Villous B cells of the small intestine are specialized for invariant NK T cell dependence.
B cells are important in mucosal microbial homeostasis through their well-known role in secretory IgA production and their emerging role in mucosal immunoregulation. Several specialized intraintestinal B cell compartments have been characterized, but the nature of conventional B cells in the lamina propria is poorly understood. In this study, we identify a B cell population predominantly composed of surface IgM(+) IgD(+) cells residing in villi of the small intestine and superficial lamina propria of the large intestine, but distinct from the intraepithelial compartment or organized intestinal lymphoid structures. Small intestinal (villous) B cells are diminished in genotypes that alter the strength of BCR signaling (Bruton tyrosine kinase(xid), Galphai2(-/-)), and in mice lacking cognate BCR specificity. They are not dependent on enteric microbial sensing, because they are abundant in mice that are germfree or genetically deficient in TLR signaling. However, villous B cells are reduced in the absence of invariant NK T cells (Jalpha18(-/-) or CD1d(-/-) mice). These findings define a distinct population of conventional B cells in small intestinal villi, and suggest an immunologic link between CD1-restricted invariant NK T cells and this B cell population.
Velázquez
Peter
P
Department of Pathology and Laboratory Medicine, University of California, Los Angeles, CA 90095, USA.
Wei
Bo
B
McPherson
Michael
M
Mendoza
Lesley Marie A
LM
Nguyen
Sandra L
SL
Turovskaya
Olga
O
Kronenberg
Mitchell
M
Huang
Tiffany T
TT
Schrage
Matthew
M
Lobato
Lynn N
LN
Fujiwara
Daisuke
D
Brewer
Sarah
S
Arditi
Moshe
M
Cheng
Genhong
G
Sartor
R Balfour
RB
Newberry
Rodney D
RD
Braun
Jonathan
J
D000375:Aging / Q000502:physiology; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology; D018949:Antigens, CD1 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002465:Cell Movement / Q000276:immunology; D002469:Cell Separation; D007413:Intestinal Mucosa / Q000166:cytology / Q000276:immunology; D007421:Intestine, Small / Q000166:cytology / Q000276:immunology* / Q000648:ultrastructure; D051379:Mice; D018345:Mice, Knockout; D008871:Microvilli / Q000276:immunology; D010641:Phenotype; D011947:Receptors, Antigen, B-Cell / Q000276:immunology; D012680:Sensitivity and Specificity; D015398:Signal Transduction / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
D018949:Antigens, CD1; D011947:Receptors, Antigen, B-Cell