Ch 8 - Immune Flashcards
1
Q
Innate vs Adaptive Immunity
A
- innate - aka nonspecific immunity
- always active
- does not attack specific pathogens
- adaptive - aka specific immunity
- target specific pathogens
- slower, but more robust and long lasting
- holds memory
- B cells and T cells
2
Q
Anatomy of Immune
A
- bone marrow - hematopoiesis of leukocytes (WBC)
- spleen - blood storage, activate B cells
- B cells are mature but naive until they are exposed to an antigen
- humoral immunity - B cells acting in the blood as part of active immune system
- Thymus - T cells mature
- cell mediated immunity
- lymph nodes - can be location for activation of B cells
- Gut-associated lymphoid tissue (GALT) - tonsils, adenoids, Peyer’s patches, appendix
3
Q
Leukocytes
A
- granulocytes - presence of granules (contain toxic enzymes and chemicals for exocytosis)
- neutrophils
- eosinophils
- basophils
- agranulocytes - no granules
- lymphocytes - produce antibodies, modulation, targeted killing
- monocytes - become macrophages, phagocytic
- microglia, Langerhans cells, osteoclasts
4
Q
physical barriers
A
- skin (integument)
- defensins - antibacterial enzymes, found on skin
- lysozyme - bacterial enzyme, tears and saliva
- respiratory system uses mucous membranes and cilia
- GI tract - highly acidic
- its own bacterial population out competes invaders
5
Q
Complement System
A
- proteins in the blood that punch holes in the bacterial cell walls to cause osmotic imbalance
- activated via classical pathway (bind antibody to pathogen) or alternative pathway (no antibodies)
- Nonspecific defense
6
Q
Interferons
A
- prevent viral replication and dispersion
- produced by cells that are virally infected
- decrease production of viral and cellular proteins
- decrease permeability of cells
- increase MHC I and II molecules to increase antigen presentation - better detection
- cause viral like symptoms
7
Q
Macrophages
A
- agranulocyte
- antigen presenting cell
- come from monocytes
- resident population - remain in a given tissue
- microglia, Langerhans cells, osteoclasts
- when bacteria in the tissue:
- endocytosis, digest via enzymes, present bacterial antigen
- major histocompatibility complex (MHC) - MHC II presents the antigen on the macrophage surface
- release cytokines - cause inflammation and recruit immune cells
8
Q
MHC
A
- Major histocompatibility complex
- binds antigens
- MHC I - displays “self” antigen of all nucleated cells
- endogenous pathway - binds antigens from inside the cell
- cytotoxic T cells - kill cells that present non-self on MHC I
- cells that have been invaded
- MHC II - on antigen presenting cells (ex. macrophage, dendritic cells, some B-cells, )
- exogenous pathway - antigens from outside the cell
- may activate innate and adaptive immune system
9
Q
Pattern recognition receptors
A
- ex. toll like receptor
- recognize category of invader (bacteria, virus, fungus, parasite)
- on macrophages and dendritic cells
- produce most effective cytokine
10
Q
Natural Killer Cells
A
- nonspecific lymphocyte
- detect downregulation of MHC (a tactic used by viruses to avoid detection)
- causes apoptosis of cell
- cancer cells downregulate MHC - NK cells help slow cancer growth
11
Q
Granulocytes
A
- neutrophils - most populous leukocyte, short lived
- phagocytic
- chemotaxis to bacteria to find source
- detect opsonized bacteria
- eosinophils - contain granules
- allergic reactions
- invasive parasite infections
- release histamine, causes inflammation
- basophils - allergic responses
- Mast cells - related to basophils
- in tissues, mucosa, epithelium
12
Q
dendritic cells
A
- present antigens
- induce active immune system
- have pattern recognition receptors that recognize type of invader
- phagocytic
13
Q
Antibody-Antigen Cause and Effect
A
- B cells - originate and mature in bone marrow
- activated in spleen and lymph nodes
- produce antibodies
- when antibodies secreted into blood:
- bind specific antigen, opsonization and attracts other WBC
- Cause aggluination, insoluble and phagocytized
- Block pathogen from entering tissue
- when a B cell surface antibody
- antigen binds and activated immune cell
- proliferate and make plasma and memory cells
- antibody on surface of mast cell
- antigen binds and causes degranulation (exocytose granule contents) - release histamine
14
Q
Antibodies
A
- aka Immunoglobulins [Ig]
- Y shaped
- 2 identical heavy chains
- 2 identical light chains
- held together by disulfide bonds
-
variable region - aka antigen binding region
- polypeptide sequence that binds ONE specific antigen sequence
- clonal selection - specific B cells with correct antibody are activated by antigen of pathogen and replicates only that B cell
- hypermutation - B cells use this to find antigen binding region that has best match for antigen
-
constant region (domain) - remainder of antibody
- used by neutrophil, macrophages, eosinophils to initiate complement cascade
- 5 isotypes of antibodies
- different isotypes used for different pathogens, locations in body, and different times
- isotype switching
15
Q
B Cells
A
- naive B cells - not exposed to antigen, wait in lymph nodes
- plasma cells - produce large amounts of antibodies
- memory cells - stay in lymph node for future response
- primary response - initial activation takes 7-10 days
- secondary response - more rapid and robust response to same antigen
- vaccinations
