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M L Bach

Publications and source records attributed to M L Bach.

At least 55 records · Page 3Linked to original sources

Beta 2-microglobulin: association with lymphocyte receptors.

beta(2)-Microglobulin (beta(2)m) is a low-molecular-weight protein constituent of lymphocyte membranes. Amino acid sequence analysis has revealed a high degree of homology between the beta(2)m and certain regions of immunoglobulin molecules, suggesting a possible recognition function for the beta(2)m, in analogy with the immunoglobulins. The data presented demonstrate that highly specific antiserum against beta(2)m blocks lymphocyte reactivity against allogeneic cells in mixed leukcocyte cultures and against phytohemagglutinin, both of which processes presumably function via a cell surface receptor on thymus-derived (T) lymphocytes. There is very little inhibition of T lymphocyte rosette formation with sheep red blood cells. The findings suggest a possible relation between the beta(2)m and recognition units on the T lymphocyte surface.

Animals↗

Cell-mediated lympholysis. Importance of serologically defined H-2 regions.

The cell-mediated lympholytic capability of mouse spleen cells stimulated in mixed lymphocyte culture is related to the major histocompatibility complex genotype on target lymphocytes. The strain combinations AQR-B10. T(6R) and B10.A(4R)-B10.A(2R) that result in significant mixed lymphocyte culture activation do not mediate cell-mediated lympholysis on sensitizing target lymphocytes; serologically defined regions (H-2K and H-2D) are identical within each combination. H-2K or H-2D region disparity alone does not cause cell-mediated lympholysis. However after mixed lymphocyte culture activation as seen with B10.A-B10.T(6R), a target cell bearing only an H-2K region difference from the effector cell is sensitive to cell-mediated lympholysis. Likewise an H-2D region difference is an adequate target after mixed lymphocyte culture activation of the effector cell in the combination B10.A(2R)-B10.D2.

Animals↗

Cell mediated immunity: separation of cells involved in recognitive and destructive phases.

The mixed leukocyte culture (MLC) and the cell mediated lympholysis (CML) assays are used as in vitro models of the afferent, or recognitive, and efferent, or destructive, phases of the homograft reaction. Activity in both of these tests has been related to differences at the major histocompatibility complex, HL-A in man and H-2 in mouse. Recent evidence suggests that the presumed cell surface differences which lead to cell proliferation in MLC are different from those which act as a target for CML. Data are presented providing further support for this hypothesis; in addition separate cell populations may respond to the differences which activate cells in MLC and to the differences which serve as targets for CML. There thus appears to be a dichotomy both for genetic control of, and cell populations involved in, the recognitive and destructive phases of cell mediated immunity.

Animals↗

Serologically defined and lymphocyte-defined components of the major histocompatibility complex in the mouse.

The mixed leukocyte culture (MLC) test is an in vitro model of the recognition phase of the homograft response. For the most part, activation in MLC is dependent on differences of the major histocompatibility complex (MHC). Our present studies in the mouse suggest that activation is primarily associated with differences of genetic regions of the MHC other than those which control the serologically defined (H-2) antigens. These differences do not lead to cytotoxic or agglutinating antibody formation despite extensive immunization; we have called these differences lymphocyte-defined (LD) differences. The strongest stimulation in MLC is associated with differences of the Ir region. It is possible that the Ir product is the T cell receptor and that it is this same molecule which can act as the stimulatory agent in MLC. Other possibilities are discussed.

Animals↗

Genetic and immunological complexity of major histocompatibility regions.

There are genetic differences within the major histocompatibility complex of the mouse which lead to skin graft rejection but which cannot be detected serologically. When confronted with these differences on allogeneic cells, lymphocytes proliferate in vitro. In other cases, in vitro lymphocyte proliferation but no skin graft rejection is associated with loci that are linked to but genetically separable from the loci controlling the serologically defined antigens.

Alleles↗