Journal: Nature Communications
Article Title: CEACAM1 as a mediator of B-cell receptor signaling in mantle cell lymphoma
doi: 10.1038/s41467-025-60208-3
Figure Lengend Snippet: a Left panel, CEACAM1 suppresses BCR signaling in Z-138 cells. Z-138 cells were transduced with control empty vector (EV), WT CEACAM1 (CC1-4L), or short cytoplasmic tail CEACAM1 (CC1-4S). Transduced cells were stimulated with 2 μg/mL of anti-IgM F(ab’)2 fragments for the indicated times, followed by immunoblot analysis probed with the indicated antibodies. HA, hemagglutinin, a protein tag in-framed with CEACAM1 to detect the 4S isoform. Right panel, Quantification of the immunoblot signals shown in the left panel. Bar graphs show the means of densitometric values from the indicated time points normalized to GAPDH loading controls from two independent experiments. P values, one-sided permutation test. b , c CEACAM1-knockout JEKO-1 cells (gCC1) or Z-138 cells were transduced with either empty vector control or full-length (4 L) CEACAM1 construct, stimulated with 2 μg/ml anti-IgM antibody for the indicated times, followed by CEACAM1 immunoprecipitation and immunoblotting with indicated antibodies. One percent of the total lysates was used as an input control ( b ). The samples shown in ( b ) derive from the same experiment, but different gels for CEACAM1, p-SYK Y352 , SYK, SHP-1, GAPDH, and another for SHP-2 were processed in parallel. Bar graphs show the quantification of the co-IP signals shown in ( c ). Shown are the means of densitometric values from two independent experiments for each timepoint normalized to the CEACAM1 pull-down signals. **** P < 0.0001, *** P < 0.001, ** P < 0.01, * P < 0.05 by two-way ANOVA. d Left panels, Proximity ligation assay (PLA) showing interactions (visualized as red dots using Airyscan FAST 2D confocal microscope and a 40x/1.2NA water objective) between CEACAM1 (CC1) and the indicated proteins in Z-138 cells or Z-138 cells transduced with CEACAM1-4L followed by stimulation with 2 μg/ml of anti-IgM antibody for the indicated times. Right panels, Quantification of PLA signals shown in the right panels for ~200 cells on average from three independent experiments using QuPath 0.3.2 software. **** P < 0.0001 by a two-sided unpaired t -test with Welch’s correction. Source data are provided as a Source Data file.
Article Snippet: Because the CEACAM1 antibodies used in immunoblotting (Santa Cruz Biotechnology, clone E-1) and IHC (Abcam, clone EPR4049) only recognize the long isoforms of CEACAM1 while the CEACAM1 antibody used in flow cytometry (eBioscience, clone CD66a-B1.1) recognizes the ectodomain of CEACAM1, CEACAM3, CEACAM5, and CEACAM6, we further clarified which CEACAM members are expressed in MCL cells.
Techniques: Transduction, Control, Plasmid Preparation, Western Blot, Knock-Out, Construct, Immunoprecipitation, Co-Immunoprecipitation Assay, Proximity Ligation Assay, Microscopy, Software