Module 1 Flashcards
Introduction to the Immune System
Describe the human microbiome
- 10^14 microorganisms (10x more than human cells)
- Contains microorganisms principally harmless or beneficial to our health and proper functioning of our bodies and a smaller proportion of types that can cause a disease state
What are pathogenic microorganisms?
Microorganisms that can cause a disease state
What are Commensal microorganisms
Microorganisms that are beneficial to our health
What are the 2 major components of the immune system?
Innate Immune System
Adaptive Immune system
What is the immune response?
Reaction of immune cells to the presence and actions of microbes of danger signals in the body
What are 2 normal functions of the immune system?
Discriminate (recognize self from non-self)
Eliminate (Destroy non-self eg: pathogen and altered self cells eg: cancer)
What are 2 dysfunctions that make the immune system overly active?
Autoimmunity
Hypersensitivity
What is dysfunction that make the immune system underactive?
Immunodeficiency (eg AIDS)
What is an antigen?
Foreign protein that induces an immune response, typically including the production of antibodies.
Contraction of the words ANTIbody GENerator
What is an antibody
Protein that is produced in response to, and countering, a specific antigen
What is the relation between antigen and antibody
Antibodies bind to foreign substances (antigens) in the body and provide a signal for their elimination
What is the most important property in order for these defence mechanisms to work properly and protect us?
magic word is BALANCE
Each component must be functional to avoid immunodeficiencies
BUT also regulated so that it does not become overly active and attack self
What are the 3 body systems that create an efficient filtering system for the body?
circulatory, lymphatic, and immune systems
What are lymphoid organs?
Organs shared in both the immune and lymphatic system
What is the lymphatic system?
Network of vessels that drains fluid (Lymph) that filtrated from the blood in the capillaries and entered the surround tissues, also called interstitial space
Prison break analogy: Lymphatic system?
Corridors of a prison, where guards circulate to make sure that everything is in order
What is the relationship between the lymphatic system and circulatory system?
Circulatory system is where the lymph comes from and goes after being filtered
Lymphatic vessels pick up the lymph and carry it toward the heart where it re-enters the circulatory system
What is the relationship between the immune system and the lymphatic + circulatory systems? (3)
1- Cells of the immune system travel between the circulatory system and the lymphatic system
2- Some immune cells reside in the tissues and can directly interact with an antigen
3- Other mature immune cells travel within the blood to the site of infection
What are the major lymphoid organs and tissues? (5)
1- Bone marrow 2- Lymph nodes 3- MALT 4- Spleen 5- Thymus
Describe the structure, location and function of the bone marrow
Structure:
- flexible, 2 types (yellow and red), filled with hematopoietic cells
Location:
- central cavity inside the bones
Function
- Red : important for immune system, site of hematopoiesis, site of B cell development
- Yellow: Some leukocyte development, produces fat and cartilatge
What are hematopoietic cells?
Cells lodged within the bone marrow and which are responsible for producing the cells which circulate in the blood (RBC, WBC and platelets)
Prison break analogy: Bone marrow
The police academy for prison guards
Describe the structure, location and function of the Lymph Nodes
Structure:
- Small (1-25mm) numerous (600 approx) bean shaped
- Divided into 3 roughly concentric regions (cortex, paracortex, medulla)
- Filled with lymphocytes, macrophages, and dendritic cells
Location:
- Grouped along the lymphatic vessels
Functions:
- Filters the lymph
- Often it is the first organized lymphoid structure that foreign molecules encounter when first entering the body
Prison Break analogy: Lymph Nodes
Locked doors within a prison that prisoners have to get permission from guards in order to pass through
What are lymphocytes?
White blood cells which arise from the lymphoid progenitor lineage during hematopoiesis. Generally refers to B- and T-cells
Describe the structure, location and function of the MALT
Structure
- Combined surface area of various areas in the body including BALT, GALT, Lamina propria of intestinal villi, Peyer’s patches, Tonsils, appendix
- Filled with various types of immune cells depending on the location
Location:
- Mucous membranes lining the digestive, respiratory, and urogenital systems
Function:
- Initiates immune responses to specific antigens encountered along all mucosal surfaces
What is the MALT?
Mucosal Associated Lymphoid Tissues
What is the BALT
Bronchus-associated lymphoid tissue; lymphoid structure part of the MALT located in lungs and bronchus
What is the GALT?
