Immunology Midterm #1:
Can normal skin microbiota be used for the treatment of some human skin related
diseases such as acne)? - Answer - - People have different microbiota in the skin,
people with skin conditions have different microbiota in their skin
- There are studies that have shown microbiota transfers from people with good skin to
people with acne which have been an effective treatment
___________ surfaces are covering the lining all our internal tubes - Answer - Mucosa
The epithetical that are part of the innate immunity have a thick _______ layer instead
of a _______ skin layer - Answer - mucosa, dead
______ cells have a high level of _____ content, so it well suited for the growth of
beneficial microbiomes - Answer - Mucosa, water
______ helps trap bad bacteria and prevent from them attaching to epithelium cells. It
has _______ to help fight any bad bacteria that does attach. - Answer - Mucin,
glycosides
Epithelia cells of which layer renew very frequently and how this help our innate
immunity response? - Answer - Epithelial cells of the mucosa layer renew very
frequently and this is part of the innate immune system, because when many pathogens
enter the body they need to multiple and colonize, at the same time epithelial cells are
being renewed at such a fast rate which isn't a good host for these pathogens. So the
turnover and shedding of epithelial are part of the innate immune system.
The ____ layer of epithelial cells is covered with a high number and diversity of
microbes, except for in the ________ - Answer - mucosa, lungs
How does our microbiota help protect prevent infections? - Answer - 1. Microbiota fill
any viable space to keep any pathogens out
2. Microbiota learn to produce antibacterial viral components to kill pathogens. The
microbiota help by using their product peptides that help kill bad bacteria that colonize
on the skin or other organs
High concentration of _____ (bacteria) are found in our UG tract - Answer - LB
High concentration of _________ (bacteria) are found in the upper respiratory tract -
Answer - Gram positive
Studies have shown that germ-free (no microbiota) animals have _____________
immune system. They were very to _________ infections and metabolic diseases. -
Answer - underdeveloped, susceptible
,Describe these 2 gut conditions and possible treatments for both of them (C.defficile
and IBD) - Answer - 1. C, Defficile: a cluster of bacteria in the gut that are antibacterial
resistant, antibiotics actually makes the condition worst by getting rid of good
microbiota, the best treatment is transplantation of healthy microbiota into the gut, it is
an effective treatment as it fills space in G.I tract and they create peptides which kills of
C. defficile
2. IBD: Is another gut condition that can be treated with microbiota transplants. They
found that the microbiota of lean mice were different than those of fat mice. In one
experiment when the microbiota from a lean mice to transplanted to a obese mine they
become lean, and this also works vice versa.
Describe the importance of microbiota in the female reproductive tract: - Answer - -
Natural immunity in female reproductive system is important for prevent viruses like
ZIKA virus
-The gut has a very diverse microbiota, but in the reproductive tract it's not a diverse at
all, it's mostly all one bacteria known as LB
-During pre-puberty and menopause the levels of LB are lower and the pH is higher.
However, during puberty the pH lowers and the LB concentration increase significantly
-We need low pH in the female reproductive tract (3.4 to 3.5) to prevent STI and thus
subclinical bacterial vaginosis occurs.
-LB produces low pH and antibacterial peptides to prevent bacterial vaginosis.
