Biomedical subjects

R J Hartzman

Publications and source records attributed to R J Hartzman.

At least 73 records · Page 4Linked to original sources

PubMed1986

Human allospecific TLCs generated against HLA antigens associated with DR1 through DRw8. II. Population analyses and blocking studies with monoclonal antibodies.

Serologic, cellular, and molecular evidence supports the concept of extreme complexity within the HLA-D region. To study the complexity and fine specificity of the HLA-D region at the level of T-cell recognition, a panel of T-cell clones was generated against alloantigens associated with HLA-DR1 through -DRw8. After initial screening of more than 800 clones, 89 representative lines were selected for extensive testing against 204 unrelated stimulator cells. Clone-by-clone correlation analyses were performed to test whether any clones recognized similar or identical epitopes. In addition, clonal reactivity patterns were correlated with known HLA specificities. Twelve clusters of clones were identified with similar reactivity patterns using clone-by-clone correlation analysis. Some groups were significantly correlated with specificities associated with various D-region haplotypes; others had no significant correlation with any defined D-region specificity. Five general types of clones obtained in our study can be categorized as follows: Those recognizing epitopes clearly demonstrating a primary association with the classically defined D-region molecules against which the clones were primed. Clones recognizing epitopes associated with one of the priming antigens and also with another unrelated D-region specificity. Clones detecting epitopes which showed significant correlation with D-region molecules totally different from those against which they were originally primed. Clones with limited reactivity in population studies and no correlation with defined D-region molecules. Clones recognizing class I-associated epitopes.

Antibodies, Monoclonal↗

PubMed1986

Clonal analysis of HLA-DPw1 (SB1) associated allodeterminants: recognition of novel epitopes and evidence for quantitative variation in class II antigen expression.

Alloreactive human T-lymphocyte clones were derived from the SB1 HLA-DPw1)-specific, primed lymphocyte typing cell line SB1A used in the Ninth International Histocompatibility Workshop. The clones from two separate subclonings were analyzed for their proliferative patterns in panel experiments with cells from unrelated individuals and in family segregation analyses. While only one clone gave a perfect correlation with the DPw1 specificity, the maturity of clones recognized multiple specificities apparently associated with but not identical to HLA-DPw1. Most clones defined "splits" or subsets of DPw1 and some also displayed "extra" reactions with DPw1-negative stimulator cells. Further evidence was also found that, of the molecules bearing epitopic subsets associated with DPw1, some may be selectively expressed on the cell surface whereas the surface density of other DPw1-associated antigens may be varied. Thus, the HLA-DP region appears to encode a complex array of alloantigens and is in this regard similar to the HLA-DR region.

B-Lymphocytes↗

PubMed1986

Recognition of an HLA-DPw1 specific alloantiserum raised by planned immunization.

This study reports identification of the first alloantiserum specific for a single HLA-DP allele and presents valuable technical information for the serological detection of the HLA-DP gene product. Serological detection of the HLA-DP gene products was undertaken by analyzing a large number of alloantisera against an HLA-DP characterized, monocyte depleted, B-lymphocyte reference panel. After absorption of contaminating DR antibodies, one alloantiserum (SOW) which had been raised by planned immunization, was shown to have a correlation coefficient of 0.91 with DPw1 as defined by primed lymphocytes. No association was seen with any other HLA-A,-B,-C,-D,-DR, or -DQ specificity in either population or family studies. The HLA-DP typing of the serum donor and immunizing recipient support the conclusion. Evidence is presented which suggests that expression of the DP molecule is not stable, at least as detected by conventional microcytotoxicity techniques.

Antigen-Antibody Complex↗

PubMed1985

Localization of C4 genes within the HLA complex by molecular genotyping.

Segregation of the complement component, C4, was analyzed in six families that each included an individual who inherited an HLA haplotype where a crossover event had occurred in the region between HLA-B and HLA-DR. Two cDNA clones corresponding to the C4 gene were utilized as probes in Southern blot analysis of DNA from members of each family. Restriction fragment length polymorphisms (RFLP) were observed and were assigned to haplotypes. In one family RFLP, hybridizing with the C4 probes, segregrated with HLA-B, and in four families RFLP segregated with HLA-DR; one family was not informative in this respect. These analyses have made it possible to localize the genes for C4 between HLA-B and HLA-DR by molecular genotyping and to characterize three different genomic configurations of C4 genes by limited restriction mapping.

