flag tag  (Proteintech)

Journal: Materials Today Bio

Article Title: Inhalable engineered probiotic outer membrane vesicles co-expressing multiple mpox antigens induce potent specific systemic and mucosal immune responses

doi: 10.1016/j.mtbio.2026.103089

Figure Lengend Snippet: Design, Preparation, and Characterization of ABM@OMV. ( A ) Schematic illustrating the preparation of ABM@OMV. The pThioHisA plasmid, encoding Trx-A9R and ClyA-B6R-M1R fusion proteins, was transformed into Δ lpxM Escherichia coli Nissle 1917 (ΔEcN). OMVs were harvested via ultracentrifugation. ( B ) Bacterial lysates analyzed by SDS-PAGE and stained with Coomassie blue. Lanes: Marker; uninduced ΔEcN; ΔEcN + IPTG; uninduced BMΔEcN; BMΔEcN + IPTG; uninduced ABMΔEcN; ABMΔEcN + IPTG. Black boxes indicate ClyA-B6R-M1R and Trx-A9R fusion proteins. ( C ) Western blot analysis of proteins of interest expressed in ABMΔECN bacteria. Anti-His tag antibody detected Trx-A9R; anti-Flag tag antibody detected ClyA-B6R-M1R. Lane order is the same as in B . ( D ) Dynamic light scattering (DLS) size distribution profiles of Δ lpxM OMVs, BM@OMV, and ABM@OMV. ( E ) Zeta potential measurements of Δ lpxM OMVs, BM@OMV, and ABM@OMV ( n = 3). ( F ) Transmission electron microscopy (TEM) images of Δ lpxM OMVs, BM@OMV, and ABM@OMV. Scale bar: 100 nm. ( G ) Western blot analysis of proteins of interest expressed in ABM@OMV. Lanes: Δ lpxM OMVs, BM@OMV, ABM@OMV. ( H ) Endotoxin levels in Δ lpxM EcN-derived OMV and wild-type EcN-derived OMV, as measured by Limulus amebocyte lysate (LAL) assay ( n = 3). ( I ) Representative western blot showing the stability of proteins of interest in Δ lpxM OMVs, BM@OMV, and ABM@OMV following storage at 4 °C (left) or −80 °C (right) for the indicated time periods for the indicated time periods. ( J, K ) Changes in particle size ( J ) and zeta potential ( K ) of OMVs stored at 4 °C and −80 °C ( n = 3). All data were analyzed with GraphPad Prism 8 and are presented as mean ± SD. For panel H , statistical significance between two groups was determined by an unpaired two-tailed t -test. ∗∗∗ P < 0.001.

Article Snippet: The membrane was blocked with 5% BSA (BSA0020, Biosharp, China), then incubated with anti-His tag antibody (1:10,000, HY-P809476X, Med ChemExpress, USA) and anti-FLAG antibody (1:10,000, HY- P80111 , Med ChemExpress, USA), respectively for A9R and B6R-M1R, followed by HRP-conjugated secondary antibodies.

Techniques: Plasmid Preparation, Transformation Assay, SDS Page, Staining, Marker, Western Blot, Bacteria, FLAG-tag, Zeta Potential Analyzer, Transmission Assay, Electron Microscopy, Derivative Assay, LAL Assay, Two Tailed Test

Journal: The Journal of Experimental Medicine

Article Title: Targeting Mettl8-Tcf1 axis promotes CD8 + T PEX differentiation and antitumor immunity

doi: 10.1084/jem.20250424

Figure Lengend Snippet: Mettl8 promotes m 3 C modification of Tcf7 mRNA and its genome-specific loops of Tox in CD8 + T cells. (A) Venn plot illustrates the overlap of downregulated genes from RNA-seq, m 3 C-seq, and Mettl8-binding genes from RIP-seq. (B) Mettl8 occupancy at the Tcf7 gene loci is revealed through m 3 C-seq (WT and Mettl8 −/− ) of EG7-OVA tumor-infiltrating OT-I cells and RIP-seq (Mettl8-tdTomato-Flag) of B16F10 tumor-infiltrating CD44 + CD8 + T cells. The binding peaks on Tcf7 loci are depicted. The m 3 C tracks are all plotted on a consistent scale. (C) The RNA decay assay demonstrates the remaining Tcf7 mRNA of CD8 + T cells from the spleens of WT and Mettl8 −/− mice detected by qRT-PCR, normalized to t = 0. (D) Heatmaps display changes in total Tcf1-targeting genes between WT and Mettl8 −/− EG7-OVA tumor-infiltrating OT-I cells and Mettl8-targeting genes in B16F10 tumor-infiltrating CD44 + CD8 + T cells of Mettl8-tdTomato-Flag mice as detected by CUT&Tag. (E) Diamond graphs exhibit chromatin interactions in WT and Mettl8 −/− tumor-infiltrating OT-I cells at the Tox gene loci (top), with CUT&Tag and ATAC-seq tracks, and gene structures on the bottom. An enlarged view highlights the signal profiles across the Tox gene region. (F) co-IP of Tcf1 by anti-Flag magnetic beads in CD3 + T cells from the spleens of Mettl8-tdTomato-Flag (RPT) and WT mice. IB, immunoblot. (G) co-IP of Tcf1 by Flag-tagged Mettl8 protein with anti-Flag magnetic beads after co-transfection into HEK293T cells. (H) Single-cell transcription levels of representative genes illustrated in the UMAP plot. Transcription levels are color coded: gray, not expressed; blue, expressed. (I) Schematic diagram of the tumor model: Mettl8 fl/fl Cd4 cre mice were subcutaneously injected with 2 × 10 5 B16F10 cells and harvested after 13 days. (J) Representative flow cytometry plots and cumulative data show the frequency of Tcf1 + Tox + cells gated on tumor-infiltrating CD8 + CD44 + T cells (right). n = 6 per group. (K) Schematic diagram of the OT-I–transferred tumor model: CD45.1 mice were subcutaneously injected with 2 × 10 5 EG7-OVA cells, followed by 2 × 10 6 WT or Mettl8 −/− OT-I cells transfer at 9 dpi. Mice were harvested at 21 dpi. Representative flow cytometry plots and cumulative data show the frequency of Tox + cells gated on Tcf1 + OT-I cells. n = 6 per group. (L) The MFI of Tox gated on Tcf1 + OT-I cells of the mice in K. n = 6 per group. Data are representative of two independent experiments. P value was calculated by two-tailed Student’s t test; *P < 0.05; **P < 0.01; ****P < 0.0001. Source data are available for this figure: .

Article Snippet: In briefly, cells were sorted enriched by ConA-magnetic beads and resuspended in wash Buffer (20 mM HEPES, pH 7.5; 150 mM NaCI, 0.5 mM spermidine; 1× protease inhibitor cocktail; 0.05% digitonin) and then incubated overnight with anti-Tcf1 (1:50, C63D9, cat. no. 2203; Cell Signaling Technology), anti-H3K27ac (1:50, cat. no. ab4729; Abcam), or anti-Flag (1:50, D6W5B, cat. no. 14793; Cell Signaling Technology).

Techniques: Modification, RNA Sequencing, Binding Assay, Quantitative RT-PCR, Co-Immunoprecipitation Assay, Magnetic Beads, Western Blot, Cotransfection, Single Cell, Injection, Flow Cytometry, Two Tailed Test