The peritoneal cavity B-2 antibody repertoire appears to reflect many of the same selective pressures that shape the B-1a and B-1b repertoires.
To assess the extent and nature of somatic categorical selection of CDR-3 of the Ig H chain (CDR-H3) content in peritoneal cavity (PerC) B cells, we analyzed the composition of V(H)7183DJCμ transcripts derived from sorted PerC B-1a, B-1b, and B-2 cells. We divided these sequences into those that contained N nucleotides (N(+)) and those that did not (N(-)) and then compared them with sequences cloned from sorted IgM(+)IgD(+) B cells from neonatal liver and both wild-type and TdT-deficient adult bone marrow. We found that the PerC B-1a N(-) repertoire is enriched for the signatures of CDR-H3 sequences present in neonatal liver and shares many features with the B-1b N(-) repertoire, whereas the PerC B-1a N(+), B-1b N(+), and B-2 N(+) repertoires are enriched for adult bone marrow sequence signatures. However, we also found several sequence signatures that were not shared with other mature perinatal or adult B cell subsets but were either unique or variably shared between the two or even among all three of the PerC subsets that we examined. These signatures included more sequences lacking N nucleotides in the B-2 population and an increased use of D(H) reading frame 2, which created CDR-H3s of greater average hydrophobicity. These findings provide support for both ontogenetic origin and shared Ag receptor-influenced selection as the mechanisms that shape the unique composition of the B-1a, B-1b, and B-2 repertoires. The PerC may thus serve as a general reservoir for B cells with Ag binding specificities that are uncommon in other mature compartments.
Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
Andre M
AM
Vale
Jason M
JM
Tanner
Robert L
RL
Schelonka
Yingxin
Y
Zhuang
Michael
M
Zemlin
G Larry
GL
Gartland
Harry W
HW
Schroeder
D000818:Animals; D000916:Antibody Diversity; D016175:B-Lymphocyte Subsets / Q000737:chemistry / Q000276:immunology*; D001402:B-Lymphocytes / Q000737:chemistry / Q000276:immunology*; D001483:Base Sequence; D002469:Cell Separation; D022801:Complementarity Determining Regions / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D005434:Flow Cytometry; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010529:Peritoneal Cavity / Q000166:cytology*; D054448:Precursor Cells, B-Lymphoid / Q000737:chemistry / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D022801:Complementarity Determining Regions