Chromosome Mapping↗

PubMed1985

Measles-specific T cell clones derived from a twin with multiple sclerosis: genetic restriction studies.

The association between multiple sclerosis (MS) and HLA-DR2 suggests that the disease may be associated with an aberrant immune response, likely directed against an antigen of either viral or host origin. We have used measles virus-specific T cell clones derived from a patient with MS to study genetic restriction patterns of antigen presentation by macrophage-enriched (E-) populations. Twenty-two clones proliferated in response to measles-infected Vero cells but not to mumps-infected or uninfected Veros. E- cells from both the autologous subject and her healthy, measles nonresponder identical twin were capable of presenting antigen to all clones. Studies with E- cells obtained from a panel of cell donors demonstrated clones which recognized antigen in association with D2/DR2, DR4, subgroups of DR4, and SB3. Three clones recognized antigen only in association with the autologous or twin's cells, but not with other sets of HLA-matched E-cells obtained from healthy donors or from other patients with MS. These studies indicate that the differing responses to measles virus demonstrated by these two identical twins are not explained by alterations in the interactions between antigen-presenting cells and T cells. Furthermore, at the clonal level, no preferential role is seen for HLA-DR2 as the restricting element for presentation of measles virus to these clones.

Antigen-Presenting Cells↗

PubMed1984

Recombination within the HLA-D region. Correlation of molecular genotyping with functional data.

Molecular genotyping of the HLA-D/DR region in a family correlated with serologic and cellular typing data. It was further possible to predict a subtle difference in SB region-related functions from such molecular studies. A family that included an individual who inherited an HLA haplotype with a paternal recombination between HLA-B and the HLA-D/DR region was identified by classic HLA typing techniques. Segregation of HLA-D/DR region genes in this family was studied by Southern blot analysis using cDNA probes for DR alpha, DR beta, DC alpha, DC beta, and SB beta. Restriction enzyme fragment polymorphisms observed for every gene tested were in concordance with assigned HLA haplotypes (including the individual known to have inherited a paternal recombinant haplotype) with one exception: two HLA identical siblings were observed to have different SB beta restriction fragment patterns. Further testing revealed that one individual inherited a maternal HLA haplotype recombinant between the HLA-D/DR region and SB beta. Although both maternal SB alleles typed as SB4, allelic differences could be detected cellularly by primed lymphocytes and by the differential expression of a class II cell surface antigen using monoclonal antibody. Therefore, predicted and nonpredicted recombinant haplotypes were detected in a family by molecular genotyping.

DNA Restriction Enzymes↗

PubMed1984

Human helper T-cell clones that recognize different influenza hemagglutinin determinants are restricted by different HLA-D region epitopes.

Human T-lymphocyte clones ( TLCs ) were generated against the hemagglutinin (HA) of A/Texas/1/77 influenza virus by limiting dilution. TLCs were then screened for antigen specificity on chemically synthesized peptides representing the HA1 molecule. It has been hypothesized that different T cells that recognize the identical antigenic determinant are controlled by (restricted by) the same class II epitope. Two TLCs , HA1.4 and HA1.7, both recognized the same HA peptide and in proliferation studies exhibited identical restriction patterns. Two other clones, HA 1.9 and HA 2.43, recognized different HA determinants and also had distinct restriction patterns. Proliferation inhibition studies with monoclonal antibodies against human class II molecules demonstrated three unique patterns of blocking with the clones, suggesting that clones may be restricted to a unique class II epitope depending on the HA determinant recognized. These data can be interpreted as supporting the argument that human immune responses to influenza hemagglutinin are under Ir gene control exerted at the level of the viral antigenic determinant recognized in association with particular D-region restricting elements. The determinant selection and clonal deletion theories are compared for their capacity to best explain these findings.

Antibodies, Monoclonal↗

PubMed1984

Linkage disequilibrium of HLA-SB1 with the HLA-A1, B8, DR3, SCO1 and of HLA-SB4 with the HLA-A26, Bw38, Dw10, DR4, SC21 extended haplotypes.

