Preliminary characterization of the cells causing an H-2-restricted GVH reaction

An H-2-restricted graft-versus-host reaction can be demonstrated when irradiated bone marrow-protected recipients receive injections of cells from radiation chimeras. The cells responsible are Thy-1-positive, thymus-dependent, radiation-sensitive and pass through a nylon wool column, i. e., they are T cells. Treatment of the cells with anti-Lyt-1 or anti-Lyt-2 serum and complement reduces but does not eliminate the activity which can be eliminated by treatment with both antisera. Combining anti-Lyt-1-treated and anti-Lyt-2-treated cells does not restore the original activity.     

H-2 effects on cell-cell interactions in the response to single non-H-2 alloantigens

Individual mice were tested for their proliferative T-cell response to H-Y- and H-3-incompatible stimulator cells in secondary mixed lymphocyte culture. Responders expressing the H-2 ^bhaplotype were restricted in their response to stimulators presenting H-Y and H-3 in the context of H-2 ^b. Lymphocytes from individual B10 females proliferated in response to H-Y presented with I-A ^band D ^b. The ratio of I-A ^b/D ^b-restricted responses varied between individual responders, indicating significant qualitative variation between genetically identical responders. The majority of the proliferative response in all tested mice was restricted to the entire H-2 ^bhaplotype suggesting complementation of I-A ^b- and D ^b-region genes in presenting the H-Y antigen. Similar observations were made in the response of individual B10.LP mice to the H-3 antigen. H-3-specific, proliferating T cells were restricted to H-3 antigen presented with K ^bA^band D ^bwith significant variation between individuals in their preference for H-3 plus K ^bA^band D ^b. In contrast to the response to H-Y, the proliferative response to H-3 plus H-2 ^bcould be accounted for by the summation of the proliferative responses to H-3. plus K ^bA^band D ^b. These observations demonstrate that the proliferative response to non-H-2 H antigens in the context of I-region determinants is not a sine qua non for the T-cell response to these antigens. Further, the individual qualitative and quantitative variation observed with individual genetically identical mice has strong implications for our knowledge of intrastrain variation in immune responsiveness and the characterization of inbred strains for immune responsiveness.     

H-2 effects on cell-cell interactions in the response to single non-H-2 alloantigens

Immune response (Ir) genes mapping in theI region of the mouseH-2 complex appear to regulate specifically the presentation of a number of antigens by macrophages to proliferating T cells. We have investigated the possibility that similarIr genes mapping in theH-2K andH-2D regions specifically regulate the presentation of target antigens to cytotoxic effector T cells. We report that the susceptibility of targets expressing specific non-H-2 H alloantigens to lysis by H-2-compatible, H-antigen-specific cytotoxic effector T cells is controlled by polymorphicH-2K/D genes. This control of susceptibility to lysis is accomplished through what we have defined operationally as antigen-specific regulation of non-H-2 H antigen immunogenicity. High immunogenicity of the H-4.2 alloantigen is determined by a gene mapping in theH-2K region ofH-2 ^b . However, high immunogenicity of H-7.1 is determined by a gene mapping in theH-2D region ofH-2 ^b . High immunogenicity of the H-3.1 alloantigen is determined by genes mapping in both theH-2K andH-2D regions ofH-2 ^b . Therefore, genes mapping in theH-2K andH-2D regions serve a function in presenting antigen to cytotoxic effector T cells. This function is analogous to that played byI-regionIr genes expressed in macrophages which present antigen to proliferating T cells. We present arguments for classification of theseH-2K/D genes as a second system ofIr genes and discuss the implications of twoH-2-linkedIr-gene systems, their possible functions, and their evolution.     

H-2-restricted GVH reaction caused by T cells from normal donors of certain strains

A comparison has been made of lethal graft-versus-host (GVH) reactions caused by T cells from radiation chimeras and from normal mice. In the recipient strains tested, T cells from both chimeric and normal A, A.SW, and CBA mice showed H-2-restricted killing, while T cells from chimeric and normal C57BL/6 failed to show any evidence for H-2-restricted GVH reactions. With other strains tested as donors, T cells from chimeras showed H-2-restricted GVH reactions, while the corresponding normal cells showed some similarities to the chimeras but not complete H-2-restriction.[/p]     

