Lecture 1: Introduction to the Immune System Flashcards
What year was smallpox eradicated?
1979
How many years were no cases of smallpox recorded?
3 years
What is the immune system made up of?
- Tissues
- Cells
- Molecules
What is innate immunity?
- the early phase of the host response
- Present in all individuals at all times
- Does not increase with repeated exposure
- Discriminates between groups of pathogens
- Predates separation of animal and plant lineages
What is adaptive immunity?
- is generated by specific lymphocytes
- Discriminates between individual pathogens
- Is associated with “memory”
- Appears abruptly in evolution in the cartilaginous fishes
Where do all the cellular elements of the blood, including the cells of the immune system, arise from?
Pluripotent hematopoietic stem cells in the bone marrow
What are the effector cells?
- Plasma cell
- Activated T cell
- Activated NK cell
- Activated ILC
What are the anatomic barriers against protection against pathogens?
- Skin
- Oral mucosa
- Respiratory epithelium
- Intestine
What are the innate immune cells?
- Macrophages
- Granulocytes
- Natural killer cells
What are the complement/ antimicrobial proteins?
- C3
- Defensins
- RegIIIy
What are part of adaptive immunity?
- B cells/ antibodies
- T cells
What are the steps in innate immunity?
- Inflammatory inducers
- Sensory cells
- Mediators
- Target tissues
What are the inflammatory inducers?
- Bacterial loppolysaccharides
- ATP
- Urate crystals
What are the sensor cells in innate immunity?
- Macrophages
- Neutrophils
- Dendritic cells
What are the mediators in innate immunity?
- Cytokines
- Cytotoxicity
What are the target tissues in innate immunity?
- Production of antimicrobial proteins
- Induction of intracellular antiviral proteins
- Killing of infected cells
What are the three phases in the response to an initial infection?
- Innate phase
- Early induced innate response
- Adaptive immune response
What do the first two phases of the response to an initial infection rely on?
Rely on the recognition of pathogens by germline-encoded receptors of the innate immune system
What does adaptive immunity of the response to an initial infection rely on?
Uses variable antigen-specific receptors that are produced as a result of gene segment rearrangements.
Why does adaptive immunity occur late?
Because the rare B cells and T cells specific for the invading pathogen must first undergo clonal expansion before they differentiate into effector cells that migrate to the site of infection and clear the infection.
What is the function of a macrophage?
Phagocytosis and activation of bactericidal mechanisms
What do myeloid cells participate in?
- Innate immunity
- Adaptive immunity
What is the function of a dendritic cell?
- Antigen uptake in peripheral sites
What is the function of a neutrophil?
Phagocytosis and activation of bactericidal mechanisms