Term | Definition |
Macro-parasites | Worms |
Micro-parasites | -Protozoa
-Fungi
-Bacteria
-Viruses |
Variance in Susceptibility | Sick cell anaemia -Mutation
-2 Copies of Gene is Fatal
-1 Copy makes red blood cells much less susceptible to Malaria Parasites |
Immune System is seen as a castell
Why is this? | -Physical/Physiological Barriers
-Innate Immunity
-Specific Adaptive/Acquired Immunity |
Barriers and Portal of Entry | -Lungs-Cilia and Mucus
-Gut -Mucus, Acid and Bacteria |
Lysozyme | -Enzyme that attacks component of bacteria cell walls
-Breaks up 'Lyses' Bacteria
-Present in tears, saliva and other secretions |
Transferrins | -Used in Iron Metabolism
-Bind Tightly to iron
-Present in plasma, milk (Lactoferrin) and other fluids |
Lactoferrin | -In milk
-Lowers 'free' iron concentration limiting ability of bacteria to multiply |
Innate Immune Responses | -Next line of defence-"Guards on Parapet"
-DO NOT require prior exposure to Agent
-Operate before other immune responses
-Operate closely with other mech responding to injury
-Hope invading org(Pathogen)posses Recognition
-Acute Phase |
Innate Immune Responses | -Overlap with mech that sense tissue damage |
Pathogen Associated Mol. | -Lipopolysaccharide-Signif. comp. of walls of gram negative bacteria
-Bacterial DNA
-Double Stranded RNA- only exists in Viruses |
Innate Immune Mechanisms | -Complement
-Phagocytes -Neutrophils & Macrophages
-Natural Killer Cells |
Phagocytes (2) | -Neutrophils
-Macrophages |
Complement (Inserting Tube) | -Use Circulating, preformed Elements (C1,C2,C3, etc)
-Components can split (e.g. C3 into C3a,C3b) Subunits are active
-Presence of Pathogen Alters Balance, Driving Formation of C3b-Complement Activation
-Leads to Formation of 'holes' in Bact Cell |
Phagocytsis | -Phagocyte recognizes Bacterium (Chemotaxis)
-Adherence Through PAMP Recognition
-Memb Activation through 'Donger' signal
-Initiation of Phagocytosis
-Phagosome formation
-Fusion of Granules
-Killing and Digesting
-Release of waste products |
Phagocytes 1-Macrophages | -Produced in Bone marrow before circulating in blood as MONOCYTES
-Settle in tissues as MACROPHAGES
-Present in tissue before pathogen arrives and recruited in response |
Phagocytes 2-Neutrophils | -Produced in Bone Marrow
-Commonest white blood cell in circulation
-Only Recruited in Tissue in response to Pathogen
-Functions as Phagocyte
-Also generates 'Reactive' mol. in a Respiratory burst (Absces) |
Eosinophil | -Worm invader Neutrophils will be replaced by Eosinophils
-Generate Respiratory Burst
-NOT Phagocytes (Worm To Big)
-Stick to surface of worm and attack with Lethal Agents
-Large No. generates greener pus |
Natural killer Cells | -Markers Inhibit NK cells
-Target cells and bring about its destruction (Apoptosis) |
Apoptosis | -Programmed cell death |
Specific Adaptive Immunity
-2 Main Effector Branches | -Next Line of Defence
-Also known as ACQUIRES IMMUNITY
-Only produced in response to invader
1) Humoral Immunity (Anitbody)
2) Cell Mediated Immunity |
Specific Adaptive Immunity | -Pathogen mol. act as ANTIGENS |
Antigens | -Stimulate Lymphocytes to produce antibodies
-Recycles to cell surface bound to a host mol (MHC1 or 2) |
Antibody | - =Immunoglobulin (Ig) |
2 Main Types of Lymphocytes | 1) B Lymphocytes
2) T Lymphocytes |
B-Lymphocytes | -Produce Antibody |
T-Cells (Lymphocytes) | -Important in process of producing antibodies |
MHC 1 | -Function to present antigens, self-molecules |
MHC 2 | -Found On Specialized Antigen Presenting Cells
e.g Macrophages, dendritic cells |
Dendritic Cell | -Antigen Presenting Cell |
Antibody Types (5) | 1) IgA
2) IgD
3) IgE
4) IgG
5) IgM |
IgA | -Secreted Across Epithelia
- N.B in Mucosal Defence-Gut, Respir Tract, Urogenital Tract |
IgD | -Stays bound to B-Cells Membrane
-Functions as Antigen Receptor |
IgG | -Major Circulating Antibody
-Stays in blood, Released into tissue by Inflammation |
IgM | -1st Antibody Type Produced in Most Instances
-Initially Memb. bound, later released
-Up to 10 binding sites therefore very 'Sticky' |
IgE | -Activates other cells especially Mast Cells
