Biomedical subjects

R M Gorczynski

Publications and source records attributed to R M Gorczynski.

At least 127 records · Page 7Linked to original sources

PubMed1985

Immunization of susceptible BALB/c mice against Leishmania braziliensis. I. Resistance induced using as immunogen adherent or nonadherent cells from infected mice.

Strategies to produce resistance to infection with Leishmania braziliensis in BALB/c mice are described. Mice infected with virulent parasites were used as spleen cell donors (adherent/nonadherent cells) with which to immunize naive recipients which were themselves later challenged with the organism. Immunization with both adherent and nonadherent spleen cells (but not serum) in the presence of adjuvant led to protection. In the former case it seems that an immunogenic form of parasite antigen presented in the context of MAC-1+ adherent cells was responsible. In contrast immunization with nonadherent spleen cells depended upon the presence of Thy-1.2+ Lyt-1+ cells in the spleen cell preparation from infected animals. Immunization with adherent cells, but not with nonadherent cells, led to the development of a population of Thy-1.2+ spleen cells capable of adoptively transferring resistance to naive mice.

Adjuvants, Immunologic↗

PubMed1985

Immunization of susceptible BALB/c mice against Leishmania braziliensis. II. Use of temperature-sensitive avirulent clones of parasite for vaccination purposes.

Avirulent clones of Leishmania braziliensis were produced by treatment of parental parasite stock with the mutagen N-methyl-N'-methyl-N'-nitro-N-nitrosoguanidine and selection for growth at 19 degrees C. These clones have a clear preference for infection and growth in vitro at 19 degrees C rather than the normal 28 degrees C. In addition, they can be used to vaccinate naive mice successfully against growth of the parental parasite clones. Immunity can be adoptively transferred from vaccinated mice by Lyt-1+ cells from immunized animals.

Animals↗

PubMed1985

Graft-versus-host disease in murine bone marrow transplantation. I. Modification of GVHD by preimmunization of recipients with spleen cells of primary recipients undergoing GVHD.

Lethally irradiated (1000 rad) CBA/J mice were transplanted with anti-Thy 1 treated BALB/c bone marrow. Under these conditions, we uniformly observed the development of pathology suggestive of acute graft-vs.-host disease (GVHD), i.e. weight loss, diarrhoea, hypogammaglobulinemia and thymic hypoplasia. If, 2 wk before irradiation, the recipients were preimmunized with spleen cells taken from mice undergoing acute GVHD, these symptoms were avoided. Instead, such animals seemed to show long term survival either with or without signs of chronic GVHD (hypergammaglobulinemia, splenomegaly, lymphoid hyperplasia). The ability to show long term survival with bone marrow allografts was dependent upon successful immunization of the recipient mice. Long term survivors contain a splenic population not bearing detectable host MHC antigens, which can elicit a memory anti-host cytotoxic response from a population of quiescent donor lymphocytes previously immunized in vitro against host MHC antigens.

Animals↗

PubMed1985

Graft-versus-host disease in murine bone marrow transplantation. II. Modulation of acute and chronic GVHD in mice receiving bone marrow allografts pretreated with immunosuppressive factor derived from a human T cell line.

BALB/c bone marrow treated with monoclonal anti-Thy 1.2 antibody and complement is unable to produce prolonged hemopoietic repopulation and survival when transplanted to lethally-irradiated allogeneic CBA recipient mice. Preincubation of the antibody treated bone marrow cells with an immunosuppressive factor (SAF) derived from a 6-thioguanine resistant cell line, itself derived from the human T cell line CEM, in contrast, allowed those bone marrow cells to produce a state of chimerism and long term survival. Parameters designed to gauge the degree of graft-versus-host reactivity (GVHR) in these animals suggested that acute GVHR was abolished with this procedure. Moreover, defining chronic GVHD as associated with abnormally high spontaneous proliferation of splenic cells, elevated anti-host mixed lymphocyte reactivity, or elevated serum immunoglobulin levels (in all cases when compared with the syngeneically repopulated BALB/c----BALB/c), our data suggest that preincubation with SAF modified chronic GVHD also.

Acute Disease↗

PubMed1985

A role for self-recognizing T cells in the regulation of antibody-forming and cell-mediated cytotoxic responses in the mouse.

