MOLECULAR MECHANISMS USED BY TUMORS TO ESCAPE IMMUNE RECOGNITION - IMMUNOGENETHERAPY AND THE CELL BIOLOGY OF MAJOR HISTOCOMPATIBILITY COMPLEX CLASS-I

In this article, we explore the hypothesis that tumor cells can escape recognition by CD8+ T cells via deficiencies in antigen processing an d presentation. Aspects of the molecular and cellular biology of major histocompatibility complex class I are reviewed. Evidence for histolo gy-specific molecular mechanisms in the antigen-processing and -presen tation deficiencies observed in some human and murine tumors is presen ted. Mechanisms identified include down-regulation of antigen processi ng, loss of functional beta2-microglobulin, and deletion of specific a lpha-chain alleles. Finally, we discuss studies using an antigen-prese ntation-deficient mouse tumor as a model for the immunogenetherapy of an antigen-presentation deficiency.