Gut-Associated lymphoid tissue; lymphoid structure part of the MALT located in the gut
What is the Lamina propria of intestinal villi?
Thin layer of connective tissue rich in immune cells located into the lumen of the small intestine
What is Peyer’s patches?
Small masses of lymphatic tissue found throughout the ileum region of the small intestine
What are the tonsils?
Collection of lymphoid tissue facing the aerodigestive tract, mainly located into the pharynx
What is the appendix
A small, pouch-like sac of tissues located in the first part of the colon (cecum) in the lower-right abdomen. Harbours bacteria and aids in immune function. Recent research suggests that it plays a larger role in estabilishing the core gut microbiome than previously thought
Prison Break analogy: MALT
Watchtowers, where guards control the weaker spots of passage between the prison walls and the outside
Describe the structure, location and function of the Spleen
Structure:
- Large ovoid divided in 2 compartments; white pulp and red pulp
Location:
- Situated in the left abdominal cavity
Function:
- Red pulp filters the blood
- White pulp is the site of development of immune responses against antigens found in the bloodstream
Prison Break analogy: Spleen
Locked door that a prisoner has to get access from the guards in order to pass through to get to the courtyard inside the prison walls
Compare and contrast Red pulp and White pulp in the spleen
White pulp: filled with macrophages, lymphocytes, T-cells, B-cells, and RBCs
Red pulp: composed of cords of billroth and splenic sinuses that are filled with blood
What are cords of Billroth?
Fibrils and connective tissue cells with a large population of monocytes and macrophages located in the the Red Pulp of the spleen
Which spleen compartment is more important to the immune system (red or white)
White, because it is made of lymphatic tissue filled with immune cells
Describe the structure, location and function of the Thymus
Structure:
- Flat and bi-lobed (each lobes are divided into lovules which are organized each in 2 compartments, cortex and medulla)
- Filled with thymocytes, epithelial cells, dendritic cells, and macrophages
Location:
- Situated above the heart
Funtion:
- Site of T-cell development and maturation
What are thymocytes?
T-cells found in the thymus
Prison Break analogy: Thymus
Police academy for officers who becomes member of the S.W.A.T. team or detectives
What are the 2 classifications of Lymphoid organs and tissues
Primary and Secondary, according to their function in the immune system
What are the Primary Lymphoid Organs? (2)
- Thymus
- Bone Marrow
What is the function of the Primary Lymphoid Organs?
Site of lymphocyte maturation into and immunocompetent cell
- B-cell -> Bone marrow
- T-cell -> Thymus
What is an immunocompetent cell?
Denoting a mature lymphocyte that is capable of recognizing a specific antigen and mediating an immune response
What are the Secondary Lymphoid Organs? (3)
- Spleen
- Lymph Nodes
- MALT
What is the function of Secondary Lymphoid Organs?
Site of lymphocyte activation into an effector cell
- through interaction with trapped antigens
What is an effector cell?
Denoting a mature lymphocyte that has been activated and mediates an immune response against a specific antigen
What is discrimination?
Ability of immune cells to distinguish between self and non-self components
How is discrimination achieved?
Almost every nucleated cell in the body expresses a molecule at their surface called Major Histocompatibility Complex class I (MHC I), which presents a “sample” of proteins found inside the cell. Another class, MHC II are present on special cells of the immune system. Immune cells are able to scan their area and recognize if there are abnormalities or antigens. If abnormalities and antigens found (non-self), an immune response can be initiated
What is elimination
Ability of immune cells to initiate an immune response
What are the 4 steps of the immune system response
1- Pathogen (antigen) enters the body
2- Immune system recognizes the antigen
3- Activation of effector cell (innate and adaptive response)
4- Elimination of pathogen
What is the MAJOR function of the immune system?
Preserve and protect the integrity of the body from environmental agents such as microbes, chemicals, or in some instances, abnormal self antigens
What is the innate immune system?
Consists of physical, soluble and cellular barriers that are scattered throughout the body to prevent the entry of any infectious agent and respond non-specifically
What is the adaptive immune system?
Consists of cells and soluble components capable of recognizing and responsding to specific pathogens
What are the 2 subdivision of the adaptive immune system?
- Humoral Immunity (B-Cell)
- Cell-Mediated Immunity (T-Cell)
What are the 2 components of Innate immunity?
