1.1.3 Innate Immunity Flashcards
What are the hallmarks of innate immunity?
Immediate response, same response to repeat encounters, respond to invariable structure and does not react to host
What is the role of the epithelial barrier?
It is a physical barrier, killing microbes by locally produced anti-biotic peptides, and killing by lymphocytes
Neutrophil characteristics?
Most abundant leukocyte in the blood, 1st responder to bacterial and fungal infection, and ingest and destroy pathogens
What are neutrophils stimulated by?
G-CSF
Increased number of band neutrophils is a sign of what?
Infection
What is severe congenital neutropenia and how is it currently treated?
Dysfunction in neutrophil generation leading to recurrent severe bacterial and fungal infections. Currently treated with G-CSF.
What is the basic role of monocytes and macrophages in innate immunity?
These ingest and destroy microbes and produce cytokines to regulate other cells
What are PAMPs?
Pathogen associated molecular patterns
What is the importance of PAMPs?
These are structures that are shared by classes of microbes and are not present in normal cells. These are required for survival and infectivity
What are some examples of PAMPs?
LPS, peptidogylcans, terminal mannose, and Unmethylated CpG rich oligonucleotides
What are PRRs?
These recognize PAMPs. Referred to as Pattern recognition receptors.
TLR-2 recognizes
Bacterial lipoglycans and peptidoglycans
TLR-4 recognizes
LPS
TLR-5 recognizes
Flagellin
TLR-9 recognizes
Unmethylated CpG rich oligonucleotides
What is the TLR signaling pathway?
MyD88 interacts with IRAK which leads to activation of NF-kB. This will create inflammatory cytokines
What is the pathway of NOD-like receptors?
NLRP3 (inflammasome) activates caspase-1 which will then cleave Pro-IL-1B to IL-1B which will activate acute inflammation.
What is important about the complement pathway
This will lead to a deposition of C3b on the surface of microbe leading to MAC complex formation
What is the basic role of CRP?
It can activate proteins of the complement pathway
What is the role of TNF and what is it secreted by?
It is secreted by macrophages and T-cells and it leads to endothelial activation, neutrophil activation, and acute phase proteins