Isolation of viable canine intestinal lymphocytes

A modification of a previously reported enzymatic technique was used to isolate 60% to 90% pure populations of viable lymphocytes from canine small intestinal mucosa. Mitogenesis assays were then simultaneously performed on these and isolated peripheral blood lymphocytes from the same dogs. A technique to isolate intraepithelial lymphocytes was not successful. Intestinal mucosal lymphocytes were simultaneously purified by 2 different techniques (suspensions B and C), which produced cell populations that responded similarly to phytohemagglutinin (PHA), concanavalin A, and pokeweed mitogens. The peripheral blood lymphocytes demonstrated greater response to PHA and concanavalin A mitogens than did the intestinal mucosal lymphocytes (P less than 0.05). Furthermore, peripheral blood lymphocytes had a significantly higher response to PHA than to pokeweed mitogen (P less than 0.05). The impure preparation of intraepithelial lymphocytes (suspension A) did not show any evidence of reactivity to mitogens. Further studies are needed to determine whether the EDTA or collagenase had any effect upon the intestinal mucosal lymphocyte responsiveness. The present study demonstrated that viable mucosal lymphocytes can be isolated from the canine intestine and that they can maintain their responsiveness to mitogens.