- First line of defence against foreign agents
- Physical, soluble and cellular barriers
What are the 2 functions of Innate Immunity
- Immediate recognition and response to invading pathogens, response within minutes or hours
- Recognizes general patterns not specific for any one antigen; limits the type of immune response initiated
What are the 2 components of adaptive immunity?
- Humoral Immunity (mediated by B-cells)
- Cell-mediated immunity (mediated by T-cells)
What are the 3 functions of adaptive immunity?
- Longer time required to initiate a response to invading pathogens - within days
- capable of recognizing and respond to specific antigens - its large diversity gives much wider range of responses that can be initiated
- Results in immunological memory - allows for a quick response upon a second infection with the same pathogen
What is the most ancient immune structure found in the evolution?
Amebocyte = a mobile cell (moving like an amoeba) in the body of invertebrates. They move by pseuopodia
What kind of cells found in the human immune system today did the amebocyte give rise to?
Phagocyte
Which branch of the immune system do phagocytes play a major role in?
Innate Immunity
What is the principle of parsimony?
The explanation requiring the fewest assumptions is most likely to be correct (…) with all thing being equal, the simplest explanation tends to be the right one – William of Ockham
In which kind of living organisms is the innate immune system found and what is the preferred model organism?
- Invertebrates, vertebrates and even plants
- Fruit fly
In which kind of living organisms is the adaptive immune system found?
- Only in subphylum vertebrata (all animals with a backbone)
- More complex organisms in this subphylum eg: B-cells and T-cells are only found in jawed vertebrates and not in jawless fish
What are pluripotent cells?
Cells capable of giving rise to several different cell types
eg: hematopoietic stem cells (HSC)
What kind of cells do EVERY immune cells originate from?
Pluripotent hematopoietic stem cells (HSC)
What is the process that gives rise to all immune cells called?
hematopoiesis
What are the 2 lineages of hematopoiesis?
Myeloid and Lymphoid
Describe the development of B-cells
They originate from hematopoietic cells in the bone marrow where they will become lymphoid progenitor and then B-cells
They then differentiate into Plasmocyte (effector B-cell) or memory B-cell
Describe the development of T-cells
They originate from hematopoietic cells in the bone marrow where they will become lymphoid progenitor.
Then they travel to the thymus where they will develop into T-cells.
They will then differentiate into helper T-cells, Memory T-cells or Cytotoxic T-cells
Myeloid progenitor cells have the ability to differentiate into four different groups of myeloid cells, what are they?
(1) Granulocyte
(2) Monocyte (macrophage)
(3) Erythrocyte (RBC)
(4) Thrombocyte (Platelet)
The myeloid progenitor cells generate the majority of cells for which branch of the immune system?
innate immune system
What are the 4 types of granulocytes
(1) Neutrophil
(2) Eosinophil
(3) Basophil
(4) Mast cell
Prison break analogy: Myeloid progenitors?
Students who started their training to become prison guards on the floor
Lymphoid progenitor cells have the ability to differentiate into different groups of lymphoid cells, what are they?
B-cell - Plasmocyte (effector B-cell) - Memory B-cell T-cell - Helper T-cell - Cytotoxic T-cell - Memory T-cells
Lymphoid progenitor cells have the ability to differentiate into the major type of cells of which branch of the immune system?
adaptive
Lymphoid progenitor have the ability to differentiate into which important cells of innate immunity?
Natural Killer cells
Prison break analogy: Lymphoid progenitor
Students who have started their specialized training to become security guards who controls the weapons room, to become a SWAT team member or to become the prison warden within the prison walls
Which 6 types of cells belong to the innate immune system?
Neutrophil, eosinophil, basophil, monocyte, natural killer cell, mast cell
Which 2 types of cells belong to both the innate immune system and the adaptive immune system?
Macrophage
dendritic cell
Which 5 types of cells belong to the adaptive immune system?
Memory B-cell Plasmocyte (effector B-cell) Helper T-cell Cytotoxic T-cell Memory T-cell
What are the functions of platelets?
Central contributor to the process of coagulation, wound healing and fibronolysis
Participate in;
- Intervention against microbial threats
- recruitment and promotion of innate effector cell functions
- modulating antigen presentation
- enhancement of adaptive immune responses
Compare and contrast Monocyte and macrophages
Monocytes and macrophages are both phagocytes. Monocytes are located in the blood while macrophages are located in the tissue.
