The distribution of Helix pomatia lectin receptors on mouse lymphoid cells and other tissues.

The distribution of receptors for the Helix pomatia lectin on mouse lymphoid cells and other tissues was investigated. Using a sensitive rosetting assay combined with immunofluorescence, lectin receptors were found on the membrane of approximately 90% of peripheral T lymphocytes, 75% of thymocytes, 30% of bone marrow cells, 20% of nude spleen cells, 15-50% of peritoneal exudate macrophages, and a subpopulation of peritoneal exudate mast cells. The Thy-1-positive nude spleen cells were predominantly Helix lectin receptor-negative. Approximately 5% of B lymphocytes were weakly positive, and neutrophils were negative. Receptors were present also on a subpopulation of cells of a fibroblast cell line and in acetone powder from the liver and, at a lower level, from the kidney and brain. Membrane receptors on all cell types were partially detectable without neuraminidase treatment of the cells. Two methods of fractionating Helix lextin-positive cells were employed, which gave significantly different results. By rosetting and depletion using density fractionation, T cell mitogen responses were abolished, while B cell mitogen responses, T cell cytotoxicity, and natural killer cytotoxicity were only slightly affected, if at all, Helix lectin-agarose column fractionation seemed more sensitive, in that essentially all natural kill cells bound to the column, as well as considerable number of B lymphocytes. Cytotoxic T cells were heterogeneous; roughly half were not bound, but the remainder were bound and eluted.