Bio Unit 4 Module 3
What is proliferation and differentiation?
-activated lymphocytes proliferate (multiply) and then differentiate into effector cells and memory cells -memory cells and effector T cells circulate continuously in the blood and lymph and throughout the secondary lymphoid organs
What are the steps of Cell-mediated immunity?
1. Antigen Presentation 2. Antigen Recognition 3. Activation 4. Proliferation and Differentiation 5. Destruction of the infected cell
What is step 3 of adaptive immune system?
After an encounter with a new pathogen, the adaptive immune system often "remembers" the pathogen, allowing for a faster response if the pathogen ever attacks again.
What is the Antigen memory phase?
Also saving specific cells (memory B and T cells) in memory so you have a better way to fight back next time
summary of inflammatory response
An inflammatory response begins when a pathogen stimulates an increase in blood flow to the infected area (histamine). Blood vessels in that area expand, and white blood cells leak from the vessels to invade the infected tissue. These white blood cells, called phagocytes engulf and destroy bacteria. The area often becomes red, swollen, and painful during this response --- 1. Bacteria infect tissue 2. Macrophages engulf bacteria and release chemical mediators 3. Cytokines induce selectins on capillary endothelia that bind to neutrophils 4. Vasoactive factors induce integrins on neutrophils, which bind ICAM and VCAM 5. Bradykinin loosens junctions to allow extravasation and triggers prostaglandin synthesis 6. Peptides from the bacteria and chemical signals from the infected tissues are released and attract neutrophils
What is the antigen Recognition Phase?
Antigen is present B Cells and T cells which have never been exposed to antigen Go through expansion and start to make more
What is the Antigen Elimination phase?
As you go down, you start to eliminate the virus By apoptosis or exposing pathogen to antibodies and target them and take them out
What happens during the secondary immune response ?
At this point immunological memory has been established and the immune system can start making antibodies immediately. You have twice as much the first time you were exposed so you can fight it more quickly
What are the 3 steps of a virus' life cycle?
Attachment: viruses are specific in the types of cells they infect. Therefore, it is possible to target either the molecules on the surface of the host cell that the virus identifies with, or the proteins that the virus uses to attach to the cell Uncoating: once inside the cell, some viruses provide an enzyme to remove their genetic material from the capsid Release: many viruses provide an enzyme that interacts with specific molecules in the host's cell's membrane to allow the newly formed viruses to escape the host cell
What are the steps of antibody-mediated immunity?
B cells fight an antigen within the tissue that they are found Such as: - spleen - lymph node - mucosa-associated lymphatic tissue (MALT) - where it becomes activated Once activated: - undergoes clonal selection - forming a clone of plasma cells and memory cells The plasma cells are: - effector cells of a B cell - that secretes specific antibodies - These antibodies circulate in lymph and blood - to reach the site of invasion. 1) Activation and Clonal Selection of B Cells. 2) Antibodies. 3) Immunological Memory.
Why are Scientists are researching ways of getting around the ability of the virus to evolve, including the use of antiviral agents and the development of the universal flu vaccine?
Bc of the 2017-2018 vaccine that was supposed to be effective against the flu virus wasn't.
What is step 1 of adaptive immune system?
Cells that belong in the body carry specific markers that identify them as "self" and tell the immune system not to attack them.
What is step 4 of the the inflammatory response?
Clotting factors close off the wound. This causes pressure to build and accounts for the red, tender appearance of inflammation.
What happens during the primary immune response ?
During this time the immune system has to learn to recognize antigen and how to make antibodies against it and eventually produce memory lymphocytes.
What is the antigen activation Phase?
Effector cells: antibody producing b cells
Explain the smallpox vaccine and why it works
For example, the smallpox vaccine contains the antigens specific to smallpox. When a person is vaccinated against smallpox, the immune system responds by stimulating antibody-producing cells that are capable of making smallpox antibodies As a result, if the body comes into contact with smallpox in the future, the body is prepared to fight it.
What is an example of Not all antigens will provoke a response.
For instance, individuals produce innumerable "self" antigens and are constantly exposed to harmless foreign antigens, such as food proteins, pollen, or dust components.
How soon does the inflammatory response start?
Happens as soon as your body is exposed to injury
What happens if the inflammatory response doesnt stop?
If this doesn't go away you can go into into septic shock
What is one of the most important aspects of our innate immune response?
Inflammation
Why wasnt the 2017-2018 vaccine that was supposed to be effective against the flu virus wasn't.
It was between 30-36% when it supposed 40-60% effectiveness The H3N2 virus which was the predominant form of the last seasons flu antigen had changed by the time the vaccine was exchanged and distrubed
There are two different forms of MHC markers in the body which are?