Monocyte are able to travel outside of the blood by moving across the blood vessel walls. When they d, they become macrophages and undergo the following changes;
- Cell gets bigger
- Increase of the number and complexity of intracellular structures (pseudopodia, phagosome, lysosome)
- Acquire better phagocytic abilities
Prison break analogy: macrophages
Experienced prison guards working on the floor, doing rounds around the prison walls. Their job is to locate and catch prisoners trying to escape
Why are macrophages called the big eaters?
they are the most efficient phagocytes of the innate immune system
What are Mast cells and what are their functions
Located in the tissues and also called granulocytes, Mast cells have large granules containing histamine and other pharmacologically active substances
Play a role in the development of allergies
Prison break analogy: mast cells
Prison guards working on the floor who stay at their post and watch the doors between indoor corridors
Describe neutrophils and their role in immunity
Most abundant type of leukocyte in the human body and possess both granulocytes (polymorphic nucleus and granules containing lytic enzymes which aids in elimination of infectious agents) and phagocytes (ability to engulf and absorb bacteria) characteristics
They are the first to arrive at the site of inflammation
Lifespan of a few days
Prison break analogy: Neutrophils
Prison guards that watch over the access doors between the prison building and the inne courtyard within the prison walls. they have the fastest access if anything happens
What is pus made of?
Yellowish opaque liquid is composed mostly of dead neutrophils, their sticky DNA forms kind of a net that catches bacteria and cell debris
Describe basophils and their role in immunity
non-phagocytic granulocytes
- They have the largest ganules
- They are the least common type of granulocyte
- Function similar to that of mast cells and still under investigation, but play a role in development of allergies
- name comes from the fact that you can stain them with basic dye
Prison break analogy: basophils
Prison guards on the ground staying at their post
Describe eosinophils and their role in immunity
Phagocytic granulocytes
- Fucntion is still under investigation, but they play a role in the defence against multicellular parasites like helminths
- Name comes from susceptibility of staining by acidic red-colour dye called eosine
Prison break analogy: eosinophils
Prison guards on the groung staying at their post
Describe Natural Killer Cells and their role in immunity
Granular lymphocytes
- Also called NK cells
- Granules contain perforin and granzymes
- Recognize tumours or virus-infected cells despite lacking antigen-specific receptors
- distinguish abnormal cells and destroy them
- Exception in lymphoid lineage as they operate under the innate immunity
Prison break analogy: Natural Killer Cells
Internal affair inspectors that control the integrity of the prison staff
Describe T cells’ characteristics, (specificity, diversity and subsets)
T-cells are key players of the cell-mediated immunity in the adaptive immunity. They are non phagocytic cells that have specific receptors at their cell surface T-cell receptors (TCR)
- One T-cell expresses many TCR that recognize the same specific antigen or epitope
- Every T-cell in the body recognizes a different antigen through their TCR specificity
- Helper T-cell (CD4) & Cytotoxic T-cell (CD8)
Describe Helper T-cell
- they express the CD4 co-stimulatory molecule on their cell surface
- Become activated when they recognize an antigen-MHC class II complex
- When activated;
(a) effector cell, activation of other cells such as B-cells and cytotoxic T-cells
(b) generate memory cells that recognize the same specific antigen
Prison break analogy: Helper T-cells
Highly ranked personnel within the prison walls who are responsible for calling for backup if the situation gets out of control. They are the crisis management team
Prison break analogy: Memory Helper T-cells
Very experienced highly ranked personnel that have already been through many crisis situations. They think and react much faster than the new employees
Describe Cytotoxic T-cells
Specialized T-cells that express the CD8 co-stimulatory molecule
- become activated when they recognize an antigen-MHC class I complex
- Once activated
(a) effector cell: key role in monitoring the cells of the body and eliminating any cells that display foreign antigen complexed with MHC class I (tumor cells, virus infected)
(b) Generate memory cells that recognize the same specific antigen
Prison break analogy: cytotoxic T-cells
SWAT team. Their role is to catch the escaped prisoner and bring them back to where they are supposed to be
Prison break analogy: memory cytotoxic T-cells
Very experienced SWAT team members that have already been through many crisis situation.
Describe B-cells
Key players of the humoral immunity, a subset of adaptive immunity
They are non phagocytic cells that have specific receptors at their cell surface called B-cell receptor (BCR)
- Specificity: one B-cell expresses many BCR that recognize the same specific antigen or epitope
- Diversity: every B-cell in the body recognizes a differen antigen through their BCR specificity
What’s an epitope?
