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B N Beck

Publications and source records attributed to B N Beck.

23 records · Page 2Linked to original sources
PubMed1982

Functional similarities of AeE alpha Ia molecules as determined by analysis with T-cell clones.

Recognition of AeE alpha Ia antigens at the functional level was investigated using T-cell clones. The reactivities of an alloreactive and an antigen-reactive clone, both of which recognized AeE alpha Ia molecules, were compared on a panel of stimulator/antigen-presenting cells of various genotypes. The two clones recognized all tested AebE alpha x Ia molecules, where x is a haplotype capable of expressing an Ia.7-bearing E alpha polypeptide. Ia antigen recognition by either clone could be inhibited by the monoclonal antibody Y-17, which recognizes a combinatorial serologic determinant on certain AeE alpha molecules. There were no differences in the recognition of Ia by the alloreactive versus the antigen-reactive clone, suggesting that Ia antigens are recognized by the two clones in a fundamentally similar way. The recognition of these various Ia molecules by the two cloned T-cell lines provides evidence that the E alpha polypeptides from H-2 haplotypes k, d, r, and u are functionally indistinguishable.

Animals↗
PubMed1982

Display of the neutral glycolipid ganglio-n-tetraosylceramide (asialo GM1) on cells of the natural killer and T lineages.

Analysis was made of the display of the neutral glycolipid asialo GM1 on cells involved in the differentiation and expression of natural killer (NK) and T cell-mediated cytotoxicity in vitro. Removal of asialo GM1-bearing cells from CBA spleens, by treatment with a specific rabbit antibody in the presence of complement, led not only to the abrogation of NK cell activity but also to the lack of responsiveness of such populations to polyinosinic: polycytidylic acid (poly I:C) and to interferon, indicating that both NK cells and interferon-responsive cells of the NK cell lineage bear asialo GM1. Cytotoxic T lymphocytes (CTLs) induced by mixed lymphocyte culture in vitro were unaffected by treatment with antiasialo GM1 serum in the presence of complement, but normal spleen cells subjected to this treatment failed to mount CTL responses to alloantigen, even in the presence of an exogenous source of Interleukin-2 (IL-2). Furthermore, spleen cell populations depleted of asialo GM1-bearing cells showed a decreased ability to produce IL-2 in response to mitogenic stimulation.

Animals↗
PubMed1980

High negative interference and recombination in bacteriophage T5.

The process of close recombinant formation in bacteriophage T5 crosses has been studied by examining the structure of internal heterozygotes (HETs), the immediate products of recombination events. The T5 system was chosen because it permits the study of internal heterozygotes exclusively, thus avoiding the ambiguities inherent in previous studies with T4. The heterozygotes were obtained by the nonselective screening of progeny phage in a prematurely lysed sample from an eight-factor cross. The molecular structure of each HET was inferred from the strand genotypes displayed among its progeny. This investigation presents unequivocal evidence that both overlap and insertion HETs are intermediates in recombinant formation and that insertion HETs are a significant source of close double recombinants. There is evidence suggesting that mismatch repair of overlap HETs could be the source of close triple exchanges. Thus, a significant part, and perhaps all, of the high negative interference for close-marker recombination observed in this system is a direct consequence of the fine structure of the recombinational intermediates. These findings are compatible with recombination models proposed by others, in which a single branched intermediate can give rise to HETs of both the overlap and insertion types.

Crosses, Genetic↗