Interaction of phagocytes with apoptotic cells leads to production of pro-inflammatory cytokines

It is generally believed that apoptosis is not associated with inflammation. To explore the possibility that the interaction of phagocytes with apoptotic cells provides a negative or null signal for inflammation, we examined the cytokine production by thioglycollate-induced peritoneal exudate cells (PEG) upon interaction with a murine T cell clone (CTLL-2) cultured in the absence of interleukin-2 (IL-2). Coculturing of PEC with apoptotic CTLL-2 cells led to the production of not only anti-inflammatory cytokines but;also pro-inflammatory ones, notably MIP-2, at the mRNA level, and neutrophils were accumulated in vivo in response to the culture supernatant. Our findings suggest the possibility that apoptosis may be associated with leukocyte infiltration in vivo in some situations. (C) 1997 Academic Press.