Mitogen- or antigen-activated murine spleen and thymus cell blasts have been used as inducer cells to stimulate production of suppressor T cells (Ts) in autologous mixed leucocyte culture. Ts cells were induced in an MHC-restricted fashion and produced suppression of cell-mediated lympholysis and antibody synthesis from fresh spleen cells sharing MHC haplotypes with the Ts pool. Ts were Thy 1+, Lyt 1+ cells. Induction of Ts depended upon expression of class II MHC antigens on stimulating cells, but the level of Ts induced by different populations of suppressor inducer cells was not correlated with the level of Ia antigen expression. Activity of suppressor inducer cells was correlated with the functional activity of the inducer pool. The data are interpreted to favour a model in which Ts are induced by associative recognition on stimulator cells of class II MHC antigens and lymphocyte recognition receptors as nominal antigen (i.e. Ts are auto anti-idiotypic in nature). Using as stimulator/responder cells in AMLR lymphocytes taken from normal (8-week) or aged (greater than 24-month) mice, data were obtained consistent with this model and with earlier evidence for an altered expression of both lymphocyte recognition receptors and/or class II antigens in senescence.

Age Factors↗

PubMed1985

Cimetidine reverses tumor growth enhancement of plasmacytoma tumors in mice demonstrating conditioned immunosuppression.

Mice were given repeated injections, at 21 day intervals, of cyclophosphamide paired with a novel taste (saccharin) in the drinking water. Subsequent challenge with a syngeneic plasmacytoma tumor led to elevated tumor growth and mortality only in conditioned mice that were reexposed to saccharin. This effect was abolished by conditioned exposure to a histamine type II-receptor antagonist.

Animals↗

PubMed1984

Alterations in lymphocyte recognition repertoire during ageing. I. Analysis of changes in immune response potential of B lymphocytes from non-immunized aged mice, and the role of accessory cells in the expression of that potential.

The repertoire of specificities recognized by endogenous plaque-forming cells of young or aged mice has been examined, as well as the repertoire of specificities represented by mitogen-activated B cells of those animals. Significant changes occur in both polyclonal endogenous plaque-forming cells and polyclonal B cell responsiveness, as well as reactivity for antigens expressed on bromelain-treated mouse erythrocytes and mouse Ig-coupled sheep erythrocytes. Adoptive transfer experiments suggest that these changes reflect a role for the differentiative environment in the regulation of the B cell recognition repertoire. Additional analysis of changes in antigen-presenting cells in aged mice suggest that alterations in the manner of presentation of environmental antigens in vivo may control the expressed B cell repertoire. Indeed, under experimental conditions it has proven less easy to induce B cell/macrophage restriction (for antigen presentation and induction of antibody formation) in cells of old animals than in cells of younger mice.

Aging↗

PubMed1984

Associative learning and regulation of immune responses.

Conventional genetically inbred mice were exposed to an immunologically inert stimulus (CS) along with a stimulus known to perturb immune functioning [either non-specifically, an immunosuppressive drug; or specifically, an antigen]. After repeated trials of this type subsequent re-exposure of such "conditioned mice" to the CS alone was found to produce a change in immune response potential. This phenomenon has been examined in situations as diverse as those in which the test antigenic challenge is a tumour cell innoculum, or a tissue allograft. Some possible clinical implications of these findings are discussed.

Animals↗

PubMed1984

Monoclonal antibodies against SSEA-1 antigen: binding properties and inhibition of human natural killer cell activity against target cells bearing SSEA-1 antigen.

We describe the properties of three monoclonal antibodies (Mab) against stage-specific embryonic antigen-1 (SSEA-1) in terms of their binding activity to HL60, K562, OTF9, and SOTF9 tumor target cells and their functional activity in modulating human natural killer (NK) cytotoxicity assays in vitro against these target cells. Indirect binding, competition, and Western blot analyses indicate that the Mab AEC3A1-9 (3A1), ASSEA-1, and AECAB1-32 (AB1) recognize cell-defined SSEA-1 antigen with activity characteristic of the cell source (HL60 greater than OTF9 greater than K562 much greater than SOTF9). The addition of anti-SSEA-1 Mab to the NK cytotoxicity assay resulted in an inhibition of LU per 1 X 10(6) PBL that correlated closely with the expression of SSEA-1 antigen on the target cell. No significant inhibition was seen for seven other Mab. Inhibition of NK activity (greater than 30%) was observed in the presence of anti-SSEA-1 Mab for 18 of 21 and 6 of 7 human donors examined for HL60 and OTF9 target cells, respectively. The pretreatment of fixed competing cells with anti-SSEA-1 Mab reduced the efficacy of those cells to act as cold competitors in a standard NK cytotoxic assay. Taken together these data suggest that SSEA-1 determinants are important at some stage in the cytolysis produced by NK cells.

