Abstract
In mammals, conventional B (B2) cells are activated within lymphoid follicles through a close relationship with T follicular helper (Tfh) cells. The interaction between CD40 expressed on B cells and its ligand (CD40L) expressed on Tfh cells is a key signal that regulates the formation of germinal centers (GCs), B cell survival, proliferation and differentiation to plasma cells (PCs) or memory cells. Additionally, certain soluble cytokines produced by T cells also strongly condition the outcome of this interaction. Despite the many differences found between fish B cells and mammalian B2 cells, and the lack of conventional GCs, rainbow trout IgM+ B cells have been shown to be stimulated by CD40L, however, whether cytokines commonly produced by T cells can further modulate this response has never been addressed to date. Thus, in this study, we determined the effects of recombinant rainbow trout adaptive cytokines interleukin 2B (IL-2B), IL-4/13A, IL-4/13B, IL-10 and IL-21 (cytokines known to activate B cells in mammals) on splenic IgM+ B cells alone or in combination with CD40L. We studied how these cytokines and CD40L cooperated to promote IgM+ B cell survival, proliferation and IgM secretion. The results obtained provide valuable information for the first time in teleost fish on how different T cell signals cooperate to activate B cells in the absence of GCs.
Original language | English |
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Article number | 103752 |
Number of pages | 11 |
Journal | Developmental and Comparative Immunology |
Volume | 111 |
Early online date | 22 May 2020 |
DOIs | |
Publication status | Published - Oct 2020 |
Bibliographical note
AcknowledgementsThis work was supported by the European Research Council (ERC Consolidator Grant 725061) and by the Spanish Ministry of Science, Innovation and Universities (project AGL2017-85494-C2-1-R).
Keywords
- B cells
- CD40L
- IL-2B
- IL-4/13
- IL-10
- IL-21