PLoS ONE (Jan 2017)

Alterations of the NK cell pool in HIV/HCV co-infection.

  • Dominik J Kaczmarek,
  • Pavlos Kokordelis,
  • Benjamin Krämer,
  • Andreas Glässner,
  • Franziska Wolter,
  • Felix Goeser,
  • Philipp Lutz,
  • Carolynne Schwarze-Zander,
  • Christoph Boesecke,
  • Christian P Strassburg,
  • Jürgen K Rockstroh,
  • Ulrich Spengler,
  • Jacob Nattermann

DOI
https://doi.org/10.1371/journal.pone.0174465
Journal volume & issue
Vol. 12, no. 4
p. e0174465

Abstract

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BACKGROUND:A relevant proportion of human immunodeficiency virus (HIV) infected patients is co-infected with the hepatitis C virus (HCV). HCV co-infection in HIV-positive patients is associated with faster progression of liver disease in comparison to HCV mono-infection. Natural killer (NK) cells critically modulate the natural course of HCV infection. Both HIV and HCV mono-infection are associated with alterations of the NK cell pool. However, little data is available concerning phenotype and function of NK cells in HIV/HCV co-infection. METHODS:A total of 34 HIV/HCV co-infected, 35 HIV and 39 HCV mono-infected patients and 43 healthy control persons were enrolled into this study. All HIV-positive patients were under effective antiretroviral therapy. NK cell phenotype, IFN-γ production and degranulation were studied by flow cytometry. RESULTS:NK cell frequency in HIV/HCV co-infection was significantly lower than in healthy individuals but did not differ from HIV and HCV mono-infection. HIV/HCV co-infection was associated with significantly decreased expression of the maturation/differentiation markers CD27/62L/127 on NK cells but increased expression of CD57 compared to healthy controls. Of note, expression also differed significantly from HCV mono-infection but was similar to HIV mono-infection, suggesting a pronounced impact of HIV on these alterations. Similar findings were made with regard to the NK cell receptors NKG2A/C and NKp30. More importantly, NK cells in co-infection displayed a highly impaired functional activity with significantly lower IFN-γ production and degranulation than in healthy donors as well as HIV and HCV mono-infection, suggesting a synergistic effect of both viruses. CONCLUSIONS:Our data indicate that HIV/HCV co-infection is associated with significant alterations of the NK cell pool, which might be involved in the rapid progression of liver disease in co-infected patients and which mainly reflect alterations observed in HIV mono-infection.