Endoplasmic reticulum expansion throughout the differentiation of teleost B cells to plasmablasts

• Published in: iScience Vol. 26; no. 1; p. 105854
• Main Authors: Morel, Esther, Herranz-Jusdado, J. Germán, Simón, Rocío, Abós, Beatriz, Perdiguero, Pedro, Martín-Martín, Alba, Andrés, Germán, Muñoz-Atienza, Estefanía, Guerra Rodriguez, Milagros, Díaz-Rosales, Patricia, Tafalla, Carolina
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 20-01-2023; Elsevier
• Subjects: Biological sciences; Immunology; Molecular biology; Molecular biology; Biological sciences; Immunology
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2022.105854

The differentiation of B cells into antibody-secreting cells is fundamental for the generation of humoral immunity. In mammals, this process involves a series of metabolic and intracellular changes, not studied to date in teleost fish, where a clear distinction between naive B cells and plasmablasts/plasma cells (PCs) is still missing. Thus, in the current study, we have established that upon activation, teleost B cells undergo an expansion of the endoplasmic reticulum (ER) but experience no significant changes in mitochondria content. In parallel, the transcription of genes implicated in B cell differentiation increases, while that of mitochondrial genes decreases. In this context, ER monitoring has allowed us to distinguish between small cells with low amounts of ER (FSCloERlo B cells), that correspond to undifferentiated cells, and large cells with expanded ER (FSChiERhi B cells), characterized as plasmablasts. The results shed new light on the B cell differentiation process in teleosts and provide us with novel tools to study B cell function in these species.
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•Fish B cells expand the ER in response to different stimuli in different tissues•Mitochondria content did not vary significantly in activated fish B cells•Transcription of mitochondrial genes decreases during fish B cell differentiation•ER monitorization allows us to differentiate fish naive B cells from plasmablasts
Biological sciences; Molecular biology; Immunology