Table 1.
Distinctive features of classic and ‘non-classic’ human T helper type 1 cells
| Feature | Classic Th1 cells | Non-classic Th1 cells |
|---|---|---|
| Cell source | CD61− naive Th cell | Activated Th17 cell |
| Site of differentiation | Lymph nodes | Inflammatory sites |
| Polarizing cytokines | IL-12, IL-18, IFNs | IL-12, TNF |
| Transcription factors | T-bet | T-bet, RORC |
| Surface receptors | ||
| Chemokine receptors | CXCR3, CCR5 | CXCR3, CCR6 |
| Cytokine receptors | IL-12, IL-18 | IL-1β, IL-23, IL-12, IL-17RE |
| Other | CD161 | |
| Regulatory genes for proliferation (mRNA expression) | IL-4I1, Tob-1 | |
| Methylation status | ||
| RORC2 | Hypermethylated | Hypomethylated |
| IL-17 | Hypermethylated | Hypomethylated |
| T-bet | Demethylated | Demethylated |
| IFN-γ | Demethylated | Demethylated |
Abbreviations:IFN-γ, interferon-γ; IL-12, interleukin-12; RORC, retinoic acid-related orphan receptor C; Th1, T helper type 1; TNF, tumour necrosis factor.