B and T cells

Question 1

Clonal selection when activated results in what?

Answer 1

Results in a large number of
identical lymphocytes that recognize the same antigen

Question 2

 Regardless of the type of lymphocyte clonal selection gives rise t

Answer 2

effector cells (cytotoxic t cells, t-helper, plasma cells) and memory cells

Question 3

 B and T lymphocytes can recognize antigens BUT

Answer 3

 T cells must recognize fragments that first must be processed by other
cells (antigen processing cells or infected cells)

 B cells can recognize antigens without processing but need help to
become activated (from a t helper cell)

Question 4

Two classes of MHC proteins. Class 1 and class 2

Answer 4

Class 1- Found in membranes of all nucleated cells (so not found in RBCs)

Class 2- Found in membranes of antigen-presenting cells (APCs) typically the
phagocytosing cells
 Found in lymphocytes

Question 5

CD markers, also known as CD antigens, are

Answer 5

-Specific types of molecules
found on the surface of cells that help differentiate one cell type from
another.
 Also called cluster of differentiation markers
 Are on T cell membranes
 Provides an additional molecular mechanism of antigen recognition
 There are more than 70 type

Question 6

Two important CD Markers are

Answer 6

CD8 and CD4 markers

Question 7

CD8 Markers are found where and what do they respond to?

Answer 7

 Found on cytotoxic T cells and suppressor T cells
 Respond to antigens on Class I MHC proteins

Question 8

CD4 Markers where is it found and what does it respond to?

Answer 8

 Found on helper T cells
 Respond to antigens on Class II MHC proteins

Question 9

The MHC class I proteins take up small peptides (antigens) that are in the
infected cell and carry them to the surface.

These antigens are from what type of pathogens?

What happens once on the surface?

Answer 9

• These antigens are from intracellular pathogens
   Once on the surface, cytotoxic T cells can bind to the antigen and
  ultimately be activated

Question 10

Th1 cells stimulat

Answer 10

cellular immune response, participate in the inhibition of macrophage activation and stimulate B cells to produce
IgM, IgG1.

Question 11

Th2 stimulates

Answer 11

s humoral immune response, promotes B cell
proliferation and induces antibody production (IL-4).

Question 12

Four Functions of Cytokines particularly IL-2

Answer 12

1. Stimulate T cell divisions
    Produce memory TH cells
    Accelerate cytotoxic T cell maturation
2. Attract and stimulate macrophages
3. Attract and stimulate activity of cytotoxic T cells
4. PROMOTE activation of B cells

Question 13

 During sensitization, antigens are:

Answer 13

 Taken into the B cell
 Processed
 Reappear on surface, bound to Class II MHC protein