FIG 2.

Human hematopoietic cells display two patterns of susceptibility to FeLV-B replication. (A) (Left) Western blot (WB) analysis of the intracellular Gag precursor protein (Pr65^Gag) in partially permissive (phenotype 2) FeLV-B-infected KYO-1 cells shows expression levels similar to those in fully permissive feline fibroblasts (AH927). In contrast, expression of Pr65^Gag is barely detectable in nonpermissive Reh cells and human PBMCs. (Right) This pattern is reflected in the levels of virus particle release, which are similar in partially permissive KYO-1 cells and permissive AH927 cells, as illustrated by Western blot analysis of pelleted virion preparations from equal volumes of culture medium. (B) Results of a separate experiment where Western blot analysis of serial 2-fold dilutions of virions released from AH927 and KYO-1 cells again showed levels of particle release from KYO-1 cells within a range similar to that for AH927 cells. (C) Western blot analysis of pelleted virions harvested from cells 14 days after infection with FeLV-B. Equal volumes of cell supernatant (2 ml) were sampled 24 h after medium change and were processed as described in Materials and Methods.