Ha, NgocPham, Duc-HungShahsafaei, AliakbarNaruse, ChieAsano, MasahideThai, To-Ha2014-07-072014Ha, Ngoc, Duc-Hung Pham, Aliakbar Shahsafaei, Chie Naruse, Masahide Asano, and To-Ha Thai. 2014. “HP-1γ Controls High-Affinity Antibody Response to T-Dependent Antigens.” Frontiers in Immunology 5 (1): 271. doi:10.3389/fimmu.2014.00271. http://dx.doi.org/10.3389/fimmu.2014.00271.1664-3224http://nrs.harvard.edu/urn-3:HUL.InstRepos:12406690In vitro observations suggest a role for the mouse heterochromatin protein 1γ (HP-1γ) in the immune system. However, it has not been shown if and how HP-1γ contributes to immunity in vivo. Here we show that in mice, HP-1γ positively regulates the germinal center reaction and high-affinity antibody response to thymus (T)-dependent antigens by limiting the size of CD8+ regulatory T-cell (Treg) compartment without affecting progenitor B- or T-cell-development. Moreover, HP-1γ does not control cell proliferation or class switch recombination. Haploinsufficiency of cbx-3 (gene encoding HP-1γ) is sufficient to expand the CD8+ Treg population and impair the immune response in mice despite the presence of wild-type HP-1α and HP-1β. This is the first in vivo evidence demonstrating the non-redundant role of HP-1γ in immunity.en-USchromatin remodelingepigeneticsadaptive immunitygerminal center responseCD8Journal Article2014-07-0710.3389/fimmu.2014.00271