Human in vitro-induced regulatory T cells display Dlgh1 dependent and PKC-θ restrained suppressive activity

• Published in: Scientific reports 2017-06, Vol.7 (1), p.1-8, Article 4258
• Main Authors: Zanin-Zhorov, Alexandra, Kumari, Sudha, Hippen, Keli L., Merkel, Sarah C., MacMillan, Margaret L., Blazar, Bruce R., Dustin, Michael L.
• Format: Article
• Language: English
• Subjects: 13; 13/106; 13/89; 14; 14/63; 631/250/1619/554; 631/250/516; 96; 96/95; AKT protein; Blood cells; CD25 antigen; CD3 antigen; CD4 antigen; Cord blood; DLG protein; Effector cells; Humanities and Social Sciences; Immunological synapses; Immunoregulation; Intercellular adhesion molecule 1; Kinases; Lipid bilayers; Lymphocytes; Lymphocytes T; Monoclonal antibodies; multidisciplinary; Phosphorylation; Protein kinase C; PTEN protein; Science; Science (multidisciplinary); Synapses; Tensin; γ-Interferon
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-04053-5

In vitro induced human regulatory T cells (iTregs) have demonstrated in vivo therapeutic utility, but pathways regulating their function have not been elucidated. Here, we report that human iTregs generated in vitro from naïve cord blood cells preferentially recruit Disc large homolog 1 (Dlgh1) and exclude protein kinase C (PKC)-θ from immunological synapses formed on supported lipid bilayers with laterally mobile ICAM-1 and anti-CD3 mAb. Also, iTregs display elevated Dlgh1 overall and Dlgh1-dependent p38 phosphorylation, higher levels of phosphatase and tensin homolog (PTEN), and diminished Akt phosphorylation. Pharmacological interruption of PKC-θ increases and Dlgh1 silencing decreases the ability of iTregs to suppress interferon-γ production by CD4 + CD25 − effector T cells (Teff). Comparison with expanded cord blood-derived CD4 + CD25 hi tTreg and expanded Teffs from the same donors indicate that iTreg are intermediate between expanded CD4 + CD25 hi tTregs and Teffs, whereas modulation of suppressive activities by PKC-θ and Dlgh1 signaling pathways are shared.