The following interleukin is characteristically produced in a TH1 response -
1.IL-2
2.IL-4
3.IL-5
4.IL-10
Explanation
A.T helper — 1 (TH1) secretes → IL-2 and interferon - γ
B.T helper — 2 (TH2) secretes →IL-4, IL-5, IL-6, IL-13
Also know
T-cell receptor (TCR)
The T cell receptor is a molecule found on T cells that is responsible for recognizing antigens bound to MHC molecules.
TCR of CD4 T cells recognizes the antigens bound to MHC class II.
TCR of CD8 T cells recognizes the antigens bound to MHC class I.
TCR is a heterodimer made up of an a and a (3 chain (TCR αβ in 95% of cases, and aγ and aδ chain in 5% of cases (TCR 75).
TCR γδ binds to antigens without MHC involvement.
TCR αβ recognizes antigens presented on MHC molecule of antigen presenting cells.
There are also some accessory molecules associated with TCR → CD3 and `C’ proteins.
These accessory molecules do not bind to antigen, but involve in signal transduction after TCR has bound to antigen.
TCR diversity is generated by somatic rearrangements of the genes that encode TCR.
Rearrangement of these genes occur only in T-cell during their development in thymus; hence the presence of TCR gene rearrangements demonstrated by molecular analysis is marker of T-lineage cells.
TCR Co-receptors
The signal from the T-cell complex is enhanced by simultaneous binding of the MHC molecules by a specific co-receptor.
On helper T cell, this co-receptor is CD4 that exclusively binds to the class H MHC on antigen presenting cells.
On cytotoxic T cell, this co-receptor is CD, that is specific for class I MHC on antigen presenting cells.
The Co-receptor not only ensures the specificity of the TCR for the correctly - presented antigen but also allows prolonged engagement between antigen presenting cells and the T-cell.
TCR costimulator
Beside TCR, MHC, CD4/CD, interaction there is another molecule on T cell that activate the T-cell → co stimulator.
It is CD-28 on the surface of T cells that interact with B7-1 (CD-80) and B7-2 (CD-86) expressed on antigen presenting cells.
So, for activation of T-cells, two signals are required
Signal 1→ via TCR by TCR, MHC, CD4/CD8 interactions.
Signal 2 → CD-28, B7-1 / B7-2 interaction.