Induction of aplastic anemia by intra-bone marrow inoculation of a molecularly cloned feline retrovirus.

Intra-bone marrow inoculation of cells infected with molecularly cloned feline retrovirus (FeLV-C-Sarma [FSC]) associated with aplastic anemia was examined to test the hypothesis that cell-to-cell transmission of virus might facilitate marrow cell infection and anemogenesis, a possibility suggested by in-vitro co-culture experiments. IBM inoculation of either FSC-infected feline marrow cells or fibroblasts of weanling cats bypassed age-related restriction of FSC replication, initiated viremia, caused irreversible depletion of erythroid burst forming units, and induced rapid fatal aplastic anemia. A second significant finding observed with FSC infection was pronounced systemic lymphoid depletion. The direct bone marrow inoculation system described facilitates experimental study of retrovirus-target cell interactions involved in erythroid aplasia.