B7S1, a novel B7 family member that negatively regulates T cell activation
Authors: Sabrina Richards
Chen Dong
Durbaka V R Prasad
Xoi Muoi Mai
Journal: Immunity (2003)
Discipline: IMMUNOLOGY
Keywords: T cell activation; antigen-presenting cells; B7S1; costimulatory molecules; GPI linkage
Affiliations: Department of Immunology, University of Washington School of Medicine, Seattle, WA 98195, USA.

Abstract:  T cell activation by antigen-presenting cells (APC) is regulated by positive and negative costimulatory molecules in the B7 family. Here we describe a novel addition in this family, designated as B7S1, which is uniquely anchored to the cell membrane via a GPI linkage. B7S1 is expressed on professional APC and widely distributed in nonlymphoid tissues. A soluble B7S1-Ig fusion protein binds to activated but not naive T cells. B7S1-Ig inhibits T cell activation and IL-2 production. A monoclonal antibody that blocks binding of B7S1 to its receptor enhances T cell proliferation in vitro and exacerbates experimental autoimmune encephalomyelitis in vivo. This study identifies a novel negative regulator of T cell activation and further reveals complex costimulatory regulation of immune responses. 

Retracted: No

PubPeer comments:
 In Figure 3B, the gating for CD11C in the Spleen is significantly different compared to CD4, CD8, and B220. Since the manuscript was comparing the cell percentage, could the authors please explain why only CD11C is different? ![file] , 
 First of all, prior to addressing this specific question, we would like to clarify that there are no guidelines within the immunology research field that FACS gating should be kept exactly the SAME for various samples, especially for samples collected from different tissues, at different time points and or stained with different combinations of intracellular or surface markers. In fact, it is the well-accepted consensus by the research community that gating could be and should be adjusted according to factors including but not limited to controls used and intensities of isotype staining. The scientific principles underlying such adjustments include varying levels of auto-fluorescence and varying degrees of laser compensation. With the above being said, we still spend time to compose comprehensive answers to each specific question on FACS gating with the hope that the user community would witness our good will and support of the Pubpeeru2019s principles of fostering open and honest discussions on scientifically related issues of high values. In this figure, we analyzed expression of B7S1 in various types of immune cells. In case the anonymous commenter is not aware, CD11C, CD4, CD8 and B220 are distinct cell surface proteins that display different expression features, naturally resulting in different staining patterns. In addition, these antibodies were conjugated with different fluorescent labels, as shown below in the blue lined boxes (CD11C and CD4 in FITC, CD8 and B220 in APC). Under these scenarios, application of different gating strategies in FACS analysis is not only legitimate but also necessary. Thus, it remains rather puzzling what scientific or technical significance the anonymous commenter is trying reach. -Chen Dong ![file] ,