Immunobiology of Langerhans cells on the ocular surface. I. Langerhans cells within the central cornea interfere with induction of anterior chamber associated immune deviation.

Inoculation of P815 tumor cells into the anterior chamber of eyes of BALB/c mice produces Anterior Chamber Associated Immune Deviation (ACAID) whereby delayed hypersensitivity responses to the minor H antigens of the tumor cells are suppressed. In our laboratory, impaired delayed hypersensitivity is obtained in the majority, but not all normal BALB/c recipients. In the minority, typcial delayed hypersensitivity responses, similar to those induced by subcutaneous immunization with tumor cells, are observed. Retrospective examination of eyes of animals that develop delayed hypersensitivity following intracameral tumor cell injection revealed a high incidence of a corneal disorder in which significant numbers of Langerhans cells are found within the corneal epithelium. BALB/c mice with corneal lesions characterized by opacity and calcium deposition, or whose corneas had become infiltrated with Langerhans cells induced to emigrate by a superficial cautery wound, received intracameral injections of P815 cells. Minimal or no significant suppression of delayed hypersensitivity was obtained, suggesting that ACAID induction had not taken place. These results suggest that the presence of Langerhans cells in the central corneal epithelium mitigates against ACAID induction.