N-Linked Glycans Shape Skin Immune Responses during Arthritis and Myositis after Intradermal Infection with Ross River Virus.

Arthritogenic alphaviruses are mosquito-borne arboviruses that include several re-emerging human pathogens, including the chikungunya (CHIKV), Ross River (RRV), Mayaro (MAYV), and o'nyong-nyong (ONNV) virus. Arboviruses are transmitted via a mosquito bite to the skin. Herein, we describe intradermal RRV infection in a mouse model that replicates the arthritis and myositis seen in humans with Ross River virus disease (RRVD). We show that skin infection with RRV results in the recruitment of inflammatory monocytes and neutrophils, which together with dendritic cells migrate to draining lymph nodes (LN) of the skin. Neutrophils and monocytes are productively infected and traffic virus from the skin to LN. We show that viral envelope N-linked glycosylation is a key determinant of skin immune responses and disease severity. RRV grown in mammalian cells elicited robust early antiviral responses in the skin, while RRV grown in mosquito cells stimulated poorer early antiviral responses. We used glycan mass spectrometry to characterize the glycan profile of mosquito and mammalian cell-derived RRV, showing deglycosylation of the RRV E2 glycoprotein is associated with curtailed skin immune responses and reduced disease following intradermal infection. Altogether, our findings demonstrate skin infection with an arthritogenic alphavirus leads to musculoskeletal disease and envelope glycoprotein glycosylation shapes disease outcome.