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D C Shreffler

Publications and source records attributed to D C Shreffler.

At least 55 records · Page 3Linked to original sources
PubMed1981

Ia-positive stimulator cells are required in primary, but not in secondary, mixed leukocyte reactions against H-2K and H-2D differences.

The expression of I region gene products on stimulator cells in primary and secondary MLR directed against differences determined by the K or D regions of the H-2 gene complex was examined in B10-congenic mice. Treatment of the stimulator cells with anti-Ia antisera and complement (C) eliminates stimulation in primary MLR against K or D region gene products, indicating that the stimulator cells must express Ia antigens on their membranes. Further, stimulation in primary MLR against D region antigens is abolished by treatment of the stimulator cells with C and antisera against either I-A or I-E subregion products, but not by treatment of stimulator cells with C and antisera against I-J subregion products. Therefore, these stimulator cells express on their membranes both I-A and I-E subregion gene products, but not I-J subregion gene products. In contrast, in secondary MLR against K or D region gene products, treatment of stimulator cells with anti-Ia antisera and C does not abolish stimulation, indicating that Ia-negative cells can stimulate primed responder cells. These results indicate that the mechanisms of cell-cell recognition necessary in secondary MLR against K or D region gene products are different from those in primary MLR to the same products.

Animals↗
PubMed1981

Differential glycosylation of murine B cell and spleen adherent cell Ia antigens.

Examination of I-A and I-E molecules from purified B cells and splenic adherent cells from various haplotypes revealed a consistent difference in isoelectric focusing (IEF) that has been localized to the alpha-chain. alpa-Chains from B cells appeared heterogeneous and contained acidic IEF bands absent from the adherent cell I-A molecules. No difference in Ia beta-chain or H-2 IEF patterns was observed when B cell and adherent cell preparatios were compared when B cell and adherent cell preparations were compared. I-A alpha-chain preparations from the 2 cell sources showed no differences in 3H-leucine-labeled tryptic peptides separated by reverse-phase high-pressure liquid chromatography. Digestion with neuraminidase, kinetics of labeling, and subcellular distribution indicated that the extra acidic IEF bands in B cell Ia represent a mature, more heavily sialated form of alpha-chain that is not present in adherent cells. The selective differential glycosylation of B cell and adherent cell Ia could have some relation to the function of those cell types or to cell type-specific recognition of those cells.

Animals↗
PubMed1981

Identification of H-2-controlled structural variants of the murine Slp protein and demonstration of cis-regulation of its expression.

H-2 haplotype-related structural variation in Slp beta-chains was detected by the limited proteolysis peptide mapping technique. Two distinct peptide patterns were distinguished: Slp.1 was found in strains carrying the S regions of the H-2d and H-2s haplotypes, and Slp.2 was found in strains bearing the S region of H-2w7. These different patterns were expressed codominantly in male (Sd X Sw7)F1 hybrids, whereas only the Slp.2 pattern was expressed in female heterozygotes. The 2 beta-chains are most likely the products of alleles of the Slp structural gene, which must then be located in the murine major histocompatibility complex, very probably in the S region.

Animals↗
PubMed1980

Murine pancreatic beta-cells express H-2K and H-2D but not Ia antigens.

Direct microcytotoxicity testing and absorption analyses were employed to determine whether H-2K, H-2D, and Ia antigens are present on murine islet of Langerhans cells. Products of the H-2K and H-2D loci were found on beta-cells from three different mouse strains, but I-region (Ia) antigens were not detected. The absence of Ia gene products from islet cells may be of importance in explaining the survival of islet allografts across major histocompatibility barriers.

Animals↗
PubMed1980

Growth of SJL/J-derived transplantable reticulum cell sarcoma as related to its ability to induce T-cell proliferation in the host. I. Dominant negative genetic influences of other parent haplotype in F1 hybrids of SJL/J mice.

