Innate Immunity COPY Flashcards
What is the body’s first line of defence against pathogens ?
Innate Immunity
Is innate immunity specific ?
No
Is adaptive immunity ?
Yes
Describe the route of entry, mode of transmission, and pathogen for the following diseases:
- Influenza
- Meningococcal Meningitis
- Typhoid Fever
- Diarrhea
- Syphillis
INFLUENZA
- Route: Airway
- Transmission: Inhaled droplets
- Pathogen: Influenza virus
MENINGOCOCCAL MENINGITIS
- Route: Airway
- Transmission: Inhaled droplets
- Pathogen: Neisseria meningiditis
TYPHOID FEVER
- Route: GI tract
- Transmission: Contaminated food or water
- Pathogen: Salmonella typhi
DIARRHEA
- Route: GI tract
- Transmission: Contaminated food or water
- Pathogen: Rotavirus
SYPHILLIS
- Route: Genito-urinary
- Transmission: Physical contact
- Pathogen: Treponoma pallidum
How may pathogens gain access ?
Through mucosal surfaces
Through external epithelia
Identify examples of diseases which involve pathogen access to mucosal surfaces.
Influenza Meningococcal meningitis Typhoid fever Diarrhea Syphillis
Identify examples of diseases which involve pathogen access through external epithelia.
Athlete’s foot Anthrax Tetanus Yellow fever Malaria Lyme disease
Describe the route of entry, mode of transmission, and pathogen for the following diseases:
Athlete’s foot Anthrax Tetanus Yellow fever Malaria Lyme disease
ATHLETE’S FOOT
- Route: External surface
- Transmission: Physical contact
- Pathogen: Tinea Pedis
ANTHRAX
- Route: Wounds and abrasions
- Transmission: Minor skin abrasions
- Pathogen: Bacillus anthracis
TETANUS
- Route: Wounds and abrasions
- Transmission: Punctures
- Pathogen: Clostridium tetani
YELLOW FEVER
- Route: Insect bites
- Transmission: Moquito
- Pathogen: Flavivirus
MALARIA
- Route: Insect bites
- Transmission: Moquito
- Pathogen: Plasmodium
LYME DISEASE
- Route: Insect bites
- Transmission: Ticks
- Pathogen: Borrelia burgdorferi
What are the three phases of response to initial infection ? Identify the onset/duration of each
1) Innate Immunity (0-4 hours)
2) Early induced response (4-96 hours)
3) Adaptive Immune Response (>96 hours)
What are the main steps in innate immunity (step 1 of response to initial infection) ?
Infection –> Recognition by preformed, nonspecific effectors –> Removal of infectious agent
What are the main steps in early induced response (step 2 of response to initial infection) ?
Infection –> Recruitment of effector cells –> Recognition and activation of effector cells –> Removal of infectious agent
What are the main steps in adaptive immune response (step 2 of response to initial infection) ?
Infection –> Transport of antigen to lymphoid organs –>
Recognition by naive B and T cells –> Clonal expansion of effector cells –> Removal of infectious agent
What are the main types of barriers to infection ?
Mechanical, chemical, microbiological
Give examples of mechanical barriers to infection.
- Tight junctions between cells prevents access
- Air and fluid flow across epithelium
- Movement of mucus by cilia
Give examples of chemical barriers to infection.
- Fatty acids on skin
- Enzymes: lysozyme in saliva, sweat and tears.
- Low pH in stomach
- Antibacterial peptides: defensins (skin and gut) cryptidins (gut)
Give examples of microbiological barriers to infection.
-Normal flora compete for nutrients and attachment (biofilms), and also produce antibacterial substances (colicins)
What happens once a microorganism has gone across an epithelial barrier ?
Recognised and ingested by mononuclear phagocytes, or macrophages.
What are examples of receptors on phagocytes which aid recognition of microorganisms ?
Mannose receptor Glucan receptor Scavenger receptor CD14 CD11b/CD18
What are some of the bactericidal effects and agents produced by phagocytes ?
- Acidification: pH 3-4, bactericidal
- Toxic oxygen derived products: superoxide, hydrogen peroxide, hydroxyl radical
- Toxic nitrogen oxides: Nitric Oxide
- Peptides: defensins and other cationic proteins
- Enzymes:Lysosyme, acidhydrolases
- Competitors: Lactoferrin, vitamin B12 binding protein
What is the progenitor cell of all cellular elements of blood, rbc, platelets, white cells (including macrophages, T cells etc.) ?
Hematopoietic stem cell
What is a monocyte ? What is the difference between a monocyte and a macrophage ?
Monocytes: one of the three types of phagocytic cell of the immune system.
Circulate in bloodstream, differentiate into macrophages in tissue.
What is another name for granulocytes ?
Polymorphonuclear (PMN) leucocytes
What are the main types of granulocytes ?
Neutrophils, Eosinophils, Basophils
What are the main types of WBCs ?
Lymphocytes
Granulocytes (Neutrophils, Eosinophils, Basophils)
Monocytes (–> Macrophages)
What are the main phagocytic cells of the immune system ?
Neutrophils, Monocytes, Dendritic Cells
What is the most important/numerous cell of innate immunity ?
Neutrophils