Cytomegalovirus-infected host cell presenting viral peptide–MHC class I complex

Cytomegalovirus-infected host cells presenting viral peptide–MHC class I complexes refer to **host cells infected by human cytomegalovirus (HCMV) that display fragments of viral proteins bound to major histocompatibility complex class I molecules on their surface**. This process is central to the adaptive immune response against intracellular pathogens. The MHC class I pathway presents peptides derived from endogenous proteins—including those produced by viruses—to CD8+ cytotoxic T lymphocytes[2][4][6]. Recognition of these complexes by specific T-cell receptors triggers targeted destruction of the infected cell[1][2]. HCMV has evolved multiple mechanisms to evade detection by interfering with various steps in the MHC-I antigen presentation pathway. For example, HCMV encodes proteins such as US2 that bind newly synthesized MHC-I molecules and target them for degradation, thereby reducing their surface expression and impairing CD8+ T-cell recognition[1][3]. Despite these evasion strategies, some level of antigen presentation persists—enabling partial immune control. This “target” is not a single molecule but rather a **functional state** defined by the presence of specific pathogen-derived peptides bound within an MHC-I molecule on an infected host cell’s surface. It serves as a key focus for both natural immunity and potential immunotherapeutic interventions such as adoptive transfer of virus-specific CTLs or vaccine development. In summary, while not a classical druggable protein target like an enzyme or receptor, **cytomegalovirus-infected host cells displaying viral peptide–MHC class I complexes represent critical targets for cellular immunity**, especially in controlling persistent infections like HCMV[4][6].

Other names

HCMV-infected cell presenting viral peptide–MHC complexHuman cytomegalovirus-infected cell with viral antigen–MHC class ICMV-infected target cell (for T-cell recognition)