To determine the role of direct infection of intestinal cells with HIV-1 in the pathogenesis of HIV-related enteropathy.Methods
We infected HT-29–18-C1 intestinal cells with the IIIB strain of HIV and examined the physiologic effects of enterocyte function. Dipeptidase-IV, aminopeptidase-N, gamma glutamic transferase, and alkaline phosphatase were measured in HIV-infected and control cultures. The cellular second messengers intracellular calcium and cyclic adenosine monophosphate were also measured in infected and control cultures.Results
A persistent infection was established for > 95 days with peak supernatant reverse transcriptase and HIV p24 antigen levels of 5.17 log10 c.p.m./ml and 45 ng/ml, respectively. Brush-border enzyme activity (nmol of product/min/mg protein) tended to be lower in infected cell cultures compared with controls early in infection (P < 0.02). Baseline second messenger concentrations were similar but infected cultures responded to stimulation with a calcium ionophore with an exaggerated increase in intracellular calcium (P=0.03).Conclusions
These results suggest that absorptive and secretory function of enterocytes may be altered by direct HIV infection and that additional physiologic experiments with this in vitro model may lead to a better understanding of the clinical syndrome of HIV enteropathy.