Week 5: Innate Immunity Flashcards
Which cells are apart of the innate immune system? Adaptive?
Innate = neutrophils, NK cells, monocytes, macrophages
Adaptive = B & T cells
What are the two methods of cellular communication?
- physical binding of receptors
- production of ligands
What are the three forms of chemical signaling?
Autocrine = cell targets itself
Paracrine = cell targets nearby cell
Endocrine = cell targets distant cell through bloodstream
What are cytokines?
Small signaling molecules released by activated immune cells
What are chemokines?
Small signaling molecules involved in recruitment: tell immune cells where to go
What is the function of cyto/chemokines? What are the 2 network pathways?
Function = regulate immune response to injury/infection
Pathways = redundant & complex
What is the first line of innate immune defense?
Mechanical barriers ex. epidermis, cilia, etc.
What do defensins and dermcidins do?
Secreted by cells on skin, bind to bacterial/fungal cell membranes, forming pores that allow nutrients to drain out
What are the four cells that are found on the second line of innate immune defense?
- antimicrobial proteins
- natural killer cells
- phagocytes
- tissue inflammatory response
What type of cells signal that a pathogen has entered the body? What is activated to induce inflammation?
Damaged cells. Pathogen recognition receptors
__________ secrete cytokines/chemokines, _______ cells secrete histamine
Phagocytes, mast cells
What is the role of neutrophils?
Primary phagocyte to move from blood to tissues quickly in acute inflammation
What is the role of monocytes?
Normally found in blood, respond to chemokines and migrate. At the site they differentiate into macrophages.
What is the role of dendritic cells?
Coordinate the innate response, carrying antigens to lymph nodes. Example of APC.
What are the 4 lymphoid organs?
Thymus, spleen, lymph nodes, red bone marrow
Where are B cells found in the lymph nodes? T cells? Macrophages?
B = primary lymphoid follicle
T = paracortical area
Macro = medullary cords
How do natural killer cells cause cell destruction? What else do they do?
Perforin & granzymes. Release cytokines.
What does tumor necrosis factor do? Interferon gamma?
TN = neutrophil activation
IG = macrophage activation, promotion of T cell differentiation
What do the 2 interleukin cells do?
8 = neutrophil recruitment from blood
6 = tissue inflammation
