Test 2: Intro to immunology Flashcards
What are the 2 types of immune system?
adaptive and innate immunity
What is the protective response for immune system?
defense against microbes and tumors
What happens if immune system goes out of control?
can cause autoimmune (type 1 diabetes) or inflammatory diseases, also cause hypersensitivities and allergies
T/F: immune system also can react to self
True!
Immune can react to substance, infection or non-infection, foreign or self
What is the substance that induces a specific adaptive immune response (T and B cells)?
Antigen
- can be proteins, nucleic acids, lipids, polysaccharides, and metals only in adaptive immune response
What is the difference between primary and secondary immune response?
primary: first antigen encounter
secondary: second encounter with same antigen (usually respond quicker and differently because more antibodies are ready)
T/F: Immune system is controlled randomly.
False!
It is a very controlled and coordinated action of cells and molecules
T/F: Immune system can respond to tissue grafts
True!
Immune response can give barriers to transplant and gene therapy
What are characteristics of innate immunity?
immediate, non-antigen specific response, no memory, no activation necessary
(fast and dumb)
T/F: Innate immunity isn’t always present
False!
Innate immunity is always present to block microbe entry
What are characteristics of adaptive immunity?
require specific antigen recognition, expansion, activation, and involve long lasting memory
Which is immediate and which is delayed: innate vs adaptive?
innate= immediate
adaptive= delayed
What does the adaptive immune system require involving lymphocytes?
adaptive immunity requires expansion/differentiation of lymphocytes
In adaptive immunity, what is humoral immunity mediated by?
antibodies; extracellular microbe
(B lymphocyte is the responder)
goal: block infections and eliminate extracellular microbes
In adaptive immunity, what is cell-mediated immunity?
T-lymphocytes– intracellular microbes
goal: eliminate phagocytosed microbes (helper T cells) and kill infected cells and eliminate reservoirs of infection (cytotoxic T cells)
In adaptive immunity, where do they recognize microbial antigens?
on microbes or host cell surface
In memory response, how long does the primary and secondary response take to arise?
primary: 1-3 weeks
(the antibodies die but some remain to become memory B cells to allow for a faster response the next exposure)
secondary: 2-7 days
Where do B and T cells mature?
B=bone marrow
T=thymus
What are the stages for B/T cell maturation?
antigen recognition-proliferation-differentiation-memory lymphocyte
What is the life span of naive T/B cells?
weeks-months but will die if no antigen
What is the life span of effector T/B cells?
short lived and die when antigen is eliminated
What is the life span of memory T/B cells?
for long period of time (years)
What does the organization of secondary lymphoid organs enable?
antigen present cells to concentrate antigens, lymphocytes to locate and respond to antigens, and cells to interact with each other
What does lymph draining into lymph nodes allow?
concentrate antigens, allow sampling of antigens by antigen presenting cells at the site
T/F: There are distinct B and T cell zones
True!
B cells on the outside (cortex)
T cells on the inside (paracortex)
What do dendritic cells do for lymph nodes?
pick up antigens in tissues and migrate to lymph nodes
What allows for blood to enter spleen and allow sampling of antigens?
antigen presenting cells
Where do activated T cells migrate to and what do they do there?
Activated T cells migrate to tissues to eliminate microbes
What is the organization of the mucosal immune system (gut)?
similar organization as lymph nodes (tonsils, Peyer’s patch)
- 25% of lymphocytes here
How is movement of T and B cells coordinated to go to their own zones?
chemokine and chemokine receptors
What are B cells attracted to?
attracted in follicles around periphery
(CXCR5–> CXCL5)
What are T cells attracted to?
attracted outside but adjacent to follicles (paracortex)
(CCR7–> CCL19)
What are the cells involved in innate immunity?
epithelial barriers, phagocytes (neutrophils, monocytes, macrophages), dendritic cells, plasma proteins, and natural killer cells
What are the cells involved in adaptive immunity?
Naive B cell to become antibodies
Naive T cell (involved in antigen recognition) to become effector T cells
T/F: Repeated antigen exposure mounts larger and more effective responses
True!
What cells are involved in specific recognition of antigens?
- B lymphocytes: mediators of humoral immunity
- T lymphocytes: mediators of cell-mediated immunity
What cells are involved in capturing antigens for display to lymphocytes (antigen presenting cells)?
- Dendritic cells: initiation of T cell responses
- Macrophages: effector phase of cell-mediated immunity
- Follicular dendritic cells: display of antigens to B lymphocytes in humoral immune responses
What cells are involved in elimination of antigens (effector cells)?
- T lymphocytes: activation of phagocytes, killing infected cells
- Macrophages: phagocytosis and killing of microbes
- Granulocytes: killing microbes
Where are the lymphocytes located?
blood/lymphoid organs
Where are the antigen presenting cells located?
tissues/lymphoid organs
Where are the effector T cells located?
blood to the infection site
(naive T cells circulate through lymphoid organs)
What cell’s main function is to produce antibodies
B lymphocyte
Where do B and T cells arise from?
bone marrow but mature in different places
T/F: The thymus grows as we age.
False!
The thymus shrinks as we age so producing less naive T cells but our memory T cells increase
What is the difference between primary and secondary lymphoid organs?
- primary: bone marrow and thymus that allow for maturation
- secondary: lymph nodes, spleen, appendix, and Peyer’s patch that allow for activation
Which tissue has the most number of lymphocytes?
lymphocytes
What are the phases of adaptive immune response?
1) antigen recognition
2) clonal expansion
3) differentiation in effector cells
4) contraction via apoptosis
5) memory cells
What do antigen presenting cells present to?
They capture and antigens and concentrate them in lymphoid organs and then present it to T cells
Describe the steps of T lymphocytes in tissues
- mature in primary lymphoid organ: thymus
- get in circulation when matured
- go through high endothelial venue
- get activated in secondary lymphoid organ
- once activated: become effector T cells
- proliferate and leave by the efferent lymphatic vessel to go to infected site
- once in tissue, can eliminate microbe