Growth of three transplantable reticulum cell sarcomas (RCS) was studied in a variety of F1 hybrids of SJL/J mice by determination of lymph node (LN) and spleen: body weights ratios 7 and 14 d after intravenous injection of RCS cells. Comparison of BIO.S x SJL and A.SW x SJL with SJL/J showed a negative effect of both the A and the BIO non-H-2 genes, particularly on growth in LN. F1 hybrid resistance was noted with F1 hybrids that carried H-2Dd and was much more evident with F1 hybrids from BIO- than from A-background mice. This resistance was less marked at 14 than at 7 d and was partially overcome by injection of higher tumor doses. Changing the I region in the F1 parent from H-2d to H-2b or H-2f had no effect on growth, but changing to H-2k or H-2d virtually abolished the ability to support tumor growth. This effect appeared partially as a result of the I-E/C and partially of the I-A(B) region and was not overcome by higher tumor dose or longer intervals after injection. There also appeared to be a negative influence on growth of H-2Kk, but this was difficult to differentiate from the I-Ak effect with the available strains. The known proliferative responsiveness that SJL/J Lyt-1 T cells exhibit to Ia determinants on gamma-irradiated RCS cells in vitro was also compared with that of cells from various F1 hybrids. Responsiveness of F1 LN cells was expressed as a percentage of the response in SJL/J LN cells to the same RCS cells, measured as [3H]thymidine incorporation. There was a striking degree of correlation between proliferative responsiveness of F1 LN cells to RCS and the ability of the F1 mice to support tumor growth. This correlation was especially clear with respect to the negative influences of non-H-2 genes, and of H-2 loci in the I region, particularly of I-Ak or -d and of I-E/Ck or -d, but there also appeared to be a (smaller) negative effect of I-Ab or -f. Negative influence of H-2Dd on growth, however, was not reflected in a similarly large effect on the proliferative response. Additional findings showed that LN cells from all F1 hybrids exhibited equivalent syngeneic mixed lymphocyte responses in the presence of polyethylene glycol to mitomycin-treated spleen cells from both the SJL/J and the other parent. The extra high response of F1 cells to RCS cells, as compared with SJL spleen cells, however, was always absent when Ik or -d was contributed by one of the F1 parents. The results suggest a promoting effect of the proliferative response on RCS growth in vivo and, furthermore, an interesting effect of I-A and I-E/C genes, possibly via an interaction product, on the ability of LN cells to be stimulated by Ia determinants on RCS cells.

Animals↗
PubMed1980

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-2-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.

Androgen-Insensitivity Syndrome↗
PubMed1980

Genetic and structural characterization of H-2-controlled allelic forms of murine C4.

The patterns of expression of several types of genetic variation in murine C4 were investigated. Dominance was assessed for S-region-determined differences in molecular weight of the C4 alpha-chain from Sw7 strains relative to all other strains examined and in C4 hemolytic titers. Codominant expression in F1 hybrids was shown for both of the above variations. Comparison of tryptic peptide profiles of radiolabeled C4 beta-chains encoded by different S regions revealed differences in their primary structures. The demonstration of codominant expression for the variant C4 traits examined and the evidence from tryptic peptide maps for haplotype differences in C4 primary structure strongly support the hypothesis that polymorphism of murine C4 is controlled by structural genes which are located in the S region.

Alleles↗
PubMed1980

Identity of molecules bearing murine Ia alloantigenic specificities Ia.7 and Ia.22: evidence for a single type of I-E molecule in homozygotes.

In homozygous mice bearing I regions derived from haplotype k, only a single type of Ia molecule bearing the alloantigenic specificities Ia.7 and Ia.22 was found using techniques of sequential immune precipitation and tryptic peptide analysis. As suggested at the fourth Ir Gene Workshop (Sachs 1978), Ia.7 is considered here to be an antigenic determinant associated with I-E-subregion-encoded molecules, i.e., it is excluded from the I-C subregion. The I-C subregion is currently defined mainly by functional traits. It is now known that the I-E molecules are composed of an alpha chain encoded in the I-E subregion, and a beta chain encoded in the I-A subregion. Since the I-C subregion is not involved with the determination of these Ia molecules, and since in homozygotes there is apparently only a single type of molecule bearing both specificities Ia.7 and Ia.22, the term "I-E/C" molecule should probably be dropped in favor of the simpler designation I-E.

Animals↗
PubMed1980

Partial amino acid sequences of the murine fourth component of complement (C4): demonstration of homology with human C4 and identification of the amino-terminal subunit in pro-C4.

Radiolabeled murine C4 and C4 precursor (pro-C4) from cultured peritoneal macrophages were purified by immunoprecipitation and preparative gel electrophoresis. The partial NH2-terminal amino acid sequences of the isolated subunits demonstrated that murine C4 alpha, beta-, and gamma-chains all show sequence homology with the corresponding subunits of human C4; of the 10 residues identified in murine C4, all are identical to those in human C4. These data extend to the primary structural level the homology between the murine serum substance (Ss) protein and human C4. Comparisons of the amino acid sequences of murine pro-C4 and the constituent polypeptide chains of secreted C4 indicate that pro-C4 and the C4 beta-chain have an identical amino acid sequence. Both molecules have lysine at position 1, leucine at positions 4, 5, and 6, and phenylalanine at position 7. No sequence homology was found between pro-C4 and either the alpha- or gamma-subunits. These results define the beta-chain as the NH2-terminal subunit in the C4 precursor molecules.

