12. Autoimmune Disease I Flashcards
(30 cards)
What is the approximate number of people affected by autoimmune diseases in the UK?
Approximately 4 million people
This represents around 10% of the population.
How many different autoimmune diseases have been identified?
Around 80 different autoimmune diseases
Among these, 19 are the most prevalent.
What percentage of autoimmune diseases occur in women?
75% of autoimmune diseases
This statistic highlights the gender disparity in autoimmune conditions.
What is the fourth largest cause of disability in women?
Autoimmune diseases
These diseases significantly impact women’s health and quality of life.
In what demographic do autoimmune diseases often manifest?
People in the prime of their lives
How common is rheumatoid arthritis in the population?
Affects approximately 1 in 100 people
What is the normal function of the immune system?
To distinguish between self and non-self
What occurs in autoimmunity?
Immune cells attack the body’s own tissues
What two factors are required for autoimmunity to develop?
Genetic predisposition and environmental triggers
Name three environmental factors that can trigger autoimmunity.
- Bacteria
- Viruses
- Toxins
- Drugs
Epstein-Barr virus is linked to multiple sclerosis.
What genetic factors are often involved in autoimmunity?
MHC (Major Histocompatibility Complex) alleles
What are the three essential components for T cell activation?
- MHC-peptide complex on antigen-presenting cell
- T cell receptor (TCR) specific for that complex
- Co-stimulatory signals
An example of a co-stimulatory signal is CD28 on T cell binding to B7 on APC.
What happens if any of the three components for T cell activation are missing?
T cells don’t become fully activated
What do activated helper T cells do?
- Activate B cells to produce antibodies
- Activate CD8+ cytotoxic T cells
- Produce cytokines to regulate immune responses
What are the two classes of MHC molecules?
- MHC Class I
- MHC Class II
What is the function of MHC molecules?
To present peptides for T cell recognition
What did Peter Doherty and Rolf Zinkernagel discover about T cells?
T cells must recognize both self MHC molecules and foreign antigens presented by MHC
What is central tolerance?
The process where developing T and B cells are educated to not attack self
Where does positive selection of T cells occur?
In the thymus
What is the outcome of positive selection in T cell development?
Only T cells that can recognize self-MHC survive
What happens during negative selection of T cells?
T cells that strongly react to self-antigens are eliminated through apoptosis
What are the binding affinity outcomes for T cells?
- No affinity: Cells die
- Low affinity: Cells survive
- Intermediate affinity: Become regulatory T cells
- High affinity: Cells die
What is peripheral tolerance?
Secondary protection mechanisms for self-reactive cells that escape central tolerance
Name two key mechanisms of peripheral tolerance.
- Lack of co-stimulation
- Anergy
- Regulatory T cells
- Ignorance
