Immunology Part I Flashcards
(41 cards)
What does TLR3 bind (innate system)?
dsRNA of viruses
What is the first cell to encounter pathogen/infection/resident in tissue?
Resident macrophage
What is the first cell that responds/migrates to infection/pathogen?
Neutrophil
What is innate immunity?
“Built-in” immunity that is non inducible, preexisting ability to recognize and destroy pathogens and associated products.
- Does not require previous exposure to pathogen to work
- Mediated be phagocytosis
- Recognizes common molecular pattern of pathogens known as PAMPs
- CANNOT BE INDUCED TO BE MORE SPECIFIC
In general, myeloid precursors give rise to. . .
. . .innate immune cells!
What are innate immune receptors called?
Pattern Recognition Receptors (PRRs) –> TLRs are a subfamily of this!
Overall goal of complement:
Control inflammation
What happens after TLR3 binds dsRNA?
- NRKB and IRF3 are activated and go the nucleus
- Causes changes in gene transcription that lead to the release of IFN-beta
- IFN-beta is a potent ANTI-VIRAL response
What are the three main functions of complement?
- Lysis
- Chemotaxis
- Opsonization
What are cytokines?
Secreted molecules involved in cell-to-cell signaling
What are chemokines?
A large family of cytokines that can attract cells into inflamed tissue and play a role in leukocyte homing. - “direct traffic of immune cells”
What are the six major categories of cytokines?
- Interferons (IFNs)
- Type I (alpha and beta)
- Type II (gamma) - Interleukins (ILs)
- Colony Stimulating Factors (CSFs)
- Chemokine
- Tumor Necrosis Factors (TNFs)
- Transforming Growth Factors (TGFs)
What are Interferons?
Generally, they are cytokines that are important in limiting the spread of viral infections.
-They induce a state of antiviral resistance in uninfected cells
What are Type I Interferons?
IFN alpha & IFN beta - Produced by cells that have become infected with virus
What are Type II Interferons?
IFN gamma - released by activated Th1 cells!
What are Interleukins?
Large group of cytokines produced mainly by T cells (also macrophages, dendritic cells, and epithelial cells, etc.).
–Variety of functions including causing neighboring cells to divide and differentiate.
What are Colony Stimulating Factors (CSF)?
- Primarily involved in directing the division and differentiation of bone marrow stem cells and precursors of blood leukocytes.
- Controls how many and what kind of leukocyte is to be produced
What is a chemokine?
Chemotactic cytokine used to direct the movement of leukocytes around the body
What is Tumor Necrosis Factor (TNFs)?
Particularly important in mediating inflammation and cytotoxic reactions
What are Transforming Growth Factors (TGFs)?
Important in regulating cell division and tissue repair.
What are important properties of Adaptive Immunity?
- It has “memory”. The secondary adaptive immune response is faster and stronger than the first.
- It shows “tolerance”. In ability to make an immune response toward self-antigens.
What are Antigen Presenting Cells (APCs)?
Bridge cells
-They link the innate and adaptive immune systems by taking up and processing antigens so they can be recognized by T cells.
[Dendritic cells, B cells, Macrophages]
What provides the “bridge back” to help phagocytes work better at cleaning infection?
Antibodies!
What is the difference between active and passive immunity?
Active - memory response - outcome of exposure to antigens through infection and usually results in protective immunity conferred by antibodies and T cells.
Passive - Immunoglobulin transfusion or breast milk. No exposure to antigen, response developed immediately but cannot be maintained.