MHC class I markers (MHC-I) MHC class II markers (MHC-II)
What are produced by the cell-mediated immunity pathway?
Memory T cells
What vaccine was created to combat the release cycle in the virus life?
Most recent is tamiflu Tamiflu targets this stage and inhibits the viral enzyme that allows the virus to leave the host so you can't escape the host and infect other cells
What is antigen presentation?
Movement of the MHC molecule and bound antigen fragment to the cell surface where it is displayed for Helper T cells to bind via their antigen receptors to activate the Helper T cell. The Helper T cell then binds to a B cell which then divides into plasma cells which secrete antibodies and memory B cells to store information for later infections.
What is step 3 of the the inflammatory response?
Neutrophils remove dead cells, wound debris, and any pathogens in the area by phagocytosis. If additional assistance is needed, neutrophils may release cytokines to recruit more immune cells to the area.
What is the first line of defense when we get wounded? Nonspecific Defense Mechanisms of the Immune System what is it? innate defenses.
Nonspecific Defense Mechanisms of the Immune System; innate defenses.
What is step 2 of adaptive immune system?
Once the immune system recognizes a pathogen (specific antigens associated with a pathogen) as "non-self," it uses cellular and chemical defenses to attack it.
What are the steps of the the inflammatory response?
Step 1: The damaged tissue and nearby immune cells release histamine, which not only causes fluid to leak from nearby capillaries, thus slowing the movement of pathogens, but also increases blood flow to the area to deliver additional white blood cells (such as macrophages) and clotting factors to repair the wound. Step 2: The macrophages identify and destroy any bacteria or viruses in the wound area. Step 3: Neutrophils remove dead cells, wound debris, and any pathogens in the area by phagocytosis. If additional assistance is needed, neutrophils may release cytokines to recruit more immune cells to the area. Step 4: Clotting factors close off the wound. This causes pressure to build and accounts for the red, tender appearance of inflammation.
What are steps of adaptive immune system? 3
Steps 1: Cells that belong in the body carry specific markers that identify them as "self" and tell the immune system not to attack them. Step 2: Once the immune system recognizes a pathogen (specific antigens associated with a pathogen) as "non-self," it uses cellular and chemical defenses to attack it. Step 3: After an encounter with a new pathogen, the adaptive immune system often "remembers" the pathogen, allowing for a faster response if the pathogen ever attacks again.
Cell-mediated immunity makes use of what?
T lymphocytes
What is the second line of defense when we get wounded?
The Inflammatory Response
What is step 1 of the the inflammatory response?
The damaged tissue and nearby immune cells release histamine, which not only causes fluid to leak from nearby capillaries, thus slowing the movement of pathogens, but also increases blood flow to the area to deliver additional white blood cells (such as macrophages) and clotting factors to repair the wound.
What are innate defenses.
The defenses that act as general defenses, meaning they are not targeting a specific pathogen, surface barriers
What is step 2 of the the inflammatory response?
The macrophages identify and destroy any bacteria or viruses in the wound area.
Explain how birds and pigs Evolution Supports Change in the Influenza Virus
The swine flu situation: bc of humans close proximity to these animals, antigenic shift virus underwent an produced new form of virus that can infect humans
Why is the Some of the activated B cells are held in reserve and not used in the first response to the antigen. Instead, they wait for a future exposure useful?
This is useful because if you are exposed to the same pathogen again—for example, the same influenza virus—the adaptive response can be much faster and more efficient.
Think of the MHC-I markers as like a campus identification card. Everyone on campus should have an identification card. However, the security officers on campus have both a campus identification card (MHC-I) and a police identification badge. explain this.
This second identification serves the same function as the MHC-II markers in the immune system: It lets the cells of the immune system identify cells with a different function, which in this case is to alert the immune system to specific pathogens.
What does the use of core proteins allow for?
This would allow single vaccine to target multiple viruses, and also provide long term effects
When is the adaptive immune system activated?
When pathogens are able to bypass innate immune defenses
Explain how the immunse system uses antigens.
When pathogens are ingested by the macrophages and dendritic cells of the immune system, they are digested, and a small portion of the pathogen is attached to the surface of the macrophage
When the influenza virus enters into an epithelial cell on the surface of our respiratory tract, the infected cell responds by posting an antigen on its surface, attached to a MHC-I marker. This acts as what?
a flag for the cytotoxic T cells, which were just activated by the helper T cells so that they can be destroyed
The immune system distinguishes "self" from "nonself" by?
a series of markers present on the plasma membrane of the cell
What are cytokines?
a small protein that is usually involved in a local response to a pathogen
What is intereron chemical signal role in the immune response?
acts as signal to nearby cells that a cell has been infected by virus
What is the third line of defense for immunity?
adaptive immunity
What is the second form of adaptive immunity?
antibody-mediated immunity.
