Infection with the human immunodeficiency virus type 1 (HIV-1) requires the presence of a CD4 receptor and a chemokine receptor, principally chemokine receptor 5 (CCR5). Homozygosity for a 32-bp deletion in the CCR5 allele provides resistance against HIV-1 acquisition. We transplanted stem cells from a donor who was homozygous for CCR5 delta32 in a patient with acute myeloid leukemia and HIV-1 infection. The patient remained without viral rebound 20 months after transplantation and discontinuation of antiretroviral therapy. This outcome demonstrates the critical role CCR5 plays in maintaining HIV-1 infection.

HIV entry into CD4 ؉ cells requires interaction with a cellular receptor, generally either CCR5 or CXCR4. We have previously reported the case of an HIV-infected patient in whom viral replication remained absent despite discontinuation of antiretroviral therapy after transplantation with CCR5⌬32/⌬32 stem cells. However, it was expected that the long-lived viral reservoir would lead to HIV rebound and disease progression during the process of immune reconstitution. In the present study, we demonstrate successful reconstitution of CD4 ؉ T cells at the systemic level as well as in the gut mucosal immune system after CCR5⌬32/⌬32 stem cell transplantation, while the patient remains without any sign of HIV infection. This was observed although recovered CD4 ؉ T cells contain a high proportion of activated memory CD4 ؉ T cells, ie, the preferential targets of HIV, and are suscep- IntroductionDestruction of the immune system by the HIV is driven by the loss of CD4 ϩ T cells in the peripheral blood and lymphoid tissues. Viral entry into CD4 ϩ cells is mediated by the interaction with a cellular chemokine receptor, the most common of which are CCR5 and CXCR4. 1 Because subsequent viral replication requires cellular gene expression processes, activated CD4 ϩ cells are the primary targets of productive HIV infection. Consequently, HIV infection leads predominantly to the depletion of activated memory CD4 ϩ T cells, most of which reside in the gastrointestinal (GI) mucosa. [2][3][4] Although therapeutic control of HIV replication allows the immune system to partially restore and delays disease progression, the cure of HIV infection remains still unachievable with use of the currently available antiretroviral drugs. The major barrier to viral eradication in patients receiving antiretroviral therapy (ART) is the establishment of HIV reservoirs, including low-level productively and latently infected cells. [5][6][7] Thus, maintenance of replicationcompetent HIV in long-lived cells and distinct anatomical sanctuaries allows the virus to reseed the body once ART is discontinued. 8 Cells of persons homozygous for the CCR5 gene variant ⌬32 (CCR5⌬32/⌬32) are naturally resistant to infection with CCR5-tropic HIV strains (R5 HIV) because of the lack of CCR5 cell-surface expression. 9 Previously, we demonstrated the feasibility of hematopoietic stem cell transplantation (SCT) with CCR5⌬32/ ⌬32 donor cells (CCR5⌬32/⌬32 SCT) in an HIV-infected patient with relapsed acute myeloid leukemia (AML) and documented absent viremia during the first 20 months of remission, during which time the patient did not receive ART. 10,11 This case clearly emphasizes the importance for continuing research in the field of CCR5-targeted treatment strategies, but uncertainty has remained over whether a cure for HIV infection has been achieved in this patient.In the setting of HIV infection, the effects of pretransplantation conditioning do not allow the complete elimination of HIV, as demonstrated by previous studies in which researchers demonstrated that HIV...

This is a PDF file of a peer-reviewed paper that has been accepted for publication. Although unedited, the content has been subjected to preliminary formatting. Nature is providing this early version of the typeset paper as a service to our authors and readers. The text and figures will undergo copyediting and a proof review before the paper is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers apply.

Suppressive HAART abrogates HIV-induced intestinal barrier defect and villous atrophy. The HIV-induced barrier defect is due to altered tight junction protein composition and elevated epithelial apoptoses. Mucosal cytokines are mediators of the HIV-induced mucosal barrier defect and villous atrophy.

The use of structured treatment interruption (STI) in human immunodeficiency virus (HIV)-infected subjects is currently being studied as an alternative therapeutic strategy for HIV-1. The potential risk for selection of drug-resistant HIV-1 variants during STI is unknown and remains a concern. Therefore, the emergence of drug resistance in sequential plasma samples obtained from 28 subjects with chronic HIV infection was studied. They underwent 4 cycles of 2-week STI, followed by 8-week retreatment with highly active antiretroviral therapy identical to that used before STI, and they had never failed treatment before undergoing STI. At week 40, treatment was stopped for a longer period. Minor populations of drug-resistant variants were detected by quantitative real-time polymerase chain reaction, by use of allele-discriminating oligonucleotides for 2 key resistance mutations: L90M (protease) and M184V (reverse transcriptase). The approximate discriminative power was 0.1%. In 14 of 25 and in 3 of 25 subjects, the M184V and the L90M mutations, respectively, were detected as minor populations, at different times during STI. Overall, these results indicate that, in subjects undergoing multiple STIs, HIV-1 variants carrying drug-resistance mutations can emerge during periods of increased HIV-1 replication.

No abstract

No abstract

European Commission and Deutsche Forschungsgemeinschaft.