Intro to autoimmune disorders Flashcards
(26 cards)
What are the 3 key properties of the immune system
- Recognize pathogens
- Have memory of those pathogens
- To avoid damage to normal self-tissues
What are considered primary lymphoid tissues (2) Secondary? (3)
Primary
- Bone marrow
- Thymus
Secondary
- Spleen
- Lymph nodes
- Mucosal-associated lymphoid tissue (MALT)
What is the function of bone marrow (2)
- 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)
What is the function of the thymus (2)
- Produce T-cells from lymphocyte progenitors
- Produce “thymic education” to ensure no self damage
What is the function of the Spleen (2)
- 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
What is the function of lymph nodes (2)
- 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)
What is the function of the MALT tissue (mucosal-associated lymphoid tissues) (2)
Contains many plasma cells
- filter/remove pathogens
- Generate antibodies
What 2 pathways are considered innate immunity, what is considered Acquired immunity
Innate
- Physical barriers
- Bloodbourne
Acquired
- T-cell immunity
- B-cell immunity
What are 5 examples of physical barriers
- Skin
- Mucous membranes
- Salive
- Flushing action of urine and tears
- Stomach acid
What is the general role for phagocytes. What are the 5 phagocytes
Important for immediately destroying pathogens that break our physical barriers
1. Neutrophils
2. Macrophages
3. Basophils
4. Eosinophils
5. Natural killer cells
What is the first cell/phagocyte to react to environment changes?
What is their other role
Macrophages
- big eater
- cuts protein into small antigens then displays on its surface
aka antigen presenting cell
What is the role of cytokines
Once Macrophages recognize something as foreign, cytokines are released to recruit other immune cells
- by recruitment, activation, growth/maturation of other cells
What phagocyte is the primary component of pus
Neutrophils
How are neutrophils attracted to the site of injury/invasion
by chemokines
Role of neutrophils
- phagocytose pathogens
- release cytokines to amplify inflammatory response (i.e recruitment of adaptive immune system)
What do autoimmune diseases originate from
T-cells acting against self-tissue
How do T-cells work in acquired immunity (3 steps)
- T-cell receptors bind to only 1 or a few antigens out of the thousands out there
- 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
- If it fits, it becomes activated and they stick to each other
Differentiate between helper T-cells and cytotoxic T-cells
Types of receptors?
Release/recognize
Helper T cells
- CD4+ receptors
- Release cytokines
Cytotoxic T cells
- CD8+ receptors
- recognize antigens
Explain how B cells work in the Acquired immunity?
- Called by the activated T cells (last cell in the chain)
- B cells differentiate into plasma cells
- Then they make antibodies that are released in the blood
What is the reason our bodies don’t go attacking itself? What is it coded by, Where is it found?
Major histocompatibility complex
- self antigens are coded by HLA (human leukocyte gene) on chromosome #6
What are the 3 classes of Major Histocompatability complex?
Where are they found?
What do they interact with
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
Which classes are involved in foreign antigen presentation? Why
Class 1 and 2
- Both have a peptide binding cleft that can bind antigens and interact with T-cells
What are the 2 pathways in the complement system/cascade? Adaptive/innate immune system why?
- Classical pathway
- Adapative
- Relies on antibodies to initiate it
- once an antigen binds an antibodies, C1 binds to those antibodies, triggers a cascade - Alternative pathway
- innate
- Does NOT need antibodies to initiate the pathway
- much slower/ takes more time
What are autoantibodies
What are they produced by?
What do they recognize?
Produced by B-cells
Recognize self-antigens
(usually the immune system removes these abnormal B cells)
