Polymorphism of minor histocompatibility genes in wild mice

H-2b-restricted cytolytic T lymphocytes (CTL) were generated against H-1, H-3, and H-4 antigens and tested against target cells of F1 hybrids between wild mice and inbred H-2b mice. The congenic strain combinations for the CTL production were such that they tested one allele each at the H-1 and H-4 loci and four alleles at the H-3 locus. Most of the wild mice tested came from Southern Germany, but a few mice came from other European countries and Egypt and Israel. Virtually all wild mice typed as positive with CTL directed against H-3b and H-4b antigens; 32% of the F1 hybrids tested reacted with anti-H-1c CTL and 9% reacted with anti-H-3d CTL. The positive results were not caused by cross-reaction with allogeneic H-2 antigens controlled by the major histocompatibility complex (Mhc) genes of the wild mice. At least some of the H-3 and H-4 antigens detected by the CTL in the F1 hybrid were not identical with antigens of the immunizing strains. These results suggest a relatively low degree of polymorphism of the tested minor H loci in wild mice and further support the notion that minor H loci are unrelated to the Mhc.

Selection of the T cell repertoire during ontogeny: limiting dilution analysis

The relative frequencies of cytotoxic T lymphocyte precursors (CTL-P) specific for minor histocompatibility antigens that are restricted to either k or b major histocompatibility complex antigens in normal B6 mice and in B6 leads to (B6 x CBA)F1 radiation chimeras were estimated. The ratio of k-restricted to b-restricted CTL-P determined for the radiation chimeras served as a base value to which the ratio of k: b-restricted CTL from normal B6 mice can be compared. The frequencies of allorestricted CTL-P in B6 mice were determined after the B6 cells had been depleted of k-reactive cells by filtration through irradiated B6.H-2k mice. Lymphocytes from immunized animals were used to obtain frequency estimates of CTL-P specific for minor H antigens. The cultures contained nu/nu spleen cells syngeneic to the responder, but no exogenous interleukin 2 (T cell growth factor) since a high degree of nonspecific killing was found in IL2-supplemented cultures. It was found that the CTL-P frequency of B6 mice to BALB.B antigens in the lymph node cells of normal or immune B6 mice were 1 in 300 000 and 1 in 8000, respectively. In B6 leads to (B6 x CBA)F1 radiation chimeras, the ratio of BALB.B/BALB.K-specific CTL-P was 3:1; this ratio was 17:1 in normal B6 mice. Twenty-five percent of CTL clones from normal B6 mice lysing BALB.K target also lysed BALB.B target whereas less than 1% of CTL clones lytic on BALB.K target from the chimeras showed this cross-reaction The results are compatible with the idea of complete positive selection of self MHC-restricted CTL-P in the absence of priming effects by foreign antigen.

Alloantigen presentation to the anterior chamber of the eye subverts specific in vitro cell-mediated immune responses

Aberrant cell-mediated immune responses are produced when minor histocompatibility antigens expressed on tumor cells are placed in the anterior chamber of the mouse eye. Mice bearing intraocular histoincompatible tumors fail to develop alloimmunity as expressed by their failure to reject orthotopic skin grafts syngeneic with the tumor cells. The cellular basis of anterior chamber-associated immune deviation (ACAID) was examined in vitro by studying lymphoid cells from BALB/c mice that had received intracameral inoculations of P815 tumor cells. It was found that both proliferative and cytotoxic T cell responses to DBA/2 alloantigens were either low or absent. Splenectomy prior to intracameral inoculation of P815 cells produced the opposite effect, i.e., lymphoid cells from these animals performed in in vitro assays as though they were specifically primed to the DBA/2 alloantigens. In an effort to identify an active process of suppression as the possible basis for ACAID, mixing experiments were conducted in which the alloreactivities of normal lymphoid cells were subjected to putative regulator cells from animals with ACAID. No evidence of suppression of the response of animal cells to DBA/2 alloantigens was discerned. Thus, the aberrant cell-mediated responses of lymphoid cells from BALB/c mice bearing intraocular P815 tumors appear to be consistent with the hypothesis that clonal deletion among mature immunocompetent cells is responsible for the ACAID phenomenon.

