tcr + mhc + antigen
DESCRIPTION
TCR + MHC + antigen. TCR and MHC Structure. Class I •expressed by nearly all cells •present antigens to T C cells • cytosolic pathway (endogenous antigen presentation). Class II •expressed only by APCs •present antigens to T H cells - PowerPoint PPT PresentationTRANSCRIPT
TCR + MHC + antigen
TCR and MHC StructureClass I
•expressed by nearly all cells •present antigens to TC cells•cytosolic pathway (endogenous antigen presentation)
Class II •expressed only by APCs•present antigens to TH cells•endocytic pathway (exogenous antigen presentation)
Antigen Processing Comparison
Antigen Presentation/Signaling
Antigen Presentation/Signaling
Antigen Presentation/Signaling
Antigen Presentation/Signaling
Antigen Presentation/Signaling
Cytotoxic Action
Cytotoxic Action
Cytokines (Chapter 12)Cytokines•Secreted protein
• Low molecular-weight
• Regulate intensity/duration of immune response
• Variety of effects on: -lymphocytes-other immune cells
•See Appendix II
Cytokines: Types of ActionAutocrine – A condition in which the cell acted on by a cytokine is the source of the cytokine.
Paracrine – Regulatory secretions that arrive by diffusion from a nearby cellular source.
Endocrine – Regulatory secretions that pass from the producer cell to target cell by via the bloodstream.
Cytokine AttributesPleiotropy – a given cytokine has different biological effects on different target cells.
Cytokine AttributesRedundancy – When two or more cytokines the mediate similar functions.
Synergy - When the combined effect of two cytokines on cellular activity is greater than the effects of the individual cytokine.
Cytokine AttributesAntagonism – the effects of one cytokine inhibit or offset the effects of another cytokine.
Target Cell Effect____________
Cytokine AttributesCascade Induction – when the action of one cytokine on a target cell induces that cell to produce one or more other cytokines, which in turn may induce other target cells to produce other cytokines.
Biological Functions of Cytokines
Classification of Cytokines Cytokine classification based their receptors:
•Immunoglobulin superfamily•Class I cytokine (Hematopoietin)•Class II cytokine (Interferon)•TNF family•Chemokine family
Classification of Cytokines