[Heterologous antisera to stromal mechanocytes of the bone marrow]

Heterologous rabbit antifibroblast serum (AFS) to stromal fibroblasts of the guinea-pig bone marrow was obtained. AFS was shown to bind specifically stromal fibroblasts and their precursors (but not macrophages) in the monolayer primary cultures of the bone marrow, thymus and spleen of guinea pigs (in the complement-dependent cytotoxic reaction and in the indirect immunofluorescence test); AFS also bound precursors of blood fibroblasts and peritoneal exudate (in the cytotoxic reaction). Precursors of the thymus fibroblasts were found to be more sensitive to the AFS action than the spleen and bone marrow precursors, this suggesting that the thymic stromal mechanocytes had a greater concentration of common tissue-specific antigens on their surface. Precursors of the stromal fibroblasts in native cell suspensions were found to be essentially more sensitive to the cytotoxic action of AFS than the colony-forming fibroblasts on the passage cultures.