The current study, investigates the roles of TLR2, TLR4, and MyD88 in clearance of Brucella following respiratory exposure and development of adaptive immune response against Brucella. Since the mucosal/respiratory system is the primary portal of entry for human infection documented in many laboratory incidents and relevant to biothreats, it is important to understand the pathogenesis and immune responses resulting from aerosol exposure. The gene discussed is TLR4; the disease is infection.