Mod 3 - Cells of Adaptive Immunity and Overview Flashcards
List the cells of adaptive immunity
Dentrites
Macrophages
B Cells –> Plasma cell
T Cells –> Cytotoxic cell, Helper Cell
What is adaptive immunity?
Adaptive immunity is a complex network of specialized cells that serves to eliminate pathogens causing an infecction.
Name the five characteristics of adaptive immunity?
- Elimination
- Specific
- Adaptive
- Delay in Response
- Memory
Describe the characteristic of elimination of adaptive immunity.
Adaptive Immunity:
- Acts to eliminates particular pathogens that have breached the innate system.
- May be exhibiting symptoms at this point if 1st time with pathogen.
Describe the specific characteristic of adaptive immunity.
B and T cells act specifically to fight a particular pathogen.
Describe the adaptive characteristic of adaptive immunity.
Not born with it; develops over lifetime. Response increases, more efficient with each subsequent exposure (to same pathogen?).
Describe the “delay in response” characteristic of adaptive immunity.
Takes time to be initiated, typ. 3-4 days the 1st time a pathogen is encountered.
If memory –> response is sooner.
Describe the memory characteristic of adaptive immunity.
Develops memory once pathogen is encountered. Upon subsequent exposures it quickly eradicates infection w/o individual feeling sick or even being aware of exposure.
The adaptive immune system are performed by cells and their actions are mediated by what kind of molecular elements?
Cytokines and Proteins.
Which two cells of the adaptive immunity are considered professional antigen presenting cells (APCs)?
Dendrites and Macrophages
To what cells do dendrite and macrophages cells present antigens to primarily? They act like a messenger for what?
T Cells
They act like a messenger for pathogen peptides.
What do dendrites engulf?
? Clarify
A phagocytic cell of the Adaptive Immune system is a ?
Macrophage
Removes particulates (bacteria, debris, dying cells, etc.)
What is another name for a macrophage in the lungs (besides alveolar macrophage)?
Dust Cell
What cell is dedicated to the production of immunoglobulins and antibodies?
B cells
What cell secretes antibodies?
Plasma cells are mature B cells that function to secrete antibodies.
What is the percentage of lymphocytes that are circulating as B cells?
5-15%
What do T cells become once activated by the presence of a pathogen?
Effector Cells: Cytotoxic or Helper Cells.
What is the percentage of lymphocytes that circulate as T cells?
80%
What effector T cell removes intracellular pathogens and which one removes extracellular pathogens?
Cytotoxic Cells, removes intracellular pathogens (i.e. viruses and tumor cells).
Helper Cells, remove extracellular pathogens (i.e. bacteria) by activating other cells of the immune system.
What are the four categories of adaptive immunity?
- Artificial active, i.e. vaccinations
- Artificial passive, i.e. hepatitis immunoglobulin, inject antibodies made, deteriorates over time.
- Natural active, from infection, e.g. chicken pox
- Natural passive, e.g. antibodies transferred from breast milk
What does “artificial” mean in terms of immunity?
Means created as a result of commercial or manufactured product.
What does natural immunity mean?
Means created from having the disease or passed from mother to baby.
What does active immunity mean?
Means a person’s immune system is stimulated to create immunological memory.
What does passive immunity mean?
Receiving antibodies from Mom or medication and so it will deteriorate over time (i.e. think antibiotics for UTIs).
What does a B cell required to attack a pathogen specifically?
Requires RECEPTORS on its surface. B cell receptor is called an IMMUNOGLOBULIN.
Interacts directly with pathogen surface which activates it to mature into a PLASMA CELL that will secrete ANTIBODIES.
What happens to antibodies after they are secreted by plasma cells?
Available within site of infection and also carried through the peripheral circulation to prevent wide spread infection.
What are the two main functions of antibodies?
- Opsonize pathogen by marking it for removal (… for removal by classical pathway/compliment cascade).
- Neutralizes pathogen or toxin so it cannot interact with healthy tissue.
Each lymphocyte carries a receptor for ___ specificity.
one
Therefore, need a variety of lymphocytes with different specificities.
If each B cell only contains a receptor with one specificity, how does it defined the body against a variety of invading pathogens?
The overall population of B cells within circulation must contain different specificities to defend against the variety of pathogens.
How many different antibodies is it estimated the body has?
10^9 different antibodies at any one time!!
What is the molecular component on the pathogen surface that the antibody will bind to?
Epitope, also called antigenic determinant.
What type of molecule is an epitope typically?
A branched carbohydrate or a protein molecule, since these substances exhibits higher antigenicities.
What does it mean when an cell (pathogen) is referred to as a multivalent? Implications?
Has more than on epitope.
Means more than one antibody can fight against the pathogen, since antibodies are specific for one epitope.
What is the term for the strength of binding at one site between the epitope and the antibody?
Affinity
What is overall binding strength called?
Avidity
What characteristic is utilized within the laboratory for identification of specific hormones within the circulation of patients?
Affinity, the higher it is the better the binding strength of that antibody to the desired epitope.
What happens if affinity is too high or if it is too low?
If too high –> antibody will have difficulty identifying the hormone (degree of tolerance is not acceptable).
If too low –> antibody will bind to other hormones other than the target.
Delicate balance to ensure false negatives and false positives test results are not obtained.