Animals↗

PubMed1984

Recognition specificities, development and possible biological function of natural killer cells in the mouse. II. Changes in NK recognition during ontogeny and ageing, and examination of role of environment in controlling the expressed recognition repertoire.

We have used a spleen fragment assay to assess subpopulations of NK effector cells in individual mice and to analyse the patterns of inhibition of lytic activity seen in the presence of different sugars (mono-, di- and tri-saccharides). Our data suggest that during ontogeny the heterogeneity (diversity) of the NK effector population increases in a fashion which is somewhat characteristic of the individual strain under investigation. Furthermore, when a similar analysis was performed on NK cells in the spleen of lethally irradiated recipient mice receiving syngeneic or semi-allogeneic bone marrow stem cell precursors, we found that the phenotype of inhibition by different sugars was a characteristic of the bone marrow donor and not of the recipient. In so far as the assay described assesses target recognition by NK cells (and not subsequent parameters involved in the lytic event) these data can be interpreted in terms of a relative independence of the expressed recognition repertoire of NK cells from the environment in which their differentiation occurs.

Aging↗

PubMed1984

Altered lymphocyte recognition repertoire during ageing. III. Changes in MHC restriction patterns in parental T lymphocytes and diminution in T suppressor function.

Irradiated C57BL/6 and (C57BL/6 X C3H)F1 mice have been reconstituted with bone marrow prepared from young (2 month) or aged (24 month) C57BL/6 donors. Indirect examination of the T cell receptor for H-2d alloantigens on H-2b splenocytes of these reconstituted mice, using the suppression of the H-2b anti-H-2d response induced by (H-2b X H-2d)F1 anti-(H-2b anti-H-2d) suppressor cells, suggests that the allo-receptor repertoire derived from bone marrow of aged mice is different from that of T cells derived from young bone-marrow precursors. These observations were supported by direct evidence, from rosette formation with murine erythrocytes, for changes in the T cell receptor of these different (radiation-chimaera) sources of H-2b-T cells. Along with these subtle changes in the allo-receptor repertoire of T cells derived from bone marrow of aged mice grown in irradiated F1 hosts, there is a decrease (compared with mice reconstituted with bone marrow from young donors) in the apparent frequency of T cells recognizing antigen in association with the new MHC-restricting elements in these parent F1 chimaeras. Analysis of those cell subsets reported to be involved in the regulation of MLC responses suggests that some of the differences observed between T cell differentiation from bone-marrow stem cells of young or aged donors may in part be explained by a diminution in the production from bone marrow of aged mice of those cells important for homeostasis within the immune system.

Aging↗

PubMed1984

Peripheral (somatic) expansion of the murine cytotoxic T lymphocyte repertoire. I. Analysis of diversity in recognition repertoire of alloreactive T cells derived from the thymus and spleen of adult or aged DBA/2J mice.

Cytotoxic T lymphocyte precursors (CTLp) in the spleen or thymus of individual adult (8 to 10 wk) or aged (greater than 20 mo) DBA/2J mice have been activated by irradiated H-2Kb antigens under limiting dilution conditions such that cytotoxic cells in responder wells result from stimulation of a single CTLp. After division into several equal samples and expansion in the presence of IL 2 and more irradiated H-2Kb stimulators, the contents of replicate individual wells were tested for their ability to lyse a panel of selected H-2Kb mutant targets. The heterogeneity within a given age group, and the similarity of CTLp repertoires between different age groups were then compared for splenic and thymic CTLp repertoires. Our data indicate a far greater mouse-to-mouse variation for the splenic CTLp repertoire of aged mice compared with young mice, despite the greater heterogeneity of the repertoire in the latter case. Less difference was seen for the thymic CTLp repertoire. When we studied the correlation between the repertoires present in the thymus and spleen within a given age group, it seemed that the most striking difference in aged mice was a loss of systematic expansion of the early appearing thymic CTLp repertoire. These findings are discussed in terms of a two-stage model of T cell differentiation.

Aging↗

PubMed1984

Peripheral (somatic) expansion of the murine cytotoxic T lymphocyte repertoire. II. Comparison of diversity in recognition repertoire of alloreactive T cells in spleen and thymus of young or aged DBA/2J mice transplanted with bone marrow cells from young or aged donors.

