Unit 5-Immunology+Viruses Flashcards
Eosinophils
Eosinophils are a type of disease-fighting white blood cell. This condition most often indicates a parasitic infection, an allergic reaction or cancer.
Immune Response Design functions
• surveillance surveillance • recognition recognition • attack attack • destruction destruction • proportional response
Levels of Defense
First Second Third
First Line of Defense
Non-specific Barrier Defenses Body Excretions (Tears, Sweat)
Second line of defense
Non-Specific Inflammation Couplement (antimicrobial proteins) Phagocytosis
Third Line of defense
Specific And adaptive Antibodies (antimicrobial proteins) Cytotoxic Cells
Levels of defense Timing
Primary (first encounter) Secondary (subsequent encounters)
Non-Specific Host Defenses
Intact Skin (Stratum Corneum) Mucous membranes Responses (Typically involve secretions)
Mechanical Host Defense responses
Mechanical • tears • saliva • ciliary action • vomiting • urination • coughing • sneezing
Chemical Host Defense Responses
lysozyme • sweat/oils • dermcidin • hydrochloric acid
Lysozyme
an enzyme that catalyzes the destruction of the cell walls of certain bacteria, occurring notably in tears and egg white
Dermcidin
an antimicrobial peptide secreted by sweat glands that attacks any bacteria on our skin
Inflammation
Increased blood flow to the affected area (arterioles constrict) Edema Phagocytosis by immune response cells Fever Completment activated Chemical signaling
Phagocytosis
the ingestion of bacteria or other material by phagocytes and amoeboid protozoans.
Pyrogens
a substance, typically produced by a bacterium, that produces fever when introduced or released into the blood.
Pluripotent stem cells can turn into what type of cells?
Erythrocytes Leukocytes Platelets
Components of blood
Platelets Erythrocytes Leukocytes Plasma
Two types of Leukocytes
Granular (Lobed Nucleus) Agranular (Round Nucleus)
Granular Leukocytes can turn into what type of cells?
Basophils Neutrophils Eosinophils
Basophils
Few in #, secrete Histamine, triggering inflammation
Neutrophils
A Majority in #, short-lived (A few days), found mostly in tissues and function in phagocytosis
Eosinophils
Few in #, directed against large, multicellular parasites; function in inflammation
Agranular Leukocytes can turn into what kind of cells?
Monocytes Lymphocytes
Monocytes
Third most common in number, function in phagocytosis
Lymphocytes
Second most common, secrete antibodies and destroy infected cells.
Monocytes can turn into what type of cells?
Macrophages
Macrophage
a large phagocytic cell found in stationary form in the tissues or as a mobile white blood cell, especially at sites of infection.
Lymphocytes turn into what type of cells?
B-Cell T-Cell
Antigen
a toxin or other foreign substance that induces an immune response in the body, especially the production of antibodies.
What cells are antigen-presenting cells
Macrophages
Humoral response
involves B cells that recognize antigens or pathogens that are circulating in the lymph or blood
Cell-Mediated Response
an immune response that does not involve antibodies, but rather involves the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen
What type of cells generate Plasma Cells?
B-Lymphocytes
what type of cells generate Cytotoxic T-Cells?
T-Lymphocytes
What type of cells generate Antibodies?
Plasma Cells
Function of Antibodies in the Immune Repsonse Cascade
Signals phagocytic cells and activates complement (Extracellularly located pathogens)
Function of Cytotoxic T-Cells
Destroy the body’s own infected cells (Intracellularly located pathogen)
secondary immune response in the cascade
Antigen causes memory B or T Cell activation, generating Plasma or Cytotoxic T-cells.
Antigen recognition and Clonal Selection
Using genetic recombination, the body produces many different cell-surface proteins capable of recognizing many different antigens
when an antigen appears, it will bind to its B or T Cell w/ the matching receptor. Then what happens?
The cell will be induced to divide to create additional copies of the cell.
Antibodies
glycoproteins (Combinations of Amino Acid Chains and sugars) that can be found in the blood serum (Soluble Antibodies) or attached to the surface of certain cells such as B-Lymphocytes
Antibody Structure
four separate polypeptide chains held together by disulfide bridges. Two are longer/larger (Heavy chains) and are identical to one another. And 2 light chains (Smaller) w their own variable and constant regions
Antibody Domain structure
Variable domain constant domain Hinge Constant Domain 2 Constant Domain 3
Paratope
Antigen-Binding Site
Binding of an antigen occurs
On the Epitope (on the antigen) and the Paratope (On the Antibody)
What are the 5 types of Antibodies
IgG IgD IgA IgM IgE
IgG
Single Monomer Triggers/activates complement proteins May enter tissue fluids can cross the placenta to protect the fetus
What is the most abundant class of Antibody?
