Date post: | 17-Dec-2015 |
Category: |
Documents |
Upload: | lorraine-may-conley |
View: | 215 times |
Download: | 1 times |
MEMBRANE RECEPTOR FOR ANTIGEN
Kelompok : 4
Ninda Sahriyani (105090100111010)
Ganys Tri S. (115090107111020)
Agatha Mia(115090101111010)
Vita Agustina(115090100111011)
Jurusan Biologi
Fakultas Matematika dan Ilmu pengetahuan Alam
Universitas Brawijaya
2013
THREE LIMBS OF IMMUNE RESPONE
Fig 1. Three Limbs Immune Respone
• Group of genes that code for proteins that found on the surfaces of cells that help the immune system recognize foreign substances
• Also known as HLA (Human Leukocyte Antigen)
Two types:Class I• Found in every
nucleated cell• Bound to cytotoxic T
cell (CD8)
Class II• Found in special cell
such as macrophage, dendritic cell, B cell, and thymus
• Bound to Helper T cell
Major Histocompatability Complex (MHC)
1.Determinate between the self and nonself antigens
2.Presenting antigen to T cells
3.Determinate interaction between B cells, T cells and other cells.
Function of MHC
There are 3 ways of processing and presentation antigens :
1. Protein from extracellular pathogen broken down and processed by exogen pathway
2. Protein from self-protein and virus protein processed by endogen pathway
3. Lipid and derivate processed like extracelular protein and endosom, with CD1, that similiar to MHC and presented to CD8 T cell.
Function of MHC
Degradation Process (Processing and Presentation) Antigen
Fig 2. MHC Structures
TABLE 1. DIFFERENCES BETWEEN CLASS I AND CLASS II MHC
Variable Class I MHC Class II MHC
Bound to CD8 T cell CD4 T cell
Enzyme to form peptide
Cytosolic protease Endosome and lysosom protease
Peptide binding site in cell
Reticulum endoplasmic Vesicle specialized compartment
Peptide size 8-9 amino acid 13-17 amino acid
Expression and Presentation
• Expressed to hematopoietic cells• Presented by all nucleated cells.
• Expressed to hematopoietic cell and stromal cell at thymus• Presented by macrophage, dendritic cell, B cell
SIMILARITIES OF ANTIGEN PRESENTING BY MHC MOLECULES
• Presented to T cell on the surface of APC (Antigen Presenting Cell)
• Every MHC can only bind to single antigen fragment at one time, at the peptide binding cleft
• The presented antigen fragment is only amino acid chain
• The binding is done intracellular
Fig 2. Class I MHC Antigen Presenting Pathway
Fig 3. Class II MHC Antigen Presenting Pathway
T
• Mature T cell have thousands identical receptor on the cell surface
• 2 kinds of receptor:–Alpha/beta (αβ) chain T cell (95%)–Gamma/delta (γδ) chain T cell (5%)
• Co-receptor : CD4 and CD8
T Cell Receptor (TCR)
Fig 5. TCR-CD3 • TCR binding to MHC-antigen• The long cytoplasmic tail of the CD3 functions in signal transduction.
T Cell Receptor Complex: TCR-CD3
Fig. 6 Role of co- receptor CD 4 and CD8 : they may act as adhesion molecule helping the T cell bind to the APC during antigen presentation for duration that is sufficient for antigen recognition or act as signal transducers.
Role of co-receptors in TCR binding affinity
THANK YOU FOR YOUR ATTENTION…
ANY QUESTION???
VIDEO
Link : T Cell Dependent Antigenshttp://highered.mcgraw-hill.com/olc/dl/120110/micro33.swf
Cytotoxic T Cellhttp://highered.mcgraw-hill.com/olc/dl/
120110/micro34.swf