Genetic control of the B cell response to LPS: opposing  effects in peritoneal versus splenic B cell populations.
Lipopolysaccharide (LPS) from gram-negative bacteria activates B cells, enabling them to proliferate and differentiate into plasma cells. This response is critically dependent on the expression of TLR4; but other genes, such as RP105 and MHC class II, have also been shown to contribute to B cell LPS response. Here, we have evaluated the role of genetic control of the B cell response to LPS at the single cell level. We compared the response to LPS of peritoneal cavity (PEC) and splenic B cells on the BALB/c genetic background (LPS-low responder) to those on the C57BL/6J background (LPS-high responder) and their F1 progeny (CB6F1). Both PEC and splenic B cells from B6 exhibited 100% clonal growth in the presence of LPS; whereas, BALB/c PEC and splenic B cells achieved only 50% and 23% clonal growth, respectively. Adding CpG to the LPS stimulus pushed PEC B cell clonal growth in the low responder strain BALB/c up to 90%, showing that the nonresponse to LPS is a specific effect. Surprisingly, PEC B cells on the F1 background behaved as high responders, while splenic B cells behaved as low responders to LPS. The data presented here reveals a previous unsuspected behavior in the genetic control of the B cell response to LPS with an opposing impact in splenic versus peritoneal cavity B cells. These results suggest the existence of an, as yet, unidentified genetic factor exclusively expressed by coelomic B cells that contributes to the control of the LPS signaling pathway in the B lymphocyte.
Vale
A M
AM
Department of Immunology, Institute of Microbiology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
Hayashi
E
E
Granato
A
A
Schroeder
H W
HW
Bellio
M
M
Nobrega
Alberto
A
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D003433:Crosses, Genetic; D005260:Female; D005786:Gene Expression Regulation; D008070:Lipopolysaccharides / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010537:Peritoneum / Q000166:cytology / Q000276:immunology*; D013154:Spleen / Q000166:cytology* / Q000276:immunology
D008070:Lipopolysaccharides