H-2 and Background influences on tissue grafts across the H-Y barrier

Male liver was grafted to kidney beds in syngeneic female mice. Relative influences ofH-2 haplotype, genetic background or interaction ofH-2 haplotype with genetic background on anti-H-Y response were evaluated using 27 inbred strains carrying eightH-2 haplotypes of independent origin and three naturally occurring recombinants. Females ofH-2 ^b haplotype acutely rejected the male graft as is reported for other tissue graft systems. AnH-2 haplotype influence was found for all haplotypes studied, with a greater variation of immunologic response revealed by histological analysis of liver grafts than is demonstrated by skin grafts. Strains carryingH-2 ^k ,H-2 ^j andH-2 ^p haplotypes expressed the greatest range of immunological variability with responses ranging from graft proliferation to graft rejection. Strains carrying theH-2 ^d haplotype had the most consistent responses with little reaction to the graft. The strong immune response by SJL/J (H-2 ^s ) female mice to the H-Y antigen is not typical of otherH-2 ^s strains, but is compatible with the reported hyperresponsiveness of this strain to alloantigens.     

The screening of non-H-2 congenic lines forSk loci

Thirty-seven histocompatibility congenic lines of mice, including at least 27non- H-2 lines, developed by Bailey on the C57BL/6 background, were screened for loci determining Sk (skin-specific) histocompatibility antigens. Background strain hosts were inoculated with lymphoid cells from the congenic lines and subsequently challenged with skin test grafts from the same donors. Comparison of the survival times of these test grafts with those of first- and second-set skin grafts in the same donor-host combinations suggests that the lymphoid cells from 35 of the congenic lines apparently immunized or tolerized at least some of the hosts. Thus, the histocompatibility antigens involved were shared by lymphoid cells and skin, and by definition could not be Sk antigens. The tests were indecisive with two of the non-H-2 lines, but if Sk antigens were involved, their contribution to the immunogenicity of conventional skin allografts probably was negligible. Hence ifSk congenic lines are desired, they probably will have to be developed on their own by procedures specifically designed to select for Sk antigens of significant immunogenicity.     

Genotypic influences on reproductive aging of inbred female mice: effects of H-2 and non-H-2 alleles

The H-2 (major histocompatibility) complex of mice influences a variety of physiologic parameters. This study describes the influences of H-2 polymorphisms and other genetic influences on age-related changes (5-20 mo) in estrous cycles and fecundity. We monitored estrous cycles of virgin or retired-breeder mice of congenic strains on the background of C57BL/10Sn (B10):B10.BR/Sg (B10.BR) and B10.RIII/Sn (B10.RIII). For another comparison, we examined the C57BL/6J (B6) strain, which has the same H-2 haplotype as the B10. Estrous cycles were categorized by length during 10 mo of observations. From 5 to 15 mo of age, B10 and B10.RIII mice displayed a preponderance of 5-day cycles, B10.BR mice displayed a preponderance of 4-day cycles, and B6 mice had diminishing numbers of 4-day cycles. Age-related acyclicity differed with strain, particularly among retired breeders; B6 mice had an earlier onset and more rapid increase of acyclicity with age than the B10 congenic mice. Litters/female, maternal age at last litter, and total pups/female differed with strain; B10.BR and B10.RIII were similar and both had greater values than B10 mice. In conclusion, reproductive senescence of female mice was influenced by genes at the H-2 locus and elsewhere.     

Murine responses to (Tyr-Glu-Ala-Gly)n: II. H-2 and non-H-2 gene effects

Mice of the H-2^b haplotype responded to the sequential polymer poly(Tyr-Glu-Ala-Gly) in the in vitro T-cell proliferative assay, irrespective of whether they were homozygous or heterozygous at the H-2^b locus. The antibody responses of the H-2^b congenic mice to this polymer were variable, with A.BY and BALB.B showing responses better than those of C57BL/6 and C57BL/10 strains. The antibody responses of the F₁ progeny of (responder × nonresponder) strains of mice to this polymer are generally lower than the responder parents. F₁ mice with C57BL/10 background were the poorest responders. Studies with F₂ mice and backcross progenies of selective breeding of high and low antibody responder (C57BL/6 × BALB/c) F₁ to high responder C57BL/6 mice indicated that both non-H-2 genes and H-2 gene dosage effects influenced the magnitude of the humoral antibody responses. Animals having low responder non-H-2 background and only half the dosage of the responder immune response genes has greatly diminished antibody responses.     

