Anti-CD20 treatment effectively attenuates cortical pathology in a rat model of widespread cortical demyelination

Background

Cortical demyelination represents a prominent feature of the multiple sclerosis (MS) brain, especially in (late) progressive stages. We recently developed a new rat model that reassembles critical features of cortical pathology characteristic to progressive types of MS. In persons affected by MS, B-cell depleting anti-CD20 therapy proved successful in the relapsing remitting as well as the early progressive course of MS, with respect to reducing the relapse rate and number of newly formed lesions. However, if the development of cortical pathology can be prevented or at least slowed down is still not clear. The main goal of this study was thus to increase our understanding for the mode of action of B-cells and B-cell directed therapy on cortical lesions in our rat model.

Methods

For this purpose, we set up two separate experiments, with two different induction modes of B-cell depletion. Brain tissues were analyzed thoroughly using histology.

Results

We observed a marked reduction of cortical demyelination, microglial activation, astrocytic reaction, and apoptotic cell loss in anti-CD20 antibody treated groups. At the same time, we noted increased neuronal preservation compared to control groups, indicating a favorable impact of anti-CD20 therapy.

Conclusion

These findings might pave the way for further research on the mode of action of B-cells and therefore help to improve therapeutic options for progressive MS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02189-w.

Inflammatory Pre-Conditioning of Adipose-Derived Stem Cells with Cerebrospinal Fluid from Traumatic Brain Injury Patients Alters the Immunomodulatory Potential of ADSC Secretomes

Immunomodulation by adipose-tissue-derived stem cells (ADSCs) is of special interest for the alleviation of damaging inflammatory responses in central nervous system injuries. The present study explored the effects of cerebrospinal fluid (CSF) from traumatic brain injury (TBI) patients on this immunomodulatory potential of ADSCs. CSF conditioning of ADSCs increased messenger RNA levels of both pro- and anti-inflammatory genes compared to controls. Exposure of phorbol-12-myristate-13-acetate-differentiated THP1 macrophages to the secretome of CSF-conditioned ADSCs downregulated both proinflammatory (cyclooxygenase-2, tumor necrosis factor alpha) and anti-inflammatory (suppressor of cytokine signaling 3, interleukin-1 receptor antagonist, and transforming growth factor beta) genes in these cells. Interleukin-10 expression was elevated in both naïve and conditioned secretomes. ADSC secretome treatment, further, induced macrophage maturation of THP1 cells and increased the percentage of CD11b⁺, CD14⁺, CD86⁺, and, to a lesser extent, CD206⁺ cells. This, moreover, enhanced the phagocytic activity of CD14⁺ and CD86⁺ cells, though independently of pre-conditioning. Secretome exposure, finally, also induced a reduction in the percentage of CD192⁺ adherent cells in cultures of peripheral blood mononuclear cells (PBMCs) from both healthy subjects and TBI patients. This limited efficacy (of both naïve and pre-conditioned secretomes) suggests that the effects of lymphocyte-monocyte paracrine signaling on the fate of cultured PBMCs are strongest upon adherent cell populations.