Part of an antigen that is recognized by the immune system, specifically by antibodies, B-cells or T-cells
Describe Plasmocytes
Plasmocytes are activated B-cells
- Produce and secrete highly specialized antibodies, which have the ability to bind free pathogens or foreign molecules in the organism
- Activation of B cells can generate memory B-cells, which have membrane-bound antibodies that have the same specificity as the mother cell
Prison break analogy: Plasmocytes
Weapon room control team. They have access to all the weapons if necessary and they can distribute them to get back the control of the situation (antibodies are the weapons)
Prison break analogy: memory B-cells
Very experienced weapon distributor. They can recall from experience which type of weapon is more efficient against each prisoner, if they’ve ever tried to escape
Name the 8 major milestones in immunology of the past 2 centuries
(1) First Vaccine, first virus eradicated
(2) Pasteurization and vaccines
(3) Complement System
(4) Inflammation
(5) Hypersensitivity/anaphylaxis
(6) Antibody structure
(7) Somatic recombination
(8) Toll-like receptors
Describe the advent of the first vaccine which led to the first virus eradicated(who, what, where, why, how)
1796
Small Pox vaccine, first virus eradicated by human intervention (1979)
Edward Jenner
Noticed that cowpox can produce cross-immunity as milkmaids were generally immune to smallpox
Describe the advent of pasteurization (who, what, where, why, how)
Louis Pasteur demonstrated that pathogens were responsible for spoiling beverages (beer wine and milk). He introduced the concept of using heat to destroy pathogens which is now used everyday
Describe the development of vaccines (who, what, where, why, how)
Louis Pasteur’s first discovery in vaccine development was with a disease called chicken cholera, where he accidentally exposed chickens to an attenuated form of the virus and the chickens became immune to the disease. Pasteur then went on to discover the causes of and developed vaccines against other diseases including anthrax and rabies
Describe the discovery of the complement system (who, what, where, why, how)
Complement system is a tightly regulated network of proteins within the body that has an important role in the defence against pathogens and inflammatory response
Discovered in the 1890s
Many scientist were involved (Nuttall, Buchner, Bordetm Ehrlich)
-At least 30 glycoproteins macromolecules that make up the complement system, Present as soluble proteins in the blood or as membrane-associated proteins.
Describe the discovery of the cause of inflammation (who, what, where, why, how)
1908
Nobel Prize - Elie Metchnikoff and Paul Ehrlich
Metchnikoff: Developed the phagocytic theory. Hypothesized that the basis of inflammation and major defence mechanism against bacterial infection was a cellular reaction where cells are able to move or migrate in order to reach and internalize solid particles within intracellular vesicles
Ehrlich: Father of humoral immunity. Introduced the concept of transferring blood serum to treat and counteract diphtheria. Side- chain theory regarding the presence of bactericidal substances in blood, lead to our understanding of antibodies today
Describe the discovery of hypersensitivity and anaphylaxis (who, what, where, why, how)
1913
Nobel Prize - Charles Richet
Discovered anaphylaxis through studies involving dogs. After an initial low dose of a substance with no effect, a new dose for several weeks produced severe reaction in the dogs and even proved fatal for most
Describe the discovery of antibody structure (who, what, where, why, how)
1972
Nobel Prize - Gerald Edelman and Rodney Porter
Knowing this structure allows us to better understand how the immune system reacts during infection and how each part of the antibody carries out its task.
Describe the discovery of somatic recombination (who, what, where, why, how)
1987
Nobel Prize - Susumu Tonegawa
Determined the mechanism by which the immune system generates an almost limitless variety of antibodies. If humans hada complete genome sequence for every antibody we produce, the genome would be never ending.
Describe the discovery of toll-like receptors (who, what, where, why, how)
2011
Nobel Prize - Jules Hoffman and Bruce Beutler
Created a better understanding of the components of innate immunity and their complexity
- 1994 first identified but role still unknown
- 1996 Hoffman discovered that TLR in fly had a role in fungal infection immunity
- 1998 Beutler discovered that lipopolysaccharides are the ligand for TLR-4
What are the 6 major types of infection agents in the context of immunology?
(1) Bacteria
(2) Viruses
(3) Fungi
(4) Protozoa
(5) Helminths
(6) Prion Proteins
What are bacteria?
Unicellular, prokaryotic organisms that have no organized internal membranous structures. Genomes are circular, dsDNA .
