Galpin/DA/N2 IIIBenv 
Further analysis of the HIV-1 env specificity of the HIV-IT (V)-induced 
CTL responses was performed using synthetic peptides derived from the 
hypervariable V3 domain of HIV-1 IIIBenv, gpl20 (i.e., amino acids 307-330). 
This sequence was previously shown to provide a dominant epitope recognized by 
HIV-1 neutralizing antibodies 54 ’ 55 ’ 56 ’ 57 as well as murine CTL 53 - 58 . CTL induced 
by IP injection of 10 6 cfu of crude HIV-IT (V) were examined for their ability to 
recognize and lyse BC cells coated with the P 1 8 1 1 1 B peptide 
(RIQRGPGRAFVTIGK) or the P18MN peptide (RIHIGPGRAFYTTKN) derived 
from the hypervariable V3 loop region of the envelope protein of the HIV-1 IIIB 
and HIV-1 MN strains, respectively 53 . The CTL showed lysis of the P18IIIB 
peptide-coated (5|iM) BC cells at approximately 60% of that observed on BCenv 
target cells expressing the entire env and rev proteins (Figure 11). Moreover, 
crossreactivity was observed using target cells coated with the P18MN peptide 
(5|iM) derived from the equivalent V3 region of the HIV-1 MN isolate. Thus, 
within the population of cytotoxic effector cells induced by injection of HIV-IT (V), 
there exist CTL that recognize determinants within the V3 loop region of gpl20 
amino acid residues 315-329 derived from the HIV-1 IIIB isolate. These CTL also 
appear to recognize and cross-react with a peptide derived from the equivalent 
region of the HIV-1 MN isolate. 
Further studies have evaluated the CTL recognition of determinants outside 
the immunodominant V3 loop region of the HIV-1 IIIBenv protein. A retroviral 
provector construct was designed to express a V3-region-deleted, HIV-1 IIIBenv 
protein, in which the gene sequence coding for amino acids 303-338 was removed 
(AV3). BC cells were transduced with this AV3 provector construct (BCenvAV3) 
54 kusche, J.R., et al., Proc. Nall. Acad. Sci (USA). 85:3198-3202 (1988). 
55 Javaherian, K., et al., Proc. Natl. Acad. Sci. (USA), 86:6768-6772 (1989). 
56 Palker, T.J., et al„ Proc. Nall. Acad. Sci. (USA), 85:1932-1936 (1988). 
57 Goudsmit, J., et al.. Proc. Nall. Acad. Sci. (USA), 85:4478-4482 (1988). 
58 Takahashi, H„ et al., Proc. Nall. Acad. Sci. (USA), 85:3105-3109 (1988) 
Recombinant DNA Research, Volume 17 
