Complement C4 Prevents Viral Infection through Capsid Inactivation (Cell Host & Microbe)

The complement system is pivotal to the humoral immune response. Bottermann et al. demonstrate that complement proteins C1 and C4 possess potent antiviral activity independent of downstream components. C4b is deposited on the viral capsid, preventing capsid disassembly and virus item into the cytosol, a prerequisite for productive virus infection.