Specific antibody production against a soluble antigen in the Harderian gland of the domestic fowl.

Three groups of chickens were immunized with bovine serum albumen (BSA). One group received the antigen i.v., the second had BSA dropped into the orbit and the third group was immunized both systemically and by topical application of BSA. Agar-gel diffusion studies showed antibodies to BSA to be present in the tears and sera of the first and third groups but only in the tears of the second group. Immunofluorescence revealed positive anti-BSA staining in lymphoid cells of the spleens of the first and third groups and in plasma cells of Harderian glands of all three groups. It is concluded that systemic and/or topical applications of BSA affect the tears and Harderian gland whereas only systemic injections produce an effect in the spleen and serum. The Harderian gland may have an important part to play in the local immunologic mechanism of the eye and upper respiratory tract of the fowl.