Lymphocyte surface IgD and IgM in Macaca monkeys: ontogeny, tissue distribution and occurrence on individual lymphocytes.

A proportion of lymphocytes in blood, spleen and lymph nodes of nonhuman primates had immunoglobulin on their surfaces detectable by fluorescent antibody to human IgM and IgD. The majority of the individual lymphocytes having either IgM or IgD on their surfaces possessed both classes of immunoglobulin. Lymphocyte surface IgD was capped independently of surface IgM on the same cell when incubated at 37 degrees with anti-IgD. Lymphocytes with surface IgM and/or IgD were present in blood at birth and the percentages over the first 6 months of life were increased compared to older monkeys. A corona of cells faintly positive for both IgM and IgD was observed around germinal centres of both lymph nodes and spleen.