Week 1 Lec: Intro to Immunology Flashcards
Can be defined as the study of a host’s reactions when foreign substances are introduced into the body.
Immunology
A foreign substance that induces such an immune response is called an?
immunogen
A foreign substance that induces such a host response is called an?
antigen
the condition of being resistant to infection
immunity
These are macromolecules that are capable of triggering an adaptive immune response.
Immunogen
True or False: All antigens are immunogens.
False
True or False: All immunogens are antigens.
True
This practice of deliberately exposing an individual to material from smallpox lesions was known as?
variolation
In 1700s, an English Doctor named ___________ discovered a remarkable relationship between exposure to cowpox and immunity to smallpox.
Edward Jenner
This procedure of injecting cellular material became known as?
Vaccination
The phenomenon in which exposure to one agent produces protection against another agent is known as?
Cross-Immunity
In 1880-1881, A scientist named _______ works with the bacteria that caused chicken cholera.
Louis Pasteur
In this type of vaccine, the pathogens are weakened/less virulent through aging, heating, and chemical means.
Attenuated vaccine
In what ways do we weaken or make a pathogen less virulent?
- aging
- heating
- chemical means
The word vaccination came from the Latin word vacca meaning?
cow
When and who: Smallpox vaccination
1798, Jenner
When and who: Phagocytosis
1862, Haeckel
When and who: Live, attenuated chicken cholera and anthrax vaccine
1880-1881, Pasteur
When and who: Cellular theory of immunity through phagocytosis
1883-1905, Metchnikoff
When and who: Therapeutic vaccination (rabies)
1885, Pasteur
When and who: Proposed Humoral theory of Immunity
1890, Von Behring and Kitasata
When and who: Delayed type Immunity, hypersensitivity reaction (Type IV)
1891, Robert Koch
When and who: Antibody formation theory, concept of immunoglobulins
1900, Paul Ehrlich
When and who: Immediate-hypersensitivity anaphylaxis (anaphylactic/hyersensitivity reaction (Types I, II, III))
1902, Portier and Richet
When and who: Arthus Reaction of intermediate hypersensitivity (Type III hypersensitivity)
1903, Arthus
continuous production of soluble antigen which will attach to circulating antibodies, results in the production of immune complexes and will be deposited to tissues
Type III hypersensitivity
When and who: Hypothesis of antigen-antibody binding
1938, Marrack
When and who: Development of polio vaccine
1949, Salk and Sabin
When and who: Vaccine against yellow fever (antibody diversity)
1951, Reed
When and who: Clonal selection theory
1957, Burnet
When: HLA
1958-1962
HLA stands for?
Human leukocyte antigen
Other term for HLA?
MHC/Major Histocompatibility Complex
The HLA in humans is an important part of the immune system and is controlled by genes located on?
chromosome 6
When: T-cell and B-cell cooperation in immune response
1964-1968
T cells are differentiated at the?
thymus
B cells are differentiated at the?
bone marrow
What do you call the lymphocyte precursor of T cells which came from the bone marrow through the bloodstream?
thymocytes
The role of T cells is to produce _______ that contribute to immunity. These are chemical messengers that influence other activities of the cell.
cytokines
Specific type of polio vaccine Salk invented?
Inactivated dead viral vaccine (Intramuscular Polio Vaccine)
Specific type of polio vaccine Sabin invented?
Attenuated live vaccine (Oral Polio Vaccine)
B cells produce antibodies, assisting in killing tumor cells or infected target cells, and help regulate both the innate and adaptive immune response. This process is called?
Cell-mediated immunity
3 types of T cells according to function?
- Regulatory
- Helper
- Cytotoxic/cytolytic
CD marker on the cell surface?
CD3
CD4 receptors are mainly?
helper or regulatory cells
CD8-positive (CD8+) population consists of?
cytotoxic T cells
The ratio of CD4+ to CD8+ cells is approximately _____ in peripheral blood.
