Persistence of an antigen recognized by Crohn's disease sera during in vivo passage of a Crohn's disease-induced lymphoma in athymic nude mice.

Previous studies from this laboratory have shown that lymphoma and lymph node hyperplasia develop in athymic nude mice injected with Crohn's disease tissue filtrates. In addition, use of an indirect immunofluorescence assay has demonstrated that an antigen(s) in these lymphoid tissues is recognized by sera from patients with Crohn's disease. In our study, one such lymphoma was passed through 10 generations of athymic nude mice and used for immunofluorescence studies. Suspended cells (1 to 5 X 10(8)/mouse) from the primary lymphoma and from the lymphomas that developed in mice of each subsequent generation were injected subcutaneously into groups of three to eight mice. As a control, lymphoma induced in a nude mouse by the injection of sarcoid lymph node filtrate was passed through successive generations in the same manner as the Crohn's disease-induced lymphoma. Lymphoma developed locally in 81% of recipient mice 3 to 6 weeks after injection of suspended cells. In 47 mice, representing 10 generations, Crohn's disease-related lymphoma developed at the sites of injection and at axillary or inguinal lymph nodes. These tumors were examined by immunofluorescence assay using a panel of 20 sera coded for Crohn's disease or control. Immunofluorescence assay yielded positive results in 61% of the lymphomas and 59% of the lymph node with sera from patients with Crohn's disease, but not with control sera. Control lymphomas did not stain with any serum. Our studies demonstrate the transmissibility or inducibility of an antigen(s) in lymphoid tissue of athymic nude mice that is recognized by sera from patients with Crohn's disease, but not by control sera.