Quality and quantity of TFH cells are critical for broad antibody development in SHIVAD8 infection

T Yamamoto, RM Lynch, R Gautam… - Science translational …, 2015 - science.org
T Yamamoto, RM Lynch, R Gautam, R Matus-Nicodemos, SD Schmidt, KL Boswell, S Darko…
Science translational medicine, 2015science.org
Broadly neutralizing antibodies (bNAbs) protect against HIV-1 infection, yet how they are
generated during chronic infection remains unclear. It is known that T follicular helper (TFH)
cells are needed to promote affinity maturation of B cells during an immune response;
however, the role of TFH during HIV-1 infection is undefined within lymph node germinal
centers (GCs). We use nonhuman primates to investigate the relationship in the early stage
of chronic SHIVAD8 (simian-human immunodeficiency virus AD8) infection between …
Broadly neutralizing antibodies (bNAbs) protect against HIV-1 infection, yet how they are generated during chronic infection remains unclear. It is known that T follicular helper (TFH) cells are needed to promote affinity maturation of B cells during an immune response; however, the role of TFH during HIV-1 infection is undefined within lymph node germinal centers (GCs). We use nonhuman primates to investigate the relationship in the early stage of chronic SHIVAD8 (simian-human immunodeficiency virus AD8) infection between envelope (Env)–specific TFH cells, Env-specific B cells, virus, and the generation of bNAbs during later infection. We found that both the frequency and quality of Env-specific TFH cells were associated with an expansion of Env-specific immunoglobulin G–positive GC B cells and broader neutralization across HIV clades. We also found a correlation between breadth of neutralization and the degree of somatic hypermutation in Env-specific memory B cells. Finally, we observed high viral loads and greater diversity of Env sequences in rhesus macaques that developed cross-reactive neutralization as compared to those that did not. These studies highlight the importance of boosting high-quality TFH populations as part of a robust vaccine regimen aimed at eliciting bNabs.
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