Effects of high doses of peptichemio upon the humoral response to sheep erythrocytes and delayed hypersensitivity reactions to oxazolone in CBA mice.

A study has been carried out on the immunosuppressive activity of high doses of peptichemio (PTC) in CBA mice. Humoral response to sheep erythrocytes, delayed hypersensitivity to oxazolone, and cellular proliferation in lymph nodes and spleen of animals sensitized with oxazolone have been investigated. The results demonstrated that PTC had a definite immunosuppressive action, as shown by the inhibition of primary response to inoculation of sheep erythrocytes, by depression of delayed hypersensitivity to oxazolone, and by marked inhibition of 125IUdr incorporation in lymph nodes of sensitized animals. It is suggested that the inhibitory action is mediated by an effect on actively proliferating B or T lymphoid cells, although involvement of macrophages cannot be ruled out.