Proliferation stimulating effects of chrysotile and crocidolite asbestos fibres on B lymphocyte cell lines.

Asbestos fibres of chrysotile, crocidolite and amosite were incubated with eight types of human cell lines in vitro. These asbestos fibre were cytotoxic to fibroblasts and monocyte like cells, as is already known. On the other hand, immature B lymphocyte lines (B1 2) were stimulated significantly by chrysotile and crocidolite, while a mature B cell line (B3) was not affected. Cell proliferation of a T cell line and an erythromyeloid cell line also was not affected by asbestos. For the stimulation of lymphocytes, the binding of the mitogen to the reactive sites on the lymphocyte surface is thought to be indispensable. It seems that chrysotile and crocidolite asbestos can bind to immature B lymphocytes, but not to mature B cells.