Cyclic AMP and immune responses: identification of prostaglandin E-producing cells in mouse spleens

Previous work has shown that normal mice respond to the intravenous injection of sheep erythrocytes (SRBC) with a transient increase in splenic cyclic AMP peaking after 2 minutes, and this cyclic AMP response has been shown to be due to prostaglandins (PGs) released from antigen-specific cells. In the present study, the cell type responsible for PG production in response to antigen was determined using a fluorescence-activated cell sorter (FACS) and an electron microscope. C57Bl/6 mice injected with SRBC showed a 2% increase of PGE-producing spleen cells relative to controls. In control mice injected with phosphate-buffered saline (PBS), 19% of the spleen cells produced PGE. An electron microscopic study of PGE-producing cells sorted on FACS showed that they were small lymphocytes and plasma cells. In addition, nude mice also increased the number of PGE-producing spleen cells in response to antigen. These findings suggest that lymphocytes involving at least B-cells respond to antigen with an increase in PGE production.