Fc receptors, Ia antigens, and immunoglobulin on normal and activated mouse T lymphocytes

Abstract

Using antibody coated bovine erythrocytes we were unable to demonstrate Fc receptors on either thymus cells or T cells prepared from lymph node cell suspensions by anti Ig column filtration. However, if parental thymus or lymph node T cells were transferred to X irradiated F1 hybrids, activated donor T cells recovered from the recipient's spleen (ATC spleen) were shown to express Fc receptors. Fc receptors were also demonstrable on ATC spleen prepared between strain combinations differing at the M locus. In marked contrast, Fc receptors were not detected on ATC recovered from thoracic duct lymph (T.TDL). This applied to (a) H 2 activated T.TDL derived from normal thymus cells, (b) H 2 activated T.TDL derived from thymus cells depleted of B cells, and (c) M locus activated T.TDL. Of these three populations, surface Ig (of B cell origin) was detected on a large proportion of the first but not on the second and third populations. Thus, the failure to detect Fc receptors on any of these populations could not be attributed to blocking by adsorbed surface Ig. In addition, various T cell populations were examined by a microcytotoxicity assay for the presence of cell surface Ia antigens. 5-10% of the thymus cells, 20-30% of cortisone resistant thymus cells, 60-70% of lymph node cells, and 60-80% of ATC spleen and T.TDL showed Ia.