2. scope
-Phases of T Cell Responses
-Antigen Recognition and Costimulation
-Functional Responses of T Lymphocytes to
Antigens and Costimulation
-T Cell Signal Attenuation
-Migration and retention of effector T cells at
site of infection
7. Ag receptor of γδT cells
-TCR γ & δ chain consist of extracellular Ig-like
V & C regions, hydrophobic transmembrane
segment, short cytoplasmic tail เช่นเดียวกับ TCR
αβ
But not express CD4/CD8
-มักพบใน epithelial tissue (intraepithelial
lymphocyte)
-recognition : hypothesis
recognize Ag ที่พบบ่อยบน epithelial boundaries
between host & external environment
10. Role of costimulators in T cell
activation
-2nd signal
-absense : fail to respond & die by apoptosis or
enter state of unresponsiveness (anergy)
-increase production of IL-2 & stabilize IL-2
mRNA
-promote survival of T cell
11. Role of costimulators in T cell
activation
1).CD28 bind to B7-1(CD80), B7-2(CD86) on
APC (dendritic cell, macrophage), B cell
2).ICOS(inducible costimulator) : activate
production of IL-10
3)CTLA-4(CD152) : self tolerance
12.
13. Others accessory molecule on T cells
-CD44 acidic sulfated membrane glycoprotein :
mature T cell, thymocyte, B cell, macrophage,
granulocyte, erythrocyte, fiboblasts
-bind to hyaluronate : retention T cell in extravascular
tissue at infection site
-binding of activated & memory T cell to endothelium
at site of inflammation, in mucosal tissue
14. Others accessory molecule on T cells
(con.)
-CD40 ligand express บน activated CD4 T cell
bind to CD40 บน B cell, macrophage, dendritic
cell, endothelial cell
-Ligand for Fas (CD95)
-apoptosis
-important for eliminating T cell that are
repeated stimulated by Ag
26. T cell signal attenuation
ทำำได้ 3 วิธี
1).activation inhibitory receptor of CD28
2).tyrosine-phospatases (SHP-1)
3).protein known as E3 ubiquitin ligases
37. Differentiation of CD8 T cell into
CTL
-ต้องกำร IL-12
-transcription factor :
T-bet & eomesodermin
-differentiated CTL secrete cytokine,
mostly IFN-γ, lymphotoxin, TNF
-cascade in differentiation same as
CD4
38. Effector of CD8+ T cell
steps in CTL-mediated lysis of target cell