AUTHOR=Moreno-Nieves Uriel Y. , Didier Céline , Lévy Yves , Barré-Sinoussi Françoise , Scott-Algara Daniel ,  ANRS HIV Vaccine Network (AHVN) 

TITLE=S100A9 Tetramers, Which are Ligands of CD85j, Increase the Ability of MVAHIV-Primed NK Cells to Control HIV Infection

JOURNAL=Frontiers in Immunology

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2015.00478

DOI=10.3389/fimmu.2015.00478

ISSN=1664-3224

ABSTRACT=<p>Natural killer (NK) cells are the major antiviral effector population of the innate immune system. We previously found that S100A9 is a novel ligand of the receptor CD85j and that S100A9 tetramers enhance the anti-HIV activity of NK cells. Also, we found that dendritic cells (DCs) infected by the HIV vaccine candidate, MVA<sub>HIV</sub>, prime NK cells to specifically control HIV infection in autologous CD4<sup>+</sup> T cells. In this study, we analyzed whether stimulation of NK cells by S100A9 tetramers prior to the priming by MVA<sub>HIV</sub>-infected DCs modulates the subsequent anti-HIV activity of NK cells. We found that S100A9 tetramers activate NK cells and that DCs enhance the anti-HIV activity of NK cells. Interestingly, we observed that stimulation of NK cells by S100A9 tetramers, prior to the priming, significantly increased the subsequent anti-HIV activity of NK cells and that the enhanced anti-HIV activity was observed following different conditions of priming, including the MVA<sub>HIV</sub>-priming. As S100A9 tetramers alone directly increase the anti-HIV activity of NK cells and as this increased anti-HIV activity is also observed following the interaction of NK cells with MVA<sub>HIV</sub>-infected DCs, we propose S100A9 tetramers as potential adjuvants to stimulate the anti-HIV activity of NK cells.</p>