Cultured keratinocyte allografts fail to induce sensitization in vivo

Background. The use of cultured keratinocyte (CK) allografts for burn wounds offers a potentially unlimited supply of skin. It is unknown, however, whether CK allografts induce rejection in vivo. This study investigated the induction of immune responsiveness to CK allografts as measured by mixed lymphocyte response and serum cytotoxic antibody. Methods. Female CBA mice (n = 160) were randomized to four equal groups, each receiving a 3 cm² flank graft of autologous CBA CK (Auto CK), allogeneic C57BL/6 CK (Allo CK), C57BL/6 full thickness skin (Allo FT), or Sham. Graft take was assessed by gross and histologic examinations. Unidirectional mixed lymphocyte response was measured with graft recipient and donor splenocytes by use of tritiated thymidine uptake. Stimulation indexes were calculated. Serum cytotoxic antibody was measured by coculturing graft recipient serum with donor splenocytes and rabbit complement and assessing resultant cell killing. Results. Overall graft take was 50% for Allo CK and 74% for Auto CK. Allo FT, but not Allo CK, were associated with significantly increased stimulation indexes compared with Auto CK and Sham (p < 0.01). Allo FT, but not Allo CK, resulted in elevated titers of alloantibody, reaching significant levels 10 days after grafting (p < 0.05). Conclusions. CK allografts do not result in increased in vitro T cell responses or enhanced alloantibody formation, indicating that sensitization to major histocompatibility antigens by CK does not occur. These data suggest that CK allografts may provide a possible source of grafts for victims of large burn wounds.