Dendritic Cells Reveal a Broad Range of MHC Class I Epitopes for HIV-1 in Persons with Suppressed Viral Load on Antiretroviral Therapy

Department of Infectious Diseases and Microbiology, Graduate School of Public Health and School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
PLoS ONE (Impact Factor: 3.53). 09/2010; 5(9):e12936. DOI: 10.1371/journal.pone.0012936
Source: PubMed

ABSTRACT HIV-1 remains sequestered during antiretroviral therapy (ART) and can resume high-level replication upon cessation of ART or development of drug resistance. Reactivity of memory CD8(+) T lymphocytes to HIV-1 could potentially inhibit this residual viral replication, but is largely muted by ART in relation to suppression of viral antigen burden. Dendritic cells (DC) are important for MHC class I processing and presentation of peptide epitopes to memory CD8(+) T cells, and could potentially be targeted to activate memory CD8(+) T cells to a broad array of HIV-1 epitopes during ART.
We show for the first time that HIV-1 peptide-loaded, CD40L-matured DC from HIV-1 infected persons on ART induce IFN gamma production by CD8(+) T cells specific for a much broader range and magnitude of Gag and Nef epitopes than do peptides without DC. The DC also reveal novel, MHC class I restricted, Gag and Nef epitopes that are able to induce polyfunctional T cells producing various combinations of IFN gamma, interleukin 2, tumor necrosis factor alpha, macrophage inhibitory protein 1 beta and the cytotoxic de-granulation molecule CD107a.
There is an underlying, broad antigenic spectrum of anti-HIV-1, memory CD8(+) T cell reactivity in persons on ART that is revealed by DC. This supports the use of DC-based immunotherapy for HIV-1 infection.

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