Immunology

• In the bone marrow, immune cells begin as myeloid and lymphoid progenitors
• Dendrites act as antigen presenting cells
• Toll-like receptors recognise PAMPS
• Cellular stress can be seen in the form of DAMPS
• Antigen presenting cells will contain peptides and MHC inside
• MHC on surface along with the release of cytokines causes the maturation of a naive T cell into a T helper cell
• The combination of signals needed is what protects us against overactivation
• Antigens can form a covalent bond with large peptide compounds. This leads to the formation of a hapten- carrier conjugate
• Haptens are too small to elicit an immune reaction on their own
• The formation of a hapten-conjugate complex produces a complete antigen which is large enough to trigger and immune response
• APCs also contain co-stimulatory molecules on their surface
• Adjuvants can upregulate costimulation
• TH2 cells leads to memory B cell formation
• TH1 cells leads to memory T cell formation
• Type 1 hypersensitivity occurs immediately
• Allergens binding to IGE causes crosslinking causes degranulation of mast cells and release of mediators (Hypersensitivity 1)
• Key symptoms of hypersensitivity 1 are skin reactions and itching
• Type IV hypersensitivity causes a delayed reaction
• Type IV is associated with the production of memory T cells
• A hapten forms a protein conjugate at the epidermis and is processed by langerhan cells (Type IV)
• • Dendrite presents hapten to memory T cells
  • Release of cytokines
  • Migration of inflammatory cells
• Type IV hypersensitivity can take up to 48 hours for a reaction to occur.
• Lipid soluble molecules can interact with intracellular peptides. This leads to presentation of antigen and MHC on surface causing tissue damage
• Allergies can develop due to co-exposure to other pollutants
• Neutrophils have a half life of 3 days meaning encountering a second compound can leads to reduced immune function