2:1
When: Identification of antibody molecule
1972
When and who: First monoclonal antibodies
1975, Kohler
When: Identification of genes for T-cells receptor
1985-1987
When: Monoclonal Hepatitis B vaccine
1986
When and who: Th1 versus Th2 model of T helper cells function
1986, Mosmann
When: Identification of toll-like receptors
1996-1998
Toll-like receptors are a class of?
pattern recognition receptors (PRRs)
Highest concentration of toll-like receptors are found in?
monocytes, neutrophils, and macrophages
They provide surveillance for pathogens.
toll-like receptors
When: FOXP3, the gene directing regulatory T cell development
2001
The gene directing regulatory T cell development is called?
FOXP3
When and who: Development of human Papilloma virus vaccine
2005, Frazer
Papilloma (human papillomavirus/HPV) is the causitive agent of?
cervical cancer
All those physiological mechanisms that endow the animal with the capacity to recognize materials as foreign to itself and to neutralize, eliminate or metabolize them with or without injury to its own tissues.
Immunity
It is structured to recognize, respond to, and destroy a wide variety of invading organism that would otherwise be capable of promoting infections, harmful to the body.
immune system
2 Types of Immunity?
- Natural Immunity
- Acquired Immunity
Ability of an individual to resist infections by means of normally present body functions.
Natural Immunity
Natural Immunity is also called?
Innate Immunity
A type of immunity that is non-specific, lacks memory, naturally-occuring, and with a standardized response to all pathogens.
Natural Immunity
Type of resistance that is characterized by specificity for each individual pathogen, or microbial agent.
Acquired Immunity
Acquired Immunity is also called?
Adaptive Immunity
Type of immunity that is specific and has a diverse response to all pathogens.
Acquired Immunity
2 defense systems under natural immunity?
- External Defense System
- Internal Defense System
composed of structural barriers that prevent most infectious agents from entering the body
External Defense System
Examples of External Defense System?
• Linings of the respiratory tract
• Skin and mucosal membrane surfaces
• Secretions
Sweat glands secrete?
lactic acid
Sebaceous glands secrete?
Fatty acid
Acidity of the stomach is due to?
HCl/hydrochloric acid, which can maintain the pH of the stomach as low as 1
A naturally-occuring enzyme found in tears and saliva.
Lysozyme
Designed to recognize molecules that are unique to infectious organism.
Internal Defense System
The most important function in the Internal Defense System?
Phagocytosis
Engulfment of cells or particulate matter by neutrophils (PMNs), macrophages and other cells (esp. monocytes).
Phagocytosis
Examples of Internal Defense System?
• Inflammation and fever
• Natural anti-microbial substances
• Complement pathway→ esp. antibody dependent pathways
• Properdin
• Interferon
• TNF
• Beta-lysin
1st line of defense?
External Defense System
2nd line of defense?
Internal Defense System
3rd line of defense?
Acquired/Adaptive Immunity
Cellular Components of the Natural Immunity?
• Phagocytes
• Other WBCs (granulocytes)
• NK cells
• LAK cells
NK cells stands for?
Natural Killer cells
kills viruses and tumor cells prior to exposure
NK/Natural Killer cells
LAK cells stands for?
Lymphokine-activated Killer Cells
kills cancer/tumor cells
LAK cells (Lymphokine-activated Killer Cells)
It has been shown that lymphocytes, when exposed to _____________, are capable of lysing fresh, non-cultured cancer cells, both primary and metastatic.
Interleukin 2
It has been shown that ____________, when exposed to Interleukin 2, are capable of lysing fresh, non-cultured cancer cells, both primary and metastatic.
lymphocytes
It has been shown that lymphocytes, when exposed to Interleukin 2, are capable of lysing __________________, both primary and metastatic.
fresh, non-cultured cancer cells
Humoral Component of the Natural Immunity?
• Cytokines (IL, IFN, TNF, G-CSF, GM-CSF)
• Complement pathway
• Lysozymes
• Anti-microbial substances
• Beta-lysin
50-70% of circulating WBCs, dominant, has 3-5 lobes, involved in phagocytosis, releases granules, increased if there is a bacterial infection, and capable of diapedesis
Neutrophils
Primary granules of neutrophils contain?
