Med Micro 5 - Specific Defense Part 1A Flashcards
What is adaptive immunity?
ability to recognize and defend itself against distinct invaders and their products; “memory” allows it to respond rapidly to a second encounter with a pathogen
Does the lymphatic system have a roll in innate immunity?
Yes. It is a one way system, so pathogens are likely to end up there. Concentrations of macrophages will probably deal with it (cells for adaptive immunity present too)
What is the real value of adaptive immunity?
More specific, so more effective, and faster the second time around.
Taking two weeks to respond is almost hopeless. What evidence is there for this?
We can look for ABs. We can use vaccines to generate this prior to seeing the antigens
Circadian rhythm and immune system
Can affect infection. Number of eosinophils varies throughout the day. Bacteria vary with time as well. Antibiotics need to consider this. Study showed amount of TLR-9 varied with time and immune response was best at peak of TLR-9 expression
Why is it so important to immunize at the peak of TLR-9 activity?
Phagocytes recognize, then play a role in antigen presentation. The vaccine will be cleared by other organs so the immune response will decrease quickly.
5 elements of adaptive immunity
Mostly in lymphatic system; Specificity (but some cross reactivity with similar proteins), Inducibility (2 weeks first time, 3-4 days after), Clonality (make clones of B and plasma cells), Unresponsiveness to self, Memory
Clonality and B cell
Have all same receptors (basically bound AB); genetically different from other B cells; when it gets induced, it will make many many copies of itself
Summary of lymphatic system
B lymphocyte grows in red bone marrow; T lymphocyte begin in bone marrow then mature in thymus; both get concentrated in lymph nodes
Age for healthy thymus
Max around 20. Decreases thereafter, don’t have a good T cell response (so more susceptible to viruses)
General function of lymphatic system
Screens the tissues of the body for foreign antigens (acts like a net). Goal as always is to contain infection.
Parts of lymphatic systems
Composed of lymphatic vessels and lymphatic cells, tissues, and organs which are directly involved in adaptive immunity
Describe Lymph
Similar to blood plasma, Move from capillaries to larger vessels, Is a one way system
Functions of lymph
Carries fats, Production of reactive immune cells, Removes excess liquid from cells and return to blood
Important lymph nodes areas
Inguinal, axillary (armpit), cervical (neck), Mucosa-associated lymphatic tissue (MALT - around intestines - common infection site)
Circulatory system
Includes the cardiovascular and lymphatic system. It’s a closed system. As it cycles, anything can be trapped (most infections don’t get to the blood due to lymphatic system)
Septicemia
Aka sepsis; infectious pathogens are in the blood.
Toxemia
Toxins are in the blood
Spleen
Major concentration of adaptive immunity cells, screens blood.
Lacteal
Like a capillary of the lymph system. Found all over, and in villi of GI tract.
Organs of lymphatic system
Primary organs include the red bone marrow and thymus, Secondary organs include lymph nodes, spleen, and other less organized accumulations of lymphoid tissue like MALT, appendix, tonsils. The defense battles really take place in the secondary organs
Relative organization of secondary lymph organs
Least: 3. Diffuse assemblages of lymphocytes and macrophages (in lung and intestinal wall) referred to as MALT and GALT. 2. Lymphoid follicles surrounded by draining lymph vessels. 1. Lymph nodes and spleen
Specific screening by lymphoid organs
loose lymphoid tissue screens mucosal surfaces, the spleen screens the blood, and the lymph nodes screen tissues
Lymphoid follicle
Many in a lymph node; Contain a high concentration of lymphocytes; The number and composition can change in the presence of an antigen (can actually swell in your neck)
