Galpin/DA/N2 IIIBenv 
BC-Bgal (6gal/neo r ) targets (Figure 10). Furthermore, multiple injections (up to 
three) of HIV-IT (V) did not induce effectors capable of causing any BC-|3gal lysis. 
These results demonstrated that the CTL induced by HIV-IT (V) were specific for 
HIV-1 env/rev determinants, and that the CTL activity was not directed against the 
neo r gene product. 
3. 1.1.4 Phenotype of Cytotoxic Effector Cells 
In additional experiments, an attempt was made to determine the phenotype 
of the HIV-IT (V)-induced cytotoxic effector cell population by depletion of 
subpopulations of T cells (i.e., CD4+ and CD8 + ) using specific mouse monoclonal 
antibodies (MAb) plus rabbit complement. Preliminary data indicate that the CD8 + 
T cell subpopulation was responsible for the measured cytotoxic activity since 
target cell lysis was abrogated following CD8 + T cell depletion, but not following 
CD4+ T cell depletion compared to control treatments. The existing data indicate 
that the majority of cytotoxic effector cells induced by injection of mice with 
HIV-IT (V) are CD8 + , CD4- cytotoxic T lymphocytes. 
Conventional CD8 + CTL are known to recognize epitopes of viral antigens 
in association with self class I MHC molecules 51 . We have preliminary evidence 
that direct vector induced CTL are class I MHC restricted to the murine H-2D d 
molecule. This is in agreement with HIV-1 IIIBenv-specific CTL responses 
generated in the BALB/c mouse using N2 IIIBenv transduced syngeneic 
fibroblasts 52 and with a recombinant vaccinia vector 53 . Therefore, these 
HIV-IT (V)-induced CTL appear to be class I MHC restricted and the effector cell 
is CD8+. 
3.1. 1.5 HIV-1 env/rev Specificity of CTL 
51 Zinkemagel, R.M., et al., Adv. Immunol ., 27:51-178 (1979). 
52 Wamer, et al., J.P., et al., AIDS Research and Human Retroviruses , 7:644-655 (1991). 
53 Takahashi, H., et al.. Science, 246:1 18-121 (1989). 
Recombinant DNA Research, Volume 17 
[879] 
