SOCS3 protein levels in C57BL/6 mice that were infected with either 1×105 pfu MAV-1 (A), 5×104 pfu γHV68 (B), or 1×104 cfu Klebsiella pneumoniae (C). BALF was collected at 7 d post-viral infection and 24 h post-Klebsiella infection. After removal of cellular debris and apoptotic bodies, BALF was concentrated using a 3 kDa exclusion filter and was briefly sonicated to disrupt SOCS3-containing MPs for analysis by ELISA. Data are expressed as mean ± SEM, *= p<0.05, n=3–7 mice per group.