B Cell Development and T-Dependent Antibody Response Are Regulated by p38γ and p38δ

• Published in: Frontiers in cell and developmental biology Vol. 8; p. 189
• Main Authors: Barrio, Laura, Román-García, Sara, Díaz-Mora, Ester, Risco, Ana, Jiménez-Saiz, Rodrigo, Carrasco, Yolanda R., Cuenda, Ana
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 24.03.2020
• Subjects: B cell; Cell and Developmental Biology; lymphocyte; p38MAPK; p38γ; p38δ; spleen; B cell; p38δ; spleen; p38γ; p38MAPK; lymphocyte
• ISSN: 2296-634X; 2296-634X
• DOI: 10.3389/fcell.2020.00189

p38MAP kinase (MAPK) signal transduction pathways are important regulators of inflammation and the immune response; their involvement in immune cell development and function is still largely unknown. Here we analysed the role of the p38 MAPK isoforms p38γ and p38δ in B cell differentiation in bone marrow (BM) and spleen, using mice lacking p38γ and p38δ, or conditional knockout mice that lack both p38γ and p38δ specifically in the B cell compartment. We found that the B cell differentiation programme in the BM was not affected in p38γ/δ-deficient mice. Moreover, these mice had reduced numbers of peripheral B cells as well as altered marginal zone B cell differentiation in the spleen. Expression of co-stimulatory proteins and activation markers in p38γ/δ-deficient B cells are diminished in response to B cell receptor (BCR) and CD40 stimulation; p38γ and p38δ were necessary for B cell proliferation induced by BCR and CD40 but not by TLR4 signaling. Furthermore, p38γ/δ-null mice produced significantly lower antibody responses to T-dependent antigens. Our results identify unreported functions for p38γ and p38δ in B cells and in the T-dependent humoral response; and show that the combined activity of these kinases is needed for peripheral B cell differentiation and function.