Cellular requirements for simulation by the purified streptococcal antigen DSR

Delayed skin reactor (DSR) was prepared from streptokinase-streptodornase. Peripheral blood mononuclear cells, were collected from a Ficoll-Hypaque gradient and subsequently subdivided into T cell-, B cell-, or monocyte-depleted populations. Mononuclear cells with complement receptors (B cells) were removed by a nylon-wool column adsorption. Sheep erythrocyte rosette forming cells (T cells) were removed by centrifugation on a second gradient. Populations of cells which did not adhere to plastic and/or ingest iron filings were monocyte-depleted. While response to DSR as measured by incorporation of tritiated thymidine into DNA was not affected by removing B lymphocytes, it was significantly diminished by removing T lymphocytes. Monocyte-depleted cells incorporated less tritiated thymidine into DNA in both antigen stimulated and control cells, but the stimulation index was not significantly altered.