Umeå universitets logga

Hantavirus infections are rodent-borne viruses causing potential lethal infections in humans. Different hantaviruses exist worldwide, reporting a fatality rate of up to 40%. The Puumala hantavirus (PUUV) is endemic in northern Sweden. This hantavirus strain has a relatively low fatality rate but the hospitalisation rate is high. No vaccine to the virus and no treatment for the disease exist. Despite differences in severity, the immune-mediated pathogenesis of Puumala virus infection is similar to that of highly lethal strains of hantavirus. It is currently unknown how the humoral immune system is affected during hantavirus infection.

The aim of this study is to characterise how the humoral immune response is affected during Puumala virus infection. A large number of longitudinal patient samples have been collected. Here, we demonstrate the longitudinal kinetics of the B cell response during Puumala virus infection and show that there is a change in B cell populations during the course of the disease. Furthermore we show that B cells carry known hantavirus receptors. This suggests that Puumala virus may directly infect B cells. Infection of the B cells could affect their function and or phenotype explaining a different immune response. Importantly, in approximately 10–15% of Puumala infected patients we could detect antibodies that could neutralise other hantaviruses in vitro. Samples from these patients could help to generate a monoclonal antibody treatment potentially treating diseases caused by several hantavirus.