Cellular cooperation in the expression of murine delayed-type hypersensitivity (DTH). 1. A normal accessory cell population enhances DTH produced by immune peritoneal exudate T lymphocytes.

A murine system for local passive transfer of delayed-type hypersensitivity (DTH) has recently been described. It was determined that untreated and T-lymphocyte-enriched (nylon-wool-nonadherent) fractions of peritoneal exudate (PE) cells from immunized donors could be transferred with soluble antigen to normal recipient footpads to efficiently produce a local DTH response. Untreated spleen or lymph node (LN) cell populations were strikingly less capable in this regard. It is now reported that addition of normal untreated PE cell populations to immune T-enriched PE cells markedly enhanced the DTH response transferred by the latter. Specific swelling was dose dependent with respect to each cell type. Removal of T lymphocytes from the normal PE cell population did not affect its enhancement of DTH. By cotransfer of 1 X 10(7) normal PE cells, significant specific swelling was obtained using 1-3 X 10(5) T-enriched immune PE cells. This represented a three- to seven-fold reduction in the requirement for the latter cell type. This scheme of DTH enhancement was employed to evaluate the mechanisms for decreased capability of immune LN and spleen for DTH transfer when compared to PE. No evidence was found that either adherent or nonadherent suppressor cells are operative at the time of DTH expression. Cotransfer of a DTH-enhancing population failed to equalize DTH expression by LN and spleen with that of PE. It is concluded that DTH effector-T-cell activity is enriched in immune peritoneal exudate and that non-T-cell population(s) from that source actively enhance DTH expression.