The influence of the route of antigen administration on the development of specific antibody-producing cells in the follicles of the popliteal lymph nodes of rabbits.

Rabbits received an injection of liposome-associated human serum albumin (HSA) and six weeks later a booster injection of HSA free in solution. Anti-HSA antibody-forming cells were demonstrated in the popliteal lymph nodes by use of a HSA-horseradish peroxidase (HRP) conjugate for their detection. After a single subcutaneous injection into the footpads, specific antibody-forming cells were found, but after a single intravenous injection no anti-HSA-forming cells were observed in the lymph nodes. During the secondary immune response specific anti-HSA antibody-producing cells were found in the lymph nodes of all animals. The localization pattern of anti-HSA antibody-forming cells within the lymph nodes depended on the route of antigen administration used for the primary and booster injection. Anti-HSA-forming cells were mainly found in the cords of the medulla and in the outer cortex. During the secondary immune response, however, they were also detected in the follicles but only when at least one of the two antigen injections was given subcutaneously.