Sec22b: A new regulator of antibody-secreting cell function and survival

What is it about?

Plasma cells are mini-factories responsible for antibody production and secretion. These cells are generated after each infection or vaccination and can persist for long periods of time in our body. The antibodies they produce are essential to protect us from infection. However, in some circumstances plasma cells and antibodies may be detrimental for our health. This is the case for example in some autoimmune diseases like systemic lupus erythematosus in which plasma cells produce pathologic antibodies. In this study, we demonstrated that the protein Sec22b is a critical regulator of antibody secretion but also of plasma cell survival. In absence of Sec22b, the antibody-mediated vaccinal and anti-viral responses were totally abrogated. At the mechanistic level, we showed that Sec22b regulates the expansion and shape of an intracellular organelle called the endoplasmic reticulum responsible for protein production and transport. Moreover, Sec22b is important for the function of mitochondria that are the energy factories within our cells.

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Photo by National Cancer Institute on Unsplash

Photo by National Cancer Institute on Unsplash

Why is it important?

Despite their importance in health and disease the mechanisms controlling plasma cell survival and antibody secretion are not fully understood. Gaining a better knowledge of these mechanisms is thus of key importance for improving vaccine responses in some populations, like in the elderly, or to target plasma cells when they turn rogue. Our study unravels that Sec22b-mediated regulation of the intracellular organelles (endoplasmic reticulum, mitochondria) is essential for plasma cell biology and thus open new avenues to target these cells.