Anti-type V collagen lymphocytes that express IL-17 and IL-23 induce rejection pathology in fresh and well-healed lung transplants

Immunity to collagen V [col(V)] contributes to lung 'rejection.' We hypothesized that ischemia reperfusion injury (IRI) associated with lung transplantation unmasks antigenic col(V) such that fresh and well-healed lung grafts have differential susceptibility to anti-col(V)-mediated injury; and expression of the autoimmune cytokines, IL-17 and IL-23, are associated with this process. Adoptive transfer of col(V)-reactive lymphocytes to WKY rats induced grade 2 rejection in fresh isografts, but induced worse pathology (grade 3) when transferred to isograft recipients 30 days post-transplantation. Immunhistochemistry detected col(V) in fresh and well-healed isografts but not native lungs. Hen egg lysozyme-reactive lymphocytes (HEL, control) did not induce lung disease in any group. Col(V), but not HEL, immunization induced transcripts for IL-17 and IL-23 (p19) in the cells utilized for adoptive transfer. Transcripts for IL-17 were upregulated in fresh, but not well-healed isografts after transfer of col(V)-reactive cells. These data show that IRI predisposes to anti-col(V)-mediated pathology; col(V)-reactive lymphocytes express IL-17 and IL-23; and anti-col(V)-mediated lung disease is associated with local expression of IL-17. Finally, because of similar histologic patterns, the pathology of clinical rejection may reflect the activity of autoimmunity to col(V) and/or alloimmunity.