Regulation of immunity

Question 1

What is the main function of the immune regulatory system?

Answer 1

To maintain a balance between immune activation against pathogens and preventing damage to self-tissues

Question 2

What are the components of the immune regulatory system?

Answer 2

Immune cells, complement system, cytokines, and other soluble factors in both innate and adaptive immunity

Question 3

How is complement activity regulated to prevent tissue damage?

Answer 3

Complement regulatory proteins inactivate complement components that do not bind to pathogens to avoid host tissue damage

Question 4

What is the role of complement regulatory proteins?

Answer 4

To limit complement activation on host cells and prevent excessive inflammation

Question 5

What conditions are associated with complement regulatory system defects?

Answer 5

Uncontrolled complement activation leading to conditions like hemolytic uremic syndrome or age-related macular degeneration

Question 6

What are natural killer NK cells?

Answer 6

Cytotoxic lymphocytes that target cells lacking MHC Class I molecules such as virus-infected and tumor cells

Question 7

What regulates NK cell activity?

Answer 7

A balance of activatory and inhibitory receptors including KIRs and CD94-NKG2

Question 8

How do macrophages contribute to immune regulation?

Answer 8

By producing anti-inflammatory cytokines like IL-10 and TGF-beta to maintain tolerance and limit inflammation

Question 9

What are regulatory macrophages Mregs?

Answer 9

Macrophages that inhibit T cell proliferation and induce T regulatory cells via IL-10 and TGF-beta production

Question 10

What is the significance of regulatory T cells Tregs in immune regulation?

Answer 10

Tregs suppress immune responses to maintain tolerance and prevent autoimmune diseases

Question 11

How do dendritic cells regulate immune responses in the gut?

Answer 11

By sampling antigens and inducing Tregs in the absence of infection to maintain tolerance to food antigens and microbiota

Question 12

What cytokines are critical for maintaining immune regulation?

Answer 12

IL-10 and TGF-beta

Question 13

How does the gut immune system prevent responses to harmless antigens?

Answer 13

Through regulatory mechanisms involving Tregs macrophages and IgA-producing B cells

Question 14

How do eosinophils assist IgA production in the gut?

Answer 14

They produce APRIL IL-6 and TGF-beta in response to commensal microbes to promote IgA class switching

Question 15

What happens when immune regulation in the gut breaks down?

Answer 15

Dysregulation can lead to inflammatory diseases like Crohn’s disease or celiac disease

Question 16

How does TGF-beta contribute to gut immune regulation?

Answer 16

It promotes Treg induction and class switching to IgA in B cells

Question 17

What is the role of IL-10 in immune regulation?

Answer 17

IL-10 limits inflammation and helps maintain tolerance in mucosal tissues

Question 18

What is physiological inflammation in the gut?

Answer 18

A state where Tregs dominate the immune environment preventing responses to harmless antigens while effector T cells remain ready to react to pathogens

Question 19

What happens during a cytokine storm?

Answer 19

Excessive production of pro-inflammatory cytokines such as IL-1 IL-6 and TNF-alpha leads to tissue damage and systemic inflammation

Question 20

How do macrophages in the gut maintain tolerance?

Answer 20

By being highly phagocytic producing IL-10 and avoiding significant inflammatory cytokine production

Question 21

What are invariant NKT cells iNKT?

Answer 21

Innate-like lymphocytes with limited TCR diversity that recognize microbial glycolipids presented by CD1d molecules

Question 22

What are mucosal-associated invariant T MAIT cells?

Answer 22

Innate-like T cells in the gut that respond to bacterially derived metabolites presented by MR1 molecules

Question 23

What is the role of Tregs in preventing inflammatory bowel diseases IBD?

Answer 23

Tregs suppress effector T cells and promote tolerance to reduce inflammation in IBD

Question 24

How does disruption of immune homeostasis lead to disease?

Answer 24

Uncontrolled immune responses can result in autoimmune diseases or chronic inflammation

Question 25

What is the balance between effector and regulatory immunity?

Answer 25

Effector immunity fights infections while regulatory immunity prevents over-activation and self-tissue damage

Question 26

How can regulatory mechanisms be harnessed in medical treatments?

Answer 26

By using therapies that enhance regulatory cell functions or cytokines like IL-10 and TGF-beta to treat autoimmune and inflammatory diseases