Adaptive Immunity Humoral Immunity (antibodies) Flashcards
B cell
Produce a protein that will circulate in blood. That neutralizes or activates parts of the immune system (produce antibodies) part of lymphocytes •adaptive immune system
Complement system
Activated by B cell antibodies
Opsonization
Coating of microbes with protein enhancing phagocytosis
What is meant by humoral Immunity where is the type of immunity located in the body
1/2 of the immune system (b cells) Antibody production to come back antigens foreign material. Circulates in bodily fluids
When Is the adaptive immune response is better
The second time we get infected by the same organism
Two parts of the adaptive immune system
Humoral immunity antibodies production ( B cells extra cellular fluid ) and cell mediated immunity ( Fights intracellular infections T cells)
Both cell types activated if foreign substance binds to receptors on cell
Antigens
Things that trigger the immune system
Possible sources protein or (sugar) polysaccharides on surface, spike on surface, flagella, capsule. Immune system chemically detects
Is an epitope the same as an antigen
And epitope is a smaller particles on the surface of an antigen that differs
What does an antibody recognize directly an antigen or an epitope
Epitope
Is it possible for an antigen to have more than one epitope why would this be the case
Yes because they need all to infect cell
Antibodies
Proteins produced by immune system. They have specific binding sites for a specific antigen. Ab3 only binds to Ep3. When they stick to epitope they use other side of antibody to interact it innate or complement immune system.
Immunoglobulin
Other name for antibodies IgG, IgM, IgA, IgD, IgE.
Produced by plasma cell from B cell . Mature over time to become better at binding
Structure of antibodies
Protein
•core shaped Y piece called (monomer) 2 identical halves. 4 chains : 2 heavy , 2 light.
• constant region : base that remains same ( interacts with immune system) each has own version
•variable region: upper parts that bind to antigen. Each monomer has same variable on each hand
IgG
Most important and abundant
• 80% of antibodies
Activates complement system
• can pass out of blood vessels and into tissue during Vasodilation
•Last about 23 days (other IG last 2-4 days)
• gives immunity to fetus from mother
•monomer very small
IgM
Very large M=macro
•5 linked monomer (linked at constant region )
•6% antibodies
•Larger prevents it from leaving blood
•Extremely effective at activating complement system.
•Agglutinates bacteria very well.
•Short lived and first responder to infection.
IgA
- Found In mucous membranes
- Secreted immunoglobulin form
- 13% of Ab in blood
- 3-5grams pumped into intestines daily
- Secreted form is dimer : 2 linked Y shaped monomer
- Resistance to digestion
- Poor at activating complement system (because it’s not in blood)
- Kills bugs in gut
- found in breastmilk and most effective in helping a nursing child avoid infection of their intestines
IgD
No one knows
IgE
- Involved in allergies and parasitic infections caused by worms
- found on surface of mast cell and basophils (histamine producers)
- Triggers inflammation in response to allergies and worms
The effects antibodies binding to antigen
- Neutralization: grab on and prevent from doing bad.
- Complement activates
- Agglutination: clumping
- Opsonization: seasonings
- Bring in other cells to attack (Antibody dependent cell mediated cytotoxicity)
How do antibodies get made
Made by B cell
1. Inactive form with B cell receptor ( that can’t bind )
2. When correct antigen binds to B cell receptor the B cell goes through process of becoming a plasma cell.
3. Plasma cell actively releases and produces antibodies into blood or mucous membranes
( can be done with or without a helper T cell) they help determine what bad guy to go after or to ease up. Involved in primary immune response
4. Some become B memory cells others plasma cells.
Memory B cell
Memory B cells have already been exposed and activated in the past. They have very specific antibodies that they will produce given an infection.
Secondary immune response.
When lymph nodes swell
B cells are in there reproducing
Vaccine
Generates large numbers of memory B cells that hangout in the lymph nodes
Do antibodies directly kill a pathogen
No they don’t, they actually only really carry out their function by activating the rest of the immune system. ( basophils, mast cells, eosinophils, the complement system.)