-Shown to be N.B in rejection of larger parasites (Worms)
-N.B in allergic disease |
Antibody Functions (3) | 1) Neutralisation
2) Agglutination (Coagulation)
3) Opsonisation |
1) Neutralisation | -Prevents viral entry into cells
-Deactivates Toxins |
2) Agglutination (Coagulation) | -Makes bacteria clump together and therefore easier for phagocytes to eliminate (IgM is very good at this) |
3) Opsonisation | -Enhances the process of phagocytosis |
Neutralisation | -Viral Molecule binds to cell receptor facilitating entry into the cell
- Antibody binds to viral mol and prevents it binding to cell receptor, thereby preventing entry into the cell |
Opsonization | 1-Antibody Binding to Bacterium
2-Antibody-coated bacterium binds to Fc receptors on cell surface
3-Macrophage Memb Surrounds Bacterium |
Lysosome | -Is a cell organelle that contains "Lytic" Products |
Antibody Functions | 1) Complement Activation
-Improved complement Function
2) Activation of cells such as mast cells, eosinophils and macrophages |
Blood Groups | -Group A
-Group B
-Group AB
-Group O |
Blood Group- A | -Antibodies Present= Anti-B
-Antigens Present= A antigen |
Blood Group- B | -Antibodies Present= Anti-A
-Antigen Present= B antigen |
Blood Group- AB (Universal Acceptor) | -Antibodies Present= NONE
-Antigens Present= A & B antigens |
Blood Group- O (Universal Donor)
Given in emergency when cant test! | -Antibodies Present= Anti-A and Anti-B
-Antigens Present= NONE |
Blood Transfusions | -Can get away with any blood for cat first time but might not work the second time |
Transfusion In Cats | -AB cats have no antibodies so can get blood from any animal
-Transfusing A blood into a B cat results in rapid destruction of donated type A blood
-Transfusion of Type B Blood into A cats produces milder clinical signs half-life of 21 days |
1)Haemolytic Disease of Newborn
(Neonatal) | -Occurs when a mother produces antibodies against the blood group antigens of their young
-Exposure in pregnancy or prior to transfusion |
2)Haemolytic Disease of Newborn
(Neonatal) | -Antibodies cross Placenta or are ingested in colostral milk and attack RBC before or just after the animal is born
-Potential Problem in Cats, horses, pigs |
Blood Groups and Parentage | -Prior to DNA testing, blood types used to be used to confirm parents |
T-Cells (2) | 1- T Helper Cells
2- Cytotoxic T cells |
1-T Helper Cells | -Help direct immune response/ Activate B-cells |
2-Cytotoxic T Cells | --Capable of killing
-Virally infected cells
-Cells with bacteria
-Tumour Cells
--Cell-Mediated Immunity |
Cytokines | -Signaling Mol. release by immune cells(especially T-Cells)
-Stimulate other immune processes
-can Bias immune response according to need
-Interleukins (IL-2, IL-5)
-Interferons (Gamma-, beta-interferons) |
Immunity & Inflammation | -Any Injury can cause inflammation
-If Sterile, Immune mechanisms stay quiet
-In presence of pathogens, initial inflammation (Acute) dominated by Neutrophils (innate immunity)
-Pathg N.C quickly, inflammation persists-becom chronic-Lymphocytes appear |
Sickness Behavior | -Fever
-Anorexia (Reduced Appetite)
-Depression |
Process Of Sickness Behaviour
Acute Phase Response | -Tied to many of the innate responses |
Process Of Sickness Behaviour
Passive Response to infection | -Debilitation and physical weekness |
Process Of Sickness Behaviour
Adaptive Response-Motivated behavior? | -Innate highly conserved behavior
-"Choices" are made
-Tied to innate immune mechanisms-Acute phase response |
Fever | -Raised set point for thermoregulation
-Inc. Metabolic Rate (13% for each Degree)
-Posture to minimize heat loss |
Anorexia | -Motivation to feed is reduced
-Motivation to rest is increased
-If immune response is not rapidly effective anorexia continues and compromises host wellbeing and survival |
Immunopathology | -Where damaged caused by immune response is greater than harm caused by invading organism
-Parasite itself does not cause much damage
-The host's response to parasite causes the damage |
Immune Evasion | -Antigenic shift in viruses
-Herpes viruses can prevent antigen presentation by MHC on infected cells
