PT - JOURNAL ARTICLE AU - Monceaux, Valérie AU - Viollet, Laurence AU - Petit, Frédéric AU - Fang, Raphaël Ho Tsong AU - Cumont, Marie-Christine AU - Zaunders, John AU - Hurtrel, Bruno AU - Estaquier, Jérôme TI - CD8<sup>+</sup> T Cell Dynamics during Primary Simian Immunodeficiency Virus Infection in Macaques: Relationship of Effector Cell Differentiation with the Extent of Viral Replication AID - 10.4049/jimmunol.174.11.6898 DP - 2005 Jun 01 TA - The Journal of Immunology PG - 6898--6908 VI - 174 IP - 11 4099 - http://www.jimmunol.org/content/174/11/6898.short 4100 - http://www.jimmunol.org/content/174/11/6898.full SO - J. Immunol.2005 Jun 01; 174 AB - Immunological and virological events that occur during the earliest stages of HIV-1 infection are now considered to have a major impact on subsequent disease progression. We observed changes in the frequencies of CD8bright T cells expressing different chemokine receptors in the peripheral blood and lymph nodes of rhesus macaques during the acute phase of the pathogenic SIVmac251 infection; the frequency of CD8bright T cells expressing CXCR4 decreased, while the frequency of those expressing CCR5 increased. These reciprocal changes in chemokine receptor expression were associated with changes in the proportion of cycling (Ki67+) CD8bright T cells, and with the pattern of CD8bright T cell differentiation as defined by expression of CCR7 and CD45RA. In contrast, during the primary phase of the attenuated SIVmac251Δnef infection, no major change was observed. Whereas during the acute phase of the infection with pathogenic SIV (2 wk postinfection) no correlate of disease protection was identified, once the viral load set points were established (2 mo postinfection), we found that the levels of cycling and of CCR5- and CXCR4-positive CD8bright T cells were correlated with the extent of viral replication and therefore with SIV-infection outcome. Our data reveal that, during primary SIV infection, despite intense CD8 T cell activation and an increase in CCR5 expression, which are considered as essential for optimal effector function of CD8+ T cells, these changes are associated with a poor prognosis for disease progression to AIDS.