PubMed Health⌕ Search

Biomedical subjects

R M Gorczynski

Publications and source records attributed to R M Gorczynski.

At least 181 records · Page 10Linked to original sources
PubMed1977

Heteroantisera prepared against B lymphocytes at different stages of differentiation. I. Preparation of sera and cytotoxicity to lymphoid cells from different organs.

A routine method is described whereby anti-mouse B-cell antisera can be raised in rabbits. As judged by trypan blue dye exclusion these sera have negligible cytotoxicity to murine T lymphocytes but seem to detect differences in non-T lymphocytes in different organs. By sedimentation analysis some of the sera may detect (in addition to mature B cells) earlier precursors of mature B lymphocytes in bone marrow and spleen.

Animals↗
PubMed1977

Heteroantisera prepared against B lymphocytes at different stages of differentiation. II. Functional analysis of cytotoxicity to different B-cell populations.

Functional studies on heteroantisera raised against mouse B cells in rabbits suggest a correlation between thymus-independent B cells and LPS-responsive B cells, and differences in either from thymus-dependent B cells. Furthermore it seems possible to follow B-lymphocyte differentiation from antigen-uncommitted precursors to antigen committed immature B cells to mature B lymphocytes by the loss and acquisition of surface markers distinguished by these heteroantisera. Additional evidence is provided that there are distinctive antigenic differences between antibody forming cells raised from the same B-cell source after in vivo or in vitro immunization.

Animals↗
PubMed1976

Control of the immune response: role of macrophages in regulation of antibody-and cell-mediated immune responses.

The ability of peritoneal macrophage subpopulations, separated into different classes according to their size, to reconstitute antibody or cellular immune responses in macrophage-depleted spleen cells has been investigated. Data are presented to show that whether reconstitution is by "normal" or "activated" macrophages, be they syngeneic or allogeneic to the lymphocyte source, different populations reconstitute antibody and cellular immunity. Reconstitution is in general by two classes of macrophages, small and large. The former seem to reconstitute only if syngeneic to the responding lymphocyte pool, whereas large macrophages reconstitute immune responses from allogeneic lymphocytes as well as syngeneic lymphocytes. Evidence is also presented to show that syngeneic large macrophages can determine the type of immune response reconstituted; that is, with greater numbers of large cells only cytotoxic responses (and not T-dependent antibody formation) were reconstituted and vice versa.

Animals↗
PubMed1976

Autoreactivity developing spontaneously in cultured mouse spleen cells. III. Inhibition of anti-embryo cytotoxicity in male T lymphocytes by female non-T cells.

Cultured female spleen cells develop less cytotoxicity to embryo-associated antigens than do cultured male spleen cells. This difference is less pronounced if the cells are treated before culture with a specific hetero-anti-B cell antiserum. Female non-T cells (especially from primiparous animals) can decrease the spontaneously developing T-cell cytotoxicity in male splenic T lymphocytes upon culture. By artificially manipulating the T cell: non-T cell ratio in the spleen population prior to culture, it seems one can alter the type of cytotoxic mechanism (to embryo-associated antigens) which develops in the cultures.

Animals↗
PubMed1976

Autoreactivity developing spontaneously in cultured mouse spleen cells. II. Comparison of cytotoxicity of cultured male and female spleen cells.

Male and female spleen cells were compared before and after culture for their cytotoxicity to autologous-embryo fibroblasts. Cultures of male cells developed significantly greater reactivity than cultures of female cells. Moreover, while the cytotoxicity derived from cultures of male cells was totally abolished by treatment of effector cells with a mouse anti-T cell antiserum, such an antiserum had less affect on the effector cells of female mouse cultures.

Animals↗
PubMed1976

Autoreactivity developing spontaneously in cultured mouse spleen cells. I. Evidence that cytotoxicity is directed against embryo-associated antigen.

We have investigated the ability of male-mouse spleen cells before and after culture in the absence of deliberate antigenic stimulation to show specific cytotoxicity to syngeneic embryo-fibroblast cells. The data suggest that cytotoxicity which develops spontaneously in such spleen cell cultures is directed primarily against embryo-associated antigens. Syngeneic Con-A-stimulated spleen cells, which, unlike fresh normal spleen cells, are also lysed by rabbit anti-mouse embryo antisera, are also a suitable target to demonstrate spontaneously developing cytotoxicity.

Animals↗
PubMed1975

Cell-mediated immunity to moloney sarcoma virus in mice. I. Analysis of antigens responsible for lymphocyte stimulation in regressor mice.

