On the Origin of Peritoneal Fluid Cells

Peritoneal fluid cells from mouse radiation chimeras were tested to determine their strain of origin by reaction with donor-specific and host-specific isoimmune sera. In all chimeras that retained donor hemopoietic grafts, peritoneal fluid cells were found to be of donor type. This was true regardless of the kind of hemopoietic tissue transplanted into the irradiated mouse. Donor hemopoietic transplant material included bone marrow, fetal liver, peripheral blood leukocytes, and peritoneal fluid cells from mice and bone marrow from rats. Irritation of the peritoneal cavity shifted differential counts but did not change the cytotoxicity results: all the free cells removed were of donor type.