2. Cells of the Innate Immune System Flashcards
What is the definition of immunity?
The process by which self is distinguished from non-self (ex. pathogens, tumors, allergens)
What are pattern recognition receptors?
THey are the activation of the innate immune system when molecules loc on pathogens or damaged cells bind to PRRs on phagocytic cells
Where are PRRs found?
On many types of host defense cells but normally on sentinel cells (macrophages, dendritic cells, mast cells)
Also on neutrophils and within blood stream
What do PRRs recognize?
Basic components common to pathogens - EX. endotoxin of gram - bact. Viral RNA
Molecules released from damaged tissue. ex. heme
Molecules not present in normal animal cellWh
When are PRRs activated?
When they are activated by a pathogen.
Stimulate inflam and/or anti-parasitic activity. Also help with adaptive immunity
What ar emobile innate immune cells?
Mobile cells can be sentinel, phagocytic or NK killer lymphocytes
Sentinel cells: found in tissue @ entry points, activate immunity, attract additional mobile defenders when needed
Tissue Sentinel cells: Macrophages, dendritic cell, Mast cell
Why are monocytes named the way they are? What are their receptor types?
Undivided nucleus, pleomorphic shape
Receptor type: PRRs, antibody receptors
What is the function of monocytes
Phagocytic - remove dying neutrophils + tissue
Sentinel Cells - Release cytokines that stim innate/adaptive immune response
Migrate into tissues to become macrophages/dendritic cells
What are the differences and simularities of macrophages and dendritic cells
Macrophages: derived from blood monocytes, most important sentinel cell, stay in tissue
Dendritic cell - derived from monocytes or lymphoid cells, moves to lymph nodes after phagocytosing foreign material and stim adapt immune
Both sentinel/phaygocytic cells and found in tissues
Where are mast cells found? What is their precursor?
Found in tissue w/ eosinophils.
Mast cells/basophils have common bone marrow precursor. Arise from bone marrow/mature in tissues
What is the function of basophils and mast cells? What activates them?
func as sentinel cells and activated by binding to PRRs, IgE, insect and animal venoms, bacteria, viruses
Degranulate and release histamine/heparin to stim inc blood flow in early inflame + w/ normal inflam, release inflam mediators is slow.
Dominant cell in allergies and anaphylaxis - stim complete degranulation
What is IgE? Give an example of it
An antibody that binds strongle to basophils/mast cells
IgE activates the basophil or mast cell when it binds to antigen
Ex. of cooperative btw innate/adaptive system
Describe neutrophils? What do they do for the immune system? Function? What are Band Cells?
Granulocytic cells - antibact granules. AKA PMNs (polymorphonuclear neutrophils)
Band cells = immature cells ( nucleus not lobulated)
1/2 major WBCs in circulation. Short life + highly mobile, phagocytic, found in blood
Describe the 3 types of receptors of neutrophils
PRRs for bact antigens - recog antigen common to groups of microbes or damaged tissue. Ex. Endotoxin
Antibody receptors - recog IgG antibodies that have bound to an antigen
Complement receptors - groups of blood proteins activated by pathogens
What is an antigen? An antibody?
A substance that will initiate an immune response
Antibody - A protein that brings to a specific antigen