Purified viruses, viral antigens, and cell extracts have been tested for their ability to stimulate protein synthesis by MSV-M-1 regressor spleen cells from BALB/c mice. Immune, but not normal cells, responded to MSV-M, but not to MSV-G virus-1, and to the type-specific viral envelope glycoprotein from MSV-M virus. Extracts of mouse embryo fibroblasts transformed by either MSV-M or MSV-G, however, specifically stimulated MSV-M regressor spleen cells. Cells stimulated by different antigens, and by phytohaemagglutinin, had the same sedimentation profile and were identified as T-lymphocytes.

Animals↗
PubMed1975

Cell-mediated immunity to Moloney sarcoma virus in mice. II. Analysis of antigenic specificities involved in T lymphocyte-mediated in vivo rejection of murine sarcoma virus-induced tumors.

Sublethally irradiated BALB/c mice innoculated with Moloney sarcoma virus (MSVm) develop progressively growing tumors and die within 30 days of virus innoculation. These animals can be protected from tumor progression (and death) by innoculation of small numbers of MSV-immune T lymphocytes from MSV-M innoculated (but unirradiated) animals. T lymphocytes in these donor animals have been shown to express immunity to a variety of viral and virally-induced antigens. We have investigated whether immunity to any one of these antigens was critically important in leading to protection of the irradiated animals by sensitizing normal T lymphocytes in vitro to different viral antigens and examining the ability of these sensitized cells to protect the irradiated recipients. Data is presented to show that cells sensitized in vitro to MSV-transformed fibroblasts, and to purified antigens with group specificity, but not to viral envelope antigens, or whole virus, are capable of protecting the irradiated MS innoculated animals.

Animals↗
PubMed1975

Immunity to murine sarcoma virus induced tumours. IV. Direct cellular cytolysis of 51Cr labelled target cells in vitro and analysis of blocking factors which modulate cytotoxicity.

The antigen specific cell mediated cytotoxicity of MSV immune spleen lymphocytes to 51Cr labelled murine lymphoma cells was wholly abolished by pretreatment of the spleen cells with anti-theta antibody and complement. Early during the immune response to MSV the cytotoxic acitivity was inhibited by incubation of immune lymphocytes with "late progressor" or "early regressor" serum. Immune lymphocytes at later times were more refractory to such inhibition by serum blocking factors. Although unfractionated cytotoxic lymphocytes, irrespective of the time after MSV infection at which they were tested, were inhibited by soluble tumour associated antigen (TAA), a subpopulation of cytotoxic T cells was identified which was inhibited neither by antigen nor serum.

Animals↗
PubMed1974

Separable populations of activated thymus-derived lymphocytes identified in two assays for cell-mediated immunity to murine tumor allografts.

The immune response of C57BL mice to a DBA/2 tumor allograft has been assessed in two assays of cell-mediated immunity, the in vitro lysis of (51)Cr-labeled target cells and the antigen-mediated inhibition of macrophage migration. Both assays were shown to be measuring a T-cell-mediated reaction. Three types of experiments suggested that distinct subpopulations of T cells mediate these reactions. The tissue distributions of these activities was distinctive; both activities were present in spleens from i.p. immunized mice, but only macrophage migration inhibition activity was found in the peripheral lymph nodes (PLN) of such mice. Adoptive transfer of immune spleen cells into irradiated syngeneic recipients revealed that while a substantial amount of migration inhibition activity could subsequently be found in PLN, cytotoxic activity was found predominantly in the spleens of these adoptive hosts. Velocity sedimentation analysis of immune cells 14 days after i.p. immunization indicated that while the majority of cytotoxic activity was associated with small and medium lymphocytes, the majority of migration inhibition activity was associated with medium and large lymphocytes. In addition, normal spleen cells were fractionated by velocity sedimentation immediately before allosensitization in vitro. Subsequent analysis of the sensitized fractions revealed that the activity profiles for cytotoxicity and macrophage migration inhibition were not coincident. The implications of these observations are discussed.

Animals↗
PubMed1974

Immunity to murine sarcoma virus induced tumours. 3. Analysis of the cell populations involved in protection from lethal tumour progression of sublethally irradiated, MSV inoculated, mice.

A comparison was made between the cells responsible for demonstrable activity against MSV antigens, using both in vivo and in vitro assays. Similar cells (in terms of size and sensitivity to anti-theta serum) were detected in both assays. However, while lymphoid cells from animals at all stages post-MSV infection were active in protecting irradiated mice from the lethal effect of induction of MSV sarcomata, cells from animals at early stages post-MSV infection (when the tumour was in a progressive phase of growth) were not active in the in vitro assay. By manipulation of the in vivo assay conditions a situation was observed in which cells from "progressor animals" were able to suppress both the in vitro and in vivo activity of regressor lymphoid cells. The potential physiological role of this cell type is disussed.

Animals↗