Contribution of Dysregulated B-Cells and IgE Antibody Responses to Multiple Sclerosis

Multiple sclerosis (MS), a debilitating autoimmune inflammatory disease that affects the brain and spinal cord, causes demyelination of neurons, axonal damage, and neurodegeneration. MS and the murine experimental autoimmune encephalomyelitis (EAE) model have been viewed mainly as T-cell-mediated diseases. Emerging data have suggested the contribution of B-cells and autoantibodies to the disease progression. However, the underlying mechanisms by which dysregulated B-cells and antibody response promote MS and EAE remain largely unclear. Here, we provide an updated review of this specific subject by including B-cell biology and the role of B-cells in triggering autoimmune neuroinflammation with a focus on the regulation of antibody-producing B-cells. We will then discuss the role of a specific type of antibody, IgE, as it relates to the potential regulation of microglia and macrophage activation, autoimmunity and MS/EAE development. This knowledge can be utilized to develop new and effective therapeutic approaches to MS, which fits the scope of the Research Topic "Immune Mechanism in White Matter Lesions: Clinical and Pathophysiological Implications".

Current Advances in Follicular Regulatory T-Cell Biology

Follicular regulatory T (TFR) cells are a population of CD4+ T-cells that concomitantly express markers for regulatory T-cells and follicular helper T (TFH) cells, and have been predominantly implicated in the regulation of humoral immunity via their suppressive functions. Rapid and robust progress has been made in the field of TFR cell research since the discovery of this subset over a decade ago. However, there is still a significant gap in our understanding of the mechanisms underlying the phenotypic and functional heterogeneity of TFR cells under various physiologic and pathologic settings. In this review article, we aim to highlight the most up-to-date concepts and investigations in both experimental animal models and human studies to provide a perspective on our understanding of TFR biology with particular emphasis on these cells in the context of disease settings.

Lineage Reprogramming of Effector Regulatory T Cells in Cancer

Regulatory T-cells (Tregs) are important for maintaining self-tolerance and tissue homeostasis. The functional plasticity of Tregs is a key feature of this lineage, as it allows them to adapt to different microenvironments, adopt transcriptional programs reflective of their environments and tailor their suppressive capacity in a context-dependent fashion. Tregs, particularly effector Tregs (eTregs), are abundant in many types of tumors. However, the functional and transcriptional plasticity of eTregs in tumors remain largely to be explored. Although depletion or inhibition of systemic Tregs can enhance anti-tumor responses, autoimmune sequelae have diminished the enthusiasm for such approaches. A more effective approach should specifically target intratumoral Tregs or subvert local Treg-mediated suppression. This mini-review will discuss the reported mechanisms by which the stability and suppressive function of tumoral Tregs are modulated, with the focus on eTregs and a subset of eTregs, follicular regulatory T (T_FR) cells, and how to harness this knowledge for the future development of new effective cancer immunotherapies that selectively target the tumor local response while sparing the systemic side effects.

Immunomodulation of ovalbumin-specific IgG and other classes of antibody response by honey in mice

It was reported earlier that intraperitoneal administration of honey had immunosuppressive activity on elicitation of allergen-specific murine antibody response as evaluated by passive cutaneous anaphylaxis and double immunodiffusion methods. In this study, the immunomudulatory effect of honey is evaluated by enzyme linked immunosorbent assay (ELISA) using ovalbumin as model allergen. It was found that ovalbumin (OVA)-specific IgG antibody responses elicited with various doses of OVA were significantly suppressed by rock bee honey (p<0.01). Honey was also found to have inhibited the production of OVA-specific IgM, IgA, IgG(1), and IgG(2b) whereas that of IgG(2a) and IgG(3) were not affected. Furthermore, honey also suppressed the OVA-specific total IgG antibody response in various inbred mice with different genetic background. In addition, the suppressive activity of honey was examined in different groups of mice by injecting honey at different time intervals, before and after immunization with OVA. The anti-OVA IgG antibody response was suppressed significantly when honey was injected 12 hours prior/latter to OVA injection. These results confirm the suppressive activity of honey on antibody response and suggest possible clinical application.