Toxicity of B Cell Products in Multiple Sclerosis

[frodo]

Again, a new report of B-cells from MS patients secreting something toxic:

Toxicity of Released B Cell Products in Multiple Sclerosis

Abstract: https://www.cambridge.org/core/journals ... EEB8659EBB

Pdf available: https://www.cambridge.org/core/services ... ocytes.pdf

OBJECTIVES/SPECIFIC AIMS:

We previously demonstrated that products released by cultured B cells from patients with Multiple Sclerosis (MS) are cytotoxic to neurons and oligodendrocytes, while minimal toxicity was observed in response to B cell secretory products from age- and sex-matched normal controls.

The goal of this proposal is to identify the range of brain cells susceptible to MS B cell-mediated cytotoxicity, to define the cytotoxic factor(s) released by MS B cells, and to determine whether particular subset(s) of MS B cells harbor the greatest pathogenic potential.

RESULTS/ANTICIPATED RESULTS:

We hypothesize that the toxicity of MS B cell products is mediated, at least in part, by extracellular vesicles, such as exosomes. We expect depletion of these exosomes from the B cell conditioned media or inhibition of their biogenesis will mitigate the observed toxicity.

Furthermore, differences in B cell-derived exosomal content, such as proteins, (mi)RNAs, or lipids, likely explain the differences in observed toxicity. Lastly, we hypothesize that memory B cells, which are enriched in the CNS of MS patients and demonstrate a more pro-inflammatory profile than naïve B cells, are responsible for the toxicity observed in supernatants of total B cells.