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Updated: Jul 24, 2025

Evaluation of T Follicular Helper Cells and Germinal Center Response During Influenza A Virus Infection in Mice
Published on: June 27, 2020
TACI and endogenous APRIL in B cell maturation
Yolanda Garcia-Carmona1, Miguel Fribourg2, Allison Sowa3
1Division of Clinical Immunology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York City, NY 10029, USA; Marc and Jennifer Lipschultz Precision Immunology Institute, Icahn School of Medicine at Mount Sinai, New York City, NY 10029, USA.
The TACI-S protein isoform is crucial for terminal B cell differentiation into plasma cells. Intracellular TACI-S, BCMA, and APRIL collaborate to direct this process and ensure plasma cell survival.
Area of Science:
- Immunology
- Molecular Biology
- Cell Biology
Background:
- Germinal center B cell response is key for antibody production, but terminal differentiation pathways are not fully understood.
- Mutations in the TACI gene are linked to common variable immunodeficiency, impaired B cell differentiation, and autoimmune disorders.
- Human B cells express TACI-L and TACI-S isoforms, with TACI-S specifically promoting plasma cell differentiation.
Purpose of the Study:
- To investigate the role of intracellular TACI-S, BCMA, and APRIL in terminal B cell differentiation.
- To elucidate the molecular mechanisms underlying B cell terminal differentiation and plasma cell survival.
Main Methods:
- Analysis of intracellular TACI-S expression and its colocalization with BCMA and APRIL during B cell activation.
- Assessment of isotype class switching, metabolic, and transcriptional changes upon loss of APRIL.
- Studies on the contribution of intracellular TACI-S, BCMA, and APRIL to plasma cell differentiation and survival.
Main Results:
- Intracellular TACI-S expression increases with B cell activation and colocalizes with BCMA and APRIL.
- Loss of APRIL significantly impairs isotype class switching and induces distinct metabolic and transcriptional alterations.
- Intracellular TACI-S, BCMA, and APRIL are essential for long-term plasma cell differentiation and survival.
Conclusions:
- Intracellular TACI-S, in conjunction with BCMA and APRIL, plays a critical role in directing terminal B cell differentiation into plasma cells.
- This molecular complex is vital for maintaining plasma cell populations and ensuring sustained antibody production.
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