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Disease Markers
Volume 31, Issue 6, Pages 337-342
http://dx.doi.org/10.3233/DMA-2011-0847

Immunosenescent CD57+CD4+ T-cells Accumulate and Contribute to Interferon-γ Responses in HIV Patients Responding Stably to ART

Sonia Fernandez,1 Martyn A. French,1,2 and Patricia Price1,2

1School of Pathology and Laboratory Medicine, University of Western Australia and PathWest Laboratory Medicine, Perth, Australia
2Department of Clinical Immunology, Royal Perth Hospital and PathWest Laboratory Medicine, Perth, Australia

Received 15 December 2011; Accepted 15 December 2011

Copyright © 2011 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

HIV-infected individuals responding to antiretroviral therapy (ART) after severe CD4+ T-cell depletion may retain low responses to recall antigens [eg: cytomegalovirus (CMV)] and altered expression of T-cell co-stimulatory molecules consistent with immunosenescence. We investigated the capacity of phenotypically senescent cells to generate cytokines in HIV patients receiving long-term ART (n = 18) and in healthy controls (n = 10). Memory T-cells were assessed by interferon (IFN)-γ ELISpot assay and flow cytometrically via IFN-γ or IL-2. Proportions of CD57brightCD28null CD4+ T-cells correlated with IFN-γ responses to CMV (p = 0.009) and anti-CD3 (p = 0.002) in HIV patients only. Proportions of CD57brightCD28null CD8+ T-cells and CD8+ T-cell IFN-γ responses to CMV peptides correlated in controls but not HIV patients. IL-2 was predominantly produced by CD28+T-cells from all donors, whereas IFN-γ was mostly produced by CD57+ T-cells. The findings provide evidence of an accumulation of immunosenescent T-cells able to make IFN-γ. This may influence the pathogenesis of secondary viral infections in HIV patients receiving ART.