Rat anti mouse cd4 biotin

Seven micrometer spleen and heart cryostat sections were air-dried and fixed in acetone. Primary mAbs specific for the following mouse epitopes were used for immunohistochemical/fluorescent staining: C4d (clone 16-D2 Abcam, Cambridge, UK), NK1.1 (PK136, Abcam) CD68 (ER-HR3, Abcam), mucosal addressin cell adhesion molecule (MAdCAM-1; clone MECA-367, Abcam), CD31 (Novus Biologicals, CO, USA), α-smooth muscle Actin (Thermo Fisher Scientific), and IgG-FITC (BD Biosciences, San Diego, CA, USA). Splenic GCs were identified by double-labeling sections with rat anti-mouse B220-APC (clone RA3-6B2) and rat anti mouse GL7-FITC (both BD Biosciences). Numbers of GL7⁺ GCs were expressed as a percentage of total B220⁺ lymphoid follicles (44 (link)). CD4 T cells within GCs were located with rat anti-mouse CD4-biotin (BD Biosciences) & Streptavidin-Alexa Fluor 555 (Thermo Fisher Scientific). Confocal images were captured with a Leica SP5 confocal microscope using LAS AF software, version 2.7.2.9586 (Leica Microsystems, Wetzlar, Germany).

Seven μm spleen and heart cryostat sections were air-dried and fixed in acetone. Primary mAbs specific for the following mouse epitopes were used for immunohistochemical/fluorescent staining: C4d (clone 16-D2 Abcam, Cambridge, UK) and IgG-FITC (BD Biosciences, San Diego, CA, USA). Splenic GCs were identified by double-labeling sections with rat anti-mouse B220-APC (clone RA3-6B2) and rat anti mouse GL7-FITC (both BD Biosciences). Numbers of GL7⁺ GCs were expressed as a percentage of total B220⁺ lymphoid follicles (13 (link)). HEL-specific GCs were detected using rat anti-mouse GL7-FITC and biotinylated-HEL protein (developed in-house) combined with Streptavidin-Alexa Fluor 555 (Thermo Fisher Scientific) after initially blocking endogenous avidin/biotin activity using an avidin/biotin blocking kit (Vector Laboratories, Burlingame, CA, USA). CD4 T cells within GCs were located with rat anti-mouse CD4-biotin (BD Biosciences) & Streptavidin-Alexa Fluor 555 (Thermo Fisher Scientific). Confocal images were captured with a Leica SP5 confocal microscope using LAS AF software, version 2.7.2.9586 (Leica Microsystems, Wetzlar, Germany). See also Table S1.