Differential effect of two monoclonal anti-Lyt-1 alloantibodies on lymphocyte distribution in vivo.

The effect of anti-Lyt-1 monoclonal antibody treatment on the in vivo migration properties of mouse T lymphocytes was examined. Cells were treated with antibody in the presence or absence of complement. T cells of the Lyt-2 cytotoxic/suppressor phenotype were selected from B6 spleen cell suspensions by cytotoxic elimination with an allospecific anti-Lyt-1.2 antibody. These cells were labelled with 51Cr and transferred to syngeneic recipients which were killed 1 or 24 hr later for assessment of radiolabel tissue distribution. In vivo migration of anti-Lyt-1.2 selected cells was similar to that of unselected T cells. By contrast, a functionally and phenotypically identical population selected from C3H spleen T cells with an anti-Lyt-1.1 monoclonal antibody showed increased accumulation in recipient liver and a decline in recovery from lymph nodes and spleen. Treatment with anti-Lyt-1.1 in the absence of complement caused even greater localization to the liver, with a simultaneous poor recovery from lymphoid tissues, similar treatment of cells from B6 Lyt-1.1. congenic mice also resulted in altered migration. Treatment of B6 lymphocytes with anti-Lyt-1.2 in the absence of complement caused little change in the normal T cell tissue localization. These results suggest that selected Lyt-2 cells, reported to express low levels of Lyt-1 antigen undetectable by conventional u.v light microscopy immunofluorescence and serological methods, may contain residual bound antibody which can result in opsonization and sequestration of the cells by recipient stromal cells after in vivo transfer. Binding of the antibody directed to the Lyt-1.2 allospecificity of B6, although of the same immunoglobulin class and selecting for a similar functional set by cytotoxic elimination, does not cause such sequestration in vivo.