Subject(s)
HIV Infections/prevention & control , Infectious Disease Transmission, Vertical/prevention & control , Pregnancy Complications, Infectious/prevention & control , Acquired Immunodeficiency Syndrome/epidemiology , Acquired Immunodeficiency Syndrome/prevention & control , Acquired Immunodeficiency Syndrome/transmission , Female , HIV Infections/epidemiology , HIV Infections/transmission , Humans , Infant, Newborn , Infectious Disease Transmission, Vertical/statistics & numerical data , Jamaica/epidemiology , Pediatrics , Pregnancy , Pregnancy Complications, Infectious/epidemiologyABSTRACT
We previously demonstrated that progeny virions are not produced after infection of adult quiescent peripheral blood lymphocytes (PBLs) by human immunodeficiency virus type 1 (HIV-1). Molecular analysis revealed that the nonproductive nature of this infection is due to failure to complete reverse transcription of the viral genome. In this study, we examined HIV-1 reverse transcription in quiescent lymphocytes from umbilical cord blood (CBLs). Using the polymerase chain reaction (PCR) to detect the presence of reverse transcription intermediates, we found that as in PBLs from adults, reverse transcription is not completed in quiescent CBLs; instead, a partial reverse transcript is formed. Quantitative PCR analysis also showed that fewer partial reverse transcripts were found in CBLs than in PBLs. Although the relevance of this restriction in reverse transcription to vertical transmission is unclear, these data suggest that the rapid progression of disease in infected children is not due to increased permissiveness of the lymphocytes of newborns for HIV-1 infection.
Subject(s)
HIV Infections/microbiology , HIV-1/enzymology , Lymphocytes/microbiology , RNA-Directed DNA Polymerase/metabolism , Transcription, Genetic , Adult , DNA, Viral/biosynthesis , Fetal Blood , HIV Infections/blood , HIV Reverse Transcriptase , Humans , Infant, Newborn , Lymphocyte Activation , Lymphocytes/immunology , Polymerase Chain ReactionABSTRACT
Genetic studies have indicated that integration of retroviral DNA into the host genome depends on the presence of the inverted repeats at the free termini of the long terminal repeats on the unintegrated DNA and on the product of the 3' end of the pol gene (the integrase [IN] protein). While the precise function of the Moloney murine leukemia virus IN protein is uncertain, others have shown that it is a DNA-binding protein and functions in the processing of the inverted repeats prior to integration. By using site-directed mutagenesis, we cloned and expressed the IN protein in Escherichia coli. Crude extracts of total cellular protein were fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, transferred to nitrocellulose filters, denatured in guanidine, renatured, and incubated with oligonucleotide probes. Single- and double-stranded oligonucleotides corresponding to the termini of unintegrated linear viral DNA were specifically bound by the IN protein in this assay. These data suggest that the role of the Moloney IN protein in the early steps of integration involves sequence-specific recognition of the DNA sequences found at the ends of the long terminal repeats.
