Browsing by Author "Young, Alicia M."

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    Coreceptor Tropism in Human Immunodeficiency Virus Type 1 Subtype D: High Prevalence of CXCR4 Tropism and Heterogeneous Composition of Viral Populations
    (Journal of virology, 2007) Huang, Wei; Eshleman, Susan H.; Toma, Jonathan; Fransen, Signe; Stawiski, Eric; Paxinos, Ellen E.; Whitcomb, Jeannette M.; Young, Alicia M.; Donnell, Deborah; Mmiro, Francis; Musoke, Philippa; Guay, Laura A.; Jackson, J. Brooks; Parkin, Neil T.; Petropoulos, Christos J.
    In human immunodeficiency virus type 1 (HIV-1) subtype B, CXCR4 coreceptor use ranges from ∼20% in early infection to ∼50% in advanced disease. Coreceptor use by non-subtype B HIV is less well characterized. We studied coreceptor tropism of subtype A and D HIV-1 collected from 68 pregnant, antiretroviral drug-naive Ugandan women (HIVNET 012 trial). None of 33 subtype A or 10 A/D-recombinant viruses used the CXCR4 coreceptor. In contrast, nine (36%) of 25 subtype D viruses used both CXCR4 and CCR5 coreceptors. Clonal analyses of the nine subtype D samples with dual or mixed tropism revealed heterogeneous viral populations comprised of X4-, R5-, and dual-tropic HIV-1 variants. In five of the six samples with dual-tropic strains, V3 loop sequences of dual-tropic clones were identical to those of cocirculating R5-tropic clones, indicating the presence of CXCR4 tropism determinants outside of the V3 loop. These dual-tropic variants with R5-tropic-like V3 loops, which we designated “dual-R,” use CCR5 much more efficiently than CXCR4, in contrast to dual-tropic clones with X4-tropic-like V3 loops (“dual-X”). These observations have implications for pathogenesis and treatment of subtype D-infected individuals, for the association between V3 sequence and coreceptor tropism phenotype, and for understanding potential mechanisms of evolution from exclusive CCR5 use to efficient CXCR4 use by subtype D HIV-1.
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    Coreceptor Tropism in Human Immunodeficiency Virus Type 1 Subtype D: High Prevalence of CXCR4 Tropism and Heterogeneous Composition of Viral Populations
    (Journal of virology, 2007) Huang, Wei; Eshleman, Susan H.; Toma, Jonathan; Fransen, Signe; Stawiski, Eric; Paxinos, Ellen E.; Whitcomb, Jeannette M.; Young, Alicia M.; Donnell, Deborah; Mmiro, Francis; Musoke, Philippa; Guay, Laura A.; Jackson, Brooks; Parkin, Neil T.; Petropoulos, Christos J.
    In human immunodeficiency virus type 1 (HIV-1) subtype B, CXCR4 coreceptor use ranges from 20% in early infection to 50% in advanced disease. Coreceptor use by non-subtype B HIV is less well characterized. We studied coreceptor tropism of subtype A and D HIV-1 collected from 68 pregnant, antiretroviral drug-naive Ugandan women (HIVNET 012 trial). None of 33 subtype A or 10 A/D-recombinant viruses used the CXCR4 coreceptor. In contrast, nine (36%) of 25 subtype D viruses used both CXCR4 and CCR5 coreceptors. Clonal analyses of the nine subtype D samples with dual or mixed tropism revealed heterogeneous viral populations comprised of X4-, R5-, and dual-tropic HIV-1 variants. In five of the six samples with dual-tropic strains, V3 loop sequences of dual-tropic clones were identical to those of cocirculating R5-tropic clones, indicating the presence of CXCR4 tropism determinants outside of the V3 loop. These dual-tropic variants with R5-tropic-like V3 loops, which we designated “dual-R,” use CCR5 much more efficiently than CXCR4, in contrast to dual-tropic clones with X4-tropic-like V3 loops (“dual-X”). These observations have implications for pathogenesis and treatment of subtype D-infected individuals, for the association between V3 sequence and coreceptor tropism phenotype, and for understanding potential mechanisms of evolution from exclusive CCR5 use to efficient CXCR4 use by subtype D HIV-1.
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    Total Lymphocyte Count: not a surrogate marker for risk of death in HIV infected Ugandan children
    (Journal of acquired immune deficiency syndromes, 2008) Musoke, Philippa M.; Young, Alicia M.; Owor, Maxensia A.; Lubega, Irene R.; Brown, Elizabeth R.; Mmiro, Francis A.; Mofenson, Lynne M.; Jackson, J. Brooks; Glenn Fowler, Mary; Guay, Laura A.
    To determine the utility of Total Lymphocyte Count (TLC) in predicting the 12 month mortality in HIV infected Ugandan children; to correlate TLC and CD4 cell %. Design—This is a retrospective data analysis of clinical and laboratory data collected prospectively on 128 HIV infected children in the HIVNET 012 trial. Methods—TLC and CD4 cell % measurements were obtained at birth, 14 weeks and 12, 24, 36, 48, and 60 months of age and assessed with respect to risk of death within 12 months. Results—Median TLC/ul (CD4 cell %) were 4150 (41%) at birth, 4900 (24%) at 12 months, 4300 (19%) at 24 months, 4150 (19 %) at 36 months, 4100 (18%) at 48 months and 3800 (20%) at 60 months. The highest risk of mortality within 12 months was 34–37% at birth and declined to 13– 15% at 24 months regardless of TLC measurement. The correlation between CD4 cell % and TLC was extremely low overall (r = 0.01). Conclusion—The TLC did not predict a risk of progression to death within 12 months and therefore TLC alone may not be a useful surrogate marker for determining those children in greatest need for antiretroviral therapy in HIV infected Ugandan children.