The soluble pattern recognition receptor PTX3 links humoral innate and adaptive immune responses by helping marginal zone B cells Academic Article uri icon

Overview

MeSH Major

  • Adaptive Immunity
  • B-Lymphocytes
  • C-Reactive Protein
  • Immunity, Humoral
  • Immunity, Innate
  • Receptors, Pattern Recognition
  • Serum Amyloid P-Component

abstract

  • Pentraxin 3 (PTX3) is a fluid-phase pattern recognition receptor of the humoral innate immune system with ancestral antibody-like properties but unknown antibody-inducing function. In this study, we found binding of PTX3 to splenic marginal zone (MZ) B cells, an innate-like subset of antibody-producing lymphocytes strategically positioned at the interface between the circulation and the adaptive immune system. PTX3 was released by a subset of neutrophils that surrounded the splenic MZ and expressed an immune activation-related gene signature distinct from that of circulating neutrophils. Binding of PTX3 promoted homeostatic production of IgM and class-switched IgG antibodies to microbial capsular polysaccharides, which decreased in PTX3-deficient mice and humans. In addition, PTX3 increased IgM and IgG production after infection with blood-borne encapsulated bacteria or immunization with bacterial carbohydrates. This immunogenic effect stemmed from the activation of MZ B cells through a neutrophil-regulated pathway that elicited class switching and plasmablast expansion via a combination of T cell-independent and T cell-dependent signals. Thus, PTX3 may bridge the humoral arms of the innate and adaptive immune systems by serving as an endogenous adjuvant for MZ B cells. This property could be harnessed to develop more effective vaccines against encapsulated pathogens.

publication date

  • January 2016

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC5030794

Digital Object Identifier (DOI)

  • 10.1084/jem.20150282

PubMed ID

  • 27621420

Additional Document Info

start page

  • 2167

end page

  • 85

volume

  • 213

number

  • 10