data demonstrate that B27 antigens can be subdivided into subsets with different molecular composition. The effects of this heterogeneity upon the associations of B27 and disease are not yet known.

Immunochemical variants of HLA-B27

Detailed study of HLA-B27 was prompted by the extremely strong associations between this antigen and spondyloarthropathies. Despite the relative homogeneity of this antigen when defined by alloantisera, B27 reactivity with the monoclonal antibody B27M2 suggests previously unrecognized heterogeneity. To define and confirm this heterogeneity on a molecular level, detergent extracts were prepared from B cell lines derived from individuals reactive (+) or unreactive (-) with the B27M2 antibody. Extracts were immunoprecipitated by specific allogeneic or monoclonal antibodies and analyzed by two-dimensional polyacrylamide gel electrophoresis. By this method the B27M2+ and B27M2- variants of HLA-B27 had different isoelectric points (pl) and could be distinguished from each other and from a different (Bw44) control alloantigen. Blockade of glycosylation by pretreatment of cells with tunicamycin did not alter pl but did reduce HLA antigens by approximately 3000 daltons. These data demonstrate that B27 antigens can be subdivided into subsets with different molecular composition. The effects of this heterogeneity upon the associations of B27 and disease are not yet known.

A simplified new method for HLA-DR typing using the TM1 monoclonal antibody

A new modification of an HLA-DR typing technique is described which makes DR typing as rapid and simple as routine HLA-A,B,C typing. In this new method, designated the TM1 technique, carboxyfluoresceindiacetate labeled peripheral blood lymphocytes are added directly to DR typing trays. The T cells are then lysed by addition of TM1, a pan-T cytotoxic IgM monoclonal antibody, and residual B-cell reactivity with cytotoxic DR alloantibodies is read as in routine fluorochromasia microlymphocytotoxicity. HLA-DR typing by the TM1 technique compares favorably to typing by methods using B cells enriched by sheep red blood cell rosetting or by Degalan bead columns. The TM1 technique also works well with cells that have been cryopreserved as well as with cells that have been separated from whole blood drawn as much as 3 days earlier. Finally, because TM1 is so effective in lysing normal T lymphocytes, this antibody may prove useful in functional in vitro and in vivo studies requiring T-cell depletion.

Production of functional human T-T hybridomas in selection medium lacking aminopterin and thymidine

The production of hybridomas between immunologically activated T cells and malignant T-cell lines offers a potentially unlimited source of soluble T-cell-derived products. Recently, human T-T hybrids have been described; however, their use has been hampered by slow growth and chromosomal instability due at least in part to the presence of thymidine in the traditional hypoxanthine/aminopterin/thymidine (HAT) selection medium. In this report, we describe the development of a rapidly growing hypoxanthine phosphoribosyltransferase-deficient human T-cell line designated J3R7, the use of azaserine/hypoxanthine (AH) medium as an alternative selection medium to HAT medium, and the production of functional T-T hybrids by using the J3R7 line and the AH selection technique. Hybrids selected in AH medium were 4-fold greater in number and 3-fold faster in growth rate than hybrids grown in HAT medium. No stable clones were obtained from HAT cultures whereas AH-derived hybrids could be readily cloned by the method of limiting dilution. Evidence for hybridization included (i) the presence of approximately twice the number of chromosomes in hybrids than in J3R7 cells; (ii) the presence on hybrid cells of the Leu-3a surface antigen, present on normal helper T cells but not on J3R7 cells; (iii) the expression of HLA antigens of both the normal T-cell partner and the J3R7 line; and (iv) the constitutive secretion of interleukin 2 from multiple hybrid clones but not from the J3R7 cell line. Thus far, these clones have maintained their rapid growth, chromosome number, surface phenotype, and constitutive secretion of interleukin 2 for 4 months.

Demonstration of gene dosage effects on antigens in the Duffy, Ss, and Rh systems using an enzyme-linked immunosorbent assay

Using a recently developed enzyme-linked immunosorbent assay, gene dosage effects were demonstrated for the Duffy, Ss, and Rh red blood cell antigen systems. We report a comparison by an antibody-binding assay of the relative amounts of Fya and Fyb antigens on FyaFya, FyaFyb, FybFyb, FyaFyx, and FyxFyx erthrocytes, and of s antigen on cells homozygous and heterozygous for s. The immunosorbent assay also was used to study Rh antigens, and data which had been obtained using radiolabelled antibodies were confirmed.