02/12 Introduction to Immunology

Question 1

What are the two divisions of the immune system? What types of threats do they recognize?

Answer 1

Innate immunity - recognizes nonspecific patterns

Adaptive immunity - recognizes specific 3D structures or protein sequences

Question 2

What are the functions, advantages, and disadvantages of the innate immune system?

Answer 2

Function - prevention and keeping you alive until specific immunity is activated
Advantages - immediate response, all components already coded for in your DNA
Disadvantages - crude screening methods, no memory

Question 3

What are the functions, advantages, and disadvantages of the adaptive immune system?

Answer 3

Function - precise elimination of specific threats
Advantages - very specific, highly potent, generates memory
Disadvantages - slow

Question 4

How does the innate immune system recognize threats?

Answer 4

Pattern recognition receptors (PRRs) sense molecule patterns that are expressed by pathogens but not our cells
PRRs can be cellular (membrane-bound) or soluble (circulating)

Question 5

What are the hallmarks of inflammation?

Answer 5

Heat, pain, redness, and swelling
Vasodilation and increased vascular permeability
Extravasation of WBCs
Stimulation of pain receptors

Question 6

Through what classes of molecules does the innate immune system sound the alarm?

Answer 6

Cytokines
Chemokines
Vasoactive and inflammatory agents

Question 7

What are the six types of cells of innate immunity?

Answer 7

Neutrophils
Monocytes
Natural killer cells
Eosinophils
Basophils

Question 8

What are the effector functions of the innate immune system?

Answer 8

Phagocytosis
Cytotoxicity
Production of ROS, destructive enzymes, and antimicrobial peptides
Production of more cytokines and chemokines

Question 9

What are the five general steps of an innate immune response?

Answer 9

1) Recognition of a threat
2) Sounds of the alarm
3) Inflammation
4) Innate immune cell recruitment
5) Innate effector functions

Question 10

What cell type is the bridge between the innate and adaptive immune systems? How?

Answer 10

Dendritic cells sample pathogens and initiate an adaptive immune response specific to that pathogen

Question 11

At what sites are adaptive immune responses initiated?

Answer 11

Secondary lymphoid organs (lymph nodes, spleen, and Peyer’s patches)

Question 12

How does the adaptive immune system prepare for the vast array of antigens that your body might encounter in your lifetime?

Answer 12

It maintains a large number of cell specificities, but a small number of cells of each specificities
All cells start off inactive, but differentiate and expand in number when stimulated

Question 13

What is clonal selection?

Answer 13

The process by which a small number of B and T cell clones bind to an antigen with high affinity, and subsequently undergo activation, proliferation, and differentiation into plasma B cells or activated T cells

Question 14

What are the three specific cell types of the primary adaptive immune response?

Answer 14

Effector CD4 T cells, or T helper cells
Effector CD8 T cells, or cytotoxic T cells
Effector B cells

Question 15

What are the general functions of effector CD4 T cells?

Answer 15

Activate and help responses in other cells, particularly cytotoxic T cells, B cells, and macrophages
Produce cytokines
T helper cell responses are tailored to the type of pathogen seen

Question 16

What is the general function of effector CD8 T cells?

Answer 16

Kill infected or abnormal cells

Question 17

What five things do antibodies do?

Answer 17

Bind and neutralize toxins
Block virus infection
Promote phagocytosis
Activate complement
Trigger cell activation

Question 18

What are MHCs?

Answer 18

Major histocompatability complexes
Found on the surfaces of antigen-presenting cells
Present processed antigens to T cells receptors