What is the role of Helper T cells?
Helper T cells raise the alarm! Cytokines released by this cell type; cytokines enhance immune response (e.g., make activated B cells, cytotoxic T cells proliferate even more).
What is meant by the "handshake" of the immune system?
So, not only do B cells express anitbodies, but ALSO need B cell activation by T cells (double system to prevent auto-immune response!).
The antigen must be exposed to a helper T cell before the specific type of B cell or cytotoxic T cell (both of which must also be exposed to the antigen) can begin to multiple rapidly (i.e. is stimulated). This provides a 'check' prior to initiating a major immune response.
Cytotoxic T Cells
Kill cells that have been infiltrated with virus/bacteria (or are cancerous).
How cytotoxic T cells detect these abnormal cells?
Once again, "wacky", abnormal proteins presented on cell surface, and cytotoxic T cells will differentiate into memory and effector T Cells (effector cytotoxic T cell kills the cell).
Via what do the cytotoxic T cels recognized an antigen presenting cell?
Cytotoxic T cells recognize an antigen-presenting cell through the MHC I complex which presents the antigen.
What in the cytotoxic T cell recognizes the presented antigen?
The antigen is recognized by a T cell receptor, which essentially is a T cell-attached antibody with the same overall structure of variable segments to recognize particular antigens. (Just like antibodies, many, many T cell receptors are created in order to ensure that all antigens can be dealt with)
What are the assisting complexes that are associated with MHC I & II?
Cytotoxic T cells are also CD8+, and these transmembrane glycoproteins help hold the MHC I complex to the T cell.
CD4 is a glycoprotein involved in assisting the T cell receptor of the T helper cells to bind to the MHC II complex.
AKA: Systemic Lupus Erythematosus
Autoimmune disease in which immune system mistakenly attack healthy tissue.
What are the symptoms of lupus?
Lupus can be mild to severe, and common symptoms include painful, swollen joints; fever, chest pain, hair loss, muscle pains, swollen lymph nodes, fatigue, red rashes.
What is the prevelance of lupus?
Occurs in approximately 1 in 2,000 individuals.
What the factors that contribute to the presence of lupus?
Thought to be due to BOTH genetic and environmental factors.
What are some of the risk factors that increase chance of lupus?
Female sex hormoens (often found in women), sunlight, smoking, vitamin D deficiency, infections can increase risk.
How heritable is lupus?
High heritability (>66%) and sibling risk ratio suggest genetic component, although no single gene involved (multigenic/oligogenic). Thus, GWAS have revaled assocaited loci.
What is often the cause of lupus?
Oftentimes (but now always) due to anti-nuclear antibodies that create an inflammatory response.
Treatments include administration of corticosteroids, immunosuppresants among other things.
What organ can be involved in lupus?
Can involved the kidneys; lupus nephritis is an inflammation of the kindeys such that the glomeruli (filtration units of the kidney) become inflamed (glomerulonephritis). Kidney failure can result.
What are the main genes that have been associated with Lupus?
- TLR/IFN Signaling
- TNF/NFkB Signaling
- Complement System
Interferon signaling - inhibiting viral protein synthesis in cell, as well as destroying RNAs, including viral
Proinflammatory cytokine signaling
Complements ability of antibodies and phagocytes to clear microbes; one ways is to facilitate binding of antibody (or other membrane protein) to pathogen, another is recruitment of inflammatory cells, while a third is direct killing of pathogens.
What are the general types of genes that are associated with lupus?
Those associated with...
- the Innate Immune Response
- Lymphocyte Activation/Function
- Immune Complex Clearance
What are the pathways associated with lupus that are related to the innate immune response?
- TLR/IFN signaling
- TNF/NFkB signaling
What are the pathways that are associated with lupus that are related to lymphocyte activation/function?
- T Cell Signaling
- B Cell Signaling
What are the pathways that are associated with lupus that are related to immune complex clearance?
- Complement System
What are the pathways associated with lupus that are not related to any previously discussed general group?