IMMUNE RESPONSE AND MITOSIS OF HUMAN PERIPHERAL BLOOD LYMPHOCYTES IN VITRO.

Phytohemagglutinin causes cultured lymphocytes to agglutinate, divide, and produce gamma-globulin. Most cells are transformed into large lymphocytes, some resembling plasmocytes. Actinomycin D stops gamma-globulin production after 2 hours. When specific antigens are added to lymphocytes from sensitized individuals, only some cells undergo morphological transformation, produce gamma-globulin, and divide. When cells or cell extracts from an unrelated individual are added to a culture, a similar reaction occurs.