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Biomedical subjects

R R Rich

Publications and source records attributed to R R Rich.

At least 109 records · Page 6Linked to original sources
PubMed1983

Differences in maternal lineages of New Zealand Black mice defined by restriction endonuclease analysis of mitochondrial DNA and by expression of maternally transmitted antigen.

Two substrains of New Zealand Black (NZB) mice have been compared with respect to expression of a maternally transmitted cell surface antigen, Mta, defined by cloned cytolytic T cells, and for restriction enzyme polymorphisms of mitochondrial DNA (mtDNA). These independent assays of maternal cytoplasmic inheritance provide strong evidence for genetic contamination of the NZB/BlPt substrain (NZB/Bl mice from Michael Potter's separate colony at the National Institutes of Health), in which the typical NZB immunologic abnormalities are at least partially ameliorated. The decisive data are the restriction enzyme maps of mtDNA for NZB/BlPt, which were identical with those of the common "old inbred" strains and quite different from those of NZB/BlN (NZB/Bl mice from the breeding facility at the National Institutes of Health). It is probable that the contamination of the NZB/BlPt substrain is related to phenotypic changes in their autoimmune state. More interestingly, the data are consistent with, although they do not prove, involvement of the mitochondrial genome in expression of a cell surface molecule.

Animals↗
PubMed1983

Antigen presentation to human T lymphocytes. II. Requirements for Mac-120+ macrophages and responsiveness to interleukin 2.

To investigate mechanisms by which antigen, macrophages, and interleukin 2 (IL2) participate in the induction of secondary T-cell proliferative responses, trinitrophenyl (TNP) was presented in three distinct modes: (i) TNP-modified peripheral blood mononuclear cells (TNP-PBMC), (ii) TNP-PBMC cell sonicates, and (iii) TNP-ovalbumin (TNP-OVA). Stimulators were depleted of Mac-120+ macrophages using Mac-120 monoclonal antibody plus complement. TNP-Mac-120 macrophages stimulated primed T cells nearly as well as TNP-unfractionated macrophages (which were about 40% Mac-120+). In contrast, although greater than 70% DR+, Mac-120- macrophages plus either TNP-OVA or TNP-PBMC sonicate elicited minimal responses compared to unfractionated macrophages plus antigen. After 21-28 days of in vitro priming, macrophage-depleted T cells were not stimulated to proliferate by either IL2 alone or sonicates alone. IL2 plus TNP-PBMC sonicates, however, stimulated significant proliferation. Furthermore, this response was considerably greater than that to IL2 plus either TNP-T cell sonicates or TNP-mouse spleen sonicates. Thus, the Mac-120+ macrophage population may have an important antigen-presenting and/or accessory function in the stimulation of primed T cells by soluble or particulate antigen, although it is unnecessary for responses to intact TNP-Ia+ PBMC. In addition, the data suggest that Ia+ sonicates alone may suffice for induction of IL2 responsiveness, but not for endogenous IL2 production and subsequent proliferation by primed T cells.

Antigens, Surface↗
PubMed1983

Characterization of determinants encoded by four Qa-1 genotypes and their recognition by cloned cytotoxic T lymphocytes.

The alloantigens encoded by the four defined Qa-1 genotypes were characterized by cloned cytotoxic T lymphocyte (CTL) recognition. CTL clones specific for Qa-1a- and for Qa-1b-encoded antigens were generated. Examination of the reactivity of these clones with target cells from H-2r and H-2f strains provided the strongest evidence to date for the designation of the Qa-1c and Qa-1d genotypes, respectively, for these strains. Qa-1c-encoded antigens were recognized by most, but not all CTL clones that specifically lysed Qa-1b target cells, thus demonstrating that these antigens lack a Qa-1b-associated determinant. Similarly, Qa-1d encoded antigens were recognized by only half of the CTL clones that lysed Qa-1a target cells. In addition, one CTL clone that was cytotoxic for Qa-1b and Qa-1c target cells demonstrated low affinity, cross-reactive recognition of a Qa-1d encoded antigen. The reactivity patterns of the monoclonal CTL defined five Qa-1 determinants. Qa-1a, Qa-1b, and Qa-1d each encode multiple determinants. Two Qa-1d encoded determinants probably reside on different molecular species. Finally, large numbers of CTL clones tested on panels of target cells indicated that the Qa-1a strains expressed indistinguishable Qa-1.1 antigens and the Qa-1b strains expressed indistinguishable Qa-1.2 antigens. Therefore, additional polymorphism among these strains is improbable.

Animals↗
PubMed1983

The Qa-1 alloantigens. II. Evidence for the expression of two Qa-1 molecules by the Qa-1d genotype and for cross-reactivity between Qa-1 and H-2K.

