A 68-year-old man comes to the office for a follow-up appointment. He has a history of advanced melanoma that is unresectable and resistant to adjuvant regimens. The patient recently began receiving monoclonal antibody infusions for advanced melanoma. The monoclonal antibodies block a specific cell surface receptor found on T lymphocytes. As a result, T cells capable of recognizing tumor antigens have improved ability to destroy cancer cells. Which of the following cell surface receptors is most likely blocked by the treatment?

Question

A 68-year-old man comes to the office for a follow-up appointment.  He has a history of advanced melanoma that is unresectable and resistant to adjuvant regimens.  The patient recently began receiving monoclonal antibody infusions for advanced melanoma.  The monoclonal antibodies block a specific cell surface receptor found on T lymphocytes.  As a result, T cells capable of recognizing tumor antigens have improved ability to destroy cancer cells.  Which of the following cell surface receptors is most likely blocked by the treatment?

Quizplus · Accepted Answer

Eductional Objective: The binding of programmed cell death protein 1 (PD-1) to one of its ligands (programmed death-ligand 1 [PD-L1]) downregulates the immune response by inhibiting cytotoxic T cells.  Many types of cancers evade immunodetection by increasing expression of PD-L1 on their surface.  Monoclonal antibodies against PD-1 upregulate the T-cell response and promote tumor cell apoptosis.

A 68-Year-Old Man Comes to the Office for a Follow-Up