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A developmental switch between fetal and adult B lymphopoiesis
Author(s) -
Li YueSheng,
Zhou Yan,
Tang Lingjuan,
Shinton Susan A.,
Hayakawa Kyoko,
Hardy Richard R.
Publication year - 2015
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/nyas.12769
Subject(s) - lymphopoiesis , immunoglobulin d , biology , cd5 , b cell , bone marrow , b 1 cell , haematopoiesis , immunology , microbiology and biotechnology , microrna , transcription factor , fetus , immune system , antibody , genetics , t cell , stem cell , antigen presenting cell , gene , pregnancy
Fluorescence‐activated cell sorting (FACS)–purified pro‐B cells from fetal liver and adult bone marrow generate B cells with distinct phenotypes: fetal cells generate few IgD high B cells and half express CD5, whereas adult cells generate mostly IgD high cells and few express CD5. These results led us to propose a model of a developmental switch in B lymphopoiesis, similar to the well‐known switch in fetal to adult erythropoiesis. More recent global analysis of mRNA and microRNA expression comparing these two types of pro‐B cells revealed differential expression of Lin28b and microRNAs from the Let‐7 family, indicating that this regulatory axis plays a role in the switch. Further analysis has provided data supporting this model, implicating Arid3a as a key transcription factor in mediating fetal‐type B cell development. Function of this regulatory axis in human B lineage precursors may also explain the predominance of CD5 + B cells in cord blood. We suggest that Lin28b‐promoted B cell development generates many cells expressing CD5 as a consequence of positively selected self‐reactivity. While such cells serve a useful role in clearance of senescent cells and in certain immune responses, they also carry the risk of progression to leukemia/lymphoma later in life.