Use of RT-defective HIV virions: new tool to evaluate specific response in chronic asymptomatic HIV-infected individuals

PLoS One. 2013;8(3):e58927. doi: 10.1371/journal.pone.0058927. Epub 2013 Mar 14.

Abstract

Background: Generation of new reagents that can be used to screen or monitor HIV-1-specific responses constituted an interesting field in the development of HIV vaccines to improve their efficacy.

Methods: We have evaluated the specific T cell response against different types of NL4-3 virions (including NL4-3 aldrithiol-2 treated, NL4-3/ΔRT and R5 envelopes: NL4-3/ΔRT/ΔEnv[AC10] and NL4-3/ΔRT/ΔEnv[Bal]) and against pools of overlapping peptides (15 mer) encompassing the HIV-1 Gag and Nef regions. Cryopreserved PBMC from a subset of 69 chronic asymptomatic HIV positive individuals have been employed using different techniques including IFN-γ ELISPOT assay, surface activation markers and intracellular cytokine staining (ICS) by flow cytometry.

Results: The differential response obtained against NL4-3 aldrithiol-2 treated and NL4-3/ΔRT virions (25% vs 55%, respectively) allow us to divide the population in three groups: "full-responders" (positive response against both viral particles), "partial-responders" (positive response only against NL4-3/ΔRT virions) and "non-responders" (negative responses). There was no difference between X4 and R5 envelopes. The magnitude of the total responses was higher against NL4-3/ΔRT and was positively correlated with gender and inverse correlated with viral load. On the contrary CD4+ T cell count was not associated with this response. In any case responses to the viruses tended to be lower in magnitude than those detected by the overlapping peptides tested. Finally we have found an increased frequency of HLA-B27 allele (23% vs 9%) and a significant reduction in some activation markers (CD69 and CD38) on T cells surface in responders vs non-responders individuals.

Conclusions: In summary these virions could be considered as alternative and useful reagents for screening HIV-1-specific T cell responses in HIV exposed uninfected people, HIV infected patients and to assess immunogenicity of new prototypes both in vitro and in vaccine trials, by a feasible, simply, effective and low cost assay.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Alleles
  • Asymptomatic Diseases*
  • CD4-Positive T-Lymphocytes / immunology
  • CD4-Positive T-Lymphocytes / virology
  • CD8-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / virology
  • Female
  • HIV Infections / immunology*
  • HIV Reverse Transcriptase / genetics
  • HIV Reverse Transcriptase / metabolism*
  • HIV-1 / enzymology*
  • HIV-1 / immunology
  • HIV-1 / physiology*
  • Humans
  • Leukocytes, Mononuclear / immunology
  • Leukocytes, Mononuclear / virology
  • Male
  • Microbial Viability / immunology
  • Middle Aged
  • Safety
  • Sex Characteristics
  • Time Factors
  • Viral Load / immunology
  • Viral Vaccines / adverse effects
  • Viral Vaccines / immunology
  • Virion / enzymology
  • Virion / immunology*
  • Virion / physiology
  • Young Adult

Substances

  • Viral Vaccines
  • reverse transcriptase, Human immunodeficiency virus 1
  • HIV Reverse Transcriptase

Grants and funding

This study was partially supported by grants FIS PI040503, FIS PI070291, FIS PI1200969, RIS - Red Temática Cooperativa de Grupos de Investigación en Sida del Fondo de Investigación Sanitaria del Instituto de Salud Carlos III (ISCIII-RETIC RD06/0006), HIVACAT - Catalan Program for HIV Vaccine Development. Dr. Montserrat Plana is a researcher from the Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) and is supported by the Spanish Health Institute Carlos III (ISCIII) and the Health Department of the Catalan Government (Generalitat de Catalunya). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.