Homozygous typing cells from 13 normal HLA-A1, B8, Dw3, DR3 and five normal HLA-A26, Bw38, Dw10, DR4 individuals were typed for the following markers: HLA-SB, MB, MT; complement proteins BF, C2, C4A, C4B; and GLO. Ninety-one percent of A1, B8, Dw3, DR3 homozygous individuals (HI) tested were homozygous for BF*S, C2*C, C4A*QO, and C4B*1 (SCO1 complotype), which indicates that the SCO1 complotype is in linkage disequilibrium with the A1, B8, DR3 haplotype in randomly selected normal populations. Sixty-seven percent of HLA-A1, B8, Dw3, DR3, SCO1 positive HI also expressed SB1; since the frequency of SB1 in random Caucasian populations is 11.2%, this finding indicates that SB1 is in linkage disequilibrium with the A1, B8, DR3, SCO1 extended haplotype. All HI with the A26, Bw38, Dw10, DR4 haplotype were homozygous for both SC21 and SB4, suggesting that SC21 and SB4 should be included in the A26, Bw38, Dw10, DR4 extended haplotype. On the other hand, neither of the GLO markers were found in association with either haplotype. The results of this study indicate that HLA-SB is included in some extended haplotypes and may be important in these markers for diseases such as insulin-dependent diabetes mellitus. This study also demonstrated an apparent influence of HLA-SB on primary mixed lymphocyte culture (MLC) responses. The mean relative response of primary MLCs between individuals matched for HLA-A, B, D, DR, MB and MT but not SB was 40% of that for the MLCs with mismatched HLA-D, significantly higher than the MLCs matched for all HLA and complotypes.

Complement System Proteins↗

PubMed1984

Measles virus-specific T4+ human cytotoxic T cell clones are restricted by class II HLA antigens.

We have generated measles virus-specific T cell clones from a patient with multiple sclerosis who has been described previously as a strong responder to measles virus. T cell clones were screened on the basis of their capacity to proliferate to measles virus. The cell surface phenotype of each clone was OKT3+, OKT4+, OKT8-. The majority of these clones (11 of 14) were cytotoxic for their autologous measles virus-infected lymphoblastoid B cell target. This cytotoxicity was specific for measles virus inasmuch as these T cell clones could not lyse influenza or mumps virus-infected B cell targets. By using a panel of HLA-defined measles virus-infected B cell lines, these clones were shown to recognize measles virus in the context of HLA class II determinants. A monoclonal antibody that recognizes HLA class II monomorphic determinants (L243), but not a monoclonal antibody that recognizes HLA class I antigens (W6/32), inhibited the lysis of the autologous measles virus-infected B cell target by these T cell clones. These results demonstrate that these cytotoxic T cell clones specific for measles virus are HLA class II restricted.

Clone Cells↗

PubMed1983

SB-restricted presentation of influenza and herpes simplex virus antigens to human T-lymphocyte clones.

The HLA-D region of the human major histocompatibility complex (MHC) has been shown to be homologous to the murine I region in terms of both structure and function. Both regions encode class II MHC molecules which restrict T-lymphocyte interactions with antigen-presenting cells. We have recently described the MHC restriction and antigen specificities of human T-lymphocyte clones directed at strain A influenza virus. The majority of T-lymphocyte clones recognized antigen in the context of cell surface interaction products encoded by HLA-D/DR genes. However, a few clones recognized antigen presented by cells histoincompatible for D/DR antigens. We report here that some of these clones recognized viral antigens in association with antigens encoded by genes identical with or closely linked to the recently described secondary B-cell (SB) locus of the MHC. This is the first report that SB-restricted antigen recognition may form an integral part of normal, human immune responses.

Antigens, Viral↗

PubMed1983

Expression of T-lymphoblast-encoded HLA-DR, MT, and SB antigens on human T-B lymphoblast hybrids.

