Ordered appearance of human immunodeficiency virus type 1 nucleic acids following high multiplicity infection of macrophages

Munis, James R.; Kornbluth, Richard S.; Richman, Douglas D.

doi:10.1099/0022-1317-73-8-1899

Cited by 40 publications

(21 citation statements)

References 28 publications

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“…We found that HIV-1 1.8-kb mRNA accumulated 12 h earlier in lymphocytes than in MDM. This comparative delay in MDM agrees with the 12-h delay observed in one study of U937 cells (39) but not the 4-h delay reported in another study (32). It also agrees with our previous work in which we found that in fully susceptible MDM, compared to freshly isolated monocytes that are resistant to infection, reverse transcription and integration are detectable by 12 and 24 h postinfection, respectively (52).…”

Section: Discussionsupporting

confidence: 82%

Selectively ReducedtatmRNA Heralds the Decline in Productive Human Immunodeficiency Virus Type 1 Infection in Monocyte-Derived Macrophages

Sonza

Mutimer

O’Brien

et al. 2002

J Virol

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The transcription and splicing of human immunodeficiency virus type 1 (HIV-1) mRNA in primary blood monocyte-derived macrophages (MDM) and CD4؉ peripheral blood lymphocytes (PBL) were compared to determine whether any differences might account for the slower noncytopathic infection of cells of the macrophage lineage. The expression of regulatory mRNAs during acute infection of MDM was delayed by about 12 h compared to that of PBL. In each cell type, an increase in spliced viral mRNAs slightly preceded virus production from the culture. Following the peak of productive infection, there was a proportional decrease in the expression of all regulatory mRNAs detected in PBL. In MDM, a dramatic additional decrease specifically in the tat mRNA species heralded a reduction in virus production. This decline in tat mRNA was reflected by a concomitant decrease in Tat activity in the cells and occurred with the same kinetics irrespective of the age of the cells when infected. Addition of exogenous Tat protein elicited a burst of virus production from persistently infected MDM, suggesting that the decrease in virus production from the cultures is a consequence of the reduction in tat mRNA levels. Our results show that modulation of HIV-1 mRNAs in macrophages during long-term infection, which is dependent on the period of infection rather than cell differentiation or maturation, results in a selective reduction of Tat protein levels at the commencement of a persistent, less productive phase of infection. Determination of the mechanism of this mRNA modulation may lead to novel targets for control of replication in these important viral reservoirs.The human immunodeficiency virus type 1 (HIV-1) genomic RNA undergoes a distinctly complex series of multiple splicing events to produce an array of 22 different 4.0-kb mRNAs for the Env, Vpu, Tat, Vpr, and Vif proteins and 22 different 1.8-kb mRNAs for the Tat, Rev, Vpr, and Nef proteins (38,44,47,48). These seven viral proteins, encoded by more than 40 alternatively spliced mRNAs, regulate virus replication and important host cell functions and are crucial for HIV-1 infectivity and in vivo pathogenesis. Alterations to the balanced splicing of these HIV mRNAs can have a dramatic impact on viral infectivity and pathogenesis (44).The large array of alternatively spliced HIV-1 mRNA primarily results from the differential use of six competing alternative 3Ј splice acceptor (SA) sites (A3, A4c, A4b, A4a, A5, and A7) (4,28,44,47) and the use of two upstream noncoding exons (exons 2 and 3) that alter the 5Ј untranslated region (Fig. 1). RNA elements called exonic splice silencers (ESS) have been identified in the splice control regions of the genomic RNA that bind cellular heterogeneous nuclear ribonucleoproteins (hnRNPs) of the A, B, and H groups (9,14,30) and act to suppress the splicing of adjacent 3Ј SA sites, such as in the second exon of tat (Fig. 1B, exon 4), the second tat/rev coding exon (exon 7), and noncoding exon 3 downstream of Vpr splice site A2 (2, 6, 57). Other elements cal...

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Section: Discussionsupporting

confidence: 82%

Selectively ReducedtatmRNA Heralds the Decline in Productive Human Immunodeficiency Virus Type 1 Infection in Monocyte-Derived Macrophages

Sonza

Mutimer

O’Brien

et al. 2002

J Virol

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“…4b). These data are consistent with those published by Munis et al (1992), who reported a significant increase of HIV-1 DNA during the first cycle of infection. No PCR products were detected in the MDM infected with heatinactivated virus stock pretreated with RNase-free DNase (data not shown).…”

supporting

confidence: 83%

Antibody-dependent cellular cytotoxicity and neutralization of human immunodeficiency virus type 1 by high affinity cross-linking of gp41 to human macrophage Fc IgG receptor using bispecific antibody

Mabondzo

Boussin²,

Raoul³

et al. 1994

Journal of General Virology

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“…Because both processes were inhibited, inhibition of the former cannot be attributed to the formation of a dead-end complex (22,36). Our results indicate that the mutant polymerase harboring mutations D67N, K70R, T215F, and K219K is either totally unable to unblock the AZT-terminated primer during the initiation of reverse transcription or at least that this process is too slow to be significant during provirus synthesis in vivo (41,42). Thus, if a resistant virus incorporates AZT during this step, its replication is definitively blocked.…”

Section: Discussionmentioning

confidence: 88%

Primer Unblocking and Rescue of DNA Synthesis by Azidothymidine (AZT)-resistant HIV-1 Reverse Transcriptase

Rigourd

Ehresmann

Parniak

et al. 2002

Journal of Biological Chemistry

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Azidothymidine (AZT) is a widely used inhibitor of type 1 human immunodeficiency virus reverse transcriptase (RT) that acts as chain terminator. Upon treatment, mutations conferring AZT resistance to RT are gradually selected. It has been shown that resistant RT is able to unblock the AZT-terminated primer by an ATP-dependent mechanism. However, this resistance mechanism has only been demonstrated for DNAdependent DNA elongation. Here, we compared the AZT resistance of mutant RT during DNA elongation on DNA and RNA templates. We showed that, during DNA elongation, primer unblocking and rescue of DNA synthesis take place with similar rate constants on DNA and RNA templates. However, the fraction of a primer eventually repaired during RNA-dependent DNA synthesis is 2؋ lower compared with that of DNA-dependent synthesis, leading to reduced resistance. We also compared the initiation of reverse transcription, which uses tRNA 3 Lys as a primer and displays characteristic kinetic features, and the subsequent RNA-dependent elongation. Unlike during elongation, resistant RT was unable to unblock the AZT-terminated primer during initiation of (؊) DNA strand synthesis. Our results demonstrate that the efficiency of primer unblocking conferred by the AZT resistance mutations greatly vary during the different steps of the provirus synthesis. These results also suggest that inhibitors specifically targeting the initiation of reverse transcription might prove to be advantageous, as compared with elongation inhibitors.

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Ordered appearance of human immunodeficiency virus type 1 nucleic acids following high multiplicity infection of macrophages

Cited by 40 publications

References 28 publications

Selectively ReducedtatmRNA Heralds the Decline in Productive Human Immunodeficiency Virus Type 1 Infection in Monocyte-Derived Macrophages

Selectively ReducedtatmRNA Heralds the Decline in Productive Human Immunodeficiency Virus Type 1 Infection in Monocyte-Derived Macrophages

Antibody-dependent cellular cytotoxicity and neutralization of human immunodeficiency virus type 1 by high affinity cross-linking of gp41 to human macrophage Fc IgG receptor using bispecific antibody

Primer Unblocking and Rescue of DNA Synthesis by Azidothymidine (AZT)-resistant HIV-1 Reverse Transcriptase

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