Proliferation of mouse lymphocytes to rye grass pollen extract: effect of inflammatory exudate cells

The ability of inflammatory peritoneal exudate cells to modify a murine lymphoproliferative response to rye grass pollen extract was investigated. Popliteal and mesenteric lymph node cells from Balb/c mice immunised with either aqueous rye or rye grass emulsified in complete Freund's adjuvant were co-cultured with 2 X 10(3)-10(5) macrophage or polymorphonuclear neutrophil (PMN)-enriched exudate cells. There was a dose-dependent increase in the response to rye grass antigen with increasing numbers of PMN. A similar enhancement was seen with up to 10(4) macrophages per culture; higher numbers were inhibitory. Lymph node cells from rye grass or ovalbumin-immune mice that had been challenged with a combination of sensitising antigen plus 10(7) PMN gave an increased antigen-specific response in vitro. Neither antigen alone, PMN nor a mixture of PMN plus heterologous antigen was active. Adoptive transfer of a similar number of peritoneal macrophages plus antigen was also without effect. These results are in accord with the suggestion that cells obtained from acute inflammatory lesions can directly influence the activity of immunocompetent lymphocytes.