Low-Dose Interleukin-2 Altered Gut Microbiota and Ameliorated Collagen-Induced Arthritis

Microbial imbalance in the gut: a new frontier in Rheumatoid arthritis research

A chronic autoimmune illness that causes joint destruction and inflammation, rheumatoid arthritis (RA) often results in disability. Genetic, environmental, and immune system variables all have a role in the pathophysiology of RA. The complex community of bacteria that live in the gastrointestinal system, known as the gut microbiota, has been implicated in the onset and progression of RA in recent years, according to mounting data. An imbalance in the gut microbiota's composition, known as dysbiosis, has been noted in RA patients. This imbalance may impact inflammatory pathways and immunological responses, which in turn may contribute to the development and severity of the illness. Research has shown that some bacterial species, including Firmicutes, Bacteroidetes, and Proteobacteria, are either more abundant or less prevalent in RA patients than in healthy people. The gut-immune system axis may be modulated, immunological tolerance may be affected, and pro-inflammatory cytokine production may be enhanced by these microbial changes, all of which may lead to systemic inflammation linked to RA. Moreover, changes in intestinal permeability and a rise in microbial metabolite translocation may make autoimmune reactions worse. Probiotics, antibiotics, and dietary changes have also been investigated as possible treatment approaches to help RA patients regain the balance of their gut microbiota. Still up for debate, however, are the precise ways in which the gut microbiome affects RA. Comprehending the complex connection between gut microbiota and RA may give new perspectives on managing and preventing the condition, as well as future prospects for medicines that target the microbiome.

Restoring immune tolerance in pre-RA: immunometabolic dialogue between gut microbiota and regulatory T cells

Rheumatoid arthritis (RA) is a complex chronic autoimmune disease that remains incurable for most patients. With advances in our understanding of the disease's natural history, the concept of pre-RA has emerged as a window of opportunity to intervene before irreversible joint damage occurs. Numerous studies have indicated that the key step driving autoimmunity in early pre-RA lies at an extra-articular site, which is closely related to the regulatory T (Treg) cell-established immune tolerance to the gut microbiota. The intricate immunometabolic crosstalk between Treg cells and the gut microbiota is beginning to be understood, with the re-recognition of Treg cells as metabolic sensors in recent years. In the future, deciphering their immunometabolic dialogue may help to elucidate the underlying mechanisms of pre-RA. Identifying novel biological pathways in the pre-RA stage will bring insights into restoring immune tolerance, thereby potentially curing or preventing the onset of RA.

Unraveling the gut microbiota's role in Rheumatoid arthritis: dietary pathways to modulation and therapeutic potential

Rheumatoid arthritis (RA) is a significant global health issue. Recent research highlights the gut microbiota's critical role in RA's development, noting how dietary factors can alter these microbial communities. This has led to an increased focus on how the gut microbiota (GM) influences RA and the potential for dietary ingredients to offer anti-RA benefits by modifying GM. This review presents a concise examination of the GM associated with RA, identifying specific microbial taxa at various levels that are implicated in the disease. It delves into dietary components known for their anti-RA properties through GM modulation and their mechanisms. Findings from numerous studies, including both animal and human research, show significant differences in the GM composition between individuals with early and established RA. Certain microbes like Tenericutes, Synergistetes, and Proteobacteria have been linked to RA progression, whereas Bacteroidetes and some strains of Lactobacillus are shown to have protective effects against RA. Dietary elements such as fibers, polysaccharides, resistant starch, and peptides have been identified as influential in combating RA. These components work by altering the GM's metabolites and impacting immune cells related to the GM. This review suggests the potential for developing functional foods aimed at treating RA by targeting GM.

New sights of low dose IL-2: Restoration of immune homeostasis for viral infection

Viral infection poses a significant threat to human health. In addition to the damage caused by viral replication, the immune response it triggers often leads to more serious adverse consequences. After the occurrence of viral infection, in addition to the adverse consequences of infection, chronic infections can also lead to virus-related autoimmune diseases and tumours. At the same time, the immune response triggered by viral infection is complex, and dysregulated immune response may lead to the occurrence of immune pathology and macrophage activation syndrome. In addition, it may cause secondary immune suppression, especially in patients with compromised immune system, which could lead to the occurrence of secondary infections by other pathogens. This can often result in more severe clinical outcomes. Therefore, regarding the treatment of viral infections, restoring the balance of the immune system is crucial in addition to specific antiviral medications. In recent years, scientists have made an interesting finding that low dose IL-2 (ld-IL-2) could potentially have a crucial function in regulating the immune system and reducing the chances of infection, especially viral infection. Ld-IL-2 exerts immune regulatory effects in different types of viral infections by modulating CD4+ T subsets, CD8+ T cells, natural killer cells, and so on. Our review summarised the role of IL-2 or IL-2 complexes in viral infections. Ld-IL-2 may be an effective strategy for enhancing host antiviral immunity and preventing infection from becoming chronic; additionally, the appropriate use of it can help prevent excessive inflammatory response after infection. In the long term, it may reduce the occurrence of infection-related autoimmune diseases and tumours by promoting the restoration of early immune homeostasis. Furthermore, we have also summarised the application of ld-IL-2 in the context of autoimmune diseases combined with viral infections; it may be a safe and effective strategy for restoring immune homeostasis without compromising the antiviral immune response. In conclusion, focusing on the role of ld-IL-2 in viral infections may provide a new perspective for regulating immune responses following viral infections and improving prognosis.

