Time-response studies of the cellular immune response to cell membrane antigens.

It was the objective of these experiments to study the time-related changes in the responsiveness of the cellular elements of the immune system following contact with single non-H-2 or multiple H-2 histocompatibility antigens. The reactivity of spleen cells from mice that received injections of spleen cells bearing H-1c, H-3c, H-13a, or H-2b cell membrane alloantigens was characterized at intervals following antigen contact. Spleen cells taken from mice not receiving injections showed no in vitro proliferative or cytolytic responsiveness to cells bearing individual non-H-2 antigens; after in vivo antigen contact with single non-H-2 antigens there was an interval of specific cellular unresponsiveness followed by alternating periods of responsiveness and unresponsiveness. The duration of the unresponsiveness immediately following injection correlated with the strength of the injected antigen--specifically, the stronger the antigen, the shorter the period of unresponsiveness. The data indicate fluctuation in the level of helper T lymphocyte activity, as well as cytotoxic T lymphocyte activity. In contrast, in vitro responsiveness elicited by H-2b antigens with and without prior in vivo antigen contact was of a similar magnitude, and both persisted at a relatively constant level. Suppressor mechanisms were not studied. Of particular interest was the observation that in vivo contact with non-H-2 antigens resulted in suppression of spleen cell production of IL-2 in response to lectin stimulation and fluctuation in the magnitude of the primary response of cytotoxic T lymphocytes to H-2 antigens.

Recognition of the beta-2 microglobulin-B molecule by a CTL clone.

In this report we offer evidence that the beta-2 microglobulin-B (beta 2M-B) molecule is recognized by a cytotoxic T lymphocyte (CTL). Production of GA5, a CTL clone reactive against a membrane antigen with the same strain distribution pattern as beta 2M-B, is described. This clone lysed syngeneic target cells in which native beta 2M-A molecules had been exchanged with beta 2M-B molecules by incubating the cells in serum from beta 2M-B-positive mouse strains. Conversely, the CTL clone GA5 failed to lyse its specific target when beta 2M-B molecules had been exchanged with beta 2M-A molecules by incubating the cells in serum from beta 2M-A-positive, beta 2M-B-negative mouse strains. Strain combinations were chosen so as to limit reactivity to beta 2M and to preclude reactivity to H-3 antigens, thus indicating CTL clone GA5 to be reacting specifically with beta 2M-B.

Abnormal bone production associated with mutant mouse genes pa and we.

A syndrome including deficient linear, endochondral, and radial bone growth associated with severe cervico-thoracic lordosis, decreased intrathoracic volume, atelectasis, and early death has been noted in mice possessing the phenotypes of the recessive mutant genes pallid (pa) and wellhaarig (we) as the result of recombination of chromosome 2 between these genes. The syndrome is not seen in the parental strains, which are homozygous for the chromosomal segment containing one or the other gene (pa +/pa + or + we/+ we), nor in the intercross mice heterozygous for both genes in the trans configuration (pa+/+we). The abnormal offspring appeared randomly in the breeding colony with no F1 breeding pair producing more than one pa we mouse. These observations rule out the presence of a mutant gene, fixed or unfixed, as an explanation for this syndrome. We hypothesize that the syndrome is the result of the complementary action of the genes or the chromosomal segments containing the genes pa and we or weBkr. The posited synergism is further supported by the finding that we, which functions as a recessive gene in mice of the pa/+ genotype, appears to function as a dominant gene in mice possessing the pa/pa genotype.

Allograft rejection-defined antigens of the B2m,H-3 region.

In this report we delineate the production and histocompatibility characteristics of two new B2m, H-3 region congenic strains, B10.SM-a and B10.FS-a, and further characterize previously described strains. Strains C57BL/10 and B10-we are shown to be histocompatible by the exchange of skin grafts, as are strains B10.UW-we,un at, B10.UW we un a, B10.UW-we + a, B10.UW-+ + a and B10.LP-a. (The latter group will be called B10-H-3b when referred to collectively). C57BL/10, B10-H-3b, B10.C-a, B10.KR-a, B10-pa at, B10.SM-a, and B10.FS-a are shown to be histoincompatible by the rejection of exchanged skin grafts, and histoincompatibility between these strains has been localized to the B2m, H-3 region. The histoincompatibility between C57BL/10 and B10.FS-a is of particular significance because of the identity of these strains at the B2m, H-3 region loci B2m and H-3. Thus the B2m, H-3 region histoincompatibility herein described defines a new locus, which we have called H-42, the a allele being assigned to C57BL/10 and the b allele to B10.FS-a. By using cross-immunization techniques, four allograft rejection-defined reactivity patterns (ADR) have been defined that show concordant strain distribution patterns with the CTL-defined reactivity patterns described elsewhere. On the basis of data presented in this report indicating C57BL/10 and B10.FS-a to differ by a histocompatibility gene in the B2m, H-3 region, and data presented by Kurtz et al. elsewhere indicating C57BL/10 and B10.FS-a to possess the same alleles at the B2m and H-3 loci, the presence of at least three B2m, H-3 region loci-defining cell membrane antigens is established.

CTL and serologically defined antigens of B2m,H-3 region.

The antigens of the B2m,H-3 region of 13 chromosome 2 congenic strains and seven inbred strains have been studied by using CML and serologic techniques. Nine patterns of cross-reactivity have been defined by CML assays. These results are in agreement with an extend previously described cross-reactivity studies. The reactivities of three monoclonal antibodies previously thought to be reacting with B2M-B are shown to differ: Ly-m11 and J-5 react with cells of strain B10-pa,at and clone 23 does not. Two H-3 region loci are hypothesized on the basis of CML and serologic activity: B2m and H-3. The CTL responses to the B2M antigens are H-2K restricted; the CTL responses to H-3 antigens are H-2D restricted. The restriction of the response to the H-3 antigen requires effector-target identity of the H-2D molecule but not the B2M molecule of the class I antigen. These loci have been separated by recombination from H-42 in the production of the congenic strain B10.FS-a. A gene order of B2m, H-3, H-42 is suggested.