title: A splenic marginal zone-like peripheral blood CD27+B220- B cell population is preferentially depleted in HIV type 1-infected individuals.
abstract: Peripheral blood CD27(+) B cells are reduced in HIV-1-infected individuals. In healthy individuals, the human peripheral blood CD27(+) B cell pool consists of two subsets defined by the expression, or lack thereof, of the CD45 isoform B220. We investigated the presence of circulating B220(+) and B220(-) memory B cells in HIV(+) individuals and found that the reduction in CD27(+) memory B cells occurs primarily among CD27(+)B220(-) B cells. Studies conducted using healthy controls indicate that CD27(+)B220(-) B cells have a splenic marginal zone like the immunophenotype IgM(hi)IgD(lo)CD21(+)CD23(-), express TLR9, and proliferate and secrete IgG and IgM in response to B cell-specific ODN. CD27(+)B220(+) B cells have the immunophenotype IgM(lo)IgD(hi)CD21(+)CD23(+), express activation-induced cytidine deaminase, and proliferate in response to SAC but do not secrete immunoglobulin. The AICD expression, along with CD86 expression, by CD27(+)B220(+) suggests these cells are of germinal center origin. The preferential depletion of CD27(+)B220(-) B cells mirrors alterations in spleen morphology and resident B cell populations due to HIV infection reported by other investigators and may play an important role in the defective B cell immunity against T-independent pathogens such as pneumococcus observed in HIV-1-infected individuals.
authors.affiliation: Human Retrovirus Section, Vaccine Branch, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, Maryland 21702, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Morrow
authors.forename: Antonio
authors.initials: A
authors.lastname: Valentin
authors.forename: Richard
authors.initials: R
authors.lastname: Little
authors.forename: Robert
authors.initials: R
authors.lastname: Yarchoan
authors.forename: George N
authors.initials: GN
authors.lastname: Pavlakis
mesh_terms: D016175:B-Lymphocyte Subsets / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002478:Cells, Cultured; D003564:Cytidine Deaminase / Q000378:metabolism; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1; D006801:Humans; D007156:Immunologic Memory; D017493:Leukocyte Common Antigens / Q000096:biosynthesis*; D007963:Leukocytes, Mononuclear; D018655:Lymphocyte Count; D009841:Oligonucleotides / Q000494:pharmacology; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000096:biosynthesis*
chemical_list: D009841:Oligonucleotides; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D017493:Leukocyte Common Antigens; D003564:Cytidine Deaminase