Question

A number of tumors and viruses (e.g., Epstein-Barr) are able to escape cytotoxic T cell degradation by inhibiting what?

A) the activation of the complement system
B) tumor antigen expression
C) the production of the class II major histocompatibility (MHC) molecule
D) the production of the class I MHC molecule
E) helper T cell activation

Answer 1

Tumors and viruses like Epstein-Barr avoid destruction by cytotoxic T cells by hindering the production of class I MHC molecules, crucial for cytotoxic T cell recognition.

Step-by-step explanation:

Many tumors and viruses, such as Epstein-Barr, escape cytotoxic T cell degradation by inhibiting the production of the class I MHC molecule. Cells infected with certain viruses produce proteins that interfere with MHC I processing and trafficking, leading to reduced MHC I molecules on the cell surface. Furthermore, tumor cells often alter gene expression to present distorted or absent MHC I molecules. Without sufficient class I MHC expression, cytotoxic T cells cannot effectively recognize and destroy the infected or abnormal cells.