Immune Responses to Measles and Tetanus Vaccines Among Kenyan Human Immunodeficiency Virus Type 1 (HIV-1)-Infected Children Pre- and Post-Highly Active Antiretroviral Therapy and Revaccination

ABSTRACT A stable latent reservoir for human immunodeficiency virus type 1 (HIV-1) in resting memory CD4+ T cells presents a barrier to eradication of the infection even in patients on highly active antiretroviral therapy. Potential mechanisms for latency include inaccessibility of the integrated viral genome, absence of key host transcription factors, premature termination of HIV-1 RNAs, and abnormal splicing patterns. To differentiate among these mechanisms, we isolated extremely pure populations of resting CD4+ T cells from patients on highly active antiretroviral therapy. These cells did not produce virus but retained the capacity to do so if appropriately stimulated. Products of HIV-1 transcription were examined in purified resting CD4+ T cells. Although short, prematurely terminated HIV-1 transcripts have been suggested as a marker for latently infected cells, the production of short transcripts had not been previously demonstrated in purified populations of resting CD4+ T cells. By separating RNA into polyadenylated and nonpolyadenylated fractions, we showed that resting CD4+ T cells from patients on highly active antiretroviral therapy produce abortive transcripts that lack a poly(A) tail and that terminate prior to nucleotide 181. Short transcripts dominated the pool of total HIV-1 transcripts in resting CD4+ T cells. Processive, polyadenylated HIV-1 mRNAs were also present at a low level. Both unspliced and multiply spliced forms were found. Taken together, these results show that the nonproductive nature of the infection in resting CD4+ T cells from patients on highly active antiretroviral therapy is not due to absolute blocks at the level of either transcriptional initiation or elongation but rather relative inefficiencies at multiple steps.

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Safety and Immunogenicity of ALVAC vCP1452 and Recombinant gp160 in Newly Human Immunodeficiency Virus Type 1-Infected Patients Treated with Prolonged Highly Active Antiretroviral Therapy

Journal of Virology ◽

10.1128/jvi.76.5.2206-2216.2002 ◽

2002 ◽

Vol 76 (5) ◽

pp. 2206-2216 ◽

Cited By ~ 58

Author(s):

Xia Jin ◽

Murugappan Ramanathan, ◽

Shady Barsoum ◽

Geoffrey R. Deschenes ◽

Lei Ba ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

T Cell ◽

Antiretroviral Therapy ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Highly Active Antiretroviral Therapy ◽

Highly Active ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT In order to boost immune responses in persons in whom highly active antiretroviral therapy (HAART) was initiated within 120 days of the onset of symptoms of newly acquired human immunodeficiency virus type 1 (HIV-1) infection, we administered vaccines containing a canarypox virus vector, vCP1452, with HIV-1 genes encoding multiple HIV-1 proteins, and recombinant gp160. Fifteen HIV-1-infected subjects who achieved sustained suppression of plasma viremia for at least 2 years were enrolled. While continuing antiretroviral therapy, each subject received at least four intramuscular injections of the vaccines on days 0, 30, 90, and 180. Adverse events were mild, with the most common being transient tenderness at the vCP1452 injection site. Of the 14 patients who completed vaccination, 13 had significant increases in anti-gp120 or anti-p24 antibody titers, and 9 had transient augmentation of their T-cell proliferation responses to gp160 and/or p24. HIV-1-specific CD8+ T cells were quantified using an intracellular gamma interferon staining assay. Among 11 patients who had increased CD8+ T-cell responses, seven had responses to more than one HIV-1 antigen. In summary, vaccination with vCP1452 and recombinant gp160 appears safe and immunogenic in newly HIV-1-infected patients on HAART.

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