Overview Info Flashcards
Immune System
complictaed and dynamic network of cells, molecules, and pathways that highly evolved and adaptable to deal with a diverse range of pathogens/ microbes
First line of Defense
SKIN!! creates a barrier to external enviroment and a breachof this activates the internal immune system
Other first lines of defense include mucus membranes, acidity of stomach acid, vagina and sweat and antimicrobial proteins secreted by epithelial cells
Immune privliaged sites
the central nervous system and brain, the eyes and the testes (and pregnant woman)
Inoculation
The act of impanting microbes or microbial substances into animals for the purpose of inducing immunity
Kochs Postulates
- The causative agent must be absent from all healthy organisms but present in all diseased organisms
- The causative agent must be isolated from the diseased organism and grown in pure culture
- The cultured agent must cause the same disease when innoculated into a healthy suseptible organism
- The same causative agent must then be reisolated from the inoculated diseased organism
Vaccination
administeration of vaccine to help activate the immune system
Vaccine
A preparation of immunogenic material used to induce immunity against pathogenic organisms
Attenuation
To decrease the virulence of a pathogen
Virulence
The degree to which a pathogenic organism can cause disease and damage
Herd Immunity
When most of the population is immune to an infectious agent this will reduce the pathogen resovoir (decreasing transmission)
Serum
Liquid, noncellular fraction of coagulated blood (liquid part of blood with all of the clotting factors/ RBCs removed)
Humoral Immunity
- host defense mediated by antibodies in various body fluids including plasma, lymph, and tissue fluids that gives protection to extracellular microbes and foreign macromolecules
Immunoglobulin
Protein consisting of 2 identical heavy chains and 2 identical light chains that recodnize an epitope on an antigen and facilitate neutralization, destruction and clearance of that antigen
AKA… an antibody
Antiserum
Antibody containing blood plasma from immunized animals
Passive Immunity
Temporary adaptive immunity conffered by the transfer of immune products from an immune to a non-immune indivisual
Natural active immunity example…
Getting an infection and body eliciting an immune esponse
Artifical Active Immunity example…
Getting vaccinated
Natural Passive immunity example…
Mother passing antibodies to child via breastfeeding
Artifical passive immunity example…
Monocolonial antibody transmission via blood transfussion
Phagocytes
cells with the capacity to internalize and degrade microbes or particular antigens (neutophiles and macrophages are the main phagocytes)
Cell mediated Immunity
Host defenses mediated by antigen specific T cells that provides protection against intracellular bacteria, viruses, and cancer
Lymphocyte
White blood cell reponsible for both cellular and humoral immunity
B cells
- cells derived from the bursa of Fabricius in birds
- devloped in the bone marrow
- express membrane bound antibodies (B cell receptor [BCR])
- activated B cells produce/ secrete antibodies
- fight extracellular pathogens
T cells
- cells derived from the thymus
- mature in the thymus
- express a T cell Receptor (TCR) and CD8 or CD4
- participate in cellular immunity
- fight off intacellular pathogens
CD4+
Regulates the immune response by being helper T cells. They produce cytokines to function as “hormones” of the immune system. They do not kill anything!
CD8+
They use their TCR to recodnize and destroy infected cells (KILLER T CELLS)
Selective Theory
A false theory that says our body has multiple receptors (pluipotent) on each of our cells that recodnize pathogens and the receptors can each bind to multiple foreign molecules
Antigen
ANy substance that binds an antibody ot TCR that elicits a specific response by T or B cells
Colonial Selection Theory
Correct theory that says that 1 B cell has 1 specific receptor and when an antigen is bound to the BCR that specific cell with that specific receptor colonial expands/ divides so there are many of that cell with that BCR
Pathogen
A disease causing infectious agent
Pathogenisis
The mechanism by which disease causing organisms attack a host
What are the 4 groups of human pathogens?
- viruses
- Fungi
- Parasites
- Bacteria
What needs to occur to elicit a proper immune response?
