Plasma cells

Plasma cells are terminally differentiated B cells that are specialized for antibody secretion. Authors show here that genomic deletion of the p38α mitogen activated protein kinase specifically in the B cell lineage leads to diminished plasma cell differentiation via impairment of a transcriptional regulatory program by BLIMP1.

Plasma B cells (PC) are a potential source for protein replacement as they could be engineered to secrete protein other than antibody. Here the authors engineer B cells to express exogenous proteins and demonstrate that these cells can persist long term in adoptive transfer experiments in mice.

Platelets have been shown to alter immune cell function but it is not clear if this includes autoimmunity. Here the authors show that phosphatase and tensin homolog (PTEN) deficient platelets promote autoimmunity in mouse models through excessive activation of T_FH cells and systemic autoimmune pathology.

Elevated levels of IgE is associated with a range of allergic pathology but the source of such IgE producing B cells during the steady state is poorly understood. Here, Kwon et al. show that homeostatic IgE is secreted by plasma cells in the thymus and link this to mast cell survival.

Sequencing of B cell receptors and expression of the corresponding monoclonal antibodies is used to characterize the evolution of the long-term B cell response to SARS-CoV-2 mRNA vaccination.

SARS-CoV-2 infection induces long-lived bone marrow plasma cells that correlate with anti-SARS-CoV-2 spike protein antibody titres in individuals who have recovered from COVID-19.