innate and adaptive immunity Flashcards
(24 cards)
What are the four main tasks performed by the immune system?
Immunological recognition, immune effector function, immune regulation, immunological memory
What are the three lines of defense in the body?
- External physical barriers
- Innate (non-specific) immunity
- Adaptive (specific) immunity
What are the characteristics of the innate immune response?
- Fast
- Non-specific
- Generic
What does phagocytosis literally mean?
Cell eating
Which cells primarily carry out phagocytosis?
- Macrophages
- Neutrophils
- Dendritic cells
What is the role of macrophages in the immune response?
Recognition of pathogens and elimination of pathogens and/or removal of dead/damaged cells by phagocytosis
Where are neutrophils produced and how long do they circulate in blood?
Produced in bone marrow; circulate for 7-10 hours
What is the lifespan of neutrophils?
2-3 days
What are Toll-like receptors (TLRs)?
Pattern Recognition Receptors that recognize PAMPs and activate transcription of genes involved in the immune response
What triggers inflammation in the body?
Dilation and increased permeability of blood vessels
What are mast cells and their role in inflammation?
Mediators of allergic and inflammatory conditions, increasing vascular permeability and attracting neutrophils
What is the difference between acute and chronic inflammation?
Acute inflammation is a short-term response; chronic inflammation is a long-term failure to resolve the initial response
What is the inflammasome?
A multi-protein complex that activates caspase-1 and cleaves pro-IL1b into an active cytokine
What is the role of type 1 interferons in the immune response?
They act as warning signals to neighboring cells and place them into an antiviral state
What are the two types of interferons?
- Type I: IFN-a and IFN-b (innate response)
- Type II: IFN-g (adaptive response)
What is the primary function of B lymphocytes?
To mount a specific immune response by producing antigen-specific antibodies
What do plasma cells do?
Produce and secrete antigen-specific antibodies
What is the role of memory B cells?
Confer immunological memory, ensuring rapid responses to future infections
How do T cells recognize antigens?
Via the T cell receptor, which recognizes antigens in the form of peptides bound to MHC molecules
What is the function of MHC Class I?
Presents peptides to CD8+ cytotoxic T cells
What is the function of MHC Class II?
Presents peptides to CD4+ T helper cells
What is required for T cell activation?
Both antigenic peptide and co-stimulation
What happens to the T cell population after an infection?
It decreases due to T-cell exhaustion or apoptosis, but memory T-cells remain
