Journal: The Journal of Clinical Investigation
Article Title: In vivo visualization and molecular targeting of the cardiac conduction system
Figure Lengend Snippet: ( A ) Antibody-dye conjugate (mCntn2-800) consists of a near-infrared (NIR) dye conjugated to an antibody against the CCS-specific surface marker Cntn2 (contactin 2). ( B ) Experimental work flow. ( C ) Whole-body biodistribution of other tissue types, showing expected clearance within the liver, bladder, and kidneys and notable absence from the brain. ( D ) Whole mouse heart ( n = 3) from a wild-type (WT) mouse injected 3 days prior with mCntn2-800, in posterior-anterior (PA) and right lateral (RL) views. Atria are outlined in white and cardiac chambers are listed. LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle. Top: Brightfield. Bottom: NIR signal demonstrating labeling of the CCS (blue→red = lowest→highest signal). Mean signal to background ratio (SBR) is indicated. ( E ) Measured intervals (in ms) from sedated surface electrocardiograms (ECGs) including PR, QRS, QTc, and RR in WT mice prior to (day 0 = baseline, n = 12) and daily (day 1 n = 3, day 2 n = 9; after injection) following a single tail vein injection of mCntn2-800. Intervals (mean ± SD) on a given day after injection were compared to each mouse’s preinjection control baseline (day 0) using 1-way ANOVA with Tukey’s post hoc test. ( F – H ) Heart sections from a WT mouse injected 2 days prior with mCntn2-800. CCS components labeled with mCntn2-800 (purple) and costained with antibodies targeting known markers of the CCS, including anti-Hcn4 (red, SAN and His) or anti-Cx40 (green, PF). DAPI (blue, nuclei). LBB/RBB, left and right bundle branches; His, His bundle; PF, Purkinje fibers; SAN, sinoatrial node; VM, ventricular myocardium. Scale bars: 10 mm ( C ), 5 mm ( D ), and 100 μm ( F – H ).
Article Snippet: A phage display system was used (Promab Biotech, Inc) to screen for monoclonal Fab antibodies targeting the human CNTN2-His recombinant protein (Acro Biosystems, CN2-H5226).
Techniques: Marker, Injection, Labeling