Mucosal surfaces in the gastrointestinal tract are continually exposed to native. commensal antigens and susceptible to foreign. infectious antigens. Immunoglobulin A (IgA) provides dual humoral responses that create a symbiotic environment for the resident gut microbiota and prevent the invasion of enteric pathogens. https://www.spidertattooz.com/Messerschmitt-Me262A-1A-Fighter-Aircraft-LT-Walter-Hagenah-III-Jagdeschwader-7-Larz-Airfield-Germany-1945-German-Luft/