Blood Cells - Tissue Functioning and Remodeling in the Circulatory and Ventilatory Systems - page 137

Table 3.34. T cells into helper T-cell subsets (T H ) and inducible

regulatory T cells (T Reg ). Following connection of antigen-presenting cells such as dendritic cells
and naive CD4

Differentiation of naive CD4 +

+ T cells via the MHC class-2 molecule-antigen peptide-TCR complex, activated

CD4 T cells can polarize into T H1 ,T H2 ,andT H17 , among others, as well as T Reg , according to the

local cytokine environment (FoxP: forkhead box-P; IL: interleukin; ROR: retinoic acid receptor-
related orphan receptor [NR1f1-NR1f3]; STAT: signal transducer and activator of transcription;
TBx: T-box transcription factor; TGF: transforming growth factor). Master transcription factor
BCL6 of follicular helper T cells (T FH ) is a transcriptional repressor, unlike TBx21 and GATA3.
Interleukin-10 can be produced by multiple cell clones (T H1 ,T H2 ,T H17 ,andiT Reg )inagiven
context, demonstrating remodeling capacity of T-cell subsets [ 251 ]. Similarly, T H2 and T H17 cells
can acquire IL9-synthesizing capacity. T H17 cells can extinguish production of their cytokines to
become selective interferon-

+

γ synthesizers. Expression of transcription activators and repressors

can also change.

Trigger cytokine Product Signature cytokines and

main cellular markers

IL12 T H1 Ifn γ ; STAT4, TBx21

IL4 T H2 IL4/13; STAT6, GATA3

TGF β ,IL6 T H17 IL17a/f; STAT3, ROR γ 2

T FH IL21; STAT3, BCL6

β β

TGF iT Reg IL10/35, TGF ; STAT5, FoxP3

Table 3.35. Cytokines in the initiation and amplification of T H2 -mediated responses

(Sour ce: [ 252 ]; ASMC: airway smooth myocyte; TSLP: thymic stromal lymphopoietin).

Cytokine Inducers Sources Targets

IL2 Antigen, IL4/13, Activated CD4 + T cell, T cells,

allergens, epithelial cells, dendritic cells,

helminth products basophils, mastocyte, basophils, mastocytes

IL4 Antigen, TSLP, Naive CD4 + T cell, T/B cells,

IgE, IL2/3/4/25 T H2 , NKT, basophil macrophages,

epithelial cells

IL25 Allergens, IL4, T H2 , basophil, T cells,

helminth products eosinophil, nuocytes

epithelial cells,

IL33 Allergens, Epi/endothelial cells, T H2 , macrophage,

helminth products ASMC, adipocyte dendritic cells,

nuocytes,
basophil, mastocyte

T H2 Cell

Helper-2-specific transcription factor is GATA-binding GATA3 protein. T H2 -cell
differentiation indeed relies on GATA3 and signal transducer and activator of tran-
scription STAT5 that can be activated by IL2 (Table 3.35 ). T H2 -cell differentiation