-Many viruses cannot bind receptors in a pH below 6, so an low pH in the vagina can
protect us from viruses
What is subclinical bacterial vaginosis? - Answer - When the female reproductive tract
pH is above this normal level
Why does the pH lower during reproductive age in the female reproductive tract? -
Answer - When there is surge of estrogen it causes the position of glycogen on
epithelium cells on the vagina to change and then LB feed on glycogen to produce lactic
acid which lowers the pH
What are the 3 types of antimicrobial substances produced by epithelial cells? - Answer
- 1. Cryptidins and Alpha defensins: produced at the base of the small intestine crypsts
2. Beta-defensins: produced within skin and respiratory
3. Surfactant proteins A and D: present in lung and vaginal tract (function as opsonins
which enhance the efficiency of phagocytosis). They are very potent anti-microbial
substances
What is the correlation between LB and bacterial vaginosis (BV)? - Answer - -In an
healthy human LB represents a large majority of their microbiota
-People with sub-clinical BV: have lower levels of LB
-People with BV: they do not produce lactic acid and have very little amounts of LB
Which age cohorts have been experiencing increased levels of STI? - Answer - STI is
on a rise in both elderly and youth
, What is the best treatment for BV and other STIs? - Answer - Many scientist think to
prevent BV and STI is microbiota transplantation
Does vaginal microbiota play any role in new born baby? How does the impact vary
between babies born naturally vs babies born via C-section? - Answer - -Babies a born
through C-sections have different vaginal and rectal microbiotas than naturally born
babies
-Naturally born babies are being enriched with vaginal secretion enriched with LB while
the baby are in the mother's birth canal. In C-sections the babies are not exposed to this
vaginal LB
-One clinical trial has revealed that rubbing a new born C section baby with vaginal
secretion of LB can help their microbiota diversity
Tears and saliva are natural ____________ as they have high ________ concentration
- Answer - disinfectant, lysozyme
How do lysosomes act on different types of gram-bacteria? - Answer - -Lysozyme are
effective in bacteria and gram-positive bacteria because these bacteria have a thick wall
which can be digest by lysozyme (this is why animals lick their wounds)
-Gram positive bacteria have a much thicker peptidoglycan than gram negative, and
lysosome digests peptidoglycan to break down the cell wall
Why are lysosomes more dangerous to gram-positive than gran-negative bacteria? -
Answer - Gran positive have a higher internal pressure (it is equal to propane gas), so if
integrity of peptidoglycan is compromised it can explode very easily
What is the complement system? - Answer - -When we encounter a pathogen one of
the first level of defensive that we have is a of soluble proteins made constitutively by
the liver and present in the blood, lymph, and extracellular fluids (these proteins are
premade which work like enzymes which are heat sensitive and are produced by the
liver). -These plasma proteins are collectively are known as the complement system or
just complement.
-Complement coats the surface of bacteria and extracellular virus particles and makes
them more easily phagocytosed.
Describe the C3 cleavage? - Answer - When the complement system is activated by
infection it leads to the cleavage of C3 into a small C3a fragment and a large C3b
fragment. C3b is chemically reactive and becomes covalently attached, or fixed, to the
pathogen's surface, thereby marking the pathogen as dangerous. C3a is a component
of the proteins are inflammatory and potent chemoattracting proteins and potent
recruiters of inflammatory cells to the site of infection.
Describe the 3 pathways of the complement system: - Answer - 1. Alternative
pathway:we don't need specific receptors or antibodies, only the presence of any
pathogen can activates the complement system right away
Can normal skin microbiota be used for the treatment of some human skin related
diseases such as acne)? - Answer - - People have different microbiota in the skin,
people with skin conditions have different microbiota in their skin
- There are studies that have shown microbiota transfers from people with good skin to
people with acne which have been an effective treatment
___________ surfaces are covering the lining all our internal tubes - Answer - Mucosa
The epithetical that are part of the innate immunity have a thick _______ layer instead
of a _______ skin layer - Answer - mucosa, dead
______ cells have a high level of _____ content, so it well suited for the growth of
beneficial microbiomes - Answer - Mucosa, water
______ helps trap bad bacteria and prevent from them attaching to epithelium cells. It
has _______ to help fight any bad bacteria that does attach. - Answer - Mucin,
glycosides
Epithelia cells of which layer renew very frequently and how this help our innate
immunity response? - Answer - Epithelial cells of the mucosa layer renew very
frequently and this is part of the innate immune system, because when many pathogens
enter the body they need to multiple and colonize, at the same time epithelial cells are
being renewed at such a fast rate which isn't a good host for these pathogens. So the
turnover and shedding of epithelial are part of the innate immune system.
The ____ layer of epithelial cells is covered with a high number and diversity of
microbes, except for in the ________ - Answer - mucosa, lungs
How does our microbiota help protect prevent infections? - Answer - 1. Microbiota fill
any viable space to keep any pathogens out
2. Microbiota learn to produce antibacterial viral components to kill pathogens. The
microbiota help by using their product peptides that help kill bad bacteria that colonize
on the skin or other organs
High concentration of _____ (bacteria) are found in our UG tract - Answer - LB
High concentration of _________ (bacteria) are found in the upper respiratory tract -
Answer - Gram positive
Studies have shown that germ-free (no microbiota) animals have _____________
immune system. They were very to _________ infections and metabolic diseases. -
Answer - underdeveloped, susceptible
,Describe these 2 gut conditions and possible treatments for both of them (C.defficile
and IBD) - Answer - 1. C, Defficile: a cluster of bacteria in the gut that are antibacterial
resistant, antibiotics actually makes the condition worst by getting rid of good
microbiota, the best treatment is transplantation of healthy microbiota into the gut, it is
an effective treatment as it fills space in G.I tract and they create peptides which kills of
C. defficile
2. IBD: Is another gut condition that can be treated with microbiota transplants. They
found that the microbiota of lean mice were different than those of fat mice. In one
experiment when the microbiota from a lean mice to transplanted to a obese mine they
become lean, and this also works vice versa.
