Lecture #1

Question 1

Microbiota and microbiome

Answer 1

Microbiota: “the extended self” a community of symbiotic microorganisms living in the human body.
Microbiome: the collective genome of these micro organisms

Question 2

How many immune cells per day does the boone marrow produces?

Answer 2

1-2*10^6

Question 3

Immunological synapse

Answer 3

The interaction between an APC and a lymphocyte

Question 4

Blast transformation

Answer 4

When a lymphocyte is activated by an immunological synapse and antigen binding it alters its cell morphology
(nucleus and cytoplasm increase, protein synthesis is activated)

Question 5

Clonal selection theory

Answer 5

Cells of the recirculationg lymphocyte pool have specific receptors. If they encounter the specific antigen they will stop migratng and be activated .
Upon activation they will proliferate to form a colony of several thousands cells, all of which express the receptor with the same specificity.

Question 6

Instruction theory

Answer 6

In the past it was thought that one lymphocyte have many receptors, each suitable for a specific different antigen, and if an antigen encounters the cell and had a good match to one of the receptors, the synthesis of this receptor was triggered.

Question 7

Cells of the innate immune system

Answer 7

Macrophages, neutrophils, mast cells, NKC, immature DC, innate lymphoid cells

Question 8

Phases of lymphocyte maturation

Answer 8

1. Lymphocyte repertoir is generated in the bone marrow and thymus
2. Activation and blast transformation - upon Ag binding
3. Central phase - differentiation and clonal expansion
4. Effector phase

Question 9

Regulatory cells of the immune system

Answer 9

Treg
Breg
immature DC
Th2

Question 10

Effector cells of the immune system

Answer 10

Th1, Th17, B , mature DC, NKC, macrophages

Question 11

Shared features of cytokines

Answer 11

1. They exert their effects through membrane receptors (high affinity binding)
2. Transitional effect due to short 1/2 life of their mRNA and due to negative feedback
3. Functional redundancy “pleiotropic effect”
   Ex many types of cells secrete IL6 and IL6 effects many types of cells
4. Antagonist, additive or synergistic effect
5. Autocrine, paracrine or endocrine effect

Question 12

Chemokines and chemokine receptors

Answer 12

Chemokines: family of small sytokines responsible to induce direct chemotaxis of nearby responsive cells
classified in to 4 subfamilies: CXC, CC, C. CX3C
C represents cysteine and X any other AA at the N’ terminus

Chemokine receptors: 7TM receptors (G proteins) usually Gq

Question 13

Adipokines

Answer 13

Cytokine secreted from adipose tissue

Leptin, adiponectin, IL6, MCP1, PAI1, TNFalpha

Question 14

TNF group

Answer 14

TNF alpha: Regulation of immune cells, fever, inflammation, apoptosis, inhibition of tumorigenesis and viral replication

TNF beta and gamma: Induction of inflammation and anti viral responses, development of secondary lymph nodes

Question 15

IFN group

Answer 15

INF alpha: Produced by fibroblasts and monocytes, DC, inhibits the replication of viral genome

INF beta: Produced by fibroblasts inhibits the replication of viral genome

INF gamma: Pro inflammatory cytokine

Question 16

Pro inflammatory cytokines

Answer 16

IL1, 6, 12, 17, 18, 33 TNFalpha, IFNgamma

Question 17

Anti inflammatory cytokines

Answer 17

IL10, 13, 35, TGFbeta, IFNalpha