-High lipid Content of Mycobacteria wall means they can be phagocytosed but not broken down
-Pathogens release immune modifying factors
-Wall off |
Where do all these cells come from? | -Bone Marrow |
B-Cells are derived from? | Bone Marrow |
T-Cells are Derived from? | Thymus |
Immunodeficiency | -Foetus only develops a working immune system later in pregnancy
-Genetic Defects in immune function
-Could be deficient in T & B Cell Function |
Acquired Immunodeficiency | -Starvation-Especially low protein diets
-"side effect" of disease
-"side Effect" of Drug
-to prevent rejection of transplant
-Corticosteroid Therapy
-Toxicity of bone marrow
-Due to infection |
Immunisation (2) | 1)Active
2)Passive |
1) Passive Immunisation | -Transfer of antibodies from mother to offspring
-In Utero
-In Colostral Milk
-Anti-venoms
-Tetanus antitoxin |
2) Active Immunisation | =Vaccination |
Principle of Vaccination | -Requires exposure to pathogen or antigen without causing disease
-Stimulate appropriate immune response (Antibody and cell-mediated immunity) |
Vaccination | -Killed Org. generally stimulates as strong an immune response and a live one
-Live org. can be used if not going to cause disease and a better cell-mediated immunity |
2 Components of Vaccinology | -Strength of immune response straight after vaccination (Ability to stop pathogen)
-Duration of immunity post-vaccination-Memory Cells |
Duration of Immunity- Might need to | Boost |
Vaccine Failure | No vaccine 100%
-Wrong strain
-Overwheling infective dose
-Rapid decline of response
-Maternally derived antibody
-Poor Responders
Misuse of Vaccine
-Wrongly manufactured or stored
-Out of date
-Wrong injection site |
Maternally derived antibody | -Vaccinating the young animal when passively transferred antibodies still present
=Enough Antibody to 'block' vaccine
=But not enough to protect anst viral exp
-Greater problem with killed vaccines |
Poor responders | -The average animal versus an animal at the lower end of response |
Adjuvants | -Non-infectious material included in vaccine
-Boosts immunity by=Promoting innate immunity
=which reinforces response
-Many killed vaccines included aluminum salts |
Example of vaccine | -Tetanus Toxoid
=Deactivated toxin
=Commonly used in horses and humans |
Kitten Vaccines | -1st Dose at 6,8-9 or 12 weeks (12 months) of age
-Core Vaccine boosters every 3 years |
Puppy Vaccines | -1st dose at 6,8 or 12 weeks of age
-Newer vaccines give at least years protection |
Vaccine to stimulate maternal antibody | -Active immunization of mother-antibodies in colostrum transfer to calf (passive) and prevent disease |
BCG | -Given to Humans to prevent Tuberculosis |
Why have some vaccines been so poor? | -Vaccines for disease that ordinarily provoke a good, solid immunity tend to work well
-Vaccines against disease where natural immunity is very poor (TB) or develops only slowly (Helminths) have worked less well |
Vaccines Needed | -Better TB Vaccine
-Malaria
-Hiv |
Vaccine Risks | -No therapy is without risk!
-For serious, life-threatening diseases
-Over-vaccination |
Over-Vaccination | -Poor knowledge of how long immune response stimulated by vaccines |
Allergic Disease | -Inappropriate response to something that would not expect to react against
-Antigen=Allergen
-Immediate Reaction or Delayed (over days) |
Role of Mast Cells and IgE | -Mast cells are immune cells that reside in tissue
-N.B. role in rejection of helminth parasites
-Critical role of IgE along mast cells
-Mast Cells Release histamine |
Anaphylaxis | -Due to Bees and Wasps
-Due to widespread Mast cell activation
Respiratory Problems
-Anaphylactic shock |
Atopy | -(genetic) predisposition to mount excessive IgE response
-Atopic Dermatitis
-Asthma |
Asthma | -Immediate response to allergens=Mast cells
-Delayed and prolonged damage to airways-eosinophils |
Autoimmune Disease | -Inappropriate expression of immune response to 'self'
-Diabetes |
Hygiene Hypothesis | -Disease increase as standard of living increases
-When hygiene standards are high, immune system has little to do
-Rather than stay quiet-Inapp Activation occurs |