Biology, Eighth Edition (Raven)

Chapter 51: The Immune System

Interaction of Antigen Presenting Cells and T-helper Cells

Why are T-cells necessary? T-cells perform a wide variety of functions in the immune system. All T-cells having membrane receptors that allow them to recognize certain signals in other cells and to respond appropriately. B-cells produce antibodies that bind to antigens and target the molecules or microbes for destruction. T-cells destroy infected cells and also use information from phagocytes that have destroyed pathogens to coordinate the overall immune response. The latter are known as helper T cells.

View the animation below, then complete the quiz to test your knowledge of the concept.


1.	Which of the following are antigen-presenting cells?

		A)	macrophages
		B)	B cells
		C)	cytotoxic T cells
		D)	A and B
		E)	A, B and C

2.	Helper T-cells interact with target cells by recognizing

		A)	antigens only.
		B)	MHC proteins only.
		C)	antigen-MHC protein complexes.
		D)	either antigens or MHC proteins.
		E)	neither antigens nor MHC proteins.

3.	Helper T-cells secrete ________ to stimulate the proliferation of B-cells.

		A)	antigens
		B)	antibodies
		C)	cytokines
		D)	agglutinins
		E)	allergens

4.	Helper T-cells interact with Class I major histocompatibility complex (MHC) proteins.

		A)	True
		B)	False

5.	Plasma cells are B cells that produce antibodies.

		A)	True
		B)	False