Diane D. Eardley

Ly-1 inducer and Ly-1,2 acceptor t cells in the feedback suppression circuit bear an I-J-subregion controlled determinant

An I-J-subregion controlled determinant is expressed on Ly-1 inducer and Ly-1,2 acceptor T cells in the feedback suppression circuit. Ly-1 T cells absorb the I-J antibody reactive with the Ly-1,2 acceptor T cell, suggesting that both inducer and acceptor T cells have the same 1-J determinant. Since less than 10 percent of Ly-1 or Ly-1,2 T cells are killed by anti-I-J plus complement treatment, the I-J determinant demarcates functionally distinct subsets of both the Ly-1 and Ly-1,2 T-cell sets. This I-J determinant is not expressed on a detectable number of Ly-1 helper T cells which induce B lymphocytes to produce anti-sheep red cell antibody in tissue culture.

T cells in a suppressor circuit and non-T: non-B cells bear different 1-J determinants

T cells involved in the generation of suppressor activity bear an I-J-subregion controlled determinant (e. g., J1) which is distinct from that (e. g., J1) found on non-T: non-13 accessory cells. T-cell subsets examined include Ly-1 inducer and Ly-1,2 acceptor cells which collaborate to generate suppressor activity in the in vitro sheep red blood cell antibody system. Non-T:non-B accessory cells examined include accessory cells involved in concanavalin-A induced, T-cell proliferative responses and in in vitro antibody responses to sheep red blood cells. These results provide evidence for serologic and genetic complexity of the I-J subregion of the murine H-2 gene complex.

Isolation and partial characterization of antigen-binding molecules produced by In vitro ‘educated’ T cells

Biosynthetic incorporation of 3H-leucine or lactoperoxidase-catalysed radioiodination of cell surface proteins was used to radiolabel antigen-specific molecules produced by murine splenic T cells cultured in vitro with heterologous erythrocytcs. Antigen-binding proteins present in detergent lysates of labelled cells or in culture media in which labelled cells were incubated were isolated by specific absorption to and elution from erythrocytes. The eluted proteins were characterized by gel electrophoresis and column chromatography and were found to be primarily 68,000–72,000 d ‡ polypeptides, although lower molecular species (35,000d, 30,000d) believed to be proteolytic fragments of the larger polypeptides were sometimes detected. Lyl +,2−, Lyl −,2+, and (by inference) Lyl +,2+ cells produced antigen-binding proteins. However, the majority of cell-associated polypeptides were derived from Ly2 + cells, while antigen-binding proteins secreted by the cells were derived primarily from Lyl + cells. Moreover, the production of detectable levels of antigen-binding proteins by Ly2 + cells required interaction with Lyl + cells.

Regulation of self-recognition by T-cell hybrids

Abstract Somatic cell hybrids were prepared between BW 5147, an AKR T lymphoma, and purified T cells from three sources: spleen cells exposed to sheep red blood cells, lymph node cells from mice sensitized to ovalbumin, and spleen cells of mice injected with azobenzenearsonate-IgG. Hybrid lines expressed constitutive markers of both parents which include H-2 antigens and the isoenzymes glucose phosphate isomerase and isocitrate dehydrogenase. Furthermore, they expressed both parental alleles of Thy 1, a differentiation antigen. Many of the hybrid lines formed rosettes with mouse erythrocytes. T-cell hybrids did not bind human or chicken red blood cells, though they did rosette with sheep erythrocytes to the same extent as with mouse red cells. We interpret the latter reaction as due to recognition of shared antigens by the murine T cells. This form of self-recognition is influenced by culture conditions and is expressed optimally by cells in late logarithmic phase of growth.