Effect of 3'-azido-3'-deoxythymidine on human immunodeficiency virus type 1 replication in human fetal brain macrophages

Abstract

We investigated whether cells derived from the fetal central nervous system can support productive infection by a human immunodeficiency virus type 1 (HIV-1) isolate termed UHC-1, produced by a cellular clone derived from HIV-1 strain HIV-IIIB chronically infected U-937 promonocytic cells, and what the effect of nucleoside analogs might be on viral replication in this system. Fractionation of human fetal brain tissue into two different populations, enriched for either astrocytes or macrophages, showed that only the latter were able to support productive UHC-1 replication and generation of detectable progeny virus. Pretreatment of fetal brain macrophages with either of two nucleoside analogs, 3'-azido-3'-deoxythymidine (AZT) or the (-) enantiomer of 2'-deoxy-3'-thiacytidine, efficiently blocked production of progeny virus. Generation of unintegrated proviral DNA and HIV-1 transcripts were inhibited by pretreatment of fetal brain macrophages with 1 microM AZT. Administration of AZT at 24 h postinfection led to a slight reduction in viral transcript levels and viral progeny production by day 15 postinfection; however, brain macrophages under these conditions did not contain detectable amounts of unintegrated viral DNA. These results suggest that AZT may interfere with the accumulation of unintegrated HIV-1 DNA in brain macrophages. This is the first demonstration that nucleoside analogs are able to block HIV-1 replication in primary cultures of brain cells.

Preferential incorporation of nucleoside analogs after template switching during human immunodeficiency virus reverse transcription

“…Comparisons of the counts per minute for these sample products with the counts per minute for the positive control (linearized pHXHXB2) are shown in Table 1. the A2-S2-and the AG4-SG4-amplified regions in (-) HIV DNA are separated by 8,500 nt. These findings are consistent with those of a previous study involving phytohemagglutininactivated peripheral blood lymphocytes exposed to HIV in the presence or absence of 1 ,uM AZT (11).…”

“…In a reaction primed with deoxyoligonucleotides from the PBS, chain termination could occur prior to the template switch. In human fetal brain macrophages, which are known to have a low dNTP pool level and a slow rate of HIV reverse transcription (26,31), we have observed that AZT prevents the formation of (-) strong-stop HIV DNA (11). In contrast, in HIV infection of Jurkat cells, in which reverse transcription occurs at a much faster rate, AZT-TP chain terminates only after synthesis of (-) strong-stop DNA and template switching.…”

Development of a Human Immunodeficiency Virus Vector-Based, Single-Cycle Assay for Evaluation of Anti-Integrase Compounds

“…This was as expected in the presence of a true IN inhibitor. In contrast, compounds such as AZT or ddI, acting at steps preceding circle formation, had the same effect on E-DNA production from IN-competent or IN-defective viruses, since E-DNA synthesis was inhibited (13,23,30,38,39) and luciferase expression fell to negligible levels. This assay was validated by comparative evaluation with the HIV-1 drug susceptibility assay performed on PBMC.…”

Human Immunodeficiency Virus Type 1: Resistance to Nucleoside Analogues and Replicative Capacity in Primary Human Macrophages

“…Although most NRTIs, non-NRTIs, and protease inhibitors have been shown to have potent antiviral activity in monocytes/ macrophages (2,4,7,27,52,54), little is known about resistance and resistance associated changes in viral RC in this cellular compartment. To our knowledge, the resistance of viruses carrying TAMs or other NRTI-associated resistance mutations in the low dNTP cellular context of monocytes/ macrophages has not been addressed.…”