Causal relationship between asthma and inflammatory bowel disease : A two-sample bidirectional mendelian randomization analysis

BACKGROUND

Based on the findings of current observational studies, asthma and inflammatory bowel disease (including Crohn's disease and ulcerative colitis) are associated; however, their causal association cannot be established due to methodological limitations.

OBJECTIVES

we use two-sample bidirectional mendelian randomization (MR) to overcome the confounding factors and explore the causal link between asthma and inflammatory bowel disease.

METHODS

After selecting asthma and IBD-related genome-wide association studies (GWAS) data and screening single nucleotide polymorphisms (SNPs), MR analysis was performed by four methods: inverse variance weighted (IVW), MR-Egger, maximum likelihood, and weighted median (WM), while Cochran's Q test was used to detect heterogeneity and MR-Egger intercept to detect horizontal pleiotropy. Finally, we used the leave-one-out method and funnel plot to perform sensitivity analysis.

RESULTS

We screened 57, 59, and 60 SNPs in the association analysis of asthma and IBD, CD, and UC, respectively. The results of MR analysis showed that asthma only increased the risk of CD (IVW: OR = 1.1712, 95% CI = 1.0418-1.3167, P value = 0.0082; maximum likelihood: OR = 1.1739, 95% CI = 1.0428-1.3215, P value = 0.0080). Neither forward nor reverse MR analysis revealed heterogeneity or horizontal pleiotropy. Similarly, we did not find potential directional pleiotropy by funnel plot, and the leave-one-out method did not suggest a significant effect of a single SNP on the overall results.

CONCLUSIONS

we found a negative correlation between asthma and Crohn's disease, but more research is needed to confirm this.

The role of lung microbiota in primary graft dysfunction in lung transplant recipients

BACKGROUND

Recent studies have shown that the lung microbiota is altered in critically ill patients and predicts clinical outcomes. Primary graft dysfunction (PGD) is a common complication and a leading cause of death within 1 month of lung transplantation, but the clinical significance of changes in the lung bacterial community during PGD is unclear. The aim of this study was to determine the contribution of the lung microbiota to the development and course of severe PGD.

METHODS

We conducted a retrospective study to characterize the lung microbiota of 32 lung transplant patients with combined PGD using next-generation sequencing of bronchoalveolar lavage samples. The relationship between lung flora dysbiosis and lung immunity in PGD was assessed by quantification of alveolar cytokines. The contribution of microbiota characteristics to patient outcomes was assessed by estimating overall survival.

RESULTS

Patients diagnosed with PGD grade 3 showed a reduction in alpha diversity, driven by a significant increase in the abundance of the genera Modestobacter, Scardovia and Selenomonas, and a reduction in the proportion of the genera Klebsiella and Oribacterium. Alpha diversity of the lung microbiota in PGD3 patients was negatively correlated with BALF interleukin (IL)-2 (r = -.752, p < .05). In addition, bacterial diversity in the lung microbiota of non-survivors was lower than that of survivors (p = .041).

CONCLUSIONS

There is variation in the lung microbiota of PGD grade 3 patients and dysbiosis of the lung microbiota is associated with lung immunity. The lung microbiota has potential in the diagnosis and treatment of PGD grade 3.

Arsenic trioxide modulates the composition and metabolic function of the gut microbiota in a mouse model of rheumatoid arthritis

The mechanism of rheumatoid arthritis (RA) has been widely investigated, and studies on the use of arsenic trioxide (ATO) in the treatment of RA have been reported in recent years. However, the exact mechanism of action of ATO in RA remains unclear. This study explores alterations in the gut microbiota and metabolism during ATO treatment in a mouse model of RA and provides an integrative analysis of the biomechanism. The purpose of this study was to verify whether ATO can alleviate RA by altering the gut microbiota. In this study, the mice were randomly divided into four different groups: the normal control (NC) group, the collagen-induced arthritis (CIA) group, the ATO 1.0 mg/kg/day group, and the ATO 2.0 mg/kg/day group. Fecal samples were collected. Through 16S rDNA gene sequencing and metabolomic analysis, the effect of ATO on the composition and metabolites of gut microbiota in CIA mice was investigated. The results showed that compared with NC mice, CIA mice showed differences at both the phylum level (Firmicutes and Bacteroidetes) and the genus level (Muribaculaceae_unclassified and Alistipes). Meanwhile, many metabolites were significantly changed between the two groups, including benzoic acid and (s)-2-acetolactate. However, these alterations were partially reversed in ATO-treated CIA mice. These results indicated that ATO treatment modulated gut microbiota disorder and improved fecal metabolite abnormalities. In conclusion, this study provided important evidence for alterations of the gut microbiota and metabolites and the role of these alterations in a potential novel mechanism of ATO treatment in RA.