Immunity
State of protection against foreign pathogens or substances
Immunology
study of immune system
Immune system
system of cells, tissues, and their soluble products that recognizes, attacks and destroys foreign entities that endanger the health of an individual
Describe live attenuated vaccines:
Living microbe is weakened, generates 'strong' immune response
Describe inactivated vaccines:
Microbe is killed via chemical, heat, or radiation
Generates 'weaker' immune response
The original small pox vaccine was :
derived from cowpox extracts
Today's smallpox vaccine:
Live attenuated
Pasteur's rabies vaccine:
Live attenuated then
Today's rabies virus:
Inactive - heat killed
Which vaccines show a 100% reductions rate post vaccine?
Small pox, Diptheria, Paralytic polio
Which vaccine has the lowest reduction %?
Pertussis
Herd Immunity
When a critical mass of people acquire protective immunity, either through vaccination or infection , they serve as a buffer for the rest
Provides an altruistic benefit to young, old , or immune compromised members
What are the 2 branches of the immune system?
Humoral Response and Cellular- mediated response
Cell- mediated immune resonse: CMI
cellular portion of blood transferred immunity
Which components are part of the CMI?
Phagocytes , T lymphocytes
Which components are part of the humoral immune response?
Antibodies ( in serum)
B cells - produces antibodies
T lymphocytes:
can eradicate pathogens, clear infected self-cells, aid other cells in immunity induction
Active immunity
Immunity produced due to contact to pathogen or antigen
- antibodies produced by body in response to pathogen
Passive immunity
Immunity produced due to antibodies from the outside
- antibodies can be transferred between individuals to provide protection to a specific antigen or pathogen
Naturally acquired immunity
mother to child
Artificially acquired
Serum, Rabies
What are the 3 key concepts in mammalian immune response?
1. Evolved to protect against ' nonself' entities'
- Viruses, bacteria, protozoans, worms, fungi
2. Establishment of Infection
3. Type of Pathogen
Extracellular pathogens
Bacteria, some parasites
Replicate first in interstitial fluid
Disseminate via the blood
Intracellular Pathogens
Viruses, some bacteria , protozoans
Enter a host and replicate
Spread of infection via blood or neighboring cells
Infection
Attachment and entry of a pathogen into host
Disease
If pathogen overwhelms body systems or interferes with cellular functions
Pathogenesis
Process by which pathogens induce disease
What are examples of diseases of diseases caused by viruses?
Polio, smallpox, influenza, measles, AIDS
What are examples of diseases caused by bacteria?
Tuberculosis, tetanus, pertussis
What are two common fungal infections?
Thrush, ringworm
What are two common parasitic infections?
Malaria, giardia
Response time of innate immunity:
Minutes to hours
Response time of adaptive immunity:
Days
Specificity of Innate Immunity:
Limited and fixed
Specificity of adaptive immunity :
Highly diverse; adapts to improve during the course of the immune respone
Response to repeat infection of innate immunity:
Same each time
Response to repeat infection of adaptive immunity :
More rapid and effective with each exposure
Major components of innate immunity:
Barriers ( skin ) ; phagocytes; pattern recognition molecules
Major components of Adaptive immunity:
T and B lymphocytes: antigen-specific receptors; antibodies
Antigen
General term for any particular foreign material that elicits a specific response by B or T lymphocytes
Recognition molecules
molecules that recognize antigen
PRR's
pattern recognition receptors
PRR's are used by the adaptive or innate response?
Innate response
BCRs
B cell receptor
TCR
T cell receptor
BCRs and TCRs are used by adaptive or innate immune response
adaptive
Describe a pattern recognition molecule
Part of the Innate Immune Response:
Germ line encoded, can recognize structures called PAMPs , present on innate leukocytes
Describe BCRs and TCRs
Part of the Adaptive immune response:
Randomly generated, recognize specific antigens , present on lymphocytes
PAMPs
Pathogen- Associated Molecular Pattern
Ex. LPS, peptidoglycan, dsRNA
Recognition of PAMPs by PRRs initiates 3 Effector functions:
1. Phagocytosis
2. Target cell lysis
3. Inflammation
Antigen specific receptors in the adaptive immune response:
BCR and TCR
Helpter T cells and cytotoxic T cells are forms of which specific antigen specific receptor?
TCR
T and B cells mature in the:
Bone marrow and thymus in the absence of antigen
Clonal selection:
If TCR or BCR of T or B cell recognizes antigen the cells receive the signal to 'live'
Clonal proliferation
* Replication of lymphocytes that recognize antigen
* Leads to many cells that can engage and destroy antigen plus memory cells
Immunological Memory involves:
1. clonal selection
2. Clonal expansion
3. Differentiation
- Effector cells (short - lived )
- Memory cells ( long lived )`
Are memory cells long lived or short lived?
Long lived
Describe a primary immune response :
Antigen A comes along and there is a primary anti-A response at about 2 weeks after infection and results in minimal amounts of serum antibody levels
Describe a secondary response?
Antigen A and antigen B infect;there is a large anti-A response with elevated serum antibody levels ; the anti- B response is about the same as the primary anti-A response
Innate Immune Responses are:
Non -specific or Broadly specific
Adaptive Immune Responses are :
Humoral or Cell mediated
Uniquely specific
Cytokines are:
Signal molecules that produced by the activation of the innate immune response that stimulate the adaptive immune response
Chemokines are :
a subst of cytokine signaling molecuels that have chemotactic activity - recruit specific cells to the site
What are the three basic phases of the host immune defenses?
1. Non- induced Innate responses
2. Induced innate responses
3. Induced adaptive responses
Skin barriers, mucosal barriers, pH, saliva , and proteases are all examples of :
non -induced innate responses
last 0-4 hrs.
How long do induced innate responses typically last?
4-96 hrs.
What is involved during the induced innate response phase?
Complement activation
Phagocytosis
Target cell lysis
Inflammation
T/F : the induced adaptive responses can last more than 96 hours:
True
What cells are activated during the induced adaptive response phase?
B cells, Th cells, Tc cells
Tolerance:
Deletion of self-reactive lymphocytes
Tolerance ensures that the immune system avoids destroying host tissue by:
Many of the random rearrangements used to create BCRs and TCRs could be anti-self
Helping to keep these anti-self cells from circulating in the bloodstream
Examples of overly active or misdirected immune responses :
Allergies/ asthma
Autoimmune diseases: (multiple sclerosis (MS) or chron's disease
Immunodeficiency dysfunctions:
Primary (genetic loss of immune function
Secondary (acquired )loss of immune function
Opportunistic infections like oral thrush can :
occur in people with impaired responses