Give an example of an illness caused by a bacteria, its symptoms, mode of transmission, diagnosis and treatment
Cholera (Vibrio Cholerae)
Symptoms: Profuse watery diarrhea, vomiting and leg cramps
Transmission: eating or drinking foods contaminated with the bacterium
Diagnosis: stool sample and rectal swab
Treatment: antibiotics and rehydration
What are viruses?
Viral genome that is surrounded by a protein coat (capsid) which rely on host cell for metabolism and reproduction
Give an example of an illness caused by a virus, its symptoms, mode of transmission, diagnosis and treatment
Influenza
Symptoms: Fever, cough, sore throat, nasal congestion, body aches, headaches
Trasmission: droplets of saliva from people snezing, coughing, talking
Diagnosis: Laboratory tests on respiratoy specimens
Treatment: bed rest or antiviral medication, can be prevented with flu vaccine
What are fungi?
Eukaryotic heterotrophic organisms that have rigid cellulose- or chitin-based cell walls and reproduce primarily by forming spores. These spores most commonly cause infection on the skin or in the lungs.
Fungi are divided into molds and years; molds are multicellular, while yeast is unicellular
More prone to fungal infection if immune system has been weakened or taking antibiotics
Give an example of an illness caused by a fungus, its symptoms, mode of transmission, diagnosis and treatment
Vaginal Yeast Infection (vulvovaginal candidiasis - VVC)
Symptoms: Genital itching (women) itchy rash on penis(men)
Transmission: Candida is always present in and on the body in small amounts but when an imbalance in the immune system occurs. Candida can multiply
Diagnosis: visual examination or confirmed via laboratory
Treatment: Antifungal cream , ointments, tablets, or suppository
What are protozoa?
Unicellular, heterotrophic eukaryotes and examples include the familiar amoedba and paramecium. They do not have cell walls, and thus capable of a variety of rapid and flexible movements
Give an example of an illness caused by a protozoa, its symptoms, mode of transmission, diagnosis and treatment
Malaria (plasmodium)
Symptoms: fever, chills, flu-like illness
Transmission: Infected mosquito bites a human
Diagnosis: Microscopic analysis of blood
treatment: preventative drugs are the most efficient
What are Helminths?
Parasitic worms which are simple invertebrates, some of which are infections parasites. They are multicellular and have differentiated tissues. They are animal and their physiology is similar in some ways to ours. This makes them difficult to treat because drugs that kill helminths are often toxic to human cells
Give an example of an illness caused by a helminth, its symptoms, mode of transmission, diagnosis and treatment
Schistosomiasis
adult worms produce eggs that travel to intestine, liver or bladder causing inflammation or scarring
Symptoms: most people show no symptoms in the early phase. Fever chills, lymphoid organs enlargement, abdominal pain, diarrhea are caused by the body,s reaction to the eggs, not by the worms.
Transmission: Found in some types of fresh water snails
Diagnosis: stool or urine sample. Blood sample too if you have signs of infection
Treatment: Short course of praziquantel which kills the worms
What are Prion Proteins?
Proteinaceous infectious=s particles, consist of only protein and are linked to degenrative disorders of the CNS.
Prion proteins are and function as normal proteins, but when misfolded they are classified as infection particles prions
Name 2 diseases that are caused by Prion Proteins
Bovine Spongiform Encephalopathy (mad cow disease)
Creutzfeldt-Jakob Disease (CJD)
Describe Bovine Spongiform Encephalopathy (BSE)
AKA Mad Cow Disease
- fatal neurodegenerative disease
Transmission: thought to have originated from food fed to cows that contained infected sheep products
Symptoms: nervousness, aggressive behaviours, difficulty with coordination, trouble standing up, decreased mil production, weight loss
Diagnosis: not prevalent anymore
What is the link between Bovine Spongiform Encephalopathy and humans?
Humans can become infected with prions by eating contaminated meat
Describe Creutzfeldt-Jakob Disease (CJD)
Most common human prion disease
Transmission: exposure to brain tissue or spinal fluid from an infected individual or inherited mutated prion protein gene (autosomal dominant)
Symptoms:
Early: loss of muscle coordination, impaired memory, and decision making, and visual disturbances.
Later: rapidly progressing dementia, involuntary muscles jerks, coma and death
Diagnosis: differential by ruling out other diseases
Treatment: focus on symptoms, incurable
