What is the first line of defense of inhaled and ingested microorganisms
Tonsils
What are the immune defenses found in the oral cavity
Saliva
Tonsils
Tight Junctions
Mucous membranes
Epithelium
What is found in the tonsils providing immune protection
Macrophages and Lymphocytes
What are the elements in Saliva that make it protective
Amylase
Bicarbonate
Lysosymes
RNAse
DNAse
Mucus
Epidermal Growth Factor (EGF)
IgA
"REDI...... BLAM saliva man!"
What elements of the stomach protect it from microorganisms
Mucus
Bicarbonate
G cells that secrete Gastrin stimulating
- Parietal cells to release HCl
- Chief cells to secrete Pepsinogen
Zollinger-Ellison Syndrome
Hypersecretion of HCl from the stomach causing gastric ulcers
What are the components of intestinal immune defense
Mucus production
Epithelium
Peristalsis
Microbiota
Microfold cells
Paneth cells
Peyers patches
What is the most important immune response in the intestines
Abundance of Lymphoid tissue
There is more lymph in the intestines then any where else in the body
What are the antimicrobial substances that the intestine secretes
Bacteriocins
Colicins
Defensins
Lactoferrin
Lysozyme
What do the intestines secrete to attract monocytes, macrophages, and dendritic cells
Chemokines
Tollip
Toll interacting protein
This inhibits TLR from reacting to commensal organisms as well as decreasing the Kinase activity in response to TLR's
How do the intestinal cells recognize antigens
Toll like receptors (TLR) on the intestinal cells bind Pathogen associated molecular patterns (PAMP's) and Microbial associtated patterns (MAMP's)
The intestines contain many foreign microbes, why isn't it then constantly in an immune response mode
The intestines have the ability to discriminate between commensal organisms and pathogens
What is the significance of TLR4 expressed in the intestines
TLR4 are poorly expressed in intestinal cells and are therefore poorly responsive to Gram negative bacteria resulting in a muted response to commensal organisms
What are the three ways that the intestines can test an antigen
Enterocyte pathway
M-cells
Dendritic cells sending extensions through tight junctions into the lumen of the Gut
What is the Enterocyte pathway
Internalizing a pathogen via receptor mediated endocytosis, and then presenting it to lymphoid cells to decide whether an immune response in warranted
M cell
Specialized epithelial cell overlying the Peyers patches with the ability to transport antigens to dendritic cells to determine if an immune response is necessary
Transcytosis
The process of an M cell in the intestines that takes in antigens and transports them to dendritic cells in the Peyers patches for immune responses
How do Paneth cells in the intestines assist in protection of the gut
Paneth cells are the scavenger cells of the intestine with the ability to mount phagocytic responses
When Paneth cells are stimulated by foreign microorganisms they release
Alpha defensins
Lysozyme
Phospholipase A2
What is the role of Peyers patches in immune responses in the intestines
Located in the mucosa and submucosa, Peyers patches are large lymphoid follicles that contain B cells for immune responses
When B cells in the Peyers patches are activated what do they differentiate into