Lecture 10 Flashcards
Does the innate immune response elicit a faster or slower response than adaptive immune response?
Innate response is a rapid one, but the adaptive response is quite slow, it may take up to two weeks to activate and respond to an infection
In the primary stage of infection (for adaptive immunity), explain the antibody concentrations of IgM and IgG. What are the long term concentrations of IgM and IgG?
IgM is the first to help clean up an infection, but its concentration decreases after about a week. IgG has high concentration in the beginning as well, but can stay in the system for much longer. (up to years)
Adaptive Immunity is mediated by which lymphocytes?
B lymphocytes (humoral= in body fluids, blood and lymph) which circulate and haven’t entered a cell. T-lymphocytes are cell mediated and can directly attack host cell with viruses (cytotoxic cells)
Name two things that B lymphocytes produce?
They produce antibodies in response to antigens, and they produce cytokines to increase phagocytosis
Are B lymphocytes APCs?
Yes, they act as APCs to directly activate other immune cells
Where are B lymphocytes produced?
In the bone marrow. At this point they are antigen independent.
When activated, what do B lymphocytes differentiate into?
Memory cells and plasma cells. Plasma cells secrete antibodies
B cells are activated by which two types of antigens?
Thymus dependent- which require T helper cells contact
Thymus independent
What is the Fab region on an antibody structure?
Antigen binding site, that can change, and different combos at the binding region gives rise to different antigen specificity
What is the Fc region?
The stem of the antibody receptor, is stays constant. It is also recognizes by other immune cells that have an Fc receptor
What is opsonization?
When an antigen is detected, antibodies attach to the antigen, the Fc part of the antibody binds to macrophages Fc receptor for phagocytosis
Explain the complement activation:
Cb3 complement protein detects bacteria and attaches to it, they cause formation of MAC and causes cell lysis
What is agglutination?
Can connect bacteria so there is a collection that can be taken up by macrophages as a whole (more efficient)
What is neutralization?
Bacteria is unable to attach to host because antibodies attach to it and block/neutralize the toxin
Explain antibody dependent cell mediated cytotoxicity:
The infected cell shows antigens on the surface and antibodies attach (showing the Fc portion). Used with NK cells that have Fc receptors to detect infected cells.
What is the difference between plasma and serum?
Plasma still contains intact blood clotting proteins that haven’t been activated, while serum contains no active blood clotting proteins
Explain what cytotoxic T Lymphocytes (CTLs) do?
Target and directly kill virus infected cells
CD8+
Explain what Helper T Lymphocytes do?
Produce cytokines that activate other immune cells and inflammation, and they activate B cells which lead to antibody production
What do regulatory T lymphocytes do?
Suppress other immune cells
Where do T lymphocytes mature?
They are produced in the bone marrow, and travel up to thymus where they are programmed to detect self and non self (dependent on MHC molecules and antigen)
What do T lymphotcytes differentiate into?
Effector cells to destroy cells or memory cells
What happens when cytotoxic T lymphocytes activate?
They will bind to MHC cell, bring it close and punch a whole in it (perforin) and injects it with granzymes to kill the cell
Adaptive immune system is composed of :
Humoral immunity (B cells and antibodies) and cell mediated immunity (cytotoxic T cells/ T helper cells)
