Lecture 1

Question 0

What are the two types of immunity?

Answer 0

Innate and Adaptive

Question 1

This is a substance that induces an immune response

Answer 1

Antigen

Question 2

Explain Innate Immunity

Answer 2

First Line of Defense of the immune system, it does not display specificity or memory. It recognizes microbes, consists of: 1. skin,epithelial barriers 2. Phagocytic cell, dendritic cells, and macrophages 3. Blood proteins- complement system.
It is the decision maker- tells adaptive what to do

Question 3

Explain Adaptive Immunity

Answer 3

Displays specificity and memory. Undergoes somatic recombination so very large. Has two subsets of immunity.

Question 4

What are the two subsets of adaptive immunity?

Answer 4

Cell Mediated and Humoral

Question 5

Explain what a cytokine is and its function

Answer 5

Large group of secreted proteins with diverse functions and structure which regulate and coordinate many activities of the cells of innate and adaptive. Cytokines aid in growth and differentiation of immune cells, and activate effectors functions of lymphocytes and phagocytes and direct movement of immune cells from blood into tissue.

Question 6

This is a subset of a cytokine that controls cell migration and movement

Answer 6

Chemokine

Question 7

Explain Humoral immunity

Answer 7

Mediated by B cells- antibodies principle defense against extracellular microbes. Ab’s recognize microbial antigens and they neutralize infectivity of microbes and target microbes for elimination with the help of helper T cells. In summary : Secretes ab’s that prevents infection and eliminate extracellular microbes

Question 8

Explain Cell Mediated Immunity

Answer 8

Mediated by T lymphocytes. Work to destroy intracellular microbes/viruses. Destruction of microbes in phagocytes or killing of cells with killer T cells.

Question 9

What is clonal selection?

Answer 9

A test batch of ab’s are made called BCR and are transported to the surface of a B cell to find its match antigen. When it recognizes a cognate antigen the B cell is triggered to double in size and divide. They develop before and independently of exposure to an antigen.

Question 10

What happens to the lymphocytes initiated in a response?

Answer 10

They die off in the contraction phase and homeostasis is restored. A few lymphocytes become ag specific memory cells and may last for years after infection.

Question 11

Father of Immunology?

Answer 11

Dr. Pasteur

Question 12

Conferred by a host response to a microbe or microbial ag’s– what type of immunity is this?

Answer 12

Active

Question 13

Conferred by adaptive transfer of antibodies or T lymphocytes specific for the microbe

Answer 13

Passive Immunity

Question 14

Can active or passive immunity generate memory cells?

Answer 14

Active

Question 15

What is the role of B lymphocytes?

Answer 15

Recognize soluble Antigens and to become Antibody secreting cells.

Question 16

What is the role of T Helper Cells

Answer 16

Recognize antigens on the surface of APC’s and secrete cytokines which stimulate different mechanisms of immunity and inflammation.

Question 17

What is the role of T Killer cells?

Answer 17

Recognize antigens on infected cells and kill them

Question 18

What is the role of Regulatory T cells?

Answer 18

Suppress and prevent immune responses e.g self antigens

Question 19

Phagocytes- Name two types and what they do

Answer 19

Neutrophils and Macrophages- ingest and destroy microbes and get rid of damaged tissues

Question 20

What are the steps of phagocytosis?

Answer 20

1. Recruitment of cells to the site of infection
2. Recognition of and activation by microbes
3. Ingestion of the microbes by phagocytosis
4. Destruction of ingested microbes
   Phagocytes also secrete cytokines

Question 21

These types of cells have 3-5 connected lobes known as PMNL’s and are the most abundant wbc in circulation. They mediate the earliest phases of the inflammatory response.

Answer 21

Neutrophils

Question 22

Neutrophils are stimulated by what?

Answer 22

G-CSF, an adult produces 1x10^11 per day

Question 23

What cell is programmed for death at the time it enters tissue from blood

Answer 23

Neutrophils

Question 24

Neutrophils contain what?

Answer 24

Azurophilic granules- lysozymes that contain enzymes and other microbicidal substances

Question 25

How do neutrophils respond to yeast and fungi?

Answer 25

They bind to yeast and internalize them via phagocytosis and the phagosomes fuse with azurophilic granules.
When neutrophils encounter hyphae, they are not able to internalize them, and azurophilic granules are free to deliver their contents instead into the nucleus, which triggers chromatin decondensation and the
release of NETs.
• NETs contribute to the immobilization and killing of extracellular organisms, but at the cost of some tissue damage

Question 26

What other types of cells are involved in the innate and adaptive immune responses that also have cytoplasmic granules and can protect against helminths and allergic diseases?

Answer 26

Mast cells, Basophils, Eosinophils

Question 27

Bone marrow derived cell present in skin and mucosal epithelia with cytoplasmic granules that contain histamine and provide defense against helminths?

Answer 27

Mast Cells

Question 28

Explain the mononuclear phagocyte system

Answer 28

Consists of specialized phenotypes of macrophages depending on the organ. Circulating monocytes and resident tissue macrophages. Cells of the macrophage lineage arise from commited precursor cells in the bonemarrow driven by monocyte/macrophate CSF, monocytes enter the blood circulation and migrate to the tissues to become macrophages- especially during inflammation

Question 29

What are dendritic cells?

Answer 29

Cells from myeloid lineage in bone marrow, differentiate into classical DC’s, Plasmacytoid DC and Inflammatory DC - may arise from monocytes in inflamed tissues-Langerhaans cells may develop embryonically

Question 30

What are APC’s

Answer 30

Antigen presenting cells capture microbial and other antigens and display them to lymphocytes and provide signals that stimulate the proliferation and differentiation of lymphocytes, dendritic cells and langerhans cells