When Things Go Wrong with the Immune System pt. 1 Flashcards
Autoimmune diseases are more prevalent in..
women
Two factors contributing to immune dysregulation
Genetic factors and infection, environments exposure.
Correlation between thymus involution and incidence of rheumatoid arthritis are
inversely correlated.
Examples of mechanisms contributing to imm. self-tolerance
- Neg. selection of B-cells in bone marrow.
- Expression of tissue-specific proteins in thymus so that they participate in negative selcetion of T cells.
- Negative selection of T cells in thymus
- Exlusion of lymphocytes from immunopriviliged tissues
- Anergy in autoreactive B and T cells
- Supression by reg. T cells
True/false. Many immune mechanism can contribute to autoimmune diseases
True
Defects in cytokine production and signaling can cause what?
Autoimmunity
Sex difference in incidence of autoimmune diseases
Wide difference in incidence between sexes for different diseases
Autoimmune manifestion
Immune response targets host cells and tissues. Antigens can’t be cleared, antigenic stimulation persists and expands the immune response
Type II hypersensitivity
Antibodies are made against cell-surface or matrix antigens.
Autoimmune hemolytic anemia
Antibodies bindss and opsonizes erythrocytes
Type II sensitivity
Formation of immune complexes
Systemic lupus erythematosus
Complexes made by response against DNA, histones, ribosomes.
Pregnancy causes biases towards which T-cell response
Th2
Pregnancy can affect autoimmune diseases how?
Aggravate Th2 conditions but alleviate Th1 conditions.
Intermolecular epitope spreading
T cell is activated by host histone protein. H1 specific B cell presents H1 peptide and is helped by H1 specific T cell. Other parts of H1 are presented to other T cells, expanding number of self-reactive T and B cells.
Type IV
T-cell mediated disease - targeting by T CD8 cells.
Multiple sclerosis.
Example of type IV disease.
Grave’s disease
Antibodies against thyroid-stimulating hormone receptor.
T cell mediated autoimmunity
Anergized T cells or Treg suppressed T cells escape and become activated.
Treg mediated suppression requires what?
Interaction with the same APC
Cross-reactive antibodies.
Antibodies created against something react with self antigens.
How har priviliged sites suppressing immune response?
By keeping antigens in the tissue.
Inter-linkage of autoimmune disease
Autoimmune disease often results in higher prevalence of other diseases.
HLA heterogeneity means what for autoimmune disease?
Higher risk
DR3 and DR4 haplotypes of HLA can increase risk of
Type 1 diabetes
TLR alteration
Can increase susceptibility of autoimmune disease
Role of infections
Some infections can increase risk because of cross reactive antigens.
Compromized gut barrier can mean what?
Facilitation of autoimmunity.
