B cells are an important part of our immune system because these cells "grow up" to be the antibody-producing cells of the immune system. Without antibodies, our bodies are not able to fight many infections. But if our body doesn't eliminate antibodies that react to allergens or our own proteins, we get allergies or auto-immune diseases. So it is important to understand how B cells develop from early precursor cells to fully-formed antibody-producing factories.

We have recently found that developing B cells secrete very small vesicles, called extracellular vesicles (EVs), when a receptor called CD24 is stimulated. These EVs are pinched off the surface of the cell and can be used to move CD24 between different cells. We know that CD24 stimulation causes B cells to kill themselves! We were then able to show that CD24 and the B cell receptor carried by these EVs are taken up by recipient cells who can then be killed via activation of these newly acquired receptors. But how are they generated and what do they do in the body? These are our next questions.

Funding for this project is from NSERC and MUN, with student support from BHCRI and MUN.

Phan HD, Longjohn MN, Gormley DJB, Smith RH, Dang-Lawson M Matsuuchi L, Gold MR, and Christian SL. (2021) CD24 and IgM Stimulation of B Cells Triggers Transfer of Functional B Cell Receptor to B Cell Recipients Via Extracellular Vesicles. Journal of Immunology. 207 (12) 3004-3015

Ayre, DC, Elstner, M, Smith, NC, Moores, ES, Hogan, AM, and Christian, SL (2015) Immature B cells Dynamically Regulate CD24 Expression and Release CD24-Containing Microvesicles Following Antibody Stimulation. Immunology. 217–233.

Ayre, D.C., Chute, I.C., Joy, A.P., Barnett, D.A., Hogan, A.M., Grüll, M.P., Peña-Castillo, L., Lang, A.S., Lewis, S.M., and Christian, S.L. (2017). CD24 induces changes to the surface receptors of B cell microvesicles with variable effects on their RNA and protein cargo. Scientific Reports 7, 8642.