Journal: Frontiers in Immunology

Article Title: PTEN-mTORC2 signaling module controls antibody isotype selection and antiviral humoral immunity

doi: 10.3389/fimmu.2026.1771230

Figure Lengend Snippet: mTOR signaling negatively regulates IgG1 isotype switching. (A) Schematic of in vitro differentiation of GC-like B cells (iGCBs) and plasmablasts (iPBs). Splenic B cells were co-cultured with feeder cells expressing CD40L and BAFF (CD40LB) in the presence of IL-4 to generate iGCBs, followed by IL-21 to induce iPB differentiation. (B) Time-course immunoblot analysis of mTOR signaling in iGCBs and iPBs. Data shown are representative of two or three independent experiments. (C) Immunoblot analysis of iGCBs treated with rapamycin (Rapa, 5 nM), torin-2 (Torin, 25 nM), or vehicle (Vh). Representative immunoblots from four independent experiments are shown. (D–F) Representative flow cytometry (FACS) plots of iGCBs cultured in the presence of Rapa, Torin, or Vh, gated on viable B cells, with percentages of the indicated populations. (G) Quantification of Ig isotype distribution in iGCBs, presented as pie charts. (H–J) Representative FACS plots of iPBs differentiated from iGCBs treated with Rapa, Torin, or Vh, gated on viable B cells, with percentages of the indicated populations. (K) Quantification of Ig isotype distribution in iPBs. Data in (D–F) and (H–J) are representative of two independent experiments, each performed with three biological replicates. Statistical significance in (G) and (K) was assessed by an unpaired two-tailed Student’s t-test: ***p < 0.001.

Article Snippet: In some experiments, iGCB cultures were treated with 5 nM Rapamycin (Tocris), 25 nM Torin-2 (Tocris), 1 μM MK-2206 (Selleckchem), or 50 μM DAPT (MCE).

Techniques: In Vitro, Cell Culture, Expressing, Western Blot, Flow Cytometry, Two Tailed Test