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- Budeus, B., et al.
(författare)
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Human cord blood b cells differ from the adult counterpart by conserved ig repertoires and accelerated response dynamics
- 2021
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 206:12, s. 2839-2851
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Tidskriftsartikel (refereegranskat)abstract
- Neonatal and infant immune responses are characterized by a limited capability to generate protective Ab titers and memory B cells as seen in adults. Multiple studies support an immature or even impaired character of umbilical cord blood (UCB) B cells themselves. In this study, we provide a comprehensive molecular and functional comparison of B cell subsets from UCB and adult peripheral blood. Most UCB B cells have a mature, naive B cell phenotype as seen in adults. The UCB Ig repertoire is highly variable but interindividually conserved, as BCR clonotypes are frequently shared between neonates. Furthermore, UCB B cells show a distinct transcriptional program that confers accelerated responsiveness to stimulation and facilitated IgA class switching. Stimulation drives extensive differentiation into Ab-secreting cells, presumably limiting memory B cell formation. Humanized mice suggest that the distinctness of UCB versus adult B cells is already reflected by the developmental program of hematopoietic precursors, arguing for a layered B-1/B-2 lineage system as in mice, albeit our findings suggest only partial comparability to murine B-1 cells. Our study shows that UCB B cells are not immature or impaired but differ from their adult mature counterpart in a conserved BCR repertoire, efficient IgA class switching, and accelerated, likely transient response dynamics. © 2021 by TheAmericanAssociation of Immunologists, Inc.
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| 2. |
- Rauschmeier, R, et al.
(författare)
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Bhlhe40 function in activated B and TFH cells restrains the GC reaction and prevents lymphomagenesis
- 2021
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Ingår i: The Journal of experimental medicine. - : Rockefeller University Press. - 1540-9538 .- 0022-1007. ; 219:2
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Tidskriftsartikel (refereegranskat)abstract
- The generation of high-affinity antibodies against pathogens and vaccines requires the germinal center (GC) reaction, which relies on a complex interplay between specialized effector B and CD4 T lymphocytes, the GC B cells and T follicular helper (TFH) cells. Intriguingly, several positive key regulators of the GC reaction are common for both cell types. Here, we report that the transcription factor Bhlhe40 is a crucial cell-intrinsic negative regulator affecting both the B and T cell sides of the GC reaction. In activated CD4 T cells, Bhlhe40 was required to restrain proliferation, thus limiting the number of TFH cells. In B cells, Bhlhe40 executed its function in the first days after immunization by selectively restricting the generation of the earliest GC B cells but not of early memory B cells or plasmablasts. Bhlhe40-deficient mice with progressing age succumbed to a B cell lymphoma characterized by the accumulation of monoclonal GC B-like cells and polyclonal TFH cells in various tissues.
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