Common cold symptoms are often mild and self-limited, but for competitive athletes even mild and self-limited symptoms may critically compromise their performance. Human Rhinovirus (HRV) is one of the most common causative viral agents for common cold symptoms. HRV type 14 (HRV-14) is known to replicate efficiently in human fibroblasts cultivated at 33 degrees and induces cytotoxicity but not at 37 degrees. In an attempt to elucidate the cellular mechanism by which HRV-14 prefers colder temperature, DNA microarray analysis was performed to compare the expression profiles of mRNA in HRV type 14 infected human fibroblastic cells cultured at 37 degrees and 33 degrees. Inhibitor of apoptosis protein (IAP) was found to be up-regulated at 37 degrees but not at 33 degrees. HRV-14 replicated and induced cytotoxicity in HRV-14 infected fibroblastic cells cultured at 37 degrees after knockdown of IAP by siRNA. Cellular temperature is thus important to protect cells from HRV induced pathogenesis. Those with lower upper respiratory truct surface temperature may be at a higher risk of HRV infection, and exercise induced lowering of upper respiratory airway may render the epithelial cells susceptible to HRV infection, which needs further to be determined.

DESCENTE SPORTS SCIENCE Vol.31/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE