Survivors of RSV bronchiolitis and pneumonia develop increased susceptibility to asthma. We showed that skewed polarization of dendritic cells (DC) towards plasmacytoid DC (pDC) in the pups in response to RSV is inhibited by exogenous administration of osteopontin (OPN) with an associated Th1 immune response. In the present study, we examined the expression of MHC-II, an indicator of antigen presenting function, on the antigen presenting cells (APC) in the RSV-infected lungs and its dependence on NKT cells. Wild type (WT) and NKT knock out (NKT-/-) pups were infected with RSV and were treated with or without OPN. Expression of MHCII on the lung APCs, including macrophages (MQ) and DCs (pDC; CD11blo/-CD11Clo/-CD45Rhi) and mDC; CD11blo/-CD11ChiCD45Rlo/-), was determined by flowcytometry (FACS). The effect of OPN on MHCII expression in the presence or absence of NKT cells was studied. FACS revealed that expression of MHCII was higher on the pDCs than mDCs in the RSV-infected WT lungs. In the absence of NKT cells, MHCII expression on pDCs was increased. OPN treatment augmented expression of MHCII on MQ and DCs, which was further enhanced in the absence of NKT cells. These data suggest that OPN- induced MHCII expression on the lung APCs is NKT dependent. Further experiments will explore the underlying mechanism of this phenomenon, which may help developing a therapeutic strategy to stop skewed polarization of DC in RSV infected lungs in preventing susceptibility to asthma.