Soluble CD4 effectively prevents excessive TLR activation of resident macrophages in the onset of sepsis

Spätzle maintains homeostasis of hemolymph microbiota in Scylla paramamosain through Toll2

The Toll pathway is crucial for innate immune responses in organisms (including Drosophila and mammals). The Spätzle protein outside of cells acts as a ligand for Toll receptors, enabling the transfer of signals from outside the cell to the inside. However, the function of Spätzle in the immune system of mud crab (Scylla paramamosain) remains unclear. This research discovered a novel Spätzle gene (Sp-Spz) in mud crab, which showed extensive expression in all the tissues that were examined. The RNA interference exhibited the correlation between Sp-Spz and the anti-lipopolysaccharide factors (ALFs). Knockdown of Sp-Spz decreased the expression of Sp-Toll2 but not Sp-Toll1. In Drosophila Schneider 2 cells, Sp-Spz was found interacted with Sp-Toll2. Moreover, the depletion of Sp-Spz caused the separation of hepatic lobules from the basement membrane, resulting in the disruption of the structural coherence of hepatopancreatic cells. Additionally, the knockdown of Sp-Spz resulted in changes to the composition of the hemolymph microbiota, specifically affecting the proportions of different phylum and family levels. The findings indicated that Sp-Spz may promote the synthesis of ALFs via Sp-Toll2, thereby influencing the homeostasis of microbiota in the hemolymph. In this study, novel insights into mud crab immunity are provided.

Intestinal homeostasis in the gut-lung-kidney axis: a prospective therapeutic target in immune-related chronic kidney diseases

In recent years, the role of intestinal homeostasis in health has received increasing interest, significantly improving our understanding of the complex pathophysiological interactions of the gut with other organs. Microbiota dysbiosis, impaired intestinal barrier, and aberrant intestinal immunity appear to contribute to the pathogenesis of immune-related chronic kidney diseases (CKD). Meanwhile, the relationship between the pathological changes in the respiratory tract (e.g., infection, fibrosis, granuloma) and immune-related CKD cannot be ignored. The present review aimed to elucidate the new underlying mechanism of immune-related CKD. The lungs may affect kidney function through intestinal mediation. Communication is believed to exist between the gut and lung microbiota across long physiological distances. Following the inhalation of various pathogenic factors (e.g., particulate matter 2.5 mum or less in diameter, pathogen) in the air through the mouth and nose, considering the anatomical connection between the nasopharynx and lungs, gut microbiome regulates oxidative stress and inflammatory states in the lungs and kidneys. Meanwhile, the intestine participates in the differentiation of T cells and promotes the migration of various immune cells to specific organs. This better explain the occurrence and progression of CKD caused by upper respiratory tract precursor infection and suggests the relationship between the lungs and kidney complications in some autoimmune diseases (e.g., anti-neutrophil cytoplasm antibodies -associated vasculitis, systemic lupus erythematosus). CKD can also affect the progression of lung diseases (e.g., acute respiratory distress syndrome and chronic obstructive pulmonary disease). We conclude that damage to the gut barrier appears to contribute to the development of immune-related CKD through gut-lung-kidney interplay, leading us to establish the gut-lung-kidney axis hypothesis. Further, we discuss possible therapeutic interventions and targets. For example, using prebiotics, probiotics, and laxatives (e.g., Rhubarb officinale) to regulate the gut ecology to alleviate oxidative stress, as well as improve the local immune system of the intestine and immune communication with the lungs and kidneys.