After ingestion by macrophages and dendritic , they are digested, and a small portion of the pathogen is attached to the surface of the macrophage where they will serve as an indicator to other immune cells. The cell is now called a(n)
antigen-presenting cell (APC).
Scientists are researching ways of getting around the ability of the virus to evolve, including the use of?
antiviral agents and the development of the universal flu vaccine
What is an antigen?
any substance that produces a specific immune response to the body
What do MHC class II markers (MHC-II) do?
are only present on the immune system cells that provide the link between the nonspecific and specific immune responses
Glycoproteins located along the plasma membrane of the cell act what?
as identification tags
How do Vaccines work
by taking advantage of antigen recognition and the antibody response.
What does histamine do?
causes fluid to leak from nearby capillaries, thus slowing the movement of pathogens, but also increases blood flow to the area to deliver additional white blood cells (such as macrophages) and clotting factors to repair the wound.
The Adaptive immunity also has the ability to target what cells?
cells of the body that are infected with the pathogen, while also responding to any pathogens that are free in the blood or interstitial fluid of the body.
Since the immune system is responsible for protecting the entire body, the majority of its work is performed by?
cells that interact with all of the tissues and organs of the body.
What are proteins within the capsid of the virus used as the basis for programming the adaptive responses called?
core proteins
What is the difference between core proteins and s H and N spikes
core proteins do not change at the same rate as H and N spikes on the virus, and are more similar between influenza viruses
What are the the chemcial signals of the immune response colletivley called?
cytokines
natural killer cells function and specificity
destroy cells of the body that have been infected by viruses or bacteria; nonspecifc
Macrophages, dentric cells, and neutrophillis function and specificity
destroy pathogens by phagocyosis; nonspecific
The lymphatic system consists of several organs and tissues that are involved in what?
either filtering and cleaning the blood and interstitial fluids of the body, or in the production and maturation of immune system cells called lymphocytes.
Vaccinations generate active immunity by ?
exposing individuals to antigens specific to pathogens.
Our immune system has several levels of defenses, what are they?
from nonspecific physical barriers to cellular mechanisms of protecting us from specific pathogens, such as the influenza virus
What is interleukin chemical signal role in the immune response?
glycoprotein that is involved in regulating the general immune response
Action of Cytotoxic T Cells. Cytotoxic T cells target the cells of our bodies that?
have been infected by a pathogen and are presenting a specific pathogen on their surface.
The suppression of immune responses to harmless macromolecules is what?
highly regulated and typically prevents processes that could be damaging to the host, known as tolerance.
What are the chemcial signals of the Immune Response?
histamine, interferon, interleukin
What is stomach description physical barriers for pathogens?
hydrochloric acid (low pH) destroys bacteria and other pathogens
Our immune system is active every minute of the day, all year long. Most of the time, however, the system works where?
in the background, protecting us from pathogens that would otherwise cause disease.
What is histamine chemical signal role in the immune response?
increases the permeability of the capillaries and causes fluid to be released into the area of the wound
Often, a second vaccination is required and the body mounts a secondary response that?
increases the production of memory B and T cells.
What is antibody-mediated immunity?
involves antigen-antibody interactions to neutralize, eliminate, or destroy foreign proteins.
Why is Inflammation is one of the most important aspects of our innate immune response?
it is often the first immediate action taken by the immune system against an injury.
One way to combat a virus that has the ability to target what?
its life cycle
When The immune system detects potentially harmful antigens, pathogens are ingested by the ______ and ______ of the immune system
macrophages; dendritic cells
What are the The glycoproteins in the immune system called?
major histocompatibility complexes or MHCs
What is release? virus
many viruses provide an enzyme that interacts with specific molecules in the host's cell's membrane to allow the newly formed viruses to escape the host cell
A primary response is mounted and what happens?
memory B and T cells are produced by the immune system.
Later exposure (the secondary response) is more what than initial response?
more rapid and effective due to the initial exposure.
What is respiratory tract description physical barriers for pathogens?
mucous membranes trap microbes; they contain chemcials that protect against pathogens; cilia
What is skin description physical barriers for pathogens?
normal bacteria (flora) on the surface, along with chemicals released by oil and sweat glands, inhibit bacterial growth
the innate immune system defenses are not what?
not directed against any one pathogen but instead, provide a guard against all infection.
