Cell-mediated immunity (Macrophage activation, stimulation of IgG production)
Defense against microbes
What do TH2 secrete?
IL-4 and IL-5
What type of immunity is elicited by TH2?
Humoral immunity (activation of mast cells, stimulation of IgE production)
Defense against helminths
What is another name for CD8 T cells?
Cytotoxic T cell
Which MHC molecule do CD8 T cells bind?
MHC Class I
When do B cells form plasma cells?
When stimulated by antigen
What is the second signal that allows B cells to recognize an antigen?
IgM and CD21
Which MHC molecule do NK cells bind?
Class I
Which chromosome has the gene that encodes MHC
Chromosome 6
What is another name for MHC gene?
HLA (human leukocyte antigens)
What are the three classes of MHC gene?
Class I – ABC (ie HLA-A, HLA-B, HLA-C)
Class II – DP, DQ, DR
Class III- complements
Where can Class I MHC be found?
Present on almost all nucleated cells and platelets
Which cells have MHC Class II?
Monocytes, macrophages, dendritic cells, B cells
What is the function of MHC Class II?
Present exogenous antigen to CD4 T cells
Ankylosing spondylosis is associated with which HLA gene?
HLA-B27
What are the types of disorders of immune system?
Hypersensitivity reactions
Autoimmune diseases
Immunologic deficiency syndromes
Amyloidosis
What is Type I Hypersensitivity?
Immediate reaction, such as anaphylaxis, allergies
What is the immune mechanism of Type I Hypersensitivity?
Production of IgE antibody, immediate release of vasoactive amines and other mediators from mast cells
What is Type II Hypersensitivity?
Antibody mediated response
What is a prototypical disorder for Type II hypersensitivity?
Autoimmune hemolytic anemia
What is the immune mechanism of Type II Hypersensitivity?
Production of IgG, IgM
What is Type III Hypersensitivity?
Immune complex-mediated response
What is a prototypical disorder of Type III Hypersensitivity?
System Lupus Erythematous
What is Type IV hypersensitivity?
T Cell-mediated hypersensitivity
What is a prototypical disorder of type IV hypersensitivity?
Contact dermatitis
What is Atopy?
Predisposition to develop localized immediate hypersensitivity reactions to a variety of inhaled and ingested allergens; have elevated IgE levels
In Autoimmune diseases, antibodies are formed to target against which antigens?
Self-antigen on surface of own cells or tissues
What are the three effector mechanisms of antibody-mediated injury (autoimmune)?
Opsonization and phagocytosis
Complement and Fc receptor mediated inflammation
Antibody-mediated cellular dysfunction
True/False: antibodies can either inhibit or stimulate cellular dysfunction
True. i.e. Inhibit: myasthenia gravis, pemphigus vulgaris. Stimulate: graves disease
Transfusion reactions are which type of antibody-mediated injury?
Opsonization and phagocytosis
What are the two types of Type III hypersensitivity?
Circulating immune complexes
In situ immune complexes
What is circulating immune complex?
Antigen combines with antibody within circulation and are deposited in vessel walls
What is in situ immune complex?
Complexes formed at extravascular sites (organs/local) where antigen may have been deposited previously
What are the two types of T cell reaction that can cause tissue injury and disease in type IV?
Delayed type hypersensitivity CD 4 cells
Direct cell cytotoxicity CD8 cells
What are some prototypical diseases that is Type IV?
RA, MS, DM type I, IBD, Psoriasis, Contact sensitivity
What are the immuneprivileged sites in the body?
Eyes
Testis
Brain
What does it mean to be immuneprivileged?
Body has never seen antigens from these organs (eyes, testis, brain) so if any of these get injured, the antigens released will cause an autoimmune effect
What is the antibody associated with Systemic sclerosis?
Scl-70
What is the antibody associated with limited scleroderma?
Anticentromere
What is the antibody associated with sjorgen syndrome?
SS-A, SS-B
What is the clinical symptom of patients with Sjorgen’s Syndrome?
Dry mouth, dry eyes
What is the clinical presentation of patients with Sjorgen’s Syndrome?
Enlarged gland, unable to produce saliva, therefore dry mouth
What do 1% of patient’s with Sjorgen’s are likely to develop?
