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Biomedical subjects

C R Parish

Publications and source records attributed to C R Parish.

At least 163 records · Page 9Linked to original sources
PubMed1977

Ontogeny of the antibody-forming cell line in mice. IV. Appearance of cells bearing Fc receptors, complement receptors, and surface immunoglobulin.

The ontogeny of Ig, FcR, and CR-bearing cells in liver and spleen has been followed by using rosetting procedures. These studies demonstrated a sequential appearance of surface receptors during development. Two types of Ig+ cells could be distinguished according to their rosette morphology and adherence to carbonyl iron: 1) an adherent cell which bound few erythrocytes was found predominantly in fetal liver from 13 days gestation and 2) a nonadherent cell which bound larger numbers of erythrocytes appeared in small numbers in fetal liver from day-16 gestation but represented the major Ig+ cell type after birth. Changes in the proportions of receptor-bearing populations occurred at two particular periods during ontogeny. The first was at birth, where an increase in the proportion of FcR+ cells occurred and the proportion of type 2 Ig+ cells rose rapidly. This probably represented the first appearance of FcR+ B lymphocytes even though cells bearing FcR were detected in fetal liver of all ages (days 12 to 18). The second period was around 10 days after birth when the proportion of Ig+ cells again increased concomitant with the appearance of CR+ nonadherent cells.

Aging↗
PubMed1977

Appearance of non-specific suppressor T cells during in vitro culture.

It was found that when normal mouse spleen cells were cultured for 4 days they were capable of non-specifically suppressing the in vitro antibody response of non-precultured spleen. The suppression was mediated by a subpopulation of viable, non-adherent, T lymphocytes with the surface phenotype Ly-1+, Ly-2- and Ia-. Furthermore, it appeared that the suppressor cells were responding to foetal calf serum antigens present in the tissue culture medium and were subsequently inactivating either B lymphocytes or accessory cells required for antibody formation, which had passively absorbed these antigens.

Animals↗
PubMed1976

Regulation of the immune response. I. Suppression of delayed-type hypersensitivity by T cells from mice expressing humoral immunity.

The ability of horse red blood cell (HRBC)-specific T cells from mice expressing humoral immunity to suppress the induction of HRBC-specific delayed-type hypersensitivity (DTH) was investigated. The transfer of Ig-negative spleen cells, from mice injected 4 days previously with HRBC, completely suppressed the development of DTH in mice treated with cyclophosphamide and sensitized with HRBC. The suppressor cell was found to be lysed by treatment with anti-theta serum and complement. Furthermore, hemocyanin-specific immune T cells were able to suppress the DTH induced to HRBC, provided these two antigens were coupled together. These studies suggest that T cells present under conditions were humoral immunity is induced can suppress DTH and that such cells play an important role in the regulation of the immune response.

Animals↗
PubMed1976

Involvement of cells with 'B' properties in development of T helpers.

Cells bearing Ig on the membrane, fractionated from either 17 day embryonic livers or from normal adult bone marrow, when transferred to splenectomized-irradiated mice, lead to development of helper cells in the thymus of the recipients. The helper function was expressed when the recipients were stimulated with flagellin-MON and the thymus cells were cultured together with anti theta treated spleen cells and stimulated with DNP-MON. The response to DNP was not enhanced when the irradiated mice were inoculated with non Ig bearing cells. Helper activity was related to cells which were eliminated with anti theta antibodies and did not have detectable Ig. Hence, cells with 'B' properties may be involved in development of T helpers.

Animals↗
PubMed1976

Evidence that carrier-specific B cells play a role in cellular collaboration.

Evidence is presented showing that carrier-specific B cells play a significant role in inducing an anti-hapten antibody response to the thymus-dependent antigen, dinitrophenylated monomeric flagellin (DNP-MON), both in vivo and in vitro. Inactivation of carrier-specific B cells by (125I) polymeric flagellin (POL) suicide decreased the anti-DNP IgM response by 40%-50% and reduced the anti-DNP IgG response by 85%-90%. Several lines of evidence established that the suicide procedure eliminated carrier-specific B cells rather than carrier-specific T (helper) cells.

Animals↗
PubMed1976

Carrier-specific B cells play a role in the production of an antigen-specific T-cell-replacing factor.

An in vitro anti-hapten response to dinitrophenylated monomeric flagellin (DNP-MON) was used to examine the ability of T cells to collaborate with B cells across a cell-impermeable Millipore membrane. It was found that T cells alone were not able to collaborate with B cells across the membrane. However, B and T cells together produced a T-cell-replacing factor that passed through the membrane and partially restored the antibody response of B cells cultured beneath the membrane. Production of the factor was abolished when carrier-specific B cells were inactivated by [125I]polymeric flagellin (POL) suicide. The T-cell-replacing factor was shown to be nondialysable and antigen-specific. It was also demonstrated that macrophages were required for production of the specific T-cell-replacing factor but that the action of the factor on B cells macrophage-independent.

