Relationship of macrophages to defective delayed-type hypersensitivity in B6/lpr mice

These experiments were undertaken to clarify whether or not suppressor macrophages contribute to deficiency of delayed-type hypersensitivity induced by BCG CW immunization in B6/lpr mice. Addition of indomethacin in vitro did not increase MIF production by immunized lpr lymph node cells. Adherent cells in lymph node cell suspensions from lpr mice did not interfere with MIF production by nonadherent lymph node cells from immunized B6 mice. On the other hand, MIF production by nonadherent lymph node cells from immunized B6/lpr mice was not restored even if they were cultured with adherent lymph node cells from immunized B6 mice. In addition, macrophages from nonimmunized B6/lpr mice showed normal reactivity to MIF when lymphocytes coexisting with the macrophages in large proportions were depleted from PEC. These results suggest that macrophages make no contribution to the deficiency of DTH expression of B6/lpr mice.