THE IMMUNE-RESPONSE AND THE EYE - THE ACAID INDUCING SIGNAL IS DEPENDENT ON THE NATURE OF THE ANTIGEN

Purpose. To examine conditions that determine the nature of the blood- borne, ACAID-inducing signal produced after intracameral injection of antigen. Methods. Balb/c mice were splenectomized, rested, and injecte d in the anterior chamber with various antigens. Two days later the an imals were bled, the plasma and white cells were isolated, and these f ractions were transferred to naive mice(with spleens). Recipients were immunized subcutaneously within 2 to 7 days and delayed type hypersen sitivity was assessed 10 to 14 days after immunization by challenge wi th the appropriate antigen. Results. The antigens HSV-1, TNP-coupled c ells, and P815 tumors cells induced a soluble ACAID-inducing signal fo und in the plasma portion of blood. The soluble protein antigens bovin e serum albumin (BSA) and conalbumin induced a cell-associated signal. When T-cells were included with protein antigens, a soluble (not cell ular) ACAID-inducing signal was induced. Conclusions. Particulate anti gens, such as HSV-1 and P815, that elicit intraocular T-cell responses or antigens that contain T-cells (e.g., TNP cells) induce a soluble, ACAID-inducing signal. Soluble antigens (e.g., BSA and conalbumin) ind uce a cell-associated ACAID signal. Additionally, T-cells are capable of modulating the type of ACAID signal produced. These results show th at two methods of delivering the ACAID signal exist that are dependent on the nature of the antigen and the presence of T-cells. The authors conclude that the eye shows great versatility in regulating potential ly damaging immune responses.