Animals↗
PubMed1976

Inflammatory process in murine lymphocytic choriomeningitis is maximal in H-2K or H-2D compatible interactions.

Capacity to transfer adoptively fatal lymphocytic choriomeningitis (LCM) to immunosuppressed, virus-infected recipients is a property of H-2 compatible, non-Ig-bearing virus-immune lymphocytes. Severe meningitis is recognized when donor and recipient share at least one allele at either H-2K or H-2D. Presence of unshared H-2 genes is not obviously inhibitory, and identity at the immune response (Ir) region of the H-2 gene complex is neither sufficient nor necessary. The same constraint applies to cytotoxic T cell activity in vitro; lymphocytes and virus-infected targets must be compatible for a minimum of one allele mapping at H-2K or H-2D. The present findings thus support the concept that populations of T cells, which are cytotoxic in vitro, also mediate inflammatory process in vivo and are a major, if not the only, effector population in murine LCM.

Animals↗
PubMed1975

A procedure for removing red cells and dead cells from lymphoid cell suspensions.

A procedure is described for simultaneously removing red cells and dead cells from lymphoid cell suspensions, based on the observation that when populations of lymphoid cells are centrifuged on a mixture of Isopaque/Ficoll, dead cells and red cells sediment whereas viable cells float. The technique very efficiently removed red cells from a wide range of lymphoid cell suspensions and eliminated lymphocytes killed by mechanical stress, by antibody and complement and by prolonged tissue culture. The depletion of red cells was greater than 99% and the recovery of viable lymphocytes usually greater than 90%, the resulting cell suspensions being around 95-100% viable. The immunological activity of B cells, helper T cells and cytotoxic T cells virtually unimpaired by the separation procedure.

Animals↗
PubMed1975

Effects of thymus-independent (B) cells and the H-2 gene complex on antiviral function of immune thymus-derived (T) cells.

Antiviral activity in vivo exerted by ectromelia virus-immune spleen cells transferred to ectromelia-infected recipients and cytotoxicity against virus-infected target cells in vitro were both properties of non-immunoglobulin (Ig)-bearing cells (which included T cells). Ig-bearing cells, including thymus-independent (B) cells and antibody-secreting cells, were much less active in vivo when injected alone and tended to block rather than amplify the effect triggered by T cells. Ig-bearing cells were also slightly active in vitro, possibly because some T cells have detectable Ig. Antiviral effects in cell transfer experiments were seen only when immune cell donors and infected recipients shared the same H-2 gene complex. These results are consistent with the hypothesis that the T cell response to ectromelia infection is directed against specific virus-induced change(s) in antigen(s), specified by gene(s) in the H-2 complex, which appear in virus-infected cells.

Animals↗
PubMed1975

Separation and functional analysis of subpopulations of lymphocytes bearing complement and Fc receptors.

A highly versatile procedure is described in this review which can be used to separate and obtain in pure form subpopulations of lymphoid cells which express different cell surface structures. The method is based on the observation that when rosetting and non-rosetting leukocytes are centrifuged on a cushion of Isopaque/Ficoll, the rosetting leukocytes and red cells sink whereas the non-rosetting leukocytes float. Thus, any subpopulation of leukocytes can be separated providing they can be identified by rosetting. The earlier sections of this review describe the method, its efficiency of separation and its advantages compared with other fractionation procedures. Subsequent sections describe experiments in which the procedure was specifically applied to separating Fc receptor (Fc+) and complement receptor (CR+) lymphocytes. On the basis of these two receptors it was possible to subdivide T and B lymphocytes into distinct subpopulations. Four subclasses of B lymphocytes were identified in mouse spleen (Fc+CR+,Fc+CR-,Fc-CR+ and Fc-CR-) and two subclasses of T cells were also detected (Fc+ and Fc-). The functional relevance of these subpopulations of lymphocytes was examined. It was found that in all cases examined, antigens could successfully activate CR+ B cells to produce antibody. However, only polymeric antigens, whether T-dependent or T-independent, were capable of triggering CR- B cells to synthesize antibody. Furthermore, preliminary experiments suggest that Fc receptors are present on functional B cells and helper T cells but are not expressed on cytotoxic T cells. On the basis of these results it is proposed that complement receptors on B lymphocytes provide an additional binding site which stabilizes the union between the antigen-specific receptors and soluble antigen. In contrast, due to their multi-determinant nature, polymeric antigens can avidly bind to B cells without involvement of the complement receptors. The possibility of Fc receptors playing a similar role in stabilizing the interaction of antigen with specific receptors on lymphocytes, particularly on T helper cells, is also discussed.

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