Lymphocytes and Lymphoid Structures Flashcards
HLA-A3 Associated with
Hemochromatosis
HLA-B27 Associated with (PAIR)
- Psoriasis
- Ankylosing Spondylitis
- Inflamatory Bowel Disease
- Reiter’s Syndrome
HLA-DQ2/DQ8 Associated with
Celiac Disease
HLA-DR2 Associated with
Multiple Sclerosis, Hay Fever, SLE, Goodpasture’s
HLA-DR3 Associated with
Diabetes Mellitus Type 1, Graves’ Disease
HLA-DR4 Associated with
Rheumatoid Arthritis, Diabetes Mellitus Type 1
HLA-DR5 Associated with
Pernicious Anemia –> B12 Deficiency, Hashimoto’s Thyroiditis
What enhances the activity of Natural Killer Cells?
IL-2, IL-12, IFN-Beta, and IFN-Alpha
What are the costimulatory signals for Naive T cell activation?
Interaction of B7 and CD28.
What are the costimulatory signals for Helper T cell activation?
CD40 Ligand (Th cell) and CD40 Receptor (B cell)
What does Th1 cells secrete and what does it activate?
- IFN-gamma and activates Macrophages
What does Th2 cells secrete and what do they activate?
- IL4, IL5, IL10, and IL-13
- Recruit Eosinophils for parasite defense and promotes IgE production by B cells.
Th1 cells are inhibited by
IL4 and IL10 from Th2 cells.
Th2 cells are inhibited by
IFN-gamma from Th1 cells.
What do Regulatory T cells express?
CD3, CD4, and CD25
What 3 things do Antibodies do?
- Promote Phagocytosis (Opsonization)
- Prevent bacterial adherence (Neutralization)
- Activates complement, enhancing opsonization and lysis (Complement Activation)
What is special about the Fc fraction of the antibody? (C’s)
- It is Constant
- It is the Carboxy Terminal
- Complement binding at CH2 (IgG + IgM)
- Carbohydrate Side Chains
- Also determines isotype (IgM, IgD, etc)
Definition of Avidity and Which Antibody has the highest?
- Avidity refers to the number of binding sites an antibody has.
- IgM > IgA > IgE, IgG
Definition of Affinity and Which Antibody has the highest?
- Affinity refers to the strength of binding an antibody has.
- IgG > IgM
Main Antibody in secondary (delayed) antigen response
IgG
Fixes Complement, Crosses Placenta, Gives Passive Immunity to Infants, Opsonizes/Neutralizes Bacterial Toxins and Viruses
IgG
Prevents Attachment of bacteria and viruses to mucous membranes and does NOT fix complement
IgA
Found in secretions (tears, saliva, mucus) and early breast milk (colostrum)
IgA
Monomer in circulation and dimer in secretions, crosses epithelial cells by transcytosis
IgA
Produced in the primary (immediate) response to antigen
IgM
Fixes complement but does NOT cross the placenta
IgM
Found on the surface of B cells as a monomer or in circulation as a pentamer
IgM
Binds mast cells and basophils; cross-links when exposed to allergen and mediates immediate, type I, hypersensitivity
IgE
