Abstract
ABSTRACTStreptococcus pyogenesinfection of the upper respiratory tract and skin can lead to severe invasive streptococcal disease (ISD). Previous studies have demonstrated that the deficiency of IL-17 in mice (IL-17-/-) reduces mucosal immunity againstS. pyogenes. However, the impact of IL-17 deficiency on the development of ISD is unknown. Here, we model single or repeated non-lethal, intranasal (IN)S. pyogenesM1 strain infections in immunocompetent and IL-17-/-mice to assess bacterial dissemination following a final IN or skin challenge. Immunocompetent mice that received a singleS. pyogenesIN infection displayed long-lasting mucosal immunity and no systemic infection. However, in the absence of IL-17, a single IN infection resulted in the dissemination ofS. pyogenesto the spleens, which was further exacerbated by repeated IN infections. Interestingly, immunity following skin challenge did not show a correlation with IL-17 and was instead associated with the activation of germinal center responses and the accumulation of neutrophils in the spleen. Our results highlight the critical role of IL-17 in preventing ISD followingS. pyogenesinfection of the respiratory mucosa.
Publisher
Cold Spring Harbor Laboratory