Immunology Flashcards
Primary lymphoid organs are the
site of
leukocyte development
leukocyte development
creation of various white blood cells and immune cells like macrophages, dendritic cells, neutrophils, and effector T cells
Two primary lymphoid organs
- thymus
- bone marrow
Secondary lymphoid organs are
sites where
lymphocytes patrol and
adaptive immune response begin
Secondary lymphoid organs
- Lymph node
- tonsil
- appendix
- spleen
Innate immunity
definition and how it protects againsts foreign bodies
Protection against foreign bodies, injuries and pathogens through:
- Physical Barriers
- Chemical Barriers
- Microbiological
Chemical barriers example
Antimicrobial enzymes in tears and saliva
Physical barrier examples
- Protection on the inside: all mucous membranes
- Protection on the outside: skin
Microbiological barrier example
Harmless bacteria that use up food and space to prevent pathogenic bacteria colonization
Adaptive immunity
definition and two modes
Exhibit memory and provide protection against specific pathogens or changed body cells through: Active Immunity and Passive Immunity
Active Immunity
Vaccines provide long lasting protection through immunological memory
Passive Immunity
Infants receive passive immunity from their mother (antibodies) providing short term protection
Are the innate and adaptive immune system mutually exclusive?
Innate and adaptive immune responses are NOT mutually exclusive. In fact, they work together to mediate effective immunity against pathogens.
Innate characteristics
- immediate (hours)
- non-specific
- fixed response
- lifelong efficacy
- constant during response
Adaptive characteristics
- Slow Response (days to weeks)
- Highly Specific to an antigen ex: allergic people
- Variable response depending on immune cell activation
- Short term, Long-term, Lifelong Efficacy
- Improved during response
Inflammation
a consequence of an active immune response, it is your body trying to get rid of the pathogen
4 main signs of inflammation
- redness
- heat
- swelling
- pain
- tingling
- numbness
How is our body able to recognize viral, bacterial, or fungal pieces?
Through Pattern Recognition Receptors
Once a pathogen encounters a toll-like receptor, the toll-like receptor will
signal various cytokines that coordinate local inflammation and immune response
Pattern Recognition Receptors
Toll like receptors are found on the surface of the cell membranes of leukocytes and are relevant because they recognized conserved bacterial and viral molecule units
IL-6
raise temperature in infected tissue
IL-12
recruits and activates natural killer cells and recruits more macrophages to try to calm down and kill the bacteria, viral molecule, or fungi
IL-1 & TNF-α
makes blood vessels more permeable which causes swelling and redness, to enable effector cells to enter infected tissue
Why do we get vaccines?
- to develop an active immune response
- to get our antibodies to develop memories
Antibodies are immune system related proteins called
immunoglobulins
Antibody constant regions are interchangeable and
come in other forms that determine the antibody class or isotype
Antibody drug therapies with the “umab” nomenclature have a lower potential for immunogenicity than
“omab” drug therapies
Affinity measures
strength of the interaction between an antigen and antibody at a singular binding site
avidity
measures the strenth of the an interaction between the antibody and antigen
affinity
looks at how the antigen bounds in that binding site that we see
Antigent binding site
- variable
- diversity
- joining
light chain
V, J
heavy chain
V, D, J
VDJ Recombination
- Defining feature of the adaptive immune system
- Goal: generate unique receptors to recognize different parts of the molecule
- Generation of diversity happens BEFORE antigen encounter
Clonal Selection
- Antigens induce proliferation of B cells and T cells that recognize that antigen
- Antigen binding cells grow and divide → Elimination of the specific antigen
Class Switch Recombination
Exchange of one CONSTANT region for another → Allows effector function of antibody molecule to be changed while maintaining antigen binding
Somatic Hypermutation
- after an antibody encounters an antigen, it will
trigger cell proliferation and differentiation –> - Point mutations in the V regions of heavy and light-chain genes occur –>
- Proliferating B cells bears an antigen-binding site that has INCREASED affinity for the antigen
Immunoglobulins are also known as
B-cells
IgG
Location, Mechanism, How I Memorize
- Blood and Lymph
- Activation of complement, neutralization, phagocytosis, ADCC, protection of fetus
- Good at everything
IgA
location, mechanism, how to memorize
- Neutralization
- mucosA Already there
- can prevent an infection entering through the GI tract
- is a secretory antibody that can be secreted by the cells lining the small intestine into the small intestine lumen.
