Local immune response in the chicken Harderian gland to antigen given by different ocular routes.

The effectiveness of three ocular routes of antigen administration to produce a local immune response in the Harderian gland was studied. The routes were by eyedrop, injection into the ocular conjunctiva and injection into the nictitating membrane. The antigen was observed in the cytoplasm of macrophages located within the lymphoid tissue only after the injection into the nictitating membrane. The numbers of germinal centres and plaque forming cells found in the gland after injection into the nictitating membrane was higher than the numbers observed following the other two ocular applications. These findings indicate that the injection of the antigen into the nictitating membrane is the most effective ocular route for producing a local immune response in the Harderian gland.