Influenza A virus infection modulates membrane regulations of complement activation

"The complement system is a key component of the immune response as it bridges innate and adaptive immunity. Moreover, it also plays a crucial role in modulating the intensity of immunological and inflammatory processes by communicating with immune cells. These interactions are beginning to be fully appreciated, and their identification is crucial, as excess complement activation is associated with severe outcomes in many infections. In order to avoid immune-mediated damage to the host, the complement cascade must be tightly regulated. The self-targeting deleterious effects of complement are avoided via a series of complement regulators (C-regs). Amongst the C-regs complement decay-accelerating factor (DAF/CD55) and CD59 block the complement cascade at the central and terminal points, respectively, and localise ubiquitously at the apical surface of polarised cells. The lack of DAF and CD59 is associated with over-stimulation of complement resulting in increased inflammatory responses and worse outcome in several models of infection and autoimmunity. In this work we have focused on the role of DAF and CD59 in the context of IAV infection(...)