Identification in human lymphoid tissues of cells that produce group 1 or group 2 gamma-globulins

The cells that produce group 1 and group 2 γ-globulins have been localized in human lymphoid tissues. This has been done with the use of antisera specific for group 1 or group 2 γ-globulins prepared by immunizing rabbits with purified Bence-Jones proteins of the corresponding group and subsequently conjugated with different fluorochromes. The immunofluorescence observations have shown that in the red pulp of the spleen of adult humans two populations of plasma cells, present in approximately equal numbers, can be differentiated on the basis of the type of γ-globulin produced. The cells in the germinal centres of lymphoid follicles in the spleen and lymph nodes appear, instead, to contain both group 1 and group 2 γ-globulins.