Inflammatory and Redox Reprogramming of Macrophages by HIV Cell-to-Cell Transmission Inhibits Bone Resorption Capacity

Franco Agustin SvierczPatricio JarmolukConstanza Andrea RussoAlicia LópezRosa Nicole FreibergerCintia CevallosM. Victoria DelpinoJorge Quarleri^*

• National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina

People with HIV experience bone loss, but how viral spread perturbs osteoclastogenesis remains unclear. We asked whether cell-to-cell transmission of HIV from infected CD4⁺ T cells to macrophages reprograms precursors and impairs osteoclast differentiation. We co-cultured Jurkat cells infected with R5-or X4-tropic HIV with human monocyte-derived macrophages (M0/M1/M2) and quantified infection (p24/GFP), inflammasome activation and death (IL-1β, AnnexinV/7-AAD, z-YVAD), adhesion molecules/tetraspanins (ICAM-1, LFA-1, CD9/CD63/CD81), mROS (MitoSOX, NAC), polarization markers/cytokines, and osteoclastogenesis (TRAP, actin ring, CD51/61, adhesion, bone resorption). R5 HIV infected M0>M2>M1 macrophages via contact, sustaining p24 release across differentiation and reducing TRAP⁺ osteoclasts and resorption. HIV-exposed macrophages showed inflammasome-linked death and IL-1β induction; contact enhanced Mf–T conjugates and upregulated ICAM-1/LFA-1 and tetraspanins. HIV-infected T cells displayed pro-inflammatory TNF-α/IFN-γ profiles, skewing macrophages toward M1-like states. Jurkat-derived ROS promoted conjugates and mROS accumulation in macrophages, while NAC reduced contact and oxidative imbalance. Nevirapine partially restored osteoclastogenesis and revealed contact-associated drug insensitivity. The effects scaled with the proportion of infected T cells. HIV cell-to-cell spread induces inflammatory and redox reprogramming in macrophage precursors that blocks osteoclast differentiation and function, offering testable targets (inflammasome, adhesion, ROS) to protect bone in HIV.