Global Proteome Analysis of a Three-Dimensional Human Chondrocyte Cell Culture System Infected with Chikungunya Virus (CHIKV) Reveals Distinct Immune and Inflammatory Signatures.

Chikungunya disease (CHIKD) presents as an acute viral fever with severe joint pain, which may progress into a chronic arthritic condition that can last for months or even years. The cell tropism of chikungunya virus (CHIKV) infection is well studied; however, the mechanisms underlying the pathogenesis of chronicity, especially in the joints, remain poorly understood. Primary chondrocytes were isolated from human joint samples, characterized and grown both as monolayers and as 3D spheroids. These cultures were infected with chikungunya virus (CHIKV) at different multiplicity of infections(MOIs), and a temporal analysis of infection in these distinct types of culture systems was conducted. Further, the global proteome was obtained from these two kinds of culture systems upon infection, and the proteomes were analyzed in detail to understand the impact of CHIKV on these culture systems. Chondrocytes grown as 3D spheroids were able to sustain CHIKV for extended periods of time, i.e., as long as 168 h, without compromising cellular integrity. Proteomic analysis revealed distinct protein regulation patterns during CHIKV infection, with the changes in 3D spheroids closely resembling those in the natural joint tissue microenvironment. Our study has, for the first time, presented a bird's-eye view of the global proteome changes in human chondrocytes in response to CHIKV infection and further established the usefulness of the 3D chondrocyte culture system in understanding CHIKV infection.