Streptococcus pyogenes, or group A streptococcus, is a bacterial pathogen capable of causing a wide diversity of superficial and invasive human infections, ranging from the relatively common pharyngitis, or “strep throat,” to the less common and more severe necrotizing fasciitis, or “flesh eating disease”. In addition, group A streptococcal infections have been linked to a number of immune-mediated conditions occurring after an acute infection, including arthritis, kidney damage, and rheumatic heart disease, among others. A safe and effective vaccine against group A streptococcus has yet to be developed, partly due to an incomplete understanding of the interaction with the bacterium and the host immune system occurring at sites of infection. Our research seeks to determine how the streptococcal bacteria evade or disable the host immune response to infection. Findings from our research may ultimately identify novel mechanisms to produce protective immunity against group A streptococcus and could eventually help in developing a candidate vaccine.