Lecture 22 (Microbiota & the Immune System) Flashcards
what are the 3 effects of butyrate from gut microbiota on promoting regulatory responses of the immune system:
a) Suppress: Macrophages or CTLs?
b) Promote: TH17 or Treg production?
c) Stimulate or Inhibit mucus production?
a) Suppress macrophages
b) Promote Treg production
c) Stimulate mucus production
what is the microbiome inhabiting animal’s bodies?
-collection of microbes (microbiota) that includes bacteria, viruses, and eukaryotes
-often referred to as ‘normal flora’
what bacteria is commonly seen to overgrow after long antibiotics treatment causes dysbiosis?
a) Bacteriodes fragilis
b) Bacillus coagulans
c) Clostridium difficile
d) Psudomonas spp.
c) Clostridium difficile
explain the importance of Vitamin D in immunity to mycobacterium
macrophages can convert Vitamin D into Cathelicidins that kill bacteria
An exaggerated TH2 response causes equine asthma. How is the immune response shifted to Treg (less inflammatory)?
a) mutation of TLR molecule
b) activation of eosinophils
c) stabling only outside
d) the protective effects of low doses of inhaled microbial antigens
d) the protective effects of low doses of inhaled microbial antigens
list the 5 clinical examples of dysbiosis
- infections
- allergies
- inflammation
- obesity
- immune dysregulation
the microbiome inhabiting an animal’s body originated from the ___________, __________, or _________ and developed a relationship on and within the body
mother, environment, or food
_______________ treatments destroy both ‘good’ and ‘bad’ bacteria in the microbiome
antibiotics
t/f: good bacteria of the microbiota are needed for optimal health
true
overuse of antibiotics causes….
antibiotic-resistant bacteria
what is one of the biggest threats to global health, sickening an estimated 2 million people in the U.S. each year?
antibiotic-resistant bacteria
there is strong evidence that some resistance in bacteria is caused by antibiotic use in ________ animals
food animals (cattle, poultry, swine)
what surfaces are populated with helpful microbes?
-skin
-respiratory tract
-parts of the genitourinary tract
-within the gastrointestinal tract
in the animal’s body, it is estimated that about half of all the cells are ___________
microbial
animals can use genes in the ____________ to utilize foods by extracting energy from plants and obtain essential vitamins
microbiota
what are some examples of a commensal relationship existing?
-termites and their flagellates
-pinworms in rabbits and tortoises
what is a commensal relationship?
-exist together without harming each other
-one species benefits while the other is unaffected
Barries:
-naturally occurring
-usually an epithelial surface
a) first line of defense
b) second line of defense
c) third line of defense
a) first line of defense
Innate Defenses:
-general defenses
-carried out by macrophages
-protects against any pathogen
a) first line of defense
b) second line of defense
c) third line of defense
b) second line of defense
Adaptive Defenses:
-known as “immunity”
-specific responses for each pathogen
-carried out by lymphocytes
a) first line of defense
b) second line of defense
c) third line of defense
c) third line of defense
what three things influence ‘health’?
-born with it: genetics
-acquire it: from mother/diet
-facts of life: infections, stress, cancers, allergies
the body is colonized by a variety of microorganisms. these microorganisms can be beneficial by ____1____ the immune system and ____2____ the growth of pathogenic microorganisms, or they can be pathogenic by ____3____ in affected tissues
- educating
- inhibiting
- producing disease
role of immune system:
co-exist with ___________ while at the same time controlling any inadvertent invasion by opportunistic pathogens through breaks in the epithelial barriers
microbiota
the diverse microbial landscape on ________ is essential for all animals, as it helps maintain essential oils and plays “guard” in the first line of immune defense
skin
there are many skin diseases that may alter skin microbe colonization, such as ___________ ____________
atopic dermatitis
what is one of the most common skin infections in dogs (and people)?
atopic dermatitis
dogs that do develop atopic dermatitis have an increased sensitivity to many __________
allergens
additionally, many dogs with allergic atopic dermatitis are subject to _________ _______ _________
bacterial skin infections
the normal skin microbiota is necessary for optimal skin function, modulating the [innate/adaptive] immune response, and preventing ______________ with potentially pathogenic microorganisms
innate; colonization
the changes in the cutaneous microbiota causing atopic dermatitis have been proposed to be due to different mechanisms, such as an altered epidermal barrier function, ____________ mutations, reduced levels of antimicrobial peptides, and/or an increased expression of extracellular metric proteins
Toll-like receptor 2 mutations
atopic dermatitis is both a hypersensitivity reaction and dogs with atopic dermatitis often suffer from secondary bacterial and/or fungal infections, most commonly due to ______________ _____________
Staphylococcus pseudintermedius
t/f: the lungs are sterile
false
healthy lungs harbor a complex ___________, closely related to but much less dense than that found in the upper respiratory tract
microbiota
the airway microbiota plays a role in resistance to __________ _________ as well as the development of asthma and probably chronic obstructive pulmonary disease
respiratory infections
in the absence of the microbiota, the airways are prone to mount exaggerated _________ responses
TH2
t/f: the Hygiene Hypothesis states that you should be hygienic at all times
false
in the absence of the microbiota, the airways are prone to mount exaggerated TH2 responses. the presence of a microbiota induces _________ activity that suppresses this
Treg
which of the following are sterile environments?