IgG (80%)
IgA comprises what % of antibodies
10-15%
IgA structure
Dimeric (2 Y-shaped w the usual 2 heavy and light chains)
IgA
Found in Body secretions (Saliva, tears, perspiration, breast milk) Bind to pathogen/antigen to prevent adhesion to body surfaces
IgD
Single Monomer Located on the cells of B-Lymphocytes Function as Antigen receptors May bind to basophils/mast cells stimulating inflammation
IgE
Single Monomer Can interact w Basophils (In bloodstream) and mast cells (In connective tissue) to release histamine and other chemical signals Generates an inflammatory response
IgM
First to appear in the infection process 10-15% of antibodies 5 Y-Structures joined around a common center (Pentameric) Functions in agglutination and complement function
Zymogen
an inactive substance that is converted into an enzyme when activated by another enzyme
Proper immune system functioning depends on
Proportional responses to the offending agents
Immunodeficiency can lead to
Cancers
Autoimmunity can lead to
Hypersensitivities (Lupus, RA, Psoriasis)
Autoimmunity
the system of immune responses of an organism against its own healthy cells and tissues. Any disease that results from such an aberrant immune response is termed an “autoimmune disease”.
Passive Immunity
the short-term immunity that results from the introduction of antibodies from another person or animal.
Active Immunity
the immunity that results from the production of antibodies by the immune system in response to the presence of an antigen
Natural (Innate) Immunity
the inborn ability of the body to protect itself against pathogens and is transferred from mother to the baby.
Artificial Immunity
can be induced by a vaccine, a substance that contains antigen. A vaccine stimulates a primary response against the antigen without causing symptoms of the disease.
The Antibiotic Discovery Void began when?
around 1990
Staphylococcus Characteristics
Gram (+) Cocci No flagellae No endospores Capsules Facultative Anaerobe Common in the environment (Soil Microbe), Harbored by humans intermittently Resistant to many physical extremes
Facultative Anaerobe
an organism that makes ATP by aerobic respiration if oxygen is present, but is capable of switching to fermentation or anaerobic respiration if oxygen is absent
Obligate Anaerobe
poisoned by oxygen, so they gather at the bottom of the tube where the oxygen concentration is lowest
What types of Exotoxins to Staphylococcus produce?
Coagulase Hyaluronidase Hemolysins Leukocidins enterotoxins Exfoliative Toxins
How does Staphylococcus usually enter the body
Typically through hair follicles or wounds (cutaneous)
Some strains of Staphylococcus aureus may be resistant
MRSA (Multiple Resistant Staphylococcus Aureus) or Penicillinase resistance
MRSA is resistant to what drugs?
Methicillin Oxacillin Penicillin Amoxicillin
Staphylococcus infections typically produce what skin lesions?
Furuncles and Carbuncles
Systemic Staphylococcus infections typically result in
Bacteremia or Sepsis
Systemic infections from staphylococcus can spread and cause
Osteomyelitis Meningitis Pneumonia
Staphylococcus is cultured on what type of Agar?
SBA (Sheep’s Blood Agar) or MSA (Mannitol Salt Agar)
Common Staphylococcus Species
S. Aureus S. Capitis S. Epidermidis S. Hominis S. Saprophyticus
Staphylococcal skin lesions
Carbuncle/Furuncle Imetigo Styes Scalded Skin Syndrome
Staphylococcal Food poisoning
usually caused by contaminated milks and cheeses Salt Tolerant Heat Resistant Sliced Meat, Pudding, pastries, sandwiches
Symptoms of Staphylococcal Food Poisoning?
nausea, vomiting, stomach cramps, diarrhea
Streptococcus characterisics
Gram (+) Cocci No Flagellae No Endospores May posess capsule+ Slime Layers Facultative Anaerobe
True or False: Streptococci are hearty bacteria which are not very sensitive to the environment?
False: They are susceptible to environmental factors 9Drying, heat, disinfectants)
What is an important part of classification of Streptococcal bacteria?
Hemolysis (Alpha, Beta, Gamma)
Alpha hemolysis
Partial Degredation of RBCs
Beta Hemolysis
Complete degredation/rupture of RBCs
Gamma Hemolysis
No Degredation of RBCs
Streptolysins
SL-O and SL-S Damage cells other than RBCs
Common Streptococcal species
S. Agalactiae S. Faecalis S. Pneumoniae