The nature of cell surface determinants detected by Qa-1-specific alloantisera and cytotoxic T lymphocytes (CTL) in mice of the H-2f, Qa-1d genotype was investigated. The H-2f, Qa-1d strains A.CA and B10.M express both Qa-1a and Qa-1b encoded alloantigenic determinants (Qa-1.1 and Qa-1.2, respectively), as defined in the prototypic A (or B6-Tlaa) and C57BL/6 (or A-Tlab) strains, respectively. Both anti-Qa-1.1 and -Qa-1.2 sera immunoprecipitate 46K m.w. glycoproteins from H-2f, Qa-1d strains. In addition to 46K m.w. proteins, anti-Qa-1.1 sera, but not anti-Qa-1.2 sera, precipitate 55 to 75K m.w. proteins; the nature of these proteins and their relationship to Qa-1 is unclear at present. Sequential immunoprecipitation experiments and the analysis of several recombinant strains revealed that anti-Qa-1.1 sera also cross-react with a 46K m.w. H-2f-encoded alloantigen, probably H-2Kf. Both Qa-1.1 and the non-Qa-1.1 cross-reacting determinants were detected by polyclonal anti-Qa-1a CTL on the Qa-1d strains. The Qa-1a encoded but not the cross-reacting determinants were detected by a cloned anti-Qa-1a CTL line. Sequential immunoprecipitation experiments on the recombinant strains B6.AC2 and B10.M(17R), which are Qa-1d but not H-2Kf, revealed that the Qa-1.1 and Qa-1.2 determinants do not reside on the same molecule. Furthermore, although Qa-1b-encoded determinants were detected on these strains with anti-sera and with bulk CTL cultures, cloned anti-Qa-1b CTL lines thus far analyzed have failed to react with Qa-1d targets, indicating that some but not all of the prototypic Qa-1b-encoded determinants are expressed by the Qa-1d strains.

Animals↗
PubMed1982

Primary cell-mediated lympholysis response to a maternally transmitted antigen.

Mta-specific cytotoxic T lymphocyte (CTL) can be generated in primary cultures of (NZB X B10.D2)F1 spleen cells with H-2-compatible BALB/c stimulator cells. The CTL lyse reciprocal Mta+ (B10.D2 X NZB)F1 as well as H-2-disparate targets, such as B10, B6, and B6-Tlaa; they do not lyse targets from NZB or any F1 hybrid of an NZB mother. The lysis of 51Cr-labeled B10 targets is completely inhibited by unlabeled targets from Mta+ (B10.D2 X NZB)F1, but not from the reciprocal Mta- F1, thus demonstrating H-2-unrestricted lysis of Mta.

Animals↗
PubMed1982

Qa-1-associated antigens. IV. Evidence for additional Qa-1 polymorphism defined biochemically and by cytotoxic T lymphocyte recognition.

Qa-1-specific, H-2-unrestricted cytotoxic T lymphocytes (CTLs) generated from reciprocally immunized B10.BR (H-2k, Qa-1a) and CBA (H-2k, Qa-1b) mice, and immunoprecipitation of cell surface Qa-1 were used to examined Qa-1 region determinant expression by H-2r and H-2f mice. The H-2b, Qa/Tla congenic mice B6-Tlaa and C57BL/6J (B6) were used as prototype Qa-1a and Qa-1b strains, respectively. Cells from H-2r strains expressed determinants recognized by B10.BR anti-CBA CTLs. Reciprocal cold target inhibition of cytolysis demonstrated that some, but not all, Qa-1b-associated determinants recognized on B6 were expressed by H-2r, Qa-1c cells. In contrast, cells from H-2f strains expressed Qa-1 determinants recognized by both B10.lBR anti-CBA and by CBA anti-B10.BR CTLs. Cold target inhibitions indicated that the H-2f, Qa-1d cells expressed some, but not all, Qa-1a-associated antigens recognized on B6-Tla and did not express the same Qa-1b-associated antigens as B6. Furthermore, H-2f strains expressed cell surface antigens immunoprecipitable by antisera specific for both Qa-1a and Qa-1b-encoded determinants; these molecules were of the same molecular weight as those immunoprecipitated from B6 and B6-Tlaa. These data suggest that CTLs and antisera define the same, closely related Qa-1 determinants encoded by a polymorphic locus.

Animals↗
PubMed1981

Antigen presentation to human T lymphocytes. I. Different requirements for stimulation by hapten-modified cells vs. cell sonicates.

We have investigated the cellular and antigenic requirements for incubation of secondary proliferative responses by human T lymphocytes. Two distinct properties of antigen-presenting peripheral blood mononuclear cells were studied: (a) the ability for appropriate cell surface constituents to construct an immunogenic moiety, and (b) the ability to present similar antigenic determinants when they are not covalently bound. Only Ia+ hapten-modified cells were effective stimulators. In contrast, both Ia+ and Ia- cell sonicates could stimulate secondary proliferative responses, but only in the presence of an accessory cell. This accessory cell was present in Ia+ macrophage, but not in Ia+ non-T lymphocyte, preparations. In contrast, macrophages or soluble factors produced by macrophages were not required for primed T cells to undergo hapten-specific proliferation in response to hapten-modified Ia+ stimulator cells. Thus, although all Ia+ cells tested can stimulate primed cells to proliferate, not all Ia+ cells can function as accessory cells for responses to sonicates. This may reflect the unique ability of a subpopulation(s) of Ia+ cells to bind or process sonicates or soluble antigens for appropriate recognition by primed T cells.