Describe the importance of microbiota in the female reproductive tract: - Answer - -
Natural immunity in female reproductive system is important for prevent viruses like
ZIKA virus
-The gut has a very diverse microbiota, but in the reproductive tract it's not a diverse at
all, it's mostly all one bacteria known as LB
-During pre-puberty and menopause the levels of LB are lower and the pH is higher.
However, during puberty the pH lowers and the LB concentration increase significantly
-We need low pH in the female reproductive tract (3.4 to 3.5) to prevent STI and thus
subclinical bacterial vaginosis occurs.
-LB produces low pH and antibacterial peptides to prevent bacterial vaginosis.
-Many viruses cannot bind receptors in a pH below 6, so an low pH in the vagina can
protect us from viruses
What is subclinical bacterial vaginosis? - Answer - When the female reproductive tract
pH is above this normal level
Why does the pH lower during reproductive age in the female reproductive tract? -
Answer - When there is surge of estrogen it causes the position of glycogen on
epithelium cells on the vagina to change and then LB feed on glycogen to produce lactic
acid which lowers the pH
What are the 3 types of antimicrobial substances produced by epithelial cells? - Answer
- 1. Cryptidins and Alpha defensins: produced at the base of the small intestine crypsts
2. Beta-defensins: produced within skin and respiratory
3. Surfactant proteins A and D: present in lung and vaginal tract (function as opsonins
which enhance the efficiency of phagocytosis). They are very potent anti-microbial
substances
What is the correlation between LB and bacterial vaginosis (BV)? - Answer - -In an
healthy human LB represents a large majority of their microbiota
-People with sub-clinical BV: have lower levels of LB
-People with BV: they do not produce lactic acid and have very little amounts of LB
Which age cohorts have been experiencing increased levels of STI? - Answer - STI is
on a rise in both elderly and youth
, What is the best treatment for BV and other STIs? - Answer - Many scientist think to
prevent BV and STI is microbiota transplantation
Does vaginal microbiota play any role in new born baby? How does the impact vary
between babies born naturally vs babies born via C-section? - Answer - -Babies a born
through C-sections have different vaginal and rectal microbiotas than naturally born
babies
-Naturally born babies are being enriched with vaginal secretion enriched with LB while
the baby are in the mother's birth canal. In C-sections the babies are not exposed to this
vaginal LB
-One clinical trial has revealed that rubbing a new born C section baby with vaginal
secretion of LB can help their microbiota diversity
Tears and saliva are natural ____________ as they have high ________ concentration
- Answer - disinfectant, lysozyme
How do lysosomes act on different types of gram-bacteria? - Answer - -Lysozyme are
effective in bacteria and gram-positive bacteria because these bacteria have a thick wall
which can be digest by lysozyme (this is why animals lick their wounds)
-Gram positive bacteria have a much thicker peptidoglycan than gram negative, and
lysosome digests peptidoglycan to break down the cell wall
Why are lysosomes more dangerous to gram-positive than gran-negative bacteria? -
Answer - Gran positive have a higher internal pressure (it is equal to propane gas), so if
integrity of peptidoglycan is compromised it can explode very easily
What is the complement system? - Answer - -When we encounter a pathogen one of
the first level of defensive that we have is a of soluble proteins made constitutively by
the liver and present in the blood, lymph, and extracellular fluids (these proteins are
premade which work like enzymes which are heat sensitive and are produced by the
liver). -These plasma proteins are collectively are known as the complement system or
just complement.
-Complement coats the surface of bacteria and extracellular virus particles and makes
them more easily phagocytosed.
Describe the C3 cleavage? - Answer - When the complement system is activated by
infection it leads to the cleavage of C3 into a small C3a fragment and a large C3b
fragment. C3b is chemically reactive and becomes covalently attached, or fixed, to the
pathogen's surface, thereby marking the pathogen as dangerous. C3a is a component
of the proteins are inflammatory and potent chemoattracting proteins and potent
recruiters of inflammatory cells to the site of infection.
Describe the 3 pathways of the complement system: - Answer - 1. Alternative
pathway:we don't need specific receptors or antibodies, only the presence of any
pathogen can activates the complement system right away