- myeloperoxidase
- elastase
- proteinase 3
- lysozyme
- cathepsin G
- defensins
Secondary granules of neutrophils contain?
- collagenase
- lysozyme
- lactoferrin
- plasminogen activators
- ALP
- NADPH
Tertiary granules of neutrophils contain?
gelatinase and plasminogen activator
Margination occurs to allow neutrophils to move from the circulating blood to the tissues through a process known as _________, or movement through blood vessel walls.
diapedesis
These are chemical messengers that cause cells to migrate in a particular direction.
Chemotaxins
Another term for diapedesis?
Leukocyte extravasation
1-3% of circulating WBCs, increases in allergic reactions and parasitic diseases, reddish-orange granules, resembles ear muffs
Eosinophils
Primary granules of eosinophils contain?
- ACP
- arylsulfatase
Secondary granules of eosinophils contain?
- Major Basic Protein
- eosinophil cationic protein
- eosinophil peroxidase
- eosinophil-derived neurotoxin
- phospholipase
- histaminase
- minopeptidase
- ribonuclease
It is an immune mechanism through which Fc receptor-bearing effector cells can recognize and kill antibody-coated target cells expressing tumor- or pathogen-derived antigens on their surface.
antibody-dependent cellular cytotoxicity/antibody-dependent cell-mediated cytotoxicity (ADCC)
less than 1% of circulating WBCs, bluish-purple granules, regulates some T cells, stimulates B cells to produce IgE antibody, has a shorter lifespan of only a few hours, involved in immediate hypersensitivity reactions
Basophils
Bluish-purple granules of basophils contain?
- histamine
- eosinophil chemotactic factor of anaphylaxis
- heparin
When basophils are destroyed, who collects them and where?
by macrophages at the spleen
In eosinophils, what secondary granule is primarily involved in fighting parasitic infections?
major basic protein
When IgE atatches to the eosinophil, what secondary granule is released?
eosinophil cationic protein
These cells can be found on connective tissues and are larger and have a longer lifespan than basophils. Their nucleus is small and rounded.
Mast Cells
Life span of mast cells?
9-18 months
Granules of mast cells contain?
ACP, ALP, and protease
largest WBC, constitutes 4-10% of circulating WBCs, possess grayish-blue cytoplasm and is ground-glass in appearance, has a kidney bean shape/horseshoe shape appearance
Monocytes
Granules of monocytes contain?
peroxidase, ACP, arylsulfatase
Other type of granule of monocytes contains?
B-glucuronidase, lysozyme, and lipase
Lifespan of monocytes in the bloodstream?
70 hours
Larger version of monocytes on tissues.
Macrophages
In macrophages, there is increase in the number of?
ER, lysosomes, and mitochondria
Granules of macrophages contain ___________ at all compared with monocytes.
no peroxidase
Monocyte-macrophage system functions in?
microbial killing, tumoricidal activity, killing of intracellular parasites, phagocytosis, secretion of cell mediators, and antigen presentation
Function is to phagocytosed antigen and present it to T-helper cells.
Dendritic Cells
Most effective antigen-presenting and potent phagocytic cell in the tissues.
Dendritic Cells
The bone marrow have _________ that give rise to dendritic cells.
progenitors
Macrophages in the brain are called?
microglial cells
Macrophages in the liver are called?
Kupffer cells
Macrophages in the lungs are called?
alveolar macrophages
Macrophages in the bone are called?
osteoclasts
Macrophages in the connective tissue are called?
histiocytes
Protein discovered in the fruit fly “Drosophila”
PRR (Toll-like Receptors)
PRR (Toll-like Receptors) is a protein discovered in the fruit fly?
Drosophila
It plays an important role in antifungal immunity in the adult fly.
PRR (Toll-like Receptors)
An invariant recognition mechanism that detects specific and unique molecular patterns associated with pathogens and inflammation.
