Allogeneic Environment Research Articles

The allogeneic bisection of carrier-specific enhancement of monoclonal B-cell responses.

The ability of T cells to enhance the response of syngeneic and allogeneic B cells to thymus-dependent hapten-carrier conjugates was analyzed. This analysis was carried out on individual primary B cells in splenic fragment cultures derived from irradiated reconstituted mice. This system has several advantages: (a) the response of the B cells is entirely dependent on carrier priming of the irradiated recipient; (b) this B-cell response can be quantitated in terms of the number of responding cells; and (c) very small B-cell responses can be readily detected and analyzed. The results indicate that the majority of hapten-specific B cells were stimulated in allogeneic and syngeneic recipients only if these recipients were previously carrier primed. The number of B cells responding in carrier-primed allogeneic recipients was 60-70% of that in syngeneic carrier-primed recipients. The antibody-forming cell clones resulting from B cells stimulated in the allogeneic environment produced small amounts of antibody and antibody solely of the IgM immunoglobulin class, while the larger responses in syngeneic recipients were predominantly IgG1 or IgM plus IgG1. The capacity of collaborative interactions between carrier-primed T cells and primary B cells to yield IgG1 antibody-producing clones was shown to be dependent on syngeny between these cells in the H-2 gene complex. It is concluded that: (a) B cells can be triggered by T-dependent antigens to clone formation through collaboration with T cells which differ at the H-2 complex as long as these T cells recognize the antigen; (b) the immunoglobulin class produced by the progeny of stimulated B cells generally depends on the nature of the stimulatory event rather than the nature of the B cell itself; and (c) stimulation to IgG1 production is dependent on syngeny between the collaborating T and B cells probably within the Ir-1A region. The role of the Ia antigens in the formation of IgG1-producing clones is not yet clear; Ia identity could permit IgG1 production or, conversely, nonidentity of Ia could induce all allogeneic interactions which prohibit IgG1 production.

Incomplete restoration of the bursa-dependent immune system after transplantation of allogeneic stem cells into immunodeficient chicks.

Transplantation of allogeneic cells from bursa of Fabricius into cyclophosphamide-treated, immunodeficient chicks resulted in immunological tolerance to donor line skin grafts; graft-versus-host disease did not occur. Allogeneic bursal stem cells taken from 3-day-old donors induced restoration of bursal morphology, of antibody formation to Brucella abortus and of occurrence of pyroninophilic cells and immunoglobulin-bearing cells in the peripheral lymphoid tissues. Secondary response to sheep red blood cells and production of germinal centers were not restored. Transplantation of histocompatible bursal stem cells resulted in a complete reconstitution of the bursa-dependent lymphoid system, both in function and in morphology. Allogeneic postbursal stem cells taken from the bursa of 10-week-old donors had a reconstitutive effect only on the production of antibodies to Brucella. Transplanted stem cells maintained their functional potential in the allogeneic environment, since, when transferred back to histocompatible hosts, they displayed normal function. These findings indicate that a complete functional and morphological restoration of the bursa-dependent immune system cannot be achieved without identity of the donor and recipient at loci near to or identical with those determining the major histocompatibility antigens, even though graft-versus-host disease is avoided. This identity permits a full cooperation of the donor and host cells.

Expulsion of Nippostrongylus brasiliensis from the intestine of rats: attempts to initiate worm expulsion by cell transfer in an immunologically inert allogeneic environment.

Parental-strain immune mesenteric lymph node cells (IMLNC) did not cause the rejection of damaged <i>Nippostrongylus brasiliensis </i>worms when transferred to non-irradiated F1-hybrid rats, even though these cells rejected damaged worms in non-irradiated, parental-strain recipients. Reconstitution of heavily irradiated rats (750 rad) with IMLNC and bone marrow cells (BMC), which were syngeneic with respect to each other but which were allogeneic with respect to the irradiated recipient, did not cause the expulsion of transplanted damaged worms. In a collateral histological study, it was shown that the irradiation dose (750 rad) was sufficient to abolish the intrinsic immunological reactivity of recipient rats as transferred IMLNC and BMC successfully repopulated the spleens of irradiated allogeneic recipients. These results show that heavily irradiated rats still exert an active allogeneic effect on adoptively transferred IMLNC and BMC. This indicates that it will not be possible to investigate the role of cell-mediated immune reactions by cellular transfer of resistance to infection with helminth parasites across major and perhaps even minor histo-incompatibility barriers.

Differences in antibody production after adoptive transfers of syngeneic and allogeneic spleen cells to irradiated mice.

Immunologically competent spleen cells from syngeneic or allogeneic donors were transferred to supralethally irradiated mice. At the same time, or 72 h after transfer, sheep red cells were administered intraperitoneally to the hosts. Five days after administration of the sheep red cells, antibody production was determined in host spleen fragments by the method of haemolysis in agarose. It was found that an incompatible allogeneic environment markedly stimulated proliferation of the donor cells and that proliferation of clones of cells reacting specifically to sheep red cells by antibody production was also stimulated.

In Vitro and in Vivo Culture of Mouse Peripheral Blood for Chromosome Preparations

SummaryThe in vitro and in vivo culture methods for consistently obtaining mitotic divisions suitable for chromosome analysis from peripheral blood of various mouse strains have been described. In the in vitro culture system pokeweed was used as the mitogenic agent. The DNA-synthesis and mitotic activity commenced much earlier than in the diffusion chamber cultures in which the allogeneic or heterologous environment provided the mitogenic stimulus. In the latter system cells could be maintained for at least 7 days. Mitoses were still frequent at this time.