THROMBIN ENHANCES OVALBUMIN-SPECIFIC IGA IN MUCOSAL SURFACES BY INTRANASAL ADMINISTRATION IN MICE

Thrombin plays a central role in blood coagulation. In addition, thrombin is an important inflammatory mediator that activates T lymphocytes and monocytes and induces the release of proinflammatory cytokines in vitro. However, it has not been clarified whether thrombin can inducethe production ofantibodies against antigens in vivo; i.e., it is not known whether thrombin has an adjuvant effect to enhance immune responses. In the present study in mice, intranasally administered thrombin plus ovalbumin enhanced not only antigen-specificIgG in blood but also antigen-specificIgA on mucosa in the nasal cavity and intestine. IgA plays a major role in protecting against infection by preventing pathogens from invading the body through mucous membranes. This study provides new information regarding thrombin as an adjuvant of mucosal immunity.