Systemic inflammation suppresses lymphoid tissue remodeling and B cell immunity during concomitant local infection

Alexandre, Yannick O; Devi, Sapna; Park, Simone L; Mackay, Laura K.; Heath, William R.; Mueller, Scott N.

Concurrent infection with multiple pathogens occurs frequently in individuals and can result in exacerbated infections and altered immunity. However, the impact of such coinfections on immune responses remains poorly understood. Here we reveal that systemic infection results in an inflammation-induced suppression of local immunity. During localized infection or vaccination in barrier tissues including the skin or respiratory tract, concurrent systemic infection induced a type I interferon-dependent lymphopenia that impairs lymphocyte recruitment to the draining lymph node (dLN). This leads to suppressed lymphoid stromal cell expansion and dLN remodeling and impaired induction of B cell responses and antibody production. Our data suggest that contemporaneous systemic inflammation constrains the induction of regional immunity.