GED Science TestLife ScienceMedium
A patient is undergoing treatment for a chronic autoimmune disease where their immune system mistakenly attacks healthy body tissues. A new class of medication aims to suppress specific immune cells that are overactive in this condition, thereby reducing inflammation and tissue damage. Which type of immune cell is most likely being targeted by this medication to modulate the autoimmune response?
- AB lymphocytes (B cells)
- BCytotoxic T lymphocytes (CD8+ T cells)
- CNatural Killer (NK) cells
- DHelper T lymphocytes (CD4+ T cells)
Show answer & explanationAnswer & explanation
Correct answer: D. Helper T lymphocytes (CD4+ T cells)
Helper T lymphocytes (CD4+ T cells) play a central role in activating both humoral (B cells) and cell-mediated (cytotoxic T cells) immune responses. In many autoimmune diseases, overactive Helper T cells mistakenly promote responses against self-antigens, making them a key target for immunosuppressive therapies.
Why the other options are wrong
- A. B cells produce antibodies, but their activation is often dependent on Helper T cells, so targeting B cells might be secondary.
- B. Cytotoxic T cells directly kill target cells, but their activation is often orchestrated by Helper T cells in autoimmune responses.
- C. NK cells primarily target virally infected cells and tumor cells, not typically the primary drivers of autoimmune tissue damage.
Helper T Lymphocytes (CD4+ T cells)
A type of T cell that plays a central role in the immune system by activating other immune cells, including B cells and cytotoxic T cells.
- Express CD4 protein
- Recognize antigens presented by MHC class II molecules
- Crucial for coordinating both humoral and cell-mediated immunity
Memory trick: B-cells Make Antibodies, T-cells Tag and Kill.