Question

I am culturing three breast cancer cell lines in the lab, made from cancer patients A, B, and C. All 3 patients are survivors. When I add white blood cells from the peripheral blood of the patients to the the cells lines, I find that A's blood cells kill A's tumor, but not B's or C's; B's blood cells kill B's tumor, but not A's or C's; and C's blood cells kills C's tumor, but not A's or B's. I conclude that the cell type doing the killing is:

a. Macrophages
b. Th1 cells
c. Activated B cells
d. NK cells
e. CTL cells

Answer 1

The cell type responsible for killing the tumor cells is (e) CTL (Cytotoxic T cells).

Step-by-step explanation:

Based on the given information, the cell type that is most likely responsible for killing the tumor cells is CTL (Cytotoxic T cells).

CTL cells are a type of T cell that can recognize and destroy cells infected with pathogens or cancerous cells. They do this by releasing toxins that enter and kill the infected or cancerous cells.

In this case, when blood cells from patients A, B, and C are added to their respective tumor cell lines, only the blood cells from the same patient are able to kill the tumor cells, indicating a patient-specific response. This matches the behavior of CTL cells, as they are able to recognize and kill cells based on specific non-self antigens.