H-2 Effects on cell-cell interactions in the response to single non-H-2 alloantigens

Mice expressing mutant H-2Kb alleles were tested for their ability to generate cytotoxic effector T-cells specific for the non-H-2 histocompatibility alloantigen H-4.2. Cytotoxic effectors specific for H-4.2 are preferentially restricted by the Kb allele. Mutant Kb alleles were observed to differentially regulate the magnitude of the H-4.2-specific cytotoxic effector response. Mice expressing the Kbm5, Kbm6, Kbm7, and Kbm9 alleles generated cytotoxic T-cells to the same level as mice expressing the wild-type Kb allele. Kbm8 and Kbm11 responders generated intermediate levels of effectors, whereas Kbm1, Kbm3, and Kbm10 responders did not generate detectable levels of cytotoxic effectors. Kbm4 responders produced high levels of H-4.2-specific cytotoxic effectors that were variably reactive with wild-type Kb antigens with no H-4.2. The ability to generate H-4.2-specific effectors generally correlated with (1) the ability of mutant Kb molecules to present H-4.2 to wild-type Kb-restricted effectors, and (2) the position of the respective amino acid interchanges on the Kb molecule. Mutations that altered the amino acid sequence in the vicinity of the disulfide bond in the C1 domain had the greatest deleterious effects on Kb-controlled responsiveness to H-4.2. The only exception was the Kbm11 intermediate responder, which differs from Kbm3 in both responsiveness and in a single amino acid interchange. Therefore, the amino acid sequence in the vicinity of the disulfide bond in the C1 domain plays a prominent role in determining the H-4.2-specific immune response potential. These observations are the first to clearly demonstrate association between particular MHC gene product, amino acid sequences and immune responsiveness.     

Effects of H-2 complex and non-H-2 background on urethane-induced chromosomal aberrations in mice

The incidence of in vivo urethane-induced chromosomal aberrations was examined in H-2 congenic strains of mice with B10 and A backgrounds. Chromosome analysis of bone-marrow cells could divide 7 lines of A.H-2 congenic strains into 2 groups: one with a higher frequency of chromosomal aberrations such as in A/Wy (haplotype H-2a), A/J (H-2a), A.AL (H-2al) and A.TL (H-2tl), and the other consisting of A.TH (H-2t2), A.CA (H-2f), A.BY (H-2b) and A.SW (H-2s). The same tendency was also observed in the spleen cells. Among B10.H-2 congenic mice, B10.A (H-2a), B10.BR (H-2k), B10.A(3R) (H-2i3), B10.A(5R) (H-2i5) and B10.S(9R) (H-2t4) exhibited significantly higher rates of induced chromosomal aberrations than those in B10 (H-2b), B10.S (H-2s), B10.A(2R) (H-2h2), B10.A(4R) (H-2h4) and B10.S(7R) (H-2t2). To determine the effect on non-H-2 genetic backgrounds on urethane-induced chromosomal aberrations, 4 pairs of strains which have the same H-2 haplotypes, such as in B10 vs. A.BY (H-2b), B10.A vs. A/Wy (H-2a), B10.S vs. A.SW (H-2s), and B10.S(7R) vs. A.TH (H-2t2), were compared. The strains with a B10 background exhibited significantly higher frequencies of deletions and lower frequencies of exchanges than the strains with an A background. These data suggested that at least two genes are involved in the regulation of urethane-induced chromosomal aberrations in mice, one of which is mapped between the S and D regions in the H-2 complex, and another not belonging to H-2.     

Role of H-2 and non-H-2 genes in the control of blood magnesium levels

Red blood cell (RBC) and plasma (P) magnesium levels have been determined in 372 male mice of 13 inbred and H-2 congenic strains with C3H or B10 genetic backgrounds. Several groups of individuals belonging to the same strains have been tested at various times over a 2-year period to verify the results. Time and interstrain variations are highly significant for both RBC and P Mg. Statistical analyses made either with or without corrections for the time effect show that the largest variations are due to the genetic background (P < 10^–10), the effect of the H-2 complex being smaller but nevertheless highly significant (P < 10^–4 to 10^–6), except for the RBC Mg of the strains with B10 background. These findings can be compared with those previously obtained in man, and they demonstrate the high heritability of blood Mg concentration and its association with the major histocompatibility complex or with closely linked genes.     

