Role of B-1 cells in the immune response against an antigen encapsulated into phosphatidylcholine-containing liposomes

Int Immunol. 2014 Aug;26(8):427-37. doi: 10.1093/intimm/dxu042. Epub 2014 Mar 11.


B-1 lymphocytes comprise a unique subset of B cells that differ phenotypically, ontogenetically and functionally from conventional B-2 cells. A frequent specificity of the antibody repertoire of peritoneal B-1 cells is phosphatidylcholine. Liposomes containing phosphatidylcholine have been studied as adjuvants and their interaction with dendritic cells and macrophages has been demonstrated. However, the role of B-1 cells in the adjuvanticity of liposomes composed of phosphatidylcholine has not been explored. In the present work, we studied the contribution of B-1 cells to the humoral response against ovalbumin (OVA) encapsulated into dipalmitoylphosphatidylcholine (DPPC) and cholesterol-containing liposomes. BALB/X-linked immunodeficient (xid) mice, which are deficient in B-1 cells, showed quantitative and qualitative differences in the anti-OVA antibody response compared with wild-type animals after immunization with these liposomes. The OVA-specific immune response was significantly increased in the BALB/xid mice when reconstituted with B-1 cells from naive BALB/c mice. Our results indicate the internalization of DPPC-containing liposomes by these cells and their migration from the peritoneal cavity to the spleen. Phosphatidylcholine significantly contributed to the immunogenicity of liposomes, as DPPC-containing liposomes more effectively stimulated the anti-OVA response compared with vesicles composed of dipalmitoylphosphatidylglycerol. In conclusion, we present evidence for a cognate interaction between B-1 cells and phosphatidylcholine liposomes, modulating the immune response to encapsulated antigens. This provides a novel targeting approach to assess the role of B-1 cells in humoral immunity.

Keywords: B-1 lymphocytes; adjuvants; humoral response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic
  • Animals
  • Antibodies / immunology
  • Antibody Formation / immunology
  • Antibody Specificity
  • Antigens / chemistry
  • Antigens / immunology*
  • B-Lymphocyte Subsets / immunology*
  • B-Lymphocyte Subsets / metabolism
  • Cell Movement
  • Female
  • Immunization
  • Liposomes
  • Mice
  • Ovalbumin / immunology
  • Phosphatidylcholines / chemistry
  • Phosphatidylcholines / immunology
  • Spleen / immunology


  • Adjuvants, Immunologic
  • Antibodies
  • Antigens
  • Liposomes
  • Phosphatidylcholines
  • Ovalbumin