PRR (Toll-like Receptors)
they hydrolyze adenosine triphosphate and signals transduction
NBS-LRR Proteins (Nucleotide-Binding Site and Leucine Rich Repeat)
TLR 1 recognizes protein in?
mycobacteria
TLR 2 binds to?
peptidoglycan in gram positive bacteria
TLR 4 binds to?
lipopolysaccharide in gram negative bacteria
Engulfment of cells and particulate matter by leukocyte, macrophage and other cells.
Phagocytosis
A process wherein cells are attracted to the site of inflammation by chemical substances.
Chemotaxis
Type of chemotaxis: Towards the stimulus
Positive chemotaxis
Type of chemotaxis: Away from the stimulus
Negative chemotaxis
Examples of negative chemotaxis?
C5a, C5b, C6, C7
Coating of antibody and/or complement to facilitate phagocytosis.
Opsonization
Examples of Opsonins?
C3b, C4b, C5b, fibronectin, leukotrienes, immunoglobulins
Steps in Phagocytosis?
- Adhesion - Physical contact between the WBC and the foreign particle
- Formation of phagosome
- Fusion with cytoplasmic granule to form phagolysosome
- Digestion and release of debris to the outside (exocytosis)
Types of Phagocytosis?
- Direct
- Indirect
Type of phagocytosis via opsonin receptors that recognize opsonins such as IgG, CRP and C3b bound to microorganisms.
Indirect
Type of phagocytosis via Pattern Recognition Receptors that recognize lipid and carbohydrate sequences on microorganisms.
Direct
Pathways of Killing Pathogens by Phagocytes?
Oxygen Dependent and Oxygen Independent
occurs when the cytoplasmic pseudopods enclose the particle within a vacuole
Respiratory Burst
Respiratory Burst is involved in?
Oxygen Dependent Pathway
Oxygen Dependent Pathway includes the use of what pathway?
Hexose monophosphate shunt
Production of nitric oxide from oxidation of L-arginine by NO synthase which is produced by IFN-gamma activated cells.
Oxygen Independent Pathway
Oxidation of ________ by ________ produces nitric oxide.
L-arginine by NO synthase
NO synthase is produced by?
IFN-gamma activated cells
is induced when the phagocytic cell comes in contact with a microorganism
Nitric oxide synthetase
is a soluble, highly labile, free radical gas that is capable of operating against organisms that invade the cytosol
Nitric oxide
In the presence of other reactive oxygen species within the phagosome, nitric oxide is converted to ___________ and other products, which are highly toxic to bacteria, yeast and viruses.
peroxynitrite
It donates electrons to oxygen.
NADPH
product of NADP which is super toxic and converts to more lethal substances
superoxide
It is the conversion of superoxide to hydrogen peroxide.
superoxide dismutase
It is an important bactericidal agent contained in lysosomes.
hydrogen peroxide
a green heme-containing peroxidase expressed mainly in neutrophils and to a lesser degree in monocytes
myeloperoxidase
The overall reaction of the body to injury or invasion by an infectious agent.
Inflammation
Both ___________________ are involved in inflammation.
cellular and humoral mechanism
Tissue damage causes the release of _____ and _____ factors that trigger a local increase in _____ and _____.
vasoactive and chemotactic factors; blood flow and capillary permeability
________ allow the influx of fluids and cells.
Permeable capillaries
________ migrate to the site of the inflammation.
Phagocytes
_____ and _____ destroy pathogen.
phagocytes and anti-bacterial exudates
5 cardinal signs of inflammation?
- rubor/redness
- calor/heat
- tumour/swelling
- dolor/pain
- functio laesa/loss of function
Acute phase reactants are produced primarily by ______ within ______?
hepatocytes within 12-24 hours
Acute phase reactants are produced primarily by hepatocytes within 12-24 hours in response to an increase in certain intracellular signaling polypeptides called _____.
cytokines
2 major types of acute phase reactants?
C-reactive protein (CRP) and Serum Amyloid A
Were originally named because they literally interfere with viral replication process in an infected cell.
Interferon (IFN)
Types of interferon?
