Madelene Lindqvist, Jan van Lunzen, Damien Z. Soghoian, Bjorn D. Kuhl, Srinika Ranasinghe, Gregory Kranias, Michael D. Flanders, Samuel Cutler, Naomi Yudanin, Matthias I. Muller, Isaiah Davis, Donna Farber, Philip Hartjen, Friedrich Haag, Galit Alter, Julian Schulze zur Wiesch, and Hendrik Streeck
HIV targets CD4 T cells, which are required for the induction of high-affinity antibody responses and the formation of long-lived B cell memory. The depletion of antigen-specific CD4 T cells during HIV infection is therefore believed to impede the development of protective B cell immunity. Although several different HIV-related B cell dysfunctions have been described, the role of CD4 T follicular helper (TFH) cells in HIV infection remains unknown. Here, we assessed HIV-specific TFH responses in the lymph nodes of treatment-naive and antiretroviral-treated HIV-infected individuals. Strikingly, both the bulk TFH and HIV-specific TFH cell populations were significantly expanded in chronic HIV infection and were highly associated with viremia. In particular, GAG-specific TFH cells were detected at significantly higher levels in the lymph nodes compared with those of GP120-specific TFH cells and showed preferential secretion of the helper cytokine IL-21. In addition, TFH cell expansion was associated with an increase of germinal center B cells and plasma cells as well as IgG1 hypersecretion. Thus, our study suggests that high levels of HIV viremia drive the expansion of TFH cells, which in turn leads to perturbations of B cell differentiation, resulting in dysregulated antibody production.
Yudanin, Naomi A; Schmitz, Frederike; Flamar, Anne-Laure; Thome, Joseph J C; Tait Wojno, Elia; Moeller, Jesper B; Schirmer, Melanie; Latorre, Isabel J; Xavier, Ramnik J; Farber, Donna L; Monticelli, Laurel A; Artis, David
Innate lymphoid cells (ILC) play critical roles in regulating immunity, inflammation, and tissue homeostasis in mice. However, limited access to non-diseased human tissues has hindered efforts to profile anatomically-distinct ILCs in humans. Through flow cytometric and transcriptional analyses of lymphoid, mucosal, and metabolic tissues from previously healthy human organ donors, here we have provided a map of human ILC heterogeneity across multiple anatomical sites. In contrast to mice, human ILCs are less strictly compartmentalized and tissue localization selectively impacts ILC distribution in a subset-dependent manner. Tissue-specific distinctions are particularly apparent for ILC1 populations, whose distribution was markedly altered in obesity or aging. Furthermore, the degree of ILC1 population heterogeneity differed substantially in lymphoid versus mucosal sites. Together, these analyses comprise a comprehensive characterization of the spatial and temporal dynamics regulating the anatomical distribution, subset heterogeneity, and functional potential of ILCs in non-diseased human tissues.