Genetic Reprogramming of Primary Human T Cells Reveals Functional Plasticity in Th Cell Differentiation

Abstract

Activation of naive T cells through the TCR and cytokine signals directs their differentiation into effector or memory subsets with different cytokine profiles. Here, we tested the flexibility of human Th1 or Th2 differentiation by forced expression of transcription factors T-bet and GATA-3. Ectopic expression of T-bet and GATA-3 in freshly isolated human TN cells resulted in their differentiation to a Th1 and Th2 phenotype, respectively, in the absence of polarizing cytokines. Introduction of GATA-3 into lineage-committed Th1 cells induced the expression of Th2-specific cytokines (IL-4 and IL-5) and chemotactic receptors (CCR4, chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2). However, these cells partially maintained their Th1-specific profile (IFN-γ and IL-12Rβ2 expression). Conversely, expression of T-bet in lineage-committed Th2 cells caused a more profound switch to the Th1 phenotype, including the up-regulation of CXCR3 and down-regulation of CCR4 and CRTH2. Interestingly, similar to the naive T cell subset, central memory T cells were also largely programmed toward Th1 or Th2 effector cells upon expression of T-bet and GATA-3, respectively. However, expression of these transcription factors in effector memory T cells was much less influential on cytokine and chemokine receptor expression profiles. Our results reveal remarkable plasticity in the differentiation programs of human memory T cells. This flexibility is progressively diminished as cells mature from naive to effector T cells. These findings have important implications in understanding the molecular mechanisms of human T cell differentiation and for devising novel therapeutic strategies aimed at immunomodulation of skewed effector T cell responses.

APOBEC3B and APOBEC3C Are Potent Inhibitors of Simian Immunodeficiency Virus Replication

“…To purify unactivated CD4 ϩ T cells, peripheral blood mononuclear cells were positively sorted on anti-CD4 Dynabeads and removed with Detachabead (Dynal Biotech) as previously described (32). The cells were further purified by negative selection on anti-CD8 and anti-CD14 (BD Biosciences) with goat anti-mouse IgG (Dynal Biotech)-coated beads.…”

Inhibition of primary human T cell proliferation byHelicobacter pylorivacuolating toxin (VacA) is independent of VacA effects on IL-2 secretion

“…IL-2 receptor (CD25) surface expression was detected by staining with phycoerythrin-conjugated anti-human CD25 (BD Biosciences), as described (26). IL-2 secretion into culture supernatants was determined by using cytometric bead array (CBA) according to the manufacturer's instructions (BD Biosciences) and analyzed by using CBA six-bead analysis software (BD Biosciences).…”

“…Activation of T cells was accomplished by using ␣-CD3 (OKT3, American Type Culture Collection) and ␣-CD28 antibodies (BD Biosciences, Franklin Lakes, NJ) (hereafter termed TCR͞CD28 stimulation) as described (26). Cells were removed from the activation signals after 48 h and expanded in media supplemented with recombinant human IL-2 (Chiron, 200 units͞ml) and cultured as described (26). Jurkat T cells were TCR͞CD28-stimulated as described above or with phorbol myristate acetate (PMA, 50 ng͞ml; Sigma) and ionomycin (500 ng͞ml; Sigma), and maintained in RPMI media 1640 containing 10% FCS.…”

Human Embryonic Stem Cells Reprogram Myeloid Precursors Following Cell–Cell Fusion

“…Given this change of mindset, it is no coincidence that a few years after the cloning of Dolly, there was a proliferation of reports that suggested adult cells were far more plastic than previously imagined [2][3][4][5][6][7][8][9][10][11]. The extent of adult stem cell plasticity remains controversial to this day, but clearly some of the "transdifferentiation" events reported were due to cell fusion [12][13][14][15][16][17].…”