OX40 Facilitates Control of a Persistent Virus Infection

During acute viral infections,clearance of the pathogen is followed by the contraction of the anti-viral t cell compartment. in contrast,t cell responses need to be maintained over a longer period of time during chronic viral infections in order to control viral replication and to avoid viral spreading. much is known about inhibitory signals such as through pd-1 that limit t cell activity during chronic viral infection,but little is known about the stimulatory signals that allow maintenance of anti-viral t cells. here,we show that the co-stimulatory molecule ox40 (cd134) is critically required in the context of persistent lcmv clone 13 infection. anti-viral t cells express high levels of ox40 in the presence of their cognate antigen and t cells lacking the ox40 receptor fail to accumulate sufficiently. moreover,the emergence of t cell dependent germinal center responses and lcmv-specific antibodies are severely impaired. consequently,ox40-deficient mice fail to control lcmv clone 13 infection over time,highlighting the importance of this signaling pathway during persistent viral infection. © 2012 boettler et al.