Different chemical structures and microenviromental cues need to be detected and evaluated to iniciate the most effective response strategy.
Responses are influenced by the structure and location of pathogens.
PAMPs
Pathogen associated molecular patterns
molecular patterns common to whole groups ofpathogens but not occuring in mammals; this is the first thing recodnized by the immune system
WHat does the process of PAMP recodnition involve?
AN interaction between the foreign organism and a recodnition molecule expressed by the host
PRRs
Pattern Recodnition Receptors
Receptors of the immune system that recodnize molecular patterns or motifs present on pathogens but absent in the host; elicit an inate immune response
these are encoded in genomic DNA and do not change
what does equal # of scannersto barcodes mean?
There are an equal amount of PRRs to PAMPs
Tolerance
a state of immunological unresponsivness to specific antigens or sets of antigens; an organism is unresponsive or tolerant to self antigens
DAMPs
released by stressed cells that can be bound to PRRs to activate the immune system (self activation of immune system)
they indicate an infection has occured
Hypersensetivity
allergy; an exaggerated immune response that causes damage to the indivisual (usually an attach of foregin but begnin foreign antibodies)
Autoimmune disease
A group of disorders caused by ones own antibodies or T cells reacting agaisnt self proteins
Immune Deficiency
Acquired or inherited disorders resulting in an insufficiency of the immune response to protect against infectious agents
Immune Imbalance
Dysregulation in the immune system that leads to aderrant activity of immune cells, especially enhanced inflammation and/or reduced immune inhibition
Compare the response time, secificity, response to repeat infection and major components of the inate and adaptive immune system.
Innate:
Response time: minutes to hours
Specificity: Limited and Fixed
Response to repeat Infection: Same each time, but can be “trained”
Major components: Barriers (such as skin…), phagocytes, and pattern recodnition molecules
Adaptive:
Response time: days (5-6 days after inicial exposure)
Specificity: Highly diverse, adapts to improve during the couse of immune response
Response to repeat infection: more rapid and effective with each subsequent exposure
Major components: T and B lymphocytes, antigen specific receptors, and antibodies
Adaptive Immunity
Host defenses mediated by B and T cells following antigen exposure. Has specificity, diversity, memory, and self/non-self recodnizing abilities
Describe the sequence of events of a typical immune response.
- Microbes enter the body through mucosal surfaces or breach he skin
- Microbes are detected by resident phagocytic cells and the innate stage of immune response begins
- Responding phagocytes are activated tocombat the infection locally via release of antimicrobial compounds, chemokines, and cytokines. This causes a fluid influx that helps recruit other immune cells to the site (inflammation)
- Free pathogen and other phagocytic cells that have engulfed pathogens flow through lymphatic vessels tward the lymph nodes where they intersect with b and t cells
- Active immunity is iniciated in secondary lymphoid structures specific B/T cells bind the pathogen and colonially expand
- Activated lymphocytes migrate out of the lymph nodes and join the bloodstream via the heart
- As the lymphocytes identify areas of infection lymphocytes exit the blood vessels and migrate toward he infection where they can help label and destroy the pathogen
- Residual long-term memory T/B cells take up residence in the various locations of the body from which they will be avalible if the pathogen is encountered again
Immunological memory
The ability of the immune system to respond more swiftly and with greater efficency during a 2nd/laer exposure to the same pathogen
Primary Response
Occurs during the 1st encounter with a foreign antigen. Lymphocytes that will be used to erradicate the pathogen are colonially selected, honed, and enlisted to resolve the infection
Second Response
All subsequent encounters with the same pathogen, utalizes nenory cells to participate in the response.
Memory Cells
Lymphocytes (b or T) generated following encounters with an antigen. Long lived and more readily stimulated than niave lymphocytes and these are the primary mediators of the secondary adaptive immune response.
How long can memory cells reemain in the body after they are generated?
Decades
Describe the kinetics of a Primary vs a Secondary Immune Response.
See graph at the end of the seond lecture notes.
