Which is involved in reacting to virus-infected cells?
A) B cells AND cell-mediated immunity
B) MHC class II molecules, B cells AND cytotoxic T cells
C) B cells, leukocytes AND MHC class II molecules
D) MHC class I molecules, helper T cells AND humoral immunity
E) MHC class I molecules, cell-mediated immunity AND cytotoxic T cells

Question

Which is involved in reacting to virus-infected cells?
A) B cells AND cell-mediated immunity 
B) MHC class II molecules, B cells AND cytotoxic T cells
C) B cells, leukocytes AND MHC class II molecules
D) MHC class I molecules, helper T cells AND humoral immunity
E) MHC class I molecules, cell-mediated immunity AND cytotoxic T cells

Quizplus · Accepted Answer

Virus-infected cells are targeted by cytotoxic T cells, which are part of the cell-mediated immune response. These T cells are activated by the binding of their T cell receptors to peptide fragments presented on MHC class I molecules, which are expressed on the surface of infected cells. Thus, MHC class I molecules are involved in reacting to virus-infected cells, along with cell-mediated immunity and cytotoxic T cells. Humoral immunity, which involves B cells and antibody production, is less involved in responding to virus-infected cells. MHC class II molecules, which are mainly involved in presenting antigens to helper T cells, may also play a role in the response to viruses, but are not as central as MHC class I molecules in this context. Leukocytes are a broad category of immune cells that include both B cells and T cells, but the answer choices that include leukocytes do not provide enough specificity to be correct.

Which Is Involved in Reacting to Virus-Infected Cells