Amino Acid Sequence↗
PubMed1980

Characterization of the stimulator cells in the murine primary mixed leukocyte response.

Macrophage-enriched and depleted spleen cell populations were examined for their ability to stimulate a murine 1 degree mixed leukocyte response. A quantitative comparison of unfractionated spleen cells, Sephadex g-10 passed spleen cells, 4-hr glass adherent and 24-hr glass adherent spleen cells revealed that a potent 1 degree MLR stimulator cell was phagocytic and that T and B lymphocytes failed to stimulate a response. By using several inb;ed and recombinant mouse strains congenic for different subregions of the MHC, it was found that macrophage-enriched cells were capable of inducing an MLR against K, D, I-A, and I-E differences and against K and D mutants. Both macrophage-enriched and depleted spleen cells failed to stimulate responses when the stimulator and responder differed at I-J, I-C, S, or G. Moreover, MLR stimulation induced by K or D region differences alone was dependent upon stimulator cells that expressed Ia antigens. Therefore, it would appear that only a minor subpopulation of the cells that express the relevant MHC alloantigens is immunogenic in the murine 1 degree MLR.

Animals↗
PubMed1980

Characterization of the oligosaccharide units of the fourth component of complement (Ss protein) synthesized by murine macrophages.

The glycosylation of murine C4 (Ss protein) synthesized by peritoneal macrophages has been investigated. Both the intracellular precursor, P-C4 (185), and the C4 alpha- and beta-chains that were secreted into medium were found to be glycosylated; however, no carbohydrate units were detected on the gamma-chain. Analyses of the oligosaccharide units showed that P-C4 (185) appears to contain both a "complex" and a "high mannose" carbohydrate group, the alpha-chain a "complex" group and the beta-chain a "high mannose" carbohydrate unit.

Acetylglucosaminidase↗
PubMed1979

Structural characterization of the murine fourth component of complement and sex-limited protein and their precursors: evidence for two loci in the S region of the H-2 complex.

The S region of the murine major histocompatibility complex controls the expression of two related, serum substance-positive proteins; one (C4) has functional complement activity, whereas the other, the sex-limited protein (Slp), is hemolytically nonfunctional. The structural relationships of these molecules to each other and to their putative intracellular precursors have been examined. Radiolabeled intracellular C4 and Slp precursors were isolated from lysates of cultured peritoneal cells. The C4 and Slp precursors and their processed subunits were purified by immunoprecipitation and sodium dodecyl sulfate/polyacrylamide gel electrophoresis. Antigenically distinct precursors for C4 and Slp were demonstrated by sequential immunoprecipitation experiments in which anti-Slp-reactive molecules were precleared by exhaustive immunoprecipitation and residual C4 molecules were precipitated by antibody to serum substance. Both molecules had apparent molecular weights of 185,000. Their molecular identities as precursors of the mature C4 and Slp proteins were established in pulse-chase studies and by comparisons of their tryptic peptide profiles with those of isolated subunits from the processed proteins. When isolated alpha- or beta-subunits from C4 and Slp proteins were compared by peptide mapping, it was possible to detect multiple distinct and multiple shared peptides. This evidence indicates that the C4 and Slp proteins derive from distinct precursor polypeptides and suggests that the primary structures of the C4 and Slp alpha- and beta-subunits are different. These results support the postulate that the S region contains two discrete structural loci that specify discrete C4 and Slp proteins.

Animals↗
PubMed1979

Selective effects of anti-Ia serum and complement treatment upon polyclonal B lymphocyte responses to dextran sulfate and lipopolysaccharide.

Subpopulations of B lymphocytes have been shown to vary in their expression of Ia alloantigens and polyclonal responsiveness to thymic independent antigens. We have demonstrated that the polyclonal B cell antibody response to dextran sulfate is less sensitive to removal of Ia-positive cells than is the response to LPS. This is a consistent finding whether alloantibody and complement (C) pretreatment is directed toward cells bearing Ia antigens coded for by the entire I region or by the I-A or I-E subregions. Heterogeneity appears to exist within the dextran sulfate-sensitive population in that using high antibody; cell ratios during antibody and C-mediated cell selection results in an inhibition of the proliferative but not the antibody response. This result may indicate a differential expression of Ia antigens on dextran sulfate-sensitive B cells that respond by proliferation versus those cells that produce antibody. Alternatively, proliferative responses to dextran sulfate may be more dependent upon Ia-positive accessory cells than is the polyclonal antibody response.

Animals↗