Effect of a garlic drench on Galectin gene expression in ovine whole blood.

Garlic, known for its immune-modulating and antibiotic properties, contains lectins that possess antimicrobial and immunomodulatory effects. Galectins (Gals), which bind ß-galactosides, play a role in modulating immunity and pathological processes. It is hypothesized that garlic's lectin components interfere with animal lectins. St. Croix sheep, known for their resistance to parasites and adaptability, are influenced by dietary supplements for innate immunity. This study evaluated the impact of garlic drench on Galectin gene expression in St. Croix sheep. Adult non-lactating ewes received either garlic juice concentrate or sterile distilled water for four weeks. Blood samples were collected, and plasma and whole blood cells were separated. Galectin secretion was assessed using a Sheep-specific ELISA, while Galectin gene transcription was analyzed through real-time PCR. Garlic administration upregulated LGALS-3 gene expression and significantly increased total plasma protein concentration. Garlic supplementation also affected Galectin secretion, with Gal-1, Gal-3, and Gal-9 showing differential effects.

Immune Gene Repertoire of Soft Scale Insects (Hemiptera: Coccidae).

Insects possess an effective immune system, which has been extensively characterized in several model species, revealing a plethora of conserved genes involved in recognition, signaling, and responses to pathogens and parasites. However, some taxonomic groups, characterized by peculiar trophic niches, such as plant-sap feeders, which are often important pests of crops and forestry ecosystems, have been largely overlooked regarding their immune gene repertoire. Here we annotated the immune genes of soft scale insects (Hemiptera: Coccidae) for which omics data are publicly available. By using immune genes of aphids and Drosophila to query the genome of Ericerus pela, as well as the transcriptomes of Ceroplastes cirripediformis and Coccus sp., we highlight the lack of peptidoglycan recognition proteins, galectins, thaumatins, and antimicrobial peptides in Coccidae. This work contributes to expanding our knowledge about the evolutionary trajectories of immune genes and offers a list of promising candidates for developing new control strategies based on the suppression of pests' immunity through RNAi technologies.

Blocking OLFM4/galectin-3 axis in placental polymorphonuclear myeloid-derived suppressor cells triggers intestinal inflammation in newborns.

Fetal growth restriction (FGR) is a major cause of premature and low-weight births, which increases the risk of necrotizing enterocolitis (NEC); however, the association remains unclear. We report a close correlation between placental polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) and NEC. Newborns with previous FGR exhibited intestinal inflammation and more severe NEC symptoms than healthy newborns. Placental PMN-MDSCs are vital regulators of fetal development and neonatal gut inflammation. Placental single-cell transcriptomics revealed that PMN-MDSCs populations and olfactomedin-4 gene (Olfm4) expression levels were significantly increased in PMN-MDSCs in later pregnancy compared to those in early pregnancy and non-pregnant females. Female mice lacking Olfm4 in myeloid cells mated with wild-type males showed FGR during pregnancy, with a decreased placental PMN-MDSCs population and expression of growth-promoting factors (GPFs) from placental PMN-MDSCs. Galectin-3 (Gal-3) stimulated the OLFM4-mediated secretion of GPFs by placental PMN-MDSCs. Moreover, GPF regulation via OLFM4 in placental PMN-MDSCs was mediated via hypoxia inducible factor-1α (HIF-1α). Notably, the offspring of mothers lacking Olfm4 exhibited intestinal inflammation and were susceptible to NEC. Additionally, OLFM4 expression decreased in placental PMN-MDSCs from pregnancies with FGR and was negatively correlated with neonatal morbidity. These results revealed that placental PMN-MDSCs contributed to fetal development and ameliorate newborn intestinal inflammation.

Galectins in epithelial-mesenchymal transition: roles and mechanisms contributing to tissue repair, fibrosis and cancer metastasis.

Galectins are soluble glycan-binding proteins that interact with a wide range of glycoproteins and glycolipids and modulate a broad spectrum of physiological and pathological processes. The expression and subcellular localization of different galectins vary among tissues and cell types and change during processes of tissue repair, fibrosis and cancer where epithelial cells loss differentiation while acquiring migratory mesenchymal phenotypes. The epithelial-mesenchymal transition (EMT) that occurs in the context of these processes can include modifications of glycosylation patterns of glycolipids and glycoproteins affecting their interactions with galectins. Moreover, overexpression of certain galectins has been involved in the development and different outcomes of EMT. This review focuses on the roles and mechanisms of Galectin-1 (Gal-1), Gal-3, Gal-4, Gal-7 and Gal-8, which have been involved in physiologic and pathogenic EMT contexts.

Targeting Galectin 3 illuminates its contributions to the pathology of uterine serous carcinoma.

BACKGROUND: Uterine serous cancer (USC) comprises around 10% of all uterine cancers. However, USC accounts for approximately 40% of uterine cancer deaths, which is attributed to tumor aggressiveness and limited effective treatment. Galectin 3 (Gal3) has been implicated in promoting aggressive features in some malignancies. However, Gal3's role in promoting USC pathology is lacking. METHODS: We explored the relationship between LGALS3 levels and prognosis in USC patients using TCGA database, and examined the association between Gal3 levels in