Distribution of Gc protein (vitamin D binding protein) on the surfaces of normal human lymphocytes and leukemic lymphocytes.

Distribution of membrane-bound Gc protein (mGc) in normal lymphocyte subpopulations and leukemic lymphocytes was studied using a rabbit antiserum specific to Gc protein. Forty to fifty percent of the normal peripheral blood mononuclear cells were stained with anti-Gc antiserum by membrane immunofluorescence, and almost all of the B cells (B1+) and NK cells (Leu 11+) were mGc-positive. Only a few resting T cells (T3+) reacted with anti-Gc, but mGc appeared in a significant number of the T cells after activation by PHA. The distribution of mGc on leukemic lymphocytes of various types nearly corresponded to that in normal lymphocyte subpopulations.