Lethally irradiated (1000 R whole body) DBA/2J mice of 10 wk or 20 mo of age were repopulated with anti-Thy-1.2-treated DBA/2J bone marrow cells of 10-wk- or 20-mo-old donors. Sixty days post-transplant, limiting dilution cultures of the spleen and thymus cell population of individual mice (for each group) were examined to assess the within-group and between-group diversity in the anti-H-2Kb allo-recognition repertoire. Our data are consistent with a significant expansion of the CTLp repertoire taking place in the periphery, beyond the early appearing specificities present in the thymus. Moreover, comparison of the repertoires in young recipients of young or aged marrow, or in aged recipients of young or aged marrow, support the notion that there is a defect in the peripheral environment of aged mice that results in altered expansion of the thymic CTLp repertoire. In addition, there is an intrinsic difference in bone marrow precursor cells of CTLp in aged mice that is revealed only in an aged environment.

Aging↗

PubMed1984

Altered tumor growth in vivo after immunization of mice with antitumor antibodies.

A comparison has been made between the growth patterns of two spontaneously appearing mammary adenocarcinomas in murine bone marrow radiation chimeras and in mice preimmunized with monoclonal antibodies (MAb) detecting embryo-associated antigenic determinants. A correlation was seen between the ability of the embryo-immunized chimeras to produce cytotoxic antibody to the tumors, as assessed by an antibody-dependent cellular cytotoxic assay, and the permissiveness of the mice for growth of a tumor transplant. In addition, mice deliberately preimmunized with cytotoxic MAb (antibody-dependent cellular cytotoxic assay) allowed more rapid growth specifically of that tumor earlier found to be most sensitive to the MAb used for immunization. By comparing the changing antigenic phenotype of tumor cells serially passaged through different immunized, nonimmunized mice, evidence was found suggesting that immunization could cause either antigen modulation of transferred tumor cells or a (transient) selective advantage to antigenically discrete subpopulations within the heterogeneous tumor population. Finally, we have studied the growth pattern of tumor cells transplanted into mice immunized with rabbit antibodies directed against the murine MAb. In this case, tumor growth was slowed preferentially for the tumor reactive with the specific MAb, and again, predictable changes in the antigenic spectrum of tumor cells harvested from these animals were observed. Our overall findings are interpreted in terms of the involvement of networks of antibodies reacting with embryo-associated antigens in the regulation of growth of the murine mammary adenocarcinomas studied.

Adenocarcinoma↗

PubMed1983

In vitro analysis of allogeneic lymphocyte interaction. VII. I-A-restricted self-reactive and alloreactive helper components of allogeneic effect factor are distinct donor T cell-derived Ia-molecules that recognize Ia determinants on antigen-presenting cells.

An allogeneic effect factor (AEF) derived from mixed lymphocyte reaction (MLR) cultures of alloactivated A.SW (H-2s) responder T cells and irradiated T cell-depleted A/WySn (H-2a) stimulator spleen cells was fractionated on the basis of molecular size and charge into two I-A-restricted helper components. The cellular origin of these components is believed to be an Lyt-1+2- -activated responder T helper (TH) cell. One alloreactive component, TIAH-1, recognizes allo-I-A determinants on an A/WySn antigen-presenting cell (APC). The other self-reactive component, TIAH-2, recognizes self-I-A determinants on an A.SW APC. The interaction of each of these components with the appropriate APC subsequently activates an in vitro primary anti-SRBC PFC response of either stimulator haplotype- or responder haplotype-derived B cells. These data demonstrate that the activity of TIAH-1 and TIAH-2 is dependent on the genotype of the APC and not the B cell, and that the target cell of action of these AEF TH components is an APC. TIAH-1 and TIAH-2 are 68,000 mol wt single polypeptide chains that have an isoelectric point (pI) of 5.8 and 5.5, respectively. Their charge difference is not attributable to altered amounts of sialylation or phosphorylation, but probably is due to other forms of altered glycosylation and/or to changes in their amino acid sequence. They share approximately 80% of their tryptic peptides and likely constitute homologous but nonidentical molecules. Papain cleaves TIAH-1 and TIAH-2 into a 40,000 mol wt fragment. TIAH-1 and TIAH-2 may represent structurally very related but nonidentical secreted forms of activated responder TH cell-derived receptors for allo-I-A and self-I-A determinants, respectively.

Amino Acid Sequence↗

PubMed1983

Alteration in lymphocyte recognition repertoire during aging. II. Changes in the expressed T-cell receptor repertoire in aged mice and the persistence of that change after transplantation to a new differentiative environment.

