Stat1-dependent synergistic activation of T-bet for IgG2a production during early stage of B cell activation.

T-bet for IgG2a Production during Early Stat1-Dependent Synergistic Activation of

T-box transcription factor T-bet, a key player in a unique type of B-cell activation essential for effective viral clearance.

IgG2a is known to be the most efficient antibody isotype for viral clearance. Here, we demonstrate a unique pathway of B-cell activation, leading to IgG2a production, and involving synergistic stimulation via B-cell antigen receptors, toll-like receptor 7 (TLR7), and IFNγ receptors on B cells. This synergistic stimulation leads to induction of T-box transcription factor T-bet expression in B ce...

Induction of IgG2a class switching in B cells by IL-27.

IL-27 is a novel IL-12 family member that plays a role in the early regulation of Th1 initiation. However, its role in B cells remains unexplored. We here show a role for IL-27 in the induction of T-bet expression and regulation of Ig class switching in B cells. Expression of WSX-1, one subunit of IL-27R, was detected at the mRNA level in primary mouse spleen B cells, and stimulation of these B...

B and T Lymphocyte Attenuator is a Target of miR-155 during Naive CD4+ T Cell Activation

Background: MicroRNA-155 (miR-155) is upregulated during T cell activation, but the exact mechanisms by which it influences CD4+ T cell activation remain unclear. Objective: To examine whether the B and T lymphocyte attenuator (BTLA) is a target of miR-155 during naïve CD4+ T cell activation. Methods: Firefly luciferase reporter plasmids pEZX-MT01-wild-type-BTLA and pEZX-MT01-mutant-BTLA were ...

An indispensable role for STAT1 in IL-27-induced T-bet expression but not proliferation of naive CD4+ T cells.

IL-27 is a novel IL-12 family member that plays a role in the early regulation of Th1 initiation, induces proliferation of naive CD4+ T cells, and synergizes with IL-12 in IFN-gamma production. It has been recently reported that IL-27 induces T-bet and IL-12Rbeta2 expression through JAK1/STAT1 activation. In the present study, we further investigated the JAK/STAT signaling molecules activated b...