HLA-DR compatibility in couples with recurrent spontaneous abortions

HLA antigens and antibodies of A,B and DR loci were investigated in order to study the relationship between early recurrent spontaneous abortions of unknown etiology and the HLA system, which is in a close relationship with the immune response. The frequencies of 8 HLA-A antigens, 21 HLA-B antigens and 10 HLA-DR antigens were determined in 26 patient couples, 45 control fertile couples without a history of abortion and 206 healthy adult controls (DR antigens in 106 controls). Sera from the wives in patient couples were tested for HLA-A, B, C and DR antibodies against their husbands' T and B lymphocytes and also against 2 panels of 29 typed T and B lymphocytes. Results obtained were as follows: 1) A significantly higher frequency of HLA-All antigen was found in the wives in patient couples as compared with the controls (corrected p less than 0.008). 2) A significantly higher frequency of one or two common HLA-DR antigens was shared by patient couples (84.6%, X2 = 21.66, p less than 0.001) as compared with control couples (24.4%). 3) Furthermore, a significantly higher frequency about HLA-DR locus without major incompatibility was found in patient couples (26.9%, X2 = 7.77, p less than 0.01) as compared with control couples (2.2%). 4) HLA-DR antibodies were not detected in the wives in patient couples at all. These results indicated that the compatibility of HLA-DR antigens or DR genes might possess some adverse influence on the maintenance of pregnancy.

T-cell responses to minor histocompatibility antigens

We have investigated the helper and cytotoxic T-cell response to minor histocompatibility antigens and generated long term antigen-specific cell lines to them. Antigen-specific activity was selected for by regular restimulation with irradiated cells bearing the antigens in the presence of interleukin 2, so that alloreactivity to other cell surface antigens was gradually lost. Helper T cells cultured over several months were active in vivo and in vitro, but the culturing method eventually selected for cytotoxic T cells at the expense of helper T cells, with concomitant changes in the proportions of cells expressing the Lyt phenotypes. Individual long term cultures of cytotoxic T cells specific for minor histocompatibility antigens were restricted by either H2K or D but not both. Helper T cells to minor histocompatibility antigens derived directly from primed F1 mice did not show restriction to the priming parental haplotype. This is consistent with antigen reprocessing by the F1 antigen presenting cells such that populations of helper T cells restricted by both parental H-2 haplotypes were primed. F1 cytotoxic T cells were restricted to the parental H-2 haplotype used for in vitro boosting, irrespective of which H-2 was used for in vivo priming.

Genetic analysis of the non-H-2-linked Ir genes controlling the cytotoxic T-cell response to H-Y in H-2d mice

The T-cell mediated immune responses to the male specific minor histocompatibility antigen H-Y in mice have been studied extensively as a model for immune responses to other weak antigens like tumor antigens or autoantigens. In a recent analysis of the strain distribution of the cytotoxic T-cell (Tc-cell) responsiveness to H-Y, it has been found that genes both within and outside the H-2 complex exert an interactive control. Whereas the H-2b strains all are high responders, independent of their non-H-2 background, other H-2 haplotypes (d, k, and s) only allow for a response if they are combined with certain non-H-2 genes. The H-2-linked immune response genes (Ir-genes) have been previously mapped to the I and K or D region of the H-2 complex, but the mapping of the non-H-2 genes has not yet been established. In this study evidence is presented, using recombinant inbred strains and immunoglobulin heavy chain (Igh) congenic strains of mice, to show that there is more than one non-H-2 Ir-gene involved, that the main controlling genes are not linked to the Igh complex, and that at least one non-H-2 Ir-gene is linked to the H-3 region on chromosome 2. This region includes genes for beta-2-microglobulin (beta 2m), the Ly-m11 alloantigen a polymorphic cell surface glycoprotein (Pgp-1), a B-cell specific antigen Ly-4, a transplantation antigen H-3, and genes (Ir-2) controlling the immune response to Ea-1 and H-13.

Assessment of some genetic non-MHC differences with GVHR-induced anti-listeria activity of macrophages

Parental cells A injected into (A X B)F1 heterozygotes induce a graft-versus-host reaction (GVHR) which induces systemic activation of anti-Listeria-bactericidal capacity of host macrophages. When donor lymphocytes differ from parent A with respect to various non-H-2 genetic markers, they may or may not be able to induce a GVHR. Some, but not all, known and some unknown non-H-2 differences can be assessed by this method within nine to 12 days. The method is described and some of the following non-H-2 differences are shown to influence GVHR-induced macrophage activation: male H-Y antigen, H-3 or H-4 (but not H-1 or H-9), and as yet underlined differences that apparently exist between mouse substrains of the same or similar designation, but obtained from different breeding establishments.