What is upcoating? virus
once inside the cell, some viruses provide an enzyme to remove their genetic material from the capsid
thymus function
organ where T lympnocytes mature
spleen function
organ wherre blood is filtered and cleaned by the action of white blood macrophages
What do MHC class I markers (MHC-I) do?
present on every nucleated cell of the body; the general "self" identification tag
B lympocytes function and specificity
produce antibodies to target specific antigens in the fluids of the body; specific
They immune system and the lymphatic system work closely to do what?
protect the body from pathogens
What is The immune system is responsible for?
protecting our bodies from foreign pathogens, such as viruses and bacteria, and works very closely with the lymphatic system.
Newer vaccines design to use other proteins within what as the basis for programming the adaptive responses?
proteins within the capsid of the virus
Not all antigens will do what?
provoke a response.
What happens to Some of the activated B cells
re held in reserve and not used in the first response to the antigen. Instead, they wait for a future exposure.
As they mature, each T lymphocyte develop what?
receptors that will allow it to recognize a single form of antigen which engulf and destroy them
What are the Characteristics of inflammation?
red, swollen tissue that is often tender to touch.
When a pathogen has invaded, the immune system may also do what?
release chemicals that increase body temperature, producing a fever.
The adaptive immune response has the ability to do what?
remember past exposures to pathogens This characteristic is called memory
What do Neutrophils do?
remove dead cells, wound debris, and any pathogens in the area by phagocytosis. If additional assistance is needed, neutrophils may release cytokines to recruit more immune cells to the area.
Throughout the unit evidence of evolution is supported with?
research and past scientific research New forms of flu virus is constantly happening
When the influenza virus enters into an epithelial cell on the surface of our respiratory tract, the infected cell does what?
responds by posting an antigen on its surface, attached to a MHC-I marker.
What is the lymphatic system involved in
returning fluids (called lymph) from the tissues of the body back to the circulatory system.
Even openings in the skin (such as the mouth and eyes) are protected by?
saliva, mucus, and tears, which contain an enzyme that breaks down bacterial cell walls.
What are physical barriers for pathogens?
skin, respiratory tract, stomach
Increased body temperature may do what to pathogens?
slow or stop pathogens from growing and helps speed up the immune response.
Vaccinations against the flu use viral _____ as the antigen.
spikes
When The immune system detects potentially harmful antigens, pathogens are ingested by the macrophages and dendritic cells of the immune system, After ingestion, they are digested, and a small portion of the pathogen is attached to the surface of the macrophage where they will serve as an indicator to other immune cells. The cell is now called a(n) antigen-presenting cell (APC). Specific immune responses will now?
target anything in the body that matches that antigens and mount an immune response against it.
T lympocytes function and specificity
target cells that have been infected by a specific pathogen; specific
What is cell-mediated immunity?
targets cells of our bodies that have become infected with pathogens and are presenting the antigen ---- an immune response that does not involve antibodies, but rather involves the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen.
What does adaptive immunity do?
targets specific antigens associated with a pathogen, and also has the ability to remember past responses
At the same time that helper T cells and cytotoxic T cells are working to target infected cells, what happens?
the B lymphocytes begin the production of antibodies.
A vaccine contains what?
the antigens of a pathogen that causes disease.
ntibodies alone are often not enough to protect the body against pathogens. In these instances,?
the immune system uses cell-mediated immunity to destroy infected body cells.
The human body has a series of nonspecific defenses that make up?
the innate immune system.
The body's most important nonspecific defense is what?
the skin, which acts as a physical barrier to keep pathogens out.
What happens if If a pathogen does make it into the body?
there are secondary nonspecific defenses that take place.
When The immune system detects potentially harmful antigens, pathogens are ingested by the macrophages and dendritic cells of the immune system, After ingestion what happens?
they are digested, and a small portion of the pathogen is attached to the surface of the macrophage where they will serve as an indicator to other immune cells.
lymph nodes function
tissue where interstiatial fluid if filtered and cleasned by white blood cells called macrophages
Vaccinations expose the immune system to what?
to an antigen specific to a pathogen, without causing the associated disease
After being formed, T lymphocytes do what?
travel to the thymus where they mature.
What is attachment? virus
viruses are specific in the types of cells they infect. Therefore, it is possible to target either the molecules on the surface of the host cell that the virus identifies with, or the proteins that the virus uses to attach to the cell
When does the primary immune response occur
when an antigen comes in contact to the immune system for the first time
When does the secondary immune response occur
when the second time (3rd, 4th, etc.) the person is exposed to the same antigen.
red bone marrow function
where the lymphocyte cells of the body are produced. location where B lymphocytes mature
What are T lymphocytes?
which are white blood cells produced in the bone marrow.