Dendritic Cell-Targeted Therapies to Treat Neurological Disorders

New insights into allergic rhinitis treatment: MSC nanovesicles targeting dendritic cells

Allergic rhinitis (AR) is a condition with limited treatment options. This study investigates the potential use of mesenchymal stem cell (MSC) nanovesicles as a novel therapy for AR. Specifically, the study explores the underlying mechanisms of MSC nanovesicle therapy by targeting dendritic cells (DCs). The researchers fabricated DC-targeted P-D2-EVs nanovesicles and characterized their properties. Transcriptomic sequencing and single-cell sequencing analyses were performed to study the impact of P-D2-EVs on AR mice, identifying core genes involved in the treatment. In vitro cell experiments were conducted to validate the effects of P-D2-EVs on DC metabolism, Th2 differentiation, and ILC2 activation. The results showed that P-D2-EVs efficiently targeted DCs. Transcriptomic sequencing analysis revealed differential expression of 948 genes in nasal tissue DCs of mice treated with P-D2-EVs. Single-cell sequencing further revealed that P-D2-EVs had inhibitory effects on DC activation, Th2 differentiation, and ILC2 activation, with Fut1 identified as the core gene. Validation experiments demonstrated that P-D2-EVs improved IL10 metabolism in DCs by downregulating Fut1 expression, thereby suppressing Th2 differentiation and ILC2 activation. Animal experiments confirmed the inhibitory effects of P-D2-EVs and their ability to ameliorate AR symptoms in mice. The study suggests that P-D2-EVs reshape DC metabolism and suppress Th2 differentiation and ILC2 activation through the inhibition of the Fut1/ICAM1/P38 MAPK signaling pathway, providing a potential therapeutic approach for AR.

Oral administration of Lactobacillus plantarum expressing aCD11c modulates cellular immunity alleviating inflammatory injury due to Klebsiella pneumoniae infection

BACKGROUND

Klebsiella pneumoniae (KP), responsible for acute lung injury (ALI) and inflammation of the gastrointestinal tract, is a zoonotic pathogen that poses a threat to livestock farming worldwide. Nevertheless, there is currently no validated vaccine to prevent KP infection. The development of mucosal vaccines against KP using Lactobacillus plantarum (L. plantarum) is an effective strategy.

RESULTS

Firstly, the L. plantarum strains NC8-pSIP409-aCD11c' and NC8-pLc23-aCD11c were constructed via homologous recombination to express the aCD11c protein either inducibly or constitutively. Both NC8-pSIP409-aCD11c' and NC8-pLc23-aCD11c strains could enhance the adhesion and invasion of L. plantarum on bone marrow-derived dendritic cells (BMDCs), and stimulate the activation of BMDCs compared to the control strain NC8-pSIP409 in vitro. Following oral immunization of mice with NC8-pSIP409-aCD11c' and NC8-pLc23-aCD11c, the cellular, humoral, and mucosal immunity were significantly improved, as evidenced by the increased expression of CD4+ IL-4+ T cells in the spleen, IgG in serum, and secretory IgA (sIgA) in the intestinal lavage fluid (ILF). Furthermore, the protective effects of L. plantarum against inflammatory damage caused by KP infection were confirmed by assessing the bacterial loads in various tissues, lung wet/dry ratio (W/D), levels of inflammatory cytokines, and histological evaluation, which influenced T helper 17 (Th17) and regulatory T (Treg) cells in peripheral blood and lung.

CONCLUSIONS

Both the inducible and constitutive L. plantarum strains NC8-pSIP409-aCD11c' and NC8-pLc23-aCD11c have been found to stimulate cellular and humoral immunity levels and alleviate the inflammatory response caused by KP infection. These findings have provided a basis for the development of a novel vaccine against KP.

CXCR1 drives the pathogenesis of EAE and ARDS via boosting dendritic cells-dependent inflammation

Chemokines secreted by dendritic cells (DCs) play a key role in the regulation of inflammation and autoimmunity through chemokine receptors. However, the role of chemokine receptor CXCR1 in inflammation-inducing experimental autoimmune encephalomyelitis (EAE) and acute respiratory distress syndrome (ARDS) remains largely enigmatic. Here we reported that compared with healthy controls, the level of CXCR1 was aberrantly increased in multiple sclerosis (MS) patients. Knockout of CXCR1 not only ameliorated disease severity in EAE mice but also suppressed the secretion of inflammatory factors (IL-6/IL-12p70) production. We observed the same results in EAE mice with DCs-specific deletion of CXCR1 and antibody neutralization of the ligand CXCL5. Mechanically, we demonstrated a positive feedback loop composed of CXCL5/CXCR1/HIF-1α direct regulating of IL-6/IL-12p70 production in DCs. Meanwhile, we found CXCR1 deficiency in DCs limited IL-6/IL-12p70 production and lung injury in LPS-induced ARDS, a disease model caused by inflammation. Overall, our study reveals CXCR1 governs DCs-mediated inflammation and autoimmune disorders and its potential as a therapeutic target for related diseases.

Targeting immunometabolism against acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are life-threatening conditions triggered by multiple intra- and extra-pulmonary injury factors, characterized by complicated molecular mechanisms and high mortality. Great strides have been made in the field of immunometabolism to clarify the interplay between intracellular metabolism and immune function in the past few years. Emerging evidence unveils the crucial roles of immunometabolism in inflammatory response and ALI. During ALI, both macrophages and lymphocytes undergo robust metabolic reprogramming and discrete epigenetic changes after activated. Apart from providing ATP and biosynthetic precursors, these metabolic cellular reactions and processes in lung also regulate inflammation and immunity.In fact, metabolic reprogramming involving glucose metabolism and fatty acidoxidation (FAO) acts as a double-edged sword in inflammatory response, which not only drives inflammasome activation but also elicits anti-inflammatory response. Additionally, the features and roles of metabolic reprogramming in different immune cells are not exactly the same. Here, we outline the evidence implicating how adverse factors shape immunometabolism in differentiation types of immune cells during ALI and summarize key proteins associated with energy expenditure and metabolic reprogramming. Finally, novel therapeutic targets in metabolic intermediates and enzymes together with current challenges in immunometabolism against ALI were discussed.

Role of Dendritic Cells in Viral Brain Infections

To gain access to the brain, a so-called immune-privileged organ due to its physical separation from the blood stream, pathogens and particularly viruses have been selected throughout evolution for their use of specific mechanisms. They can enter the central nervous system through direct infection of nerves or cerebral barriers or through cell-mediated transport. Indeed, peripheral lymphoid and myeloid immune cells can interact with the blood-brain and the blood-cerebrospinal fluid barriers and allow viral brain access using the "Trojan horse" mechanism. Among immune cells, at the frontier between innate and adaptive immune responses, dendritic cells (DCs) can be pathogen carriers, regulate or exacerbate antiviral responses and neuroinflammation, and therefore be involved in viral transmission and spread. In this review, we highlight an important contribution of DCs in the development and the consequences of viral brain infections.