The Ia-like antigens of hybrids of the B-lymphoblastoid cell line (B-LCL) WI-L2 and a subline of the T-lymphoblastoid cell line (T-LCL) HSB were examined. Antigens of the HLA-DR and MT series were analyzed by indirect immunofluorescence with chimpanzee anti-DR sera and monoclonal antibodies, and antigens of the SB series were analyzed by primed lymphocyte typing (PLT). The WI-L2 X HSB hybrids expressed antigens of each series not found on either parent cell. In each case, the novel antigens were indistinguishable from those found on SB, a B-LCL established from the same individual as HSB, and are thus presumably HSB encoded.

Animals↗

PubMed1983

Primary and secondary MLR characterization of three allelic variants of HLA-Dw7 segregating in a single family.

Three of four parental haplotypes of a kindred from the Old Order Amish religious isolate carried HLA-DR7 and specificities of the HLA-Dw7 "cluster." Intrafamily primary and secondary mixed lymphocyte responses clearly distinguished the three Dw7-related allelic specificities. Two of the specificities fall within the Dw11 crossreacting group, designated here as Dw11 "short" (Dw11S) and Dw11 "long" (Dw11L), while the third is more closely related to Dw7. Reaction patterns in this family illustrate the complexity of antigen recognition in primary and secondary mixed lymphocyte responses and the important role played by the responder cell in generating discriminatory primed lymphocyte typing reagents.

Alleles↗

PubMed1982

Antibacterial activity of a human monoclonal antibody to haemophilus influenzae type B capsular polysaccharide.

Human splenic lymphocytes were fused with a new mutant human myeloma cell line (HFB-1) to produce hybridomas that secrete human monoclonal antibodies. A cloned hybridoma line was selected that secretes IgG antibodies reactive with Haemophilus influenzae type b polyribosylribitolphosphate (PRP) capsular polysaccharide. This human monoclonal antibody was active in an in-vitro neutrophil-mediated bactericidal assay, and provided significant protection in an animal model of H. influenzae type b disease. Human monoclonal antibody to H. influenzae type b may have prophylactic value in man, particularly in infants who do not produce protective antibody after active immunisation with PRP.

Antibodies, Monoclonal↗

PubMed1982

Characterization of human T-lymphocyte clones (TLCs) specific for HLA-region gene products.

Clones of lymphocytes, primed in vitro to HLA-DR1;Dw1, were tested for allospecific proliferation on a panel of thirty-one HLA-phenotyped stimulating cells. No clone was restimulated exclusively by cells sharing the DR1;Dw1 priming antigens and most clones were restimulated by subsets of cells bearing DR1;Dw1. Generally, positive responses were at least 20-fold higher than autologous negative controls. Peak proliferative responses occurred around 72 h and varied, depending on the stimulating cell as well as the responding clone. Selected clones were induced to proliferate only by cells incapable of forming rosettes with sheep erythrocytes. Specific proliferation by TLCs was blocked by monoclonal DR-specific antibodies, but not by monoclonal anti-Thy 1.2. Genetic studies demonstrated that TLCs detected some cell-surface determinants that are encoded by genes in linkage disequilibrium with HLA and others that may not be linked to the human major histocompatibility complex.

Antibodies, Monoclonal↗

PubMed1982

Antigen-specific human T-lymphocyte clones. Genetic restriction of influenza virus-specific responses to HLA-D region genes.

Human T lymphocytes, primed in vitro to influenza virus, were cloned by limiting dilution and expanded using medium containing interleukin 2 and feeder cells. A detailed analysis of the genetic requirements for induction of T-cell proliferation was conducted using a panel of cells from unrelated donors and two families who had previously been extensively phenotyped for HLA region antigens. Clones obtained from a Dw1, Dw3 individual required Dw1,DR1 histocompatibility for successful presentation of viral antigens by antigen-presenting cells. The antigen-presenting ability segregated with HLA-B,D,DR in an informative HLA-A/B recombinant individual. In contrast, some TLCs responded to antigen presented by cells that did not share known HLA antigens, and in one informative family, reactivity did not segregate with HLA. None of the T-cell clones reacted to allogeneic cells in the absence of antigen, suggesting that the TLCs do not bear receptors that recognize both influenza virus and alloantigen. In antibody-blocking studies, Dw1, DR1-restricted clones were blocked by all monoclonal anti-DR framework antibodies. The non-HLA-restricted TLCs were blocked by some, but not all, of the anti-DR framework monoclonal antibodies. These results confirm and extend the role of HLA-D region gene products in antigen presentation and also provide evidence that yet undefined cell interaction products, which may include hybrid structure, are able to participate in antigen-specific proliferative responses by human T cells.

