Separation of mouse T cell subsets by a fluorescent activated cell sorter using fluorescence-labeled peanut agglutinin.

Nylon non-adherent spleen T cells obtained from concanavalin A-injected mice were labeled with fluorescein-labeled peanut agglutinin and separated into peanut agglutinin-positive (PNA+) cells and peanut agglutinin-negative (PNA-) cells by a fluorescent activated cell sorter. PNA+ cells were found to exert marked suppressive effect on primary anti-sheep red blood cells antibody response, but PNA- cells did not affect the antibody response. From these results and from the sugar-binding specificity of PNA, suppressor T cells are supposed to possess abundant galactosyl residues exposed on the cell surface, which are not masked by sialyl residues.