Cell-mediated and humoral immunity to chick type II collagen and its cyanogen bromide peptides in guinea-pigs.

Cell-mediated immunity (CMI) to chick type II collagen and its cyanogen bromide (CB) peptides was studied in guinea-pigs using cutaneous delayed hypersensitivity reactions. Responses were largely independent of molecular conformation in animals immunized with either native or denatured collagen, and reactions obtained with CB peptides 8, 9, 10 and 12 suggested that sites in the central regions of collagen chains were recognized in CMI. Antibodies to collagen were detected by haemagglutination and immunofluorescence only in animals immunized with native molecule and not in animals immunized with denatured or CB-digested material. Humoral and CMI responses were similar in that neither recognized the pepsin-labile non-helical regions of the molecule. The responses differed in that humoral reactions were conformation-dependent and type-specific and CMI reactions were not.