Immune Responses Flashcards
What three things contribute to the diversity of an antibody?
- Random Recombination
- Random addition of nucleotides by terminal deoxynucletotidyl transferase
- Random combination of heavy chain with light chain
Which part of the antibody determines the isotype?
Fc portion
What are the three functions of antibodies?
- Compliment
- Neutralization
- Opsonization
Which portion of the antibody has the carboxy terminal?
Fc
Which portion of the antibody participates in antigen binding?
Fab
Which portion of the antibody has carbohydrate side chains?
Fc
Mature B cells have what three things on them?
MHC Class II
IgD antibody
IgM antibody
Which two antibody isotypes fix complement?
IgG and IgM
What antibody can cross the placenta?
IgG
Which antibody is produced in the primary immune response?
IgM
Which antibody requires a secretory component?
IgA
protects it from lipases
Which ab contributes to immunity against parasites?
IgE (eosinophils)
Which antibody is given to the baby thru breast milk?
IgA
Which antibody protects against GI infection?
IgA
Which antibody neutralizes bacterial toxins and viruses>
IgG
What form does IgM take in a B cell?
Monomer
becomes tetratmer when released into serum
What class switching will occur if a B cells presents to Th1 cell?
IgG
What class switching will occur if a B cell presents to a Th2 cell?
IgE
Which type of memory is the most robust and why?
Thymus Dependent The most robust memory is the one that includes IgG and B cells can not undergo class switching without T cells.
Why is thymus independent memory not as strong?
Antigens that lack a peptide component (gram negative) means that B cells can not display the antigen on MHC molecules therefore only IgM can be produced. IgM is not as robust as IgG
Which complement molecules vasodilate?
C3a, C4a, C5a
Which complement molecule acts as an opsonin?
C3b
Which pathway is initiated with gram negative bacterial endotoxin A?
Alternative pathway
What sets off the classical pathway?
Antibody-Antigen Complex
What inhibits the complement cascade?
CD55 or DAF and C1 esterase inhibitor
What are the two primary opsonins in bacterial defense?
C3b and IgG
Classical pathway is mediated by what ab?
IgM and IgG
Classical pathway is important for protection against what specific bacteria?
Neisseria
IL-1 Has what functions?
Induces fever thru PGE-2
Acute inflammation
Activates endothelium to express adhesion molecules
Induces chemokine secretion to recruit WBCs
Also known as osteoclast activating factor (multiple Myeloma)
IL-6 has what functions?
Fever and stimulates production of acute phase proteins
IL-8 has what function?
Major chemotactic factor for neutrophils
IL-12 has what function?
Induces differentiation of T cells into Th1 cells and activates NK cells
TNF alpha function?
Activates endothelium and causes WBC recruitment, vascular leak
IL-2 function?
Stimulate growth of helper, cytotoxic, and regulatory T cells
IL-3 function?
Supports growth and differentiation of bone marrow stem cells. Functions like GM-CSF
Interferon gamma?
Secreted by NK cells and T cells into Th 2 cells in response to antigen or IL-12 from macrophages
Stimulates macrophage to kill phagocytosed pathogens
Inhibits differentiation of Th2 cells
IL-4 function
Induced differentiation of T cells in Th2 cells
Promotes growth of B cells
Enhances class switching to IgE and IgG
IL-5 function
Promotes growth and differentiation of B cells
Enhanced class switching to IgA
Stimulates growth and differentiation of eosinophils
IL-10 function
Attenuates inflammatory response
Decreases expression of MHC class II and Th1 cytokines
Inhibits activated macrophages and dendritic cells
Also secreted by reg T cells
Pt who are deficient in NADPH oxidase are at an increase risk for what pathogens?
Catalase positive pathogens
Which molecules are important in viral immune response?
Interferon alpha, beta, gamma They decrease the synthesis of viral mRNA via ribonuclease and increase the expression of MHC class I
What is the receptor on B cells responsible for EBV entry?
CD 21 (Eptein Barr must be over 21)
What are the receptors on T cells that are responsible for HIV entry?
CXCR4 and CCR5
What receptors on macrophages is responsible for PAMPs?
CD14
What is anergy?
Is type of self tolerance where a T or B cells is in a state that they can not become activated by exposure to antigen. Usually do to lack of signal 2 in the co-stim cascade
After exposure to tetanus, botulinum, HBV, varicella, and rabies patient are given PREFORMED Ab. What type of immunity is this?
Passive -> RAPID
What are the toxoid vaccines? (2)
Clostridium Tetani
Corynebacterium diptheriae
What are the subunit vaccines? (7)
HBV HPV Acellular pertusis N. meningitidis S. pneumoniae Haemophilus influenzae B
What are the Killed or Inactivated vaccines? (4)
Rabies Influenza Polio Hep A (Killed vaccine -> RIP Always)
Killed vaccines mainly induce what response?
Humoral
as compared to live vaccines which induce Cellular response
What is one example of a type 1 HS rxn?
Anaphylaxis
IgE and mast cell degranulation
What are some examples of a type 2 HS rxn?
Autoimmune-Hemolytic Anemia Immune Thrombocytopenia Hemolytic Disease of a Newborn Goodpasture Rheumatic Fever Graves Disease Myasthenia Gravis Pemphigus Vulgaris
What are some examples of type 3 HS rxn?
SLE
Polyarteritis nodosa
Post-strep glomerulonephritis
What are some examples of type 4 HS rxn?
Contact Dermatitis
Graft vs Host Disease
PPD Skin Test
Patch Test
If a women has been pregnant before but has had no blood transfusions, the pregnancy put her at increase risk for what type of transfusion reaction?
Febrile Non-Hemolytic
(Host Ab against donor HLA and WBC- a person that has never had a transfusion SHOULD NOT have ab against HLA or WBC but a women who has prev been pregnant can have them due to babies blood)
What is delayed hemolytic transfusion reaction?
Memory B cells present from a prev exposure (pregnancy or transfusion) but no antibodies so you get a massive proliferation of B cells leading to plasma cells.
Presents about a week later with jaundice
