B-1 CELLS IN INNATE AND ACQUIRED IMMUNITY

MARIANO M.(1)

(1)Discipline of Immunology, Department of Microbiology, Immunology and Parasitology, Federal University of São Paulo, São Paulo, Brazil.

The term B-1 cell was originally proposed to describe a subtype of B lymphocytes, which differs from B conventional cells by anatomical localization, developmental origin, surface markers expression, antibody repertoire and growth properties. B-1 cells express high levels of surface IgM, low levels of B220 (CD45R) and IgD, but not CD23, whereas conventional B-2 cells express high levels of B220 and IgD, CD23 and low levels of IgM. Besides, typical B-1 cells residing in peritoneal cavity also express low levels of Mac-1 (CD11b). Further, B-1 cells are sub classified in B-1a cells, which express CD5, and their phenotypic CD5- “twins”, B-1b cells. Our laboratory has demonstrated that B-1b cells proliferate in cultures of adherent mouse peritoneal cells and differentiate into a mononuclear phagocyte, provisionally named “lymphophage”. Yet, that these cells migrate from the peritoneal cavity to a non specific inflammatory lesion. From these observations the origin, differentiation and function of these cells in normal and pathological conditions has being intensively investigated in our laboratory.  Results bringing evidence that B-1 cells participate in innate and acquired immunity will be presented and discussed.

CORRESPONDENCE TO:

Mário Mariano, Universidade Federal de São Paulo. Rua Dr. Bacelar nº 1212, 4º andar, Vila Clementino, CEP 04026-002, São Paulo, SP, Brasil. Email: mmariano@ecb.epm.br