Treatment with native heterodimeric IL-15 increases cytotoxic lymphocytes and reduces SHIV RNA in lymph nodes.

• Main Authors: Dionysios C Watson, Eirini Moysi, Antonio Valentin, Cristina Bergamaschi, Santhi Devasundaram, Sotirios P Fortis, Jenifer Bear, Elena Chertova, Julian Bess, Ray Sowder, David J Venzon, Claire Deleage, Jacob D Estes, Jeffrey D Lifson, Constantinos Petrovas, Barbara K Felber, George N Pavlakis
• Format: Article
• Language: English
• Published: Public Library of Science (PLoS) 2018-02-01
• Series: PLoS Pathogens
• Online Access: https://doi.org/10.1371/journal.ppat.1006902

B cell follicles in secondary lymphoid tissues represent an immune privileged sanctuary for AIDS viruses, in part because cytotoxic CD8+ T cells are mostly excluded from entering the follicles that harbor infected T follicular helper (TFH) cells. We studied the effects of native heterodimeric IL-15 (hetIL-15) treatment on uninfected rhesus macaques and on macaques that had spontaneously controlled SHIV infection to low levels of chronic viremia. hetIL-15 increased effector CD8+ T lymphocytes with high granzyme B content in blood, mucosal sites and lymph nodes, including virus-specific MHC-peptide tetramer+ CD8+ cells in LN. Following hetIL-15 treatment, multiplexed quantitative image analysis (histo-cytometry) of LN revealed increased numbers of granzyme B+ T cells in B cell follicles and SHIV RNA was decreased in plasma and in LN. Based on these properties, hetIL-15 shows promise as a potential component in combination immunotherapy regimens to target AIDS virus sanctuaries and reduce long-term viral reservoirs in HIV-1 infected individuals.<h4>Trial registration</h4>ClinicalTrials.gov NCT02452268.