New aspects in the regulation of human B cell functions by complement receptors CR1, CR2, CR3 and CR4

Immunol Lett. 2021 Sep:237:42-57. doi: 10.1016/j.imlet.2021.06.006. Epub 2021 Jun 26.

Abstract

The involvement of complement in the regulation of antibody responses has been known for long. By now several additional B cell functions - including cytokine production and antigen presentation - have also been shown to be regulated by complement proteins. Most of these important activities are mediated by receptors interacting with activation fragments of the central component of the complement system C3, such as C3b, iC3b and C3d, which are covalently attached to antigens and immune complexes. This review summarizes the role of complement receptors interacting with these ligands, namely CR1 (CD35), CR2 (CD21), CR3 (CD11b/CD18) and CR4 (CD11c/CD18) expressed by B cells in health and disease. Although we focus on human B lymphocytes, we also aim to call the attention to important differences between human and mouse systems.

Keywords: B cell; CR1 (CD35); CR2 (CD21); CR3 (CD11b/CD18); CR4 (CD11c/CD18); Complement receptors; Regulation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Antibody Formation
  • Autoimmune Diseases / genetics
  • Autoimmune Diseases / immunology
  • B-Lymphocytes / immunology*
  • Cell Division
  • Complement C3 / immunology*
  • Gene Expression
  • Humans
  • Immunologic Memory
  • Ligands
  • Mice
  • Organ Specificity
  • Receptors, Antigen, B-Cell / immunology
  • Receptors, Complement / chemistry
  • Receptors, Complement / genetics
  • Receptors, Complement / immunology*
  • Species Specificity
  • Structure-Activity Relationship

Substances

  • Complement C3
  • Ligands
  • Receptors, Antigen, B-Cell
  • Receptors, Complement