Antigens, Surface↗
PubMed1981

The Qa-1 alloantigens. I. Identification and molecular weight characterization of glycoproteins controlled by the Qa-1a and Qa-1b alleles.

Splenocytes from the Qa-Tla congenic strain pairs, A and A-Tlab or B6 and B6-Tlaa, were biosynthetically labeled with 3H-amino acids or cell surface labeled with 125I. Membrane proteins were solubilized with detergent and chromatographed on lentil lectin-Sepharose, and the resulting adherent pools were immunoprecipitated with antisera specific for determinants controlled by the Qa-1a and Qa-1b alleles, Qa-1.1 and Qa-1.2, respectively. Polyacrylamide gel electrophoresis analysis of immunoprecipitates from biosynthetically labeled preparations indicated that both the Qa-1.1 and Qa-1.2 antigens were glycoproteins with a m.w. of approximately 46,000. Qa-1.2 isolated from radioiodinated spleen cells similarly had a m.w. of 46,000. Analysis of anti-Qa-1.1 precipitates from 125I-labeled Qa-1a lysates demonstrated in addition to the 46,000 m.w. component, an electrophoretically heterogeneous protein or series of proteins in the m.w. range of 55,000 to 75,000. The specificity of these reactivities was shown by both antiserum and genetic control immunoprecipitations. These findings indicate that the Qa-1.1 and Qa-1.2 antigens are cell surface glycoproteins that are distinct from the TL antigens, and suggest a further complexity at the Qa-1--Tla locus.

Alleles↗
PubMed1981

Cellular and antigenic requirements for production of mixed leukocyte reaction suppressor factor.

When murine spleen cells, alloantigen-sensitized previously in vivo, are incubated with spleen cells bearing the sensitizing alloantigens, a supernatant factor is produced that inhibits 3H-thymidine incorporation by responding lymphocytes in the mixed leukocyte reaction. This study evaluates the cellular and antigenic requirements during restimulation for elaboration of this suppressor factor, MLR-TsF. BALB/c spleen cells, sensitized to C57BL/6 (B6) alloantigens in vivo, produced MLR-TsF when cultured with B6 spleen cells in vitro, despite depletion of Sephadex G-10-adherent cells from factor-producing cells, stimulator cells, or from both populations. T cells were not required within the stimulating population, but a requirement for viable stimulator cells was demonstrated when heat-killed or glutaraldehyde-fixed stimulator cells failed to induce MLR-TsF production. The alloantigenic requirements for MLR-TsF production were addressed by 2 approaches. Treatment of stimulator cells with appropriate anti-I region antisera and complement did not affect MLR-TsF production, demonstrating that an absolute requirement for cells expressing I region determinants did not exist. However, spleen cells primed against entire H-2 haplotype differences produced significant quantities of MLR-TsF when they were restimulated with spleen cells homologous to the priming cells in only the I region, in the K and D regions, or in the D region alone. The additive nature of subregion-specific restimulation suggests that distinct subpopulations of K, I, and D region-specific MLR-Ts comprise the MLR-Ts population primed to entire H-2 haplotype differences.

Animals↗
PubMed1980

Role of Ia-positive cells in induction of secondary human immune responses to haptens in vitro.

We have described techniques for induction of primary and secondary human immune responses in vitro to lymphoid cells modified with trinitrophenyl, dinitrophenyl, and fluorescein isothiocyanate. Optimal secondary proliferative responses required the presentation of hapten on stimulator cells that shared HLA-D region determinants with the responder cell and/or the original stimulator cell. In contrast, hapten-specific cytotoxic responses assessed on modified allogeneic targets with no detected HLA homology with the responder were comparable in magnitude to those detected on modified autologous targets. Furthermore, secondary proliferative, but not cytotoxic, responses required presentation of Ia+ stimulator populations. Modified B cells, surface-immunoglobulin-negative, non T cells (null-cells), and Ia+ activated T cells all induced proliferative responses at least as effectively as equal numbers of hapten-conjugated macrophage/monocytes. Conversely, Ia(-) null cells and macrophages were entirely unable to stimulate. The data thus suggest that for proliferative responses, primed human T cells respond to modified lymphoid cells only when hapten is recognized in the context of Ia molecules.

Cytotoxicity, Immunologic↗
PubMed1979

Primary in vitro cytotoxic response of NZB spleen cells to Qa-1b-associated antigenic determinants.

We have shown that cytotoxic lymphocytes generated in primary cultures of NZB spleen cells with H-2-identical BALB/c or B10.D2 stimulator cells exhibit specificity for Qa-1b-associated antigenic determinants. This unidirectional cytotoxicity constitutes the initial demonstration of a primary in vitro response to antigens of the Qa-Tla system. Such responses do not require H-2 homology between effector and target cells in the assay system. In fact, when H-2Dd homologous target cells were employed there was little, if any, evidence for development of primary H-2-restricted responses to minor locus histocompatibility antigens or viral antigens. In view of the recently defined role of Qa-1+, Ly-1,2,3+ cells as regulators of antibody responses, and of the deficiency of such cells in NZB mice, the observation of hyperreactivity for determinants of this system may be relevant to the development of autoimmunity in these animals.

Animals↗