Freshly isolated PBMC's were stimulated with PHA (5 ng/ml) 
for 48 hours, washed twice in fresh medium, and 5xl0 6 cells 
resuspended in 0.5 ml fresh medium. HIV was mixed with the cells 
(5xl0 4 TCID 50 ) and incubated at 37 °C for 2 hours. Cells were 
then washed once and resuspended in 10 ml fresh medium with or 
without 40 nM Nevirapine. At the indicated times, supernatants 
(10 /i 1) were assayed for RT activity. The original concentration 
(~ 40 nM) of Nevirapine was maintained throughout the experiment. 
Background cpm from uninfected cells alone, is approximately 200, 
with SD 50. 
V. Animal models of HIV infection. 
There is currently no suitable animal model for HIV 
infection which can be used to evaluate the efficacy of this 
treatment. Although there are non-primate model systems in which 
viremia can be achieved, the nature and virulence of these 
diseases differs significantly from those seen in man. It is 
therefore felt that the most suitable context in which to 
determine the efficacy of Rev M10 function is in humans. If 
successful, it would also allow for more rapid optimization for 
therapeutic efficacy. To adapt this study to an in vivo setting, 
we have adopted the model of HIV infection of human peripheral 
blood lymphocytes reconstituted in a SCID-HU mouse as described 
by Mosier et al. (22). In this system, we have transduced human 
peripheral blood lymphocytes with Rev M10 or ARev M10 retroviral 
vectors, selected for 8-15 days in vitro with G418. Resistance 
to HIV infection in vitro was confirmed, followed by adoptive 
[40] 
Recombinant DNA Research, Volume 18 
