Rainbow trout IgM+ B cells preferentially respond to thymus-independent antigens but are activated by CD40L

In the absence of class switch recombination and germinal centers, the mechanisms through which B cells from teleost fish mount extrafollicular immunoglobulin M (IgM) memory responses remains mostly unexplored. In this report, we demonstrate that teleost IgM+ B cells respond to CD40L, a thymus-depen...

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Bibliographic Details
Authors: Granja, Aitor, Perdiguero Jiménez, Pedro, Martín-Martín, Alba, Díaz-Rosales, Patricia, Soleto, Irene, Tafalla, Carolina
Format: article
Publication Date:2019
Country:España
Institution:Universidad Complutense de Madrid (UCM)
Repository:Docta Complutense
Language:English
OAI Identifier:oai:docta.ucm.es:20.500.14352/96689
Online Access:https://hdl.handle.net/20.500.14352/96689
Access Level:Open access
Keyword:577.112
Teleost fish
B cells
IgM
Extrafollicular responses
CD40L
Bioquímica (Biología)
31 Ciencias Agrarias
2403 Bioquímica
Description
Summary:In the absence of class switch recombination and germinal centers, the mechanisms through which B cells from teleost fish mount extrafollicular immunoglobulin M (IgM) memory responses remains mostly unexplored. In this report, we demonstrate that teleost IgM+ B cells respond to CD40L, a thymus-dependent activation signal, similarly to mammalian B2 cells. However, when stimulated with different types of antigens, fish IgM+ B cells only reach a general activation state in response to antigens cataloged as thymus-independent 1 (TI-1) in mammals, as established through both functional assays and RNA sequencing. Interestingly, fish IgM+ B cells remained completely unresponsive to TI-2 antigens, suggesting that the engagement of innate receptors provided by TI-1 antigens is required for the activation of teleost B cells. Finally, a synergy between CD40L and TI-1 antigens was also demonstrated, further supporting that there is no clear dichotomy between thymus-dependent and TI responses in teleost fish