Susceptibility of human cell lines to feline leukemia virus and feline sarcoma virus

The susceptibility of human fibroblasts and human lymphoid cell lines to feline leukemia virus (FeLV) and feline sarcoma virus (FeSV) was investigated. Human cells were highly sensitive to infection by FeLV subgroups B and C and FeSV but resistant to infection by FeLV subgroup A. The cells became infected, produced infectious virus, and displayed no differences in morphology or viability. T-cell lines appeared to be more sensitive to FeLV and FeSV infection and to produce more virus than did autochthonous B-cells. B-cell lines with membrane IgG appeared more resistant to infection than did those with no membrane IgG.