Week 10 Flashcards
What is immune system?
A complex network of cells, tissues, organs, and the substances they make that helps the body fight infections and other diseases
What is the innate immune system?
The body’s first line of defense against germs entering the body
What is the function of the adaptive immune system?
To destroy invading pathogens and any toxic molecules they produce
What are T cells?
A part of the immune system that focuses on specific foreign particles
Where are T-cells developed?
A common lymphoid progenitor in the bone marrow that also gives rise to B lymphocytes, but those progeny destined to give rise to T cells leave the bone marrow and migrate to the thymus
Where are B cells located and what is their function?
At the centre of the adaptive humoral immune system and are responsible for mediating the production of antigen-specific immunoglobulin (Ig) directed against invasive pathogens
What is an immune response?
A reaction which occurs within an organism for the purpose of defending against foreign invaders
What is inflammation?
Part of the body’s defense mechanism
What is the body’s response to tissue injury?
The body initiates a chemical signaling cascade that stimulates responses aimed at healing affected tissues
What is acute inflammation characterised by?
Local edema, redness, tenderness and pain, increased temperature, and restricted function
What is the process of leukocyte chemotaxis?
A critical feature of the innate immune response is the movement of neutrophils and macrophages from one site in the body to another to provide effector functions
What is systemic acute inflammation?
A serious condition in which there is inflammation throughout the whole body
What is chronic inflammation also referred to?
Slow, long-term inflammation lasting for prolonged periods of several months to years
What is autoimmunity?
Sometimes the immune system makes a mistake and attacks the body’s own tissues or organs
What’s the difference between autoimmunity and autoinflammatory?
Autoinflammatory diseases are due to hyperactivation of the innate immune system. Autoimmune disease results from abnormalities of the adaptive immune system
What causes autoimmune diseases?
- Some medications
- Having relatives with autoimmune diseases
- Smoking
- Already having one autoimmune disease
- Exposure to toxins.
- Being female — 78% of people who have an autoimmune disease are women.
- Obesity
- Infections
How is self-tolerance broken?
Alloreactive cells from an animal that had been immunized with cells from the allogeneic donor before transfer; such cells probably break tolerance by killing the allogeneic donor cells
What are six tips to enhance immunity?
- Eat Well.
- Be Physically Active.
- Maintain a Healthy Weight
- Get Enough Sleep
- Quit Smoking
- Avoid Too Much Alcohol
What is the standard treatment for autoimmune or autoinflammatory diseases?
Immunosuppressive agents until the advent of immunomodulatory biologic drugs, which aimed at blocking inflammatory mediators, including proinflammatory cytokines
What are the functions of TNF-alpha blockers?
These therapies inhibit the proinflammatory action of TNF-α in common autoimmune diseases such as rheumatoid arthritis, psoriasis, ulcerative colitis, and Crohn’s disease
What are the limitations of anti-TNF-α therapies?
Known adverse safety risk, loss of therapeutic efficacy due to drug resistance, and lack of efficacy in numerous autoimmune diseases, including multiple sclerosis
What are cytokines?
Small proteins that are crucial in controlling the growth and activity of other immune system cells and blood cells
What are cytokine receptors?
Cell-surface glycoproteins that bind specifically to cytokines and transduce their signals
What are the members of the cytokine superfamily?
Interleukins, chemokines, colony-stimulating factors (CSF), interferons, and the transforming growth factors (TNF) and tumor necrosis factor (TGF) familes
What is the IL-1 family?
A group of 11 cytokines that plays a central role in the regulation of immune and inflammatory responses to infections or sterile insults
Why is the IL-12 family unique?
It has the only heterodimeric cytokines, including IL-12, IL-23, IL-27 and IL-35
Where do cytokines have a important role in?
Chemically induced tissue damage repair, in cancer development and progression, in the control of cell replication and apoptosis, and in the modulation of immune reactions such as sensitization
What are hematopoietic cytokines?
Large family of extracellular ligands that stimulate hematopoietic cells to differentiate into eight principle types of blood cells
What are the different cytokines in hematopoietic systems?
Interleukins (ILs), colony-stimulating factors (CSFs), interferons, erythropoietin (EPO) and thrombopoietin (TPO)
What are cytokines crucial in?
Controlling the growth and activity of other immune system cells and blood cells
What do cytokines affect?
The growth of all blood cells and other cells that help the body’s immune and inflammation responses
What are cytokines fundamental in?
The differentiation of memory T cells
Do cytokines reduce inflammation?
Some cytokines act to make disease worse (proinflammatory), whereas others serve to reduce inflammation and promote healing (anti-inflammatory)
What are the currently approved recombinant cytokine products for cancer immunotherapy?
Intron A (interferon alfa-2b) and Proleukin (aldesleukin)
What is the role of TNFα in inflammation?
TNFα is a powerful pro-inflammatory agent that regulates many facets of macrophage function. It is rapidly released after trauma, infection, or exposure to bacterial-derived LPS and has been shown to be one of the most abundant early mediators in inflamed tissue
What are TNF inhibitors?
Drugs that help stop inflammation
How do cytokines act on their target cells?
Binding to specific cytokine receptors on the cell surface
What are the sub-families of class I cytokine receptors?
This subfamily includes the receptors for IL-3, IL-5, and GM-CSF
What is GM-CSF?
A pluripotent cytokine produced by many cells in the body, which regulates normal and malignant hemopoiesis as well as innate and adaptive immunity
What does the active heterodimeric receptor complex on the surface of myeloid cells initiate?
Multiple signaling pathways that control key functions such as cell survival, cell proliferation, and functional activation
How is the cytokine receptor family characterised?
By four conserved cysteine residues and a tryptophan-serine-X-tryptophan-serine motif above the transmembrane domain
What family does IL-2 belong to?
IL-2 is a member of a cytokine family, each member of which has a four alpha helix bundle; the family also includes IL-4, IL-7, IL-9, IL-15 and IL-21. IL-2 signals through the IL-2 receptor, a complex consisting of three chains, termed alpha (CD25), beta (CD122) and gamma (CD132)
What are type II cytokine receptors?
Transmembrane proteins that are expressed on the surface of certain cells
What is the TNF receptor superfamily?
A protein superfamily of cytokine receptors characterized by the ability to bind tumor necrosis factors via an extracellular cysteine-rich domain
What are chemokine receptors?
A superfamily of GPCRs that control immune cell behavior; they promote chemotaxis, cell adhesion, and mediator release
How do cytokine receptors signal?
These receptors enable cells to communicate with the extracellular environment by responding to signals generated in the vicinity or in other parts of the organism
What does the JAK-STAT pathway play a critical role in?
Transduction of extracellular signals from cytokines and growth factors involved in hematopoiesis, immune regulation, fertility, lactation, growth and embryogenesis
What does the JAK family contain?
Four cytoplasmic tyrosine kinases, JAK1-3 and Tyk2
What are some negative regulators of the JAK-STAT pathway?
Tyrosine phosphatases (SHP1 and 2, CD45), protein inhibitors of activated STATs (PIAS), suppressors of cytokine signaling (SOCS) proteins, and cytokine-inducible SH2-containing protein (CIS)
What are JAK inhibitors used for?
To treat several chronic inflammatory disorders
