HISTORY :
HISTORY 1970 – Discovered CTL specific for virus infected cells
CTL failed to bind free LCM virus of viral antigen
Zinkernagel and Doherty – antigen recognition by T cells specific not only for viral antigen but also for an MHC molecule- Nobel prize
Self MHC restriction
Two models 1. Dual receptor
2. altered self model
Kappler and Marrack experiment
Slide 3:
T cell specific for KLH+IAf T cell hybridoma specific
for OVA +IA k
H-2 f/k with single receptor H-2f/k with OVA+IAk and
For KLH, OVA, IAk, IAf KLH+IAf receptor
both antigen presented either H-2k or H-2f
Slide 4:
Isolation of t cells
Mab against TCR – clonotypic antibodies
Some antigen bind to all the clone
Where as others were clone specific
TCR alpha and beta like immunoglobulin light and heavy chain
Gamma and delta 2-5% and alpha and beta 95%
STRUCTURE OF TCR :
STRUCTURE OF TCR T cell posses 50k to 100k identical TCR
T cell clone express only one type of TCR
Not secreted into body fluids
All chain having similar overall structure except size
Gamma/delta TCR :
Gamma/delta TCR Three isoform- g/d with disulfide bond- 40kDa
g/d without -s-s- 40
g/d without - 55
Two exon for gamma g1 and g2
G1 encode –s-s-
Found in immature cells
First T cell colonize in embryonic thymus
Emigrate colonize skin and reproductive system
In human distribute throughout tissue and same location of a/b
Do not develop into a/b cells
Cytotoxic lyse various target like cRBC, leukemic cells, cells infected with
Mycobacteria
Increase during measles and leprosy
Recognize bacterial HSP
Involve in T and non T lineage maturation
Anti CD3 antibody induce cytotoxic activity and IL-2 secretion
Most reports indicate that they are MHC unrestricted
Slide 8:
TCR-CD3 COMPLEX
Slide 10:
CD4 AND CD8 CORECEPTORS