CD4 and infection: Furthermore, we only observed an early increase in CD4+ T-cell specific pSmad2/3 signalling during a chronic Th1-promoting low dose infection and not during an acute Th2 promoting high dose infection in C57BL/6 mice (Figure S8 in Text S1) Thus, our data suggests that activation of TGFβ by integrin αvβ8 early during T. muris infection is important in suppression of protective Th2 cell development, which leads instead to production of an inappropriate Th1 response and development of chronic infection.