Blood Lecture 2 / Immunoglobulins and humoral immunity / ch7 Flashcards
Antigen (Ag) definition ?
Any foreign matter that enters the body and and meets either or both of the following criteria: 1.) Can bind antibody 2.) Can bind to a T or B cell receptor
Antigenic cells that are destined to be destroyed by the immune system are called what ?
Target cells
Technically an _____ is a molecule or a portion there of, of Protein, carbohydrate or lipid found on surface of microorganism, infected cell, tumor cell and allogenic cell
antigen
Any surface that can generate an immune response?
Immunogen
Protein molecules produced by B cells / Plasma cells and are always present in small amounts in blood and body tissue.
Antibody (Ab)
Antibody (Ab) AKA
immunoglobulin
Antibody production in response to antigen is known as what?
Humoral Immunity
Antibody (Ab) has 2 major functions, what are they?
1.) To Opsonize (coat) antigen 2.) To activate the complement cascade.
Primary exposure called sensitization or immunization takes 14 days to reach full power. The time from antigen recognition to antibody production is called what ?
lag period
Antibody destroys antigen in many different ways, the following mechanisms are involved:
- Oposonize ( coat surface) - Mark the Antigen for recognition and destruction by 1.) Complement cascade (MAC Complex) 2.) Granulocytes and Natural Killer cells (phagocytosis) 3.) Neutralization; A coat of Antibody may make the Antigen harmless
Synthesis of Antibodies process?
B cell recognize Antigen > B cell makes differentiate into plasma cells > Each plasma cell makes lots of Antibodies and releases them into circulation
During the primary exposure to a specific Antigen the Antibody production takes about 14 days and its concentration is low. What happens after this?
• Memory cells produced for future exposure
Re-exposure to same antigen produces antibody causes Memory cells from primary exposure respond very quickly. Antibodies are produced:
– In larger quantities – In response to lower concentrations of Antigen – With a higher affinity to Antigen
Antibody Types
• IgG and IgM are the primary classes produced
IgG Class Antibody
- Most potent
- Makes up 80% of antibody in circulation
- Produced in greater quantities than any other Antibody.
- Diffuses into tissue and across the PLACENTA.
– Maternal RhAb can attack fetal Rh+ fetal RBC causing hemolytic disease of the newborn
Maternal Rh-Ab (anti-D) can attack
fetal Rh+ fetal RBC causing hemolytic disease of the newborn
IgM Class Antibody
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- First Antibody to be produced during primary exposure
- 10-15% strong
- LARGE; 5 linked Ab molecules
– Can not diffuse out of circulation
• Effective at gathering Ag into clumps (agglutination)
Whats used to type blood (A, B) bound by Anti-A and Anti-B which are IgM Antibodies?
Antigen on RBC
IgD Class
• Found in small amounts • Has limited immunologic effect against Ag • May assist the b cell in reacting to helper T cells
IgA Class
- Primary Ab in body fluids and secreted by mucus membranes – Tears, breast milk, saliva, others
- Binds to Anigen & immobilizes it for removal in mucus
– Marks it for destruction by granulocytes
IgE Class
• Very low concentration in circulation • Primarily responsible for defense against parasites • Involved in allergic reactions – Asthma, hay fever, others – Anaphylaxis • Stimulates Basophils into releasing histamine. – Edema, sinus inflammation, itching, bronchiole constriction
• The specific region of the Ag molecule recognized by Ab or lymphocyte receptor • One half of a pair of interlocking puzzle pieces
Epitope
• The immune system can produce Ab against any Ag in the universe those that exist and those that do not yet exist. • T cells recognize self • How’s that work?
Clonal Selection
Antibody from the same class have same
amino acid arrangement in certain areas
