Differences in mouse and human nonmemory B cell pools.
Identifying cross-species similarities and differences in immune development and function is critical for maximizing the translational potential of animal models. Coexpression of CD21 and CD24 distinguishes transitional and mature B cell subsets in mice. In this study, we validate these markers for identifying analogous subsets in humans and use them to compare the nonmemory B cell pools in mice and humans, across tissues, and during fetal/neonatal and adult life. Among human CD19(+)IgM(+) B cells, the CD21/CD24 schema identifies distinct populations that correspond to transitional 1 (T1), transitional 2 (T2), follicular mature, and marginal zone subsets identified in mice. Markers specific to human B cell development validate the identity of marginal zone cells and the maturation status of human CD21/CD24 nonmemory B cell subsets. A comparison of the nonmemory B cell pools in bone marrow, blood, and spleen in mice and humans shows that transitional B cells comprise a much smaller fraction in adult humans than mice. T1 cells are a major contributor to the nonmemory B cell pool in mouse bone marrow, in which their frequency is more than twice that in humans. Conversely, in spleen, the T1:T2 ratio shows that T2 cells are proportionally ∼ 8-fold higher in humans than in mice. Despite the relatively small contribution of transitional B cells to the human nonmemory pool, the number of naive follicular mature cells produced per transitional B cell is 3- to 6-fold higher across tissues than in mice. These data suggest differing dynamics or mechanisms produce the nonmemory B cell compartments in mice and humans.
Department of Basic Sciences, Loma Linda University, Loma Linda, CA 92350;
Abigail
A
Benitez
Abby J
AJ
Weldon
Lynnette
L
Tatosyan
Vani
V
Velkuru
Steve
S
Lee
Terry-Ann
TA
Milford
Olivia L
OL
Francis
Sheri
S
Hsu
Kavoos
K
Nazeri
Carlos M
CM
Casiano
Rebekah
R
Schneider
Jennifer
J
Gonzalez
Rui-Jun
RJ
Su
Ineavely
I
Baez
Keith
K
Colburn
Ioana
I
Moldovan
Kimberly J
KJ
Payne
D000328:Adult; D000818:Animals; D018941:Antigens, CD19 / Q000276:immunology*; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D051927:CD24 Antigen / Q000276:immunology*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D051379:Mice; D008875:Middle Aged; D017464:Receptors, Complement 3d / Q000276:immunology*; D013045:Species Specificity
D018941:Antigens, CD19; D051927:CD24 Antigen; C497889:CD24 protein, human; C497890:Cd24a protein, mouse; D017464:Receptors, Complement 3d