The purpose of this study was to understand how the gut microbial system responds to retinal injury.
Adult C57BL/6J mice were subjected to retinal laser burns or hypotony-induced retinal detachment (RD). One, 4, and 24 hours later, gut permeability (8 male mice and 8 female mice) was assessed using Evan's blue assay and the expression of ZO-1 in intestinal epithelial cells was examined by immunofluorescence. Circulating immune cells were evaluated by flow cytometry. The feces from control and lasered mice (n = 8) were collected under strict sterile conditions and processed for 16S DNA paired-end sequencing using the Illumina platform. The impact of gut dysbiosis on retinal wound healing was evaluated following treatment with Peros antibiotics (n = 8). Retinal pathologies were examined by immunohistochemistry.
Retinal laser injury significantly altered gut microbial profiles within 1 hour (β-diversity, multi-response permutation procedure [MRPP], P = 0.05). The abundance of Lignipirellula and Faecalibacterium was 100- and 6.67-fold lower, and the abundance of Akkermansia and Colidextribacter was 3.65- and 17.72-fold higher than non-lasered controls, respectively. Retinal laser burns and RD, not sham surgery, increased gut permeability at 1 hour and 4 hours by 3.82- and 24.76-fold, respectively, disrupted intestinal epithelial ZO-1 expression, accompanied by an increased population of circulating neutrophils and monocytes (P < 0.01) at 1 hour and 4 hours. Antibiotic treatment attenuated laser-/RD-induced gut permeability and the increased neutrophils and monocytes (in RD, P < 0.05). Antibiotic treatment also significantly reduced the severity of laser-induced choroidal neovascularization (CNV; P < 0.001) and RD-mediated photoreceptor apoptosis (P < 0.01), and suppressed Gr-1+ neutrophils (CNV, P < 0.001) and Iba-1+ cell infiltration (P < 0.001).
A retina-gut axis exists. Retinal injury induces rapid gut microbial alteration, which in turn modulates innate immune cell activation and regulates the wound healing response.

Nonobese diabetic (NOD) mice are a widely used animal model to study mechanisms leading to autoimmune diabetes. A gluten-free diet reduces and delays the incidence of diabetes in NOD mice, but the underlying mechanisms remain largely unknown. In this study, we performed single-cell transcriptomic and flow cytometry analysis of T cells and innate lymphocytes in the spleen and pancreatic lymph nodes of NOD mice fed a gluten-free or standard diet. We observed that the gluten-free diet did not induce a substantial alteration in the abundance or phenotype of any lymphocyte subset that would directly explain its protective effect against diabetes. However, the gluten-free diet induced subtle changes in the differentiation of subsets with previously proposed protective roles in diabetes development, such as Tregs, activated γδT cells, and NKT cells. Globally, the gluten-free diet paradoxically promoted activation and effector differentiation across multiple subpopulations and induced genes regulated by IL-2, IL-7, and IL-15. In contrast, the standard diet induced type I interferon-responsive genes. Overall, the gluten-free diet might prevent diabetes in NOD mice by inducing small-scale changes in multiple cell types rather than acting on a specific lymphocyte subset.
© 2025 The Author(s). European Journal of Immunology published by Wiley‐VCH GmbH.

A hallmark feature of pancreatic ductal adenocarcinoma (PDAC) is massive intratumoral fibrosis, designated as desmoplasia. Desmoplasia is characterized by the expansion of cancer-associated fibroblasts (CAFs) and a massive increase in extracellular matrix (ECM). During fibrogenesis, distinct genes become reactivated specifically in fibroblasts, e.g., the disintegrin metalloprotease, ADAM12. Previous studies have shown that immunotherapeutic ablation of ADAM12+ cells reduces fibrosis in various organs. In preclinical mouse models of PDAC, we observe ADAM12 expression in CAFs as well as in tumor cells but not in healthy mouse pancreas. Therefore, we tested prophylactic and therapeutic vaccination against ADAM12 in murine PDAC and observed delayed tumor growth along with a reduction in CAFs and tumor desmoplasia. This is furthermore associated with vascular normalization and alleviated tumor hypoxia. The ADAM12 vaccine induces a redistribution of CD8+ T cells within the tumor and cytotoxic responses against ADAM12+ cells. In summary, vaccination against the endogenous fibroblast target ADAM12 effectively depletes CAFs, reduces desmoplasia and delays the growth of murine PDACs. These results provide proof-of-principle for the development of vaccination-based immunotherapies to treat tumor desmoplasia.
© 2024. The Author(s).

The Bursa of Fabricius, an avian unique humoral immune organ, is instrumental to B cell development. Bursal-derived peptide BP9 fosters B-cell development and formation. Yet, the exact mechanism wherein BP9 impacts B cell differentiation and antigenic presentation remains undefined. In this paper, B cell activation and differentiation in the spleen cells from mice immunized with the AIV vaccine and BP9 were detected following flow cytometry (FCM) analysis. Furthermore, the molecular mechanism of BP9 in B cell differentiation in vivo was investigated with RNA sequencing technology. To verify the potential functional mechanism of BP9 in the antigenic presentation process, the transcriptome molecular basis of chicken macrophages stimulated by BP9 was measured via high-throughput sequencing technology. The results proved that when given in experimental dosages, BP9 notably accelerated total B cells, and enhanced B-cell differentiation and plasma cell production. The gene expression profiles of B cells from mice immunized with 0.01 mg/mL BP9 and AIV vaccine disclosed that 0.01 mg/mL BP9 initiated the enrichment of several biological functions and significantly stimulated key B-cell pathways in immunized mice. Crucially, a total of 4093 differentially expressed genes were identified in B cells with BP9 stimulation, including 943 upregulated genes and 3150 downregulated genes. Additionally, BP9 induced various cytokine productions in the chicken macrophage HD11 cells and activated 9 upregulated and 20 downregulated differential miRNAs, which were involved in various signal and biological processes. Furthermore, BP9 stimulated the activation of multiple transcription factors in HD11 cells, which was related to antigen presentation processes. In summary, these results suggested that BP9 might promote B cell differentiation and induce antigen presentation, which might provide the valuable insights into the mechanism of B cell differentiation upon bursal-derived immunomodulating peptide stimulation and provide a solid experimental groundwork for enhancing vaccine-induced immunity.

The unfolded protein response (UPR) aims to restore ER homeostasis under conditions of high protein folding load, a function primarily serving secretory cells. Additional, non-canonical UPR functions have recently been unraveled in immune cells. We addressed the function of the inositol-requiring enzyme 1 (IRE1) signaling branch of the UPR in NK cells in homeostasis and microbial challenge. Cell-intrinsic compound deficiency of IRE1 and its downstream transcription factor XBP1 in NKp46+ NK cells, did not affect basal NK cell homeostasis, or overall outcome of viral MCMV infection. However, mixed bone marrow chimeras revealed a competitive advantage in the proliferation of IRE1-sufficient Ly49H+ NK cells after viral infection. CITE-Seq analysis confirmed strong induction of IRE1 early upon infection, concomitant with the activation of a canonical UPR signature. Therefore, we conclude that IRE1/XBP1 activation is required during vigorous NK cell proliferation early upon viral infection, as part of a canonical UPR response.
© 2023 The Author(s).