Mitogenic and adjuvant activity of a methanol extraction residue (MER) of tubercle bacilli on mouse lymphoid cells in vitro.

The mitogenic and adjuvant effect in vitro of MER (methanol extracted residue of tubercle bacilli), on Balb/C and nu/nu immunocompetent cells was examined and compared with the effect of PPD, LPS, DS, PHA and ConA. MER activated DNA synthesis in spleen cells of Balb/C and nu/nu mice and in blood cultures of Balb/C. The stimulation of DNA synthesis by MER in spleen cells was not macrophage dependent. Bone marrow and 1ymph node cells were slightly stimulated while thymus cells were not affected. Both MER and PPD enhanced the in vitro immune response of Balb/C mice to SRBC and to TNP (trinitrophenyl) hapten. MER, LPS and PPD enhanced the immune response of nude spleen cells to SRBC in vitro.