a) the lungs
b) the bladder
c) the newborn’s GIT
d) all of the above
c) the newborn’s GIT
Dysbiosis in the lung microbiota is associated with:
a) Exaggerated TH1 response
b) Exaggerated TH2 response
c) Exaggerated Treg response
b) Exaggerated TH2 response
t/f: the canine urinary bladder is a sterile environment
false
t/f: the canine urinary bladder possesses its own unique and diverse microbiota compared to the rectal and genital microbiota
true
the predominant bacterial genus for either sex in the urine and genital tracts was __________________
Pseudomonas sp.
what is dysbiosis?
microbial imbalance
subfertile women are more often diagnosed with a vaginal _________ compared with fertile women
dysbiosis
in the reproductive tract, there is protection via ______-______ producing bacteria that keeps pathogens from growing
lactic-acid
________ is considered as one of the most frequent causes of subfertility in mares
endometritis
in a comparison of healthy cows to cows with either metritis or endometritis, a reduced bacterial diversity is seen in cows with __________ disease
uterine
t/f: the function of the microbiome in the reproductive tract is not yet fully understood
true
it has been estimated that the canine small intestine harbors more than _____ different bacterial species, while the canine colon may house up to a thousand species
200
disturbances in rumen metabolism, often caused by feeding very ______________ diets, results in changes in the ruminal microbiota
high-energy diets
disturbances in rumen metabolism, often caused by feeding very high-energy diets, results in changes in the ruminal microbiota, leading to what three things?
-an increase in fatty acid and ethanol production
-a drop in rumen pH
-the development of subacute rumen acidosis
changes in the ruminal microbiota can lead to an increase in fatty acid and ethanol production, a drop in rumen pH, and the development of subacute rumen acidosis. this in turn results in what three additional things?
-local inflammation
-opening of intercellular junctions
-a disruption in the barrier function of the ruminal squamous epithelium
hindgut fermenters:
under certain conditions such as carbohydrate overload, the microbiota of the large gut change drastically, as a result of which their pH drops and bacterial PAMPs escape into the bloodstream. this can result in the development of…
acute laminitis
identify the functional role of the microbiota seen when a foal eats feces
a) nutritional efficiency
b) intestinal protection
c) lymphoid development
d) signaling function
a) nutritional efficiency
*there are things in the mare’s manure that help foals digest their food - helping with nutritional efficiency
with ___% of the body’s immune system residing in the gastrointestinal tract, we can easily deduct that its health is paramount to the proper functioning of the entire body
80%
t/f: at birth, the digestive tract is sterile
true
why do foals eat their mother’s manure?
-establish/replenish their digestive flora
-promoting a healthy life
aside from horses, what other species purposefully consume each other’s feces?
-rabbits
-koalas
-rhinos
-lizards
identify the functional role of the microbiota (seen in image on quizlet)
a) nutritional efficiency
b) intestinal protection
c) lymphoid development
d) signaling function
b) intestinal protection
how does microbiota protect the intestines?
blocks colonization by pathogenic bacteria by covering the surface and secreting inhibiting substances such as acids
aside from teaching/research, what is the purpose of a canulated/fistulated cow?
can be used as a source of microbiota to transfer to another cow that is sick = microbiome restorative therapy
t/f: germ-free animals have larger peyer’s patches, mesenteric lymph nodes, more CD4+ T cells; therefore, more B cells and IgA production
false:
*smaller peyer’s patches
*less CD4+ T cells
*less B cells and IgA production
_________ is a short-chain fatty acid that suppress macrophages and promote Treg production, influences noble cell differentiation, and mucus production
Butyrate
intestinal helper T cell phenotypes are “plastic,” and precursor cells can differentiate into either ________ or _______ cells
Treg or Th17
chemicals produced by the microbiota do not stimulate the dendritic cells to produce inflammatory cytokines and instead produce ________ down regulating inflammation with _____________
IL-10; FOXP3 + Treg
lack of early childhood exposure to infectious agents, symbiotic microorganisms, and parasites [decreases/increases] susceptibility to allergic diseases by suppressing the natural development of the immune system
increases
preventing or eliminating an animal’s exposure and colonization of bacteria into its microbiome cause __________
dysbiosis
____________ treatment is an important cause of dysbiosis
antibiotic
equine laminitis:
limited ability to digest starch in small intestine. get overspill to hind gut, where starch is instead ___________ releasing toxins into the blood stream which inflame the capillaries of the lamina
fermented
rumen acidosis:
feeding of rapidly digestible carbohydrates (grains) when fermented increases and eventually can over produce D-lactate causing pH to [increase/decrease]
decrease
inflammatory bowel disease in dogs:
symptoms?
presents with a history of chronic vomiting, diarrhea, and weight loss
Rumen dysbiosis in cattle is caused by:
a) drinking contaminated water
b) high COH diet
c) not getting milked in time
d) cold weather
b) high COH diet
inflammatory bowel disease in dogs:
breed predispositions?
-Weimaraners
-Rottweilers
-German Shepherds
-Border Collies
-Boxers
microbiota are mostly non-pathogenic organisms. their presence allows the immune system to: (2)
- ‘see’ important bacterial components
- prepare the immune system to react to pathogens without causing inflammation themselves
if the microbiota is disrupted by infections, using antibiotics, or high COH diets, __________ occurs
dysbiosis
