Insufficient Production and Tissue Delivery of CD4+Memory T Cells in Rapidly Progressive Simian Immunodeficiency Virus Infection

The mechanisms linking human immunodeficiency virus replication to the progressive immunodeficiency of acquired immune deficiency syndrome are controversial, particularly the relative contribution of CD4+ T cell destruction. Here, we used the simian immunodeficiency virus (SIV) model to investigate the relationship between systemic CD4+ T cell dynamics and rapid disease progression. Of 18 rhesus macaques (RMs) infected with CCR5-tropic SIVmac239 (n = 14) or CXCR4-tropic SIVmac155T3 (n = 4), 4 of the former group manifested end-stage SIV disease by 200 d after infection. In SIVmac155T3 infections, naive CD4+ T cells were dramatically depleted, but this population was spared by SIVmac239, even in rapid progressors. In contrast, all SIVmac239-infected RMs demonstrated substantial systemic depletion of CD4+ memory T cells by day 28 after infection. Surprisingly, the extent of CD4+ memory T cell depletion was not, by itself, a strong predictor of rapid progression. However, in all RMs destined for stable infection, this depletion was countered by a striking increase in production of short-lived CD4+ memory T cells, many of which rapidly migrated to tissue. In all rapid progressors (P < 0.0001), production of these cells initiated but failed by day 42 of infection, and tissue delivery of new CD4+ memory T cells ceased. Thus, although profound depletion of tissue CD4+ memory T cells appeared to be a prerequisite for early pathogenesis, it was the inability to respond to this depletion with sustained production of tissue-homing CD4+ memory T cells that best distinguished rapid progressors, suggesting that mechanisms of the CD4+ memory T cell generation play a crucial role in maintaining immune homeostasis in stable SIV infection

Early short-term treatment with neutralizing human monoclonal antibodies halts SHIV infection in infant macaques

Prevention of mother-to-child transmission (MTCT) of HIV remains a major objective where antenatal care is not readily accessible. We tested HIV-1–specific human neutralizing monoclonal antibodies (NmAbs) as a post-exposure therapy in an infant macaque model for intrapartum MTCT. One-month-old rhesus macaques were inoculated orally with the simian-human immunodeficiency virus SHIVSF162P3. On days 1, 4, 7 and 10 after virus exposure, we injected animals subcutaneously with NmAbs and quantified systemic distribution of NmAbs in multiple tissues within 24 h after antibody administration. Replicating virus was found in multiple tissues by day 1 in animals that were not treated. All NmAb-treated macaques were free of virus in blood and tissues at 6 months after exposure. We detected no anti-SHIV T cell responses in blood or tissues at necropsy, and no virus emerged after CD8+ T cell depletion. These results suggest that early passive immunotherapy can eliminate early viral foci and thereby prevent the establishment of viral reservoirs.Fil: Hessell, Ann J.. Oregon Health and Science University; Estados UnidosFil: Jaworski, Juan Pablo. Oregon Health and Science University; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Epson, Erin. Oregon Health and Science University; Estados UnidosFil: Matsuda, Kenta. National Institutes of Health; Estados UnidosFil: Pandey, Shilpi. Oregon Health and Science University; Estados UnidosFil: Kahl, Christoph. Oregon Health and Science University; Estados UnidosFil: Reed, Jason. Oregon Health and Science University; Estados UnidosFil: Sutton, William F.. Oregon Health and Science University; Estados UnidosFil: Hammond, Katherine B.. Oregon Health and Science University; Estados UnidosFil: Cheever, Tracy A.. Oregon Health and Science University; Estados UnidosFil: Barnette, Philip T.. Oregon Health and Science University; Estados UnidosFil: Legasse, Alfred W.. Oregon Health and Science University; Estados UnidosFil: Planer, Shannon. Oregon Health and Science University; Estados UnidosFil: Stanton, Jeffrey J.. Oregon Health and Science University; Estados UnidosFil: Pegu, Amarendra. National Institutes of Health; Estados UnidosFil: Chen, Xuejun. National Institutes of Health; Estados UnidosFil: Wang, Keyun. National Institutes of Health; Estados UnidosFil: Siess, Don. Oregon Health and Science University; Estados UnidosFil: Burke, David. Oregon Health and Science University; Estados UnidosFil: Park, Byung S.. Oregon Health and Science University; Estados UnidosFil: Axthelm, Michael K. Oregon Health and Science University; Estados UnidosFil: Lewis, Anne. Oregon Health and Science University; Estados UnidosFil: Hirsch, Vanessa M.. National Institutes of Health; Estados UnidosFil: Graham, Barney S.. National Institutes of Health; Estados UnidosFil: Mascola, John R.. National Institutes of Health; Estados UnidosFil: Sacha, Jonah B.. Oregon Health and Science University; Estados UnidosFil: Haigwood, Nancy L.. Oregon Health and Science University; Estados Unido