Type 1 and Type 2 IFN
Type 1 IFN is also known as?
non-immune IFN
Why is type 1 IFN called non-immune IFN?
because they are produced primarily during the initial innate response to viral infection
IFN-α is primarily produced by?
Mononuclear Phagocytes by NK
IFN-β is primarily produced by?
Fibroblast
Type 2 IFN is also known as?
Immune IFN/gamma interferon
Why is type 2 IFN called immune IFN?
because it is primarily produced as a component of the specific immune response to viral and other pathogens
What type of T-helper cells produce Type 2 IFN?
T-helper type 1 cells
What type of T-helper cells produce IL-4, 5, and 10?
T-helper type 2 cells
Major mediator of the innate defense against gram negative bactreria.
TNF/Tumor Necrosis Factor
TNF can also directly trigger _______ of some tumor cells through a receptor-mediated mechanism.
apoptotic death
TNF is a pro-inflammatory agent together with?
IL-1, IL-6, IL-8
TNF induce secretion of?
APRs
TNF-α is also known as?
cachectin
TNF-α is produced by?
macrophages
TNF-β is also known as?
lymphotoxin
TNF-β is produced by?
CD4+ and CD8+ cells
____________ is a complex series of more than 30 soluble and cell-bound proteins that interact in a very specific way to enhance host defense mechanisms against foreign cells.
Complement
Complement Pathway is a heat-_____ substance.
Heat-labile substance
A termed “Complement” was given by?
Paul Ehrlich (1980’s)
In 1919, _______ was awarded a Noble Prize for elucidating the nature of complement.
Jules Bordet
Complement activation promotes?
- Activation of the immune system
- Opsonization (C3b, C4b, C5b)
- Eventually result in lysis of foreign cells and immune complexes
Chronic Activation of Complement leads to?
inflammation and tissue damage
Most plasma complement proteins are synthesized in the?
Liver
Complement proteins are released in inactive precursors called?
zymogens
The complement system can be activated in three different
ways?
- Classical Pathway: Pillemer and colleagues discovered an antibody-independent pathway in the 1950s, and this plays a major role as a natural defense system
- Alternative Pathway: “Properdin system”
- Lectin Pathway: Its major constituent, mannose- (or mannan-) binding lectin (MBL)
Cellular components of Adaptive Immunity?
T cells and B cells
Humoral components of Adaptive Immunity?
lymphokines and antibodies
2 types of adaptive immunity?
Active and Passive
2 subtypes of Active Adaptive Immunity?
- Natural Active
- Artificial Active
2 subtypes of Passive Adaptive Immunity?
- Natural Passive
- Artificial Passive
What type of adaptive immunity: Your body produces its own antibodies.
Naturally-Acquired Active
What type of adaptive immunity: attenuated vaccines.
Artificially-Acquired Active
Example of attenuated vaccines?
BCG or bacillus Calmette-Guerin for tuberculosis (TB) disease
Since attenuated vaccines are not recommended for the immunocompromised and elderly, what type of vaccine is suitable for them?
Inactivated dead viral vaccines
Examples of inactivated dead viral vaccines?
Cholera and Typhoid Vaccine
Specific examples of typhoid vaccine?
- Tetanus Toxoid - Tetanospamin - C. tetani
- Diptheria Toxoid - Diptheria toxin - C. diptheriae
- Botulinum Toxoid - Botulin - C. botulinum
What type of adaptive immunity: placental transfer of IgG from pregnant mom to fetus and nursing moms feeding breast milk with colostrum containing IgA and IgG.
Naturally-Acquired Passive
What type of adaptive immunity: administration of immunoglobulins such as anti-rabies.
Artificially-Acquired Passive
Hallmark features of innate immunity?
- Mechanisms involved are non-specific
- Mechanisms that pre-exist the invasion of foreign agents.
- Components are pre-formed.
- They are non-adaptive, have a standardized magnitude of response.
- Lacks immunologic memory.
Hallmark features of adaptive immunity?
- Reinforcement
- Inducibility
- Specificity
- Diversity
- Memory
- Specialization
- Self-Limitation
- Discrimination