Deviant immune responses to allogeneic tumors injected intracamerally and subcutaneously in mice

The ability to introduce carefully controlled numbers of viable cells into the anterior chamber of mouse eyes made it possible to examine the interrelationship between presentation of antigens intracamerally and into conventional body sites and their synergistic/antagonistic effects on the immune system. P815 mastocytoma (DBA/2; H-2(d)) cells are synergic with BALB/c hosts at the major histocompatibility complex but differ at numerous minor histocompatibility loci. When these cells are injected intracamerally into BALB/c mice, they subvert the host's immune response; that is, tumor cells injected subcutaneously developed into tumors. The dynamics of this anterior chamber-associated immune deviation was manipulable. When subcutaneous (SC) inoculations preceded intracameral (IC) inoculations by 5 days or more, systemic anti-DBA/2 immunity elicited by SC inoculation prevented successful engraftment of P815 tumors in the anterior chamber. As the time interval between SC and IC inoculations of P815 cells decreased, the balance between destruction or survival of intraocular tumors was tipped in favour of tumor growth. Intraocular tumor growth increased when IC inoculations preceded SC inoculation and was most impressive when this interval was 7 days. In these mice the tumors grew briskly and aggressively in a fashion comparable to that seen in hosts not receiving prior SC inoculations. The apparent capacity of the immune system to prevent or enhance the growth of tumors can be successfully manipulated inways that suggest the possibility of therapeutic benefit in ophthalmologic disease.