A 58-year-old woman comes to the emergency department due to abdominal discomfort and bloating. Physical examination reveals ascites. Abdominal ultrasonography shows a mass in the left ovary, and subsequent paracentesis reveals malignant cells. Surgical excision of the mass is performed. Histopathology shows high-grade serous carcinoma composed of atypical cells with pleomorphic nuclei and mitotic figures. Large numbers of T cells are present in the tumor stroma; further evaluation shows the tumor expresses PD-1 ligands that interact with the PD-1 receptor on the infiltrating T cells. Which of the following is most likely occurring in the tumor microenvironment as a result of this interaction?

Question

A 58-year-old woman comes to the emergency department due to abdominal discomfort and bloating.  Physical examination reveals ascites.  Abdominal ultrasonography shows a mass in the left ovary, and subsequent paracentesis reveals malignant cells.  Surgical excision of the mass is performed.  Histopathology shows high-grade serous carcinoma composed of atypical cells with pleomorphic nuclei and mitotic figures.  Large numbers of T cells are present in the tumor stroma; further evaluation shows the tumor expresses PD-1 ligands that interact with the PD-1 receptor on the infiltrating T cells.  Which of the following is most likely occurring in the tumor microenvironment as a result of this interaction?

Quizplus · Accepted Answer

Eductional Objective: Tumor cells must develop adaptations to avoid destruction by the innate and adaptive immune response.  A common adaptation is to overexpress programmed cell death 1 ligand 1 (PD-L1), which converts effector T cells to exhausted T cells.  Other adaptations include down-regulating class I major histocompatibility complexes, blocking T-cell costimulation, and increasing immunoinhibitory cytokine secretion.

A 58-Year-Old Woman Comes to the Emergency Department Due to Abdominal