Intro to autoimmune disorders

Question 1

What are the 3 key properties of the immune system

Answer 1

1. Recognize pathogens
2. Have memory of those pathogens
3. To avoid damage to normal self-tissues

Question 2

What are considered primary lymphoid tissues (2) Secondary? (3)

Answer 2

Primary
- Bone marrow
- Thymus

Secondary
- Spleen
- Lymph nodes
- Mucosal-associated lymphoid tissue (MALT)

Question 3

What is the function of bone marrow (2)

Answer 3

• Conducts hematopoiesis (all cellular components of the blood)
• Cells migrate out of bone marrow EITHER as mature cells OR as T-cells (to continue maturation elsewhere)

Question 4

What is the function of the thymus (2)

Answer 4

• Produce T-cells from lymphocyte progenitors
• Produce “thymic education” to ensure no self damage

Question 5

What is the function of the Spleen (2)

Answer 5

• Removes damaged erythrocytes (RBCs) from blood
• provides space for B-cells and T-cells to interact with pathogen debris IN THE BLOOD -> immune response/antibody production

Question 6

What is the function of lymph nodes (2)

Answer 6

• provides space for B-cells and T-cells to interact with pathogen debris IN THE LYMPATHIC SYSTEM
• During infection, may sequester active immune cells –> leads to inflammed lymph nodes

(during cancer, WBCs are often caught in lymph nodes –> suggests cancer diagnosis)

Question 7

What is the function of the MALT tissue (mucosal-associated lymphoid tissues) (2)

Answer 7

Contains many plasma cells
- filter/remove pathogens
- Generate antibodies

Question 8

What 2 pathways are considered innate immunity, what is considered Acquired immunity

Answer 8

Innate
- Physical barriers
- Bloodbourne

Acquired
- T-cell immunity
- B-cell immunity

Question 9

What are 5 examples of physical barriers

Answer 9

1. Skin
2. Mucous membranes
3. Salive
4. Flushing action of urine and tears
5. Stomach acid

Question 10

What is the general role for phagocytes. What are the 5 phagocytes

Answer 10

Important for immediately destroying pathogens that break our physical barriers
1. Neutrophils
2. Macrophages
3. Basophils
4. Eosinophils
5. Natural killer cells

Question 11

What is the first cell/phagocyte to react to environment changes?
What is their other role

Answer 11

Macrophages
- big eater
- cuts protein into small antigens then displays on its surface
aka antigen presenting cell

Question 12

What is the role of cytokines

Answer 12

Once Macrophages recognize something as foreign, cytokines are released to recruit other immune cells
- by recruitment, activation, growth/maturation of other cells

Question 13

What phagocyte is the primary component of pus

Answer 13

Neutrophils

Question 14

How are neutrophils attracted to the site of injury/invasion

Answer 14

by chemokines

Question 15

Role of neutrophils

Answer 15

• phagocytose pathogens
• release cytokines to amplify inflammatory response (i.e recruitment of adaptive immune system)

Question 16

What do autoimmune diseases originate from

Answer 16

T-cells acting against self-tissue

Question 17

How do T-cells work in acquired immunity (3 steps)

Answer 17

1. T-cell receptors bind to only 1 or a few antigens out of the thousands out there
2. When an APC (macrophage, dendritic cell) and a T-cell meet each other, they see if the antigens presented by the APC will fit into the T-cell receptors
3. If it fits, it becomes activated and they stick to each other

Question 18

Differentiate between helper T-cells and cytotoxic T-cells
Types of receptors?
Release/recognize

Answer 18

Helper T cells
- CD4+ receptors
- Release cytokines

Cytotoxic T cells
- CD8+ receptors
- recognize antigens

Question 19

Explain how B cells work in the Acquired immunity?

Answer 19

1. Called by the activated T cells (last cell in the chain)
2. B cells differentiate into plasma cells
3. Then they make antibodies that are released in the blood

Question 20

What is the reason our bodies don’t go attacking itself? What is it coded by, Where is it found?

Answer 20

Major histocompatibility complex
- self antigens are coded by HLA (human leukocyte gene) on chromosome #6

Question 21

What are the 3 classes of Major Histocompatability complex?
Where are they found?
What do they interact with

Answer 21

Class 1:
- found on all nucleated cells
- interacts with CD8 receptor (cytotoxic T cells)

Class 2:
- found primarily on APCs
- interacts with CD4 receptor (helper T cells)

Class 3:
- Unrelated
- Part of complement system

Question 22

Which classes are involved in foreign antigen presentation? Why

Answer 22

Class 1 and 2
- Both have a peptide binding cleft that can bind antigens and interact with T-cells

Question 23

What are the 2 pathways in the complement system/cascade? Adaptive/innate immune system why?

Answer 23

1. Classical pathway
   - Adapative
   - Relies on antibodies to initiate it
   - once an antigen binds an antibodies, C1 binds to those antibodies, triggers a cascade
2. Alternative pathway
   - innate
   - Does NOT need antibodies to initiate the pathway
   - much slower/ takes more time

Question 24

What are autoantibodies
What are they produced by?
What do they recognize?

Answer 24

Produced by B-cells
Recognize self-antigens
(usually the immune system removes these abnormal B cells)

Question 25

What are the risk factors for autoimmune diseases

Answer 25

1. Family history
2. Environment
3. Ethnicity
4. Female sex (child bearing age)

Question 26

What is the only auto-immune condition that is more common in males than females

Answer 26

Ankylosing Spondylitis