- The other antibodies (IgG, IgM, and IgE) can’t be secreted out of the body and would only be effective once the bacteria has entered the body.
IgM
Location, Mechanism, How I Memorize
- Blood and Secretions
- Activation of complement, neutralization
- compleMent
- is good at fixing complement and is the first antibody isotype made during an immune response
- When your body senses an invader, your IgM level will rise for a short time.
- It will then begin to drop as your IgG level kicks in and increases to protect you long-term.
IgE
Location, Mechanism, How to Memorize
- Bound to mast cells and basophils
- Mast cell and basal cell degranulation
- allergEe
- subclass of immunoglobulins that plays a critical role in the allergy response
- binds to allergens which in turn bind to Fc receptors on the mast cells, triggering the release of numerous inflammatory mediators, including histamine
IgD
Location, Mechanism, How to Memorize
- Membrane bound BCR
- Generally not secreted as antibody
- Not secreteD
Which antibody type is responsible for symptoms like runny nose and itchy eyes during Spring time? It’s a specific antibody type that is responsible for activating mast cells.
IgE
Which antibody type would be most
effective in preventing the type of infection that causes diarrhea and stomach upset, caused by consistent diarrhea and stomach upset?
IgA
Which antibody isotype serves as the first line of defense during an immune response?
IgM
heumatoid arthritis (RA)
autoimmune condition that leads to the destruction of joints
All dendritic cells are
Antigen Presenting Cell
T-cells
Characteristics
- Recognizes protein-derived
- Antigens are located on on MHC molecules
- Receptor is the TCR
- Location of Receptor is the cell surface
B-cells
Characteristics
- Recognizes all types of molecules
- Antigens are located bound to the cell or free
- receptor is the immunoglobulin
- location of the receptor is either the cell surface or free
Effector can be
- cytotoxic
- helper cell
Cytotoxic effector cells
- recognize MHC class I
- CD8
- directly kills cells
Helper effector t-cells
- coordinates immune response
- CD4
- recognize MHC class II
What would happen to someone’s immune response if they were NOT vaccinated for tetanus and received a tetanus infection?
- After one is exposed to the bacteria that causes tetanus, their innate immunity is triggered, which usually detects early infection.
- Since innate immunity recognizes the infection quickly, the immune system responds very rapidly (usually within hours).
- But, because innate immunity is limited in the number of specificities, the response cannot increase and remains constant throughout the lifetime of the infection
Describe what would happen to someone’s immune response if they WERE vaccinated for tetanus and received a tetanus infection?
- After one is exposed to tetanus AFTER receiving the vaccine series, their adaptive
immunity would be triggered and their immune response would be faster and “stronger” because she has more antibodies specifically for the bacteria that causes tetanus. - Through clonal selection, the antigen would trigger T and B cells to be produced that are specific to that antigen and would lead to the production of cells that can recognize the antigen.
- Basically, if someone is exposed to the bacteria, her immune response will be faster and “bigger” compared to someone who has not been exposed to the bacteria via immunization
Describe the difference between lacking an innate immune response vs. an adaptive
immune response
- Innate immunity is important early in infection, but the person’s body receives antibodies from their mother.
- These antibodies are highly specific for various antigens, and may not be triggered by the antigens that one comes in contact with on a day-to-day basis.
- Therefore, they will be more susceptible to infections and it will last longer.
- If someone is lacking adaptive immunity, the innate immune response will be able to respond to the antigen, but their “memory” to the antigen will be lost.
- Therefore, even if their body has “seen” the antigen, without the pertinent antibodies created by the adaptive immune response, it will not mount a strong response, which also lengthens the time of infection