Antibodies, Monoclonal↗

PubMed1982

Monoclonal antibodies specific for human polymorphic cell surface antigens. I. Evaluation of methodologies. Report on a workshop.

Five techniques, the direct and the antiglobulin enhanced cytotoxicity assays, indirect immunofluorescence, the enzyme-linked immunosorbent assay, and the radioimmunoassay, were evaluated in a workshop to determine their utility in studies of the interactions of monoclonal antibodies with HLA antigens expressed on lymphocytes. Several well-defined antibodies, both cytotoxic and noncytotoxic, were tested against well-characterized human lymphoid cells. All the methods suffer from some deficiency. The enhanced cytotoxicity assay, however, is most useful as a routine screening tool because of its ease and simplicity; whereas, the enzyme-linked immunosorbent assay is most useful when dissection of antigenic structure is sought because it yields information on the quantities of the antigenic determinants expressed on the cell surface without requiring radioactive reagents.

Antibodies, Monoclonal↗

PubMed1982

Clonal analysis of restriction antigens for human TNP-specific cytotoxic T lymphocytes.

Previous studies of populations of human TNP-specific cytotoxic T lymphocytes have shown a preference for HLA-matched, TNP-modified targets. However, substantial killing of modified targets mismatched for serologically defined HLA antigens is also observed. The present report concerns oligoclonal and monoclonal populations of TNP-specific cytotoxic lymphocytes from a single donor whose lymphocytes were primed in vitro to TNP-modified autologous lymphocytes and frozen in aliquots. Conditions for the expansion of precursors of cytotoxic cells to sufficient numbers for assay are described. Expansion required IL 2-containing supernatants and stimulator or feeder lymphocytes in great excess; PHA, present in the IL 2-containing supernatants, was not required. TNP modification of the stimulators in secondary cultures was not required but appeared to enhance activity. Oligoclonal populations showed marked preference for TNP-modified targets sharing any of 3 of the 4 HLA-A and -B antigens of the donor (Aw24, B8, Bw44) when compared with targets sharing only the 4th antigen (A1) or no antigens. Monoclonal TNP-specific populations showed marked preference for certain TNP-modified targets when tested against a panel, but the pattern often did not correspond with the serologically defined HLA-A and -B antigens. The data suggest that most or all TNP-specific cytotoxic clones are restricted in their killing patterns by determinants associated closely with but not necessarily identical to the serologically defined HLA-A and -B antigens.

Clone Cells↗

PubMed1982

Antigen-specific human T lymphocyte clones: induction, antigen specificity, and MHC restriction of influenza virus-immune clones.

Human peripheral blood lymphocytes from an HLA-Dw1,3 individual were primed in vitro with influenza A virus (A/Texas/1-77/x-49) and subsequently cloned by limiting dilution in TCGF. Of the 96 TLCs originally obtained, nine were characterized in detail. TLCs were antigen specific, responding to influenza A virus, not to influenza B, TGAL, GAT, tetanus toxoid, or KLH, and only when antigen was presented by cells unable to form rosettes with AET-treated SRBC. Presentation of antigen by unseparated PBL often resulted in significant "back stimulation," probably via production of growth factors. The MHC requirements for the induction of TLC proliferation were analyzed. Of four representative clones analyzed, three required Dw1;DR1 compatibility for successful presentation of viral antigens by a panel of antigen-presenting cells. In contrast, one TLC showed an unusual pattern of response that could not be correlated to a particular HLA haplotype. Monoclonal anti-T cell antibody analysis of the surface phenotype of two TLCs maintained in continuous culture for 5 mo indicated that they were OKT3+, 4+, and 8-, consistent with an inducer/helper phenotype. To confirm the clonal nature of TLCs, data on the functional properties of TLC subclones are also presented.

Clone Cells↗