H-2 and non-H-2 interaction in expression of mutant histocompatibility geneH(KH-11)

H(KH-11) is a mouse mutant histocompatibility gene, the expression of which, as detected by skin graft rejection, requires the presence of a second gene in the graft donor which is associated with theH-2 ^b haplotype, but not withH-2 ^d. The mutant gene is not linked to theH-2 complex and may be carried and transmitted with or without expression, as predicted by classical Mendelian genetics.This research was supported by Grants CA 12662 and GM 18421 from the National Institutes of Health. We wish to express our gratitude to Dr. Ian McKenzie for performing the serological typing and to Ms. Geraldine Spencer and Mr. Ernest White for their faithful technical assistance.     

Activation of natural killer (NK) cells in vivo with H-2 and non-H-2 alloantigens

Intraperitoneal inoculation of allogeneic lymphoid cells rapidly activates cytotoxic cells in the peritoneum which are nonadherent and express the NK-1, asialo-GM₁, and Thy-1 antigens. Allogeneic spleen cells were very efficient at activating these natural killer (NK) cells, while allogeneic thymocytes were much less effective. Heat-killed allogeneic cells or sonicates also could augment NK activity. — Incompatibility atH-2K, H-2I-A, orH- 2D readily evoked NK cell activity, whileH-2S- andH-2I-E/C-associated disparities did not. Non-H- 2 differences also stimulated NK activity and augmentation was particularly evident inMls-disparate combinations. Thus, the same alloantigens which efficiently activate T cells also activate NK cells.     

Female expression of the H-2-linked sex-limited protein (Slp) due to non-H-2 genes

Female mice of 15 inbred strains in which males express the H-2-linked sex-limited protein (Slp) were tested for the production of this protein. Four inbred strains (FM, LG/J, NZB, PL/J) were found in which females produce Slp in the absence of hormonal manipulation. Crosses have been made between strains FM, NZB, or PL/J and several Slp-negative strains. Slp-typing of the F₁, F₂, and backcross progeny, as well as of a number of recombinant inbred strains, indicates that production of Slp by normal females of these strains depends upon the concurrent presence of an Slp-positive,H-t2-linked allele and of permissive alleles of one or two non-H-2 autosomal genes. Complementation studies with two of the strains (FM and PL) indicate that an identical genetic mechanism mediates expression of Slp in females of these two strains. FM-derived animals carrying the testicular feminization mutation (tfm) also express Slp, as do castrated NZB mice, indicating that Slp expression in these instances is not dependent upon testosterone as it is in other inbred strains. It is concluded from these results that genes distinct from the putative structural gene for Slp influence the sex-limitation of its expression.     

The role of H-2 and non-H-2 antigens and genes in the rejection of murine cardiac allografts

Genes of the major histocompatibility complex (MHC) in the mouse (H-2 complex) have been shown to be an important factor in determining the immune responsiveness of various strains of mice to isolated antigens (e. g., lysozyme). The role of MHC genes in controlling the responsiveness of mice to multiple alloantigens is less well-defined, and although non-MHC genes have been shown to be important in determining responsiveness in some systems (e. g., haptens), they have not been demonstrated as yet to influence the rejection of vascularized organ allografts. In this study, the responsiveness of mice to vascularized cardiac allografts transplanted across well-defined major (H-2) and minor (non-H-2) histocompatibility barriers was investigated using congenic mice in 32 different donor/recipient combinations. The results show that both H-2 and non-H-2 gene products can act as target alloantigens for rejection. At the responder level, they may interact to effect responsiveness of a recipient strain to multiple alloantigens. In no case in this study has any one gene or group of genes been found to confer universal high or low responder status.     

Restriction in adoptive transfer of resistance to Listeria monocytogenes. I. Influence of non-H-2 loci

In vivo adoptive transfer of T-cell-mediated immunity to the facultative intracellular bacterium Listeria monocytogenes is restricted, not only by the H-2 haplotype of the mice, but also by incompatibilities at non-H-2 loci. Thus, transfer between H-2 identical strains of mice with different background genes was reproducibly and significantly less efficient than transfer between completely syngeneic mice, although the restriction was less marked than that across the H-2 barrier. Restriction also occurred when parental cells were injected into semisyngeneic F1 hybrids and when cells from F1 hybrids were injected into parental strains. Using congenic strains of mice differing only at defined minor histocompatibility antigens, it was found that, of those loci available for study, antigens arising from the H-4 and H-8 loci strongly restricted transfer, whereas those specified by H-1, H-3, and H-7 did not.