Suppression of B-cell and T-cell responses by the prostaglandin-induced T-cell-derived suppressor (PITS). II. Resolution of multiple PITS beta factors.

It has been shown that T cells cultured with prostaglandin E2 are induced to release at least two peptide-containing lymphokines (PITS). Both the high-molecular-weight (35,000; PITS alpha) and the low-molecular-weight (2000 to 5000; PITS beta) factors were shown to be potent inhibitors of both T-cell- and B-cell-dependent mitogen responses. Data are reported here which show that the PITS beta factor may be reproducibly resolved into seven components by high-pressure liquid chromatography. Although each of these components is capable of suppressing the phytohemagglutinin-induced blastogenic response, not all of these factors will suppress the in vitro antibody response to sheep erythrocytes, or a mixed lymphocyte reaction. Nevertheless, the broad-range suppressive effects previously reported for PITS beta now seem to be mediated by multiple low-molecular-weight PITS factors.