Changes in the T-lymphocyte alloreceptor repertoire associated with aging by exploring the frequency of cytotoxic T-lymphocyte precursors (CTLp) available for activation by various major histocompatibility complex (MHC) haplotypes in mice of different ages have been investigated. There was no consistent pattern of change in CTLp frequencies. Thus, for instance, while the frequency of responder C57B1/6 CTLp for ATH alloantigen decreased with age, the frequency for C3H alloantigen increased. There was no significant change in the overall frequency of splenic CTLp (assessed irrespective of antigen specificity). No evidence was found that CTL produced by activated CTLp of aged mice were less specific in their lytic capacity that CTL produced by CTLp of young mice. However, by assaying responder CTLp cultures at limiting dilution we obtained evidence that the "burst size" (mean lytic capacity per responder well assayed at limiting dilution) was diminished with age of the donor of the CTLp pool. Furthermore, we obtained evidence that the apparent affinity of CTL for their target antigen was consistently decreased when those effector cells were derived from a pool of CTLp of aged mice. All of these changes reflected in mature T cells derived from aged mice were already apparent in the bone marrow stem cell pool of aged individuals and were not due to environmental influences alone, as assessed by the phenotype of T cells derived from young or old bone marrow stem cells transplanted to young or aged recipient mice. A final study has examined evidence for more subtle changes in the T-cell alloreceptor repertoire, reflecting heterogeneity in young or aged mice in the recognition repertoire associated with a given antigenic specificity. By preparing F1 anti (parent anti-F1)-suppressor cells directed against CTL from young parental mice (a, b, c), or aged parental mice (x, y, z), we have explored the heterogeneity in the anti-C3H alloreceptor repertoire in individual young or aged C57B1/6 mice. Suppression by immunized F1 animals was assessed in tissue culture (inhibition of mixed lymphocyte culture (MLC) responses) or in vivo (inhibition of lethal GvHD induced by inoculation of parental lymphocytes into sublethally irradiated F1 hybrid mice). Irrespective of the assay system used, the data suggests that the receptor repertoire of aged T lymphocytes uses recognition structures different from those of young individuals, and that there is less individual-to-individual variation in the receptor repertoire of aged mice than in young mice.

Aging↗

PubMed1983

In vitro analysis of immune responses of inbred guinea pigs infected in vivo with Leishmania enriettii and an investigation of active immunization of susceptible animals.

Adherent skin cell monolayers have been prepared from the infected area of inbred guinea pigs inoculated with Leishmania enriettii. Cells from those animals most susceptible to disease (2/N) are less able to promote proliferation and the production of macrophage migration inhibition factor (MIF) from leishmania-immune lymphocytes than are infected cells taken from the more resistant 13/N or (2/N X 13/N)F1 animals. Exposure of immune lymphocytes of all strains to parasite antigen in the relative absence of autologous antigen-presenting cells induced the development of a suppressor pool capable of inhibiting lymphocyte proliferation in response to immunogenic signals. Decreased lymphocyte proliferation during the course of disease may be caused by the endogenous release of products of arachidonic acid metabolism from host monocytes, though along with the decline in DTH reactivity in infected animals, and apparently in concert with the healing of the primary lesion, there occurs an increase in titer of anti-leishmania antibody in infected animals. Preliminary attempts to confer protection of naive animals by preimmunization with lymphocytes from previously infected, susceptible, or resistant guinea pigs suggested a role for interacting "helper" and suppressor lymphocyte pools in the immunoprotection from leishmania infection.

Animals↗

PubMed1983

Recognition specificities, development, and possible biological function of natural killer cells in the mouse. I. Spleen focus forming assay for natural killer activity and analysis of lectin-like recognition structures on the surface of murine natural killer cells.

A number of simple sugars have been tested and found to be effective in blocking lysis of YAC-1 tumor target cells by nonimmune murine natural killer (NK) effector cells. Using a spleen fragment culture system an assay has been developed which allows us to compare the inhibition of lysis observed in replicate culture wells prepared from cells contained in one spleen fragment (less than or equal to 1 X 10(6) cells). The inhibition pattern of any well was found to fall naturally into 1 of 25 (of the total 128 possible tested) patterns. Using this panel analysis of NK activity in individual mice of the same or different strain has been compared. Our data suggest that within any given strain the inhibition pattern of NK effector cells is quite uniform. Consistent differences are seen between strains which are interpreted in terms of a genetic control of the final expression of the NK recognition repertoire. In adult F1 hybrid individuals the pattern of recognition by NK cells is best considered a result of the codominant expression of genes contributed by each parent.

Animals↗