week 7 microbiome-health and disease
what is the two types of immune system?
Innate (non-specific)
Adaptive (specific)
how does the innate system prevent the organisms to enter the human body and what will happen if anything entered?
Skin on the outside of the body protects from organisms entering.
Digestive tract and respiratory prevent organisms entering from inside.
If anything does pass, the innate system stimulates the adaptive
describe the adaptive system
it is slower
contains macrophages that engulf bacteria and present its antigen to helper T cell and cytotoxic cell.
cytotoxic T cells kill organism
helper T cells recruit B cell, which replicate and generate antibodies.
those tagged with antibodies are set for destruction
which part of the immune system communicate
skin microbiota, epithelial cells and innate and adaptive arms of the immune system communicate
who begins the communication
keratinocytes begin the communication by sensing microorganism.
pattern recognition receptors identify pathogen-associated molecular patterns.
so the binding of PAMPs to PRRs triggers innate immune responses.
expression of some antimicrobial peptides is controlled by members of.....
skin microbiota
how does S epidermidis inhibits S. aureus biofilm formation?
• Production of the serine protease glutamyl endopeptidase (ESP) break down those biofilm connections.
• Induce antimicrobial peptide production by skin cells to kill s. aureus.
how does S. hominis decrease S. aureus colonisation?
by producing antibiotics which combine with humam antimicrobial peptides
how can S. aureus biofilm formation is enhanced?
Propionibacterium acnes can enhance S. aureus biofilm formation through production of coproporphyrin III.
what is the role of oral microbiota
Oral microbes secreted proteins, peptides and proteases altering the host actin cytoskeleton in the gingival epithelium. (break it down)
Allows bacteria to enter the blood stream.
Bacteria form biofilms within atherosclerotic plaques and cause coronary artery disease.
what is the immune resoponse on getting dysbiosis
• Secreted proteins activate the immune system causing inflammation.
• Cytokines-mediated (IL-6 and IL-8) inflammation (because of the immune response) is associated with coronary artery disease.
• Also, some proteases activate the complement system generation and inflammatory response.
the vagina is colonised soon after birth with
• corynebacterial
• staphylococci
• streptococci
• E. coli
• Lactic acid bacterium (lactobacillus)
which one is the predominent
lactic acid bacteria predominent as it is able to metbolise the glycoen to lactic acid
why women are more likely to have more disease afetr menopause
because of the absence of the lacric acid that inhibit colinisation by non lactic acid bacteria
what protect the brain the spinal cord
meninges and it contains range of immune cells
what is the effect of liver dysfunction
• Influences immunity and metabolism of gut and a range of organs.
• Brain malfunction due to Hepatic encephalopathy and kidney disorders observed in people with liver ailments.
• Impaired brain function often observed in patients with advanced liver diseases.
• Decreased metabolism of ammonia associated with liver failure are also associated with HE.
• cardiovascular diseases of the heart and blood vessels (CVD) are associated with fatty liver and other liver disorders.
expain Gut-Liver axis
• Dysbiosis increases gut permeability allowing microbial metabolites to reach the liver-->Affect hepatic immunity and inflammation.
• Immune cells activated by these metabolites can also reach liver through lymphatic circulation.
• Liver influences immunity and metabolism in multiple organs in the body, including gut.
• It releases bile acids and other metabolites into biliary tract from where they enter the systemic circulation.