RT Journal Article T1 Vulnerability to reservoir reseeding due to high immune activation after allogeneic hematopoietic stem cell transplantation in individuals with HIV-1. A1 Eberhard, Johanna M A1 Angin, Mathieu A1 Passaes, Caroline A1 Salgado, Maria A1 Monceaux, Valerie A1 Knops, Elena A1 Kobbe, Guido A1 Jensen, Björn A1 Christopeit, Maximilian A1 Kröger, Nicolaus A1 Vandekerckhove, Linos A1 Badiola, Jon A1 Bandera, Alessandra A1 Raj, Kavita A1 van Lunzen, Jan A1 Hütter, Gero A1 Kuball, Jürgen H E A1 Martinez-Laperche, Carolina A1 Balsalobre, Pascual A1 Kwon, Mi A1 Díez-Martín, José L A1 Nijhuis, Monique A1 Wensing, Annemarie A1 Martinez-Picado, Javier A1 Schulze Zur Wiesch, Julian A1 Sáez-Cirión, Asier AB Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only medical intervention that has led to an HIV cure. Whereas the HIV reservoir sharply decreases after allo-HSCT, the dynamics of the T cell reconstitution has not been comprehensively described. We analyzed the activation and differentiation of CD4+ and CD8+ T cells, and the breadth and quality of HIV- and CMV-specific CD8+ T cell responses in 16 patients with HIV who underwent allo-HSCT (including five individuals who received cells from CCR5Δ32/Δ32 donors) to treat their underlying hematological malignancy and who remained on antiretroviral therapy (ART). We found that reconstitution of the T cell compartment after allo-HSCT was slow and heterogeneous with an initial expansion of activated CD4+ T cells that preceded the expansion of CD8+ T cells. Although HIV-specific CD8+ T cells disappeared immediately after allo-HSCT, weak HIV-specific CD8+ T cell responses were detectable several weeks after transplant and could still be detected at the time of full T cell chimerism, indicating that de novo priming, and hence antigen exposure, occurred during the time of T cell expansion. These HIV-specific T cells had limited functionality compared with CMV-specific CD8+ T cells and persisted years after allo-HSCT. In conclusion, immune reconstitution was slow, heterogeneous, and incomplete and coincided with de novo detection of weak HIV-specific T cell responses. The initial short phase of high T cell activation, in which HIV antigens were present, may constitute a window of vulnerability for the reseeding of viral reservoirs, emphasizing the importance of maintaining ART directly after allo-HSCT. YR 2020 FD 2020 LK http://hdl.handle.net/10668/15523 UL http://hdl.handle.net/10668/15523 LA en DS RISalud RD Apr 7, 2025