Tolerance, Autoimmunity and Autoimmune diseases Flashcards
exam 4
tolerence
- (def) the specific unresponsiveness of an individual to an antigen
- Specific to T cells and B cells because of antigen specific receptors
- also used as the process by which the body ensures that immune responses are directed against bad instead of self
T lymphocyte receptor
TCR
B lymphocyte receptor
membrane bound Ig
central tolerance
Tolerance that occurs in lymphocyte development
teaching the cells to evoke response against foreign not self
peripheral tolerance
regulation of the “escapees” of central tolerance
Central T cell tolerance
T cells whose TCR recognizes self-peptides presented in MHC molecules undergo apoptosis
Peripheral T cell tolerance
- (Anergy)without stimulation of B7-CD28 results in functional anergy
- (apoptosis)repeated stimulation causes apoptosis
- (suppression)inhibition by regulatory t cells by self peptide/MHC
sympathetic opthamia
- inflammatory lesion that appears 2 to 6 weeks after a perforating wound to a contralateral eye
- response to self antigens (normally hidden) due to activation of immune response in a immunological priveleged site
- failure of tolerance
molecular mimicry
the immune response to a pathogen or foreign antigen may cross-react with self tissues
Ankylosing spondylitis
HLA-B27 positive. antigens on klebsiella/bacteria cross-react with host. chronic inflammation, fibrosis, and ossification of spine
Rheumatic fever
strep disease - heart valve cross-react
guillian-barre syndrome
anti-LPS antibodies - cross react with gangliosides of motor nerve, severe paralysis
Heat shock proteins
ex:hsp60
gamma/beta TCR+ lymphocytes play a critical role in identifying/autoimmune induction
Autoimmune disease development factors
- genetic (HLA-B27)
- hormone/gender (estrogen)
- Immune system dysregulation (immunodeficiencies/age)
- environmental (diet)
Celiac Disease
- malnutrition, diahrrea, and abdominal pain due to inflammation - eating gluten found in wheat, barley, and rye
- T-cell mediated
- HLA-DQ
- IgA deficiency
- CD autoantibodies against transglutimate
Myastenia Gravis
- organ specific autoimmunity
- antibodies against ACh receptors at nueromuscular junctions
- Type 2 hypersensitivity
- HLA-DR3
- severe muscle weakness -> respiratory failure
Systemic Lupus Erythematosus
- systemic autoimmunity
- Type 3 hypersensitivity reaction
- antinuclear antibodies - antibodies against double-stranded DNA
- HLA-DR3 or -DR2
- lack of C3b -> deficient in C1, C2, C4, and eventually phagocytic cells
Scleroderma
- systemic autoimmune disease
2. nuclear antigen autoantibodies - topoisomerase-1 and RNA polymerase 1
Sjogren’s syndrome
- systemic autoimmune disease
- destruction of exocrine glands
- antibodies against SS-A (Ro) and SS-B (La) and M3R
Graves disease
- antibody mediated autoimmune disease
- antibody against TSH
- HLA-DR3
Multiple sclerosis
- t-cell mediated autoimmune disease
- Type IV hypersensitivity with CD4+ and CD8+
- epstien barr virus
- HLA-DR2
Type 1 diabetes
- t-cell mediated autoimmune disease
2. CD8+ CTL
Rheumatoid arthritis
- systemic autoimmune, both antibody and t cell mediated
- ACPAs and RF (IgM antibodies against IgG Fc portion)
- activate complement cascade and release chemotactic factors
Hashimoto’s disease
- antibody and t-cell mediated
- HLA-DR5, HLA-DR3, HLA-B8
- infiltrate of mononuclear cells
Metabolic control therapy
organ-specific autoimmune disease treatment - putting back into the body what is being destroyed
immunosuppressive therapy
- therapy with antimitotic drugs and cyclosporine and anti-inflammatory drugs
- do not reverse the process that initiates the disease state
cytokine treatment
type of targeted treatment
Interferon beta-1a or interferon beta-1b for MS
inhibit Th1 response
IL-10 and IL-4 (Th2 cytokines)
suppressor of T lymphocyte proliferation
TGF-B
