because recent findings suggested that most of the polyclonal anti-akr/gross virus ctl activity appeared to be directed to n-ecotropic proviral determinants , we further investigated the nature of these two antigenic systems by use of additional target cells including lipopolysaccharide ( lps ) -stimulated spleen cell blasts from akxl recombinant inbred strains and retrovirus-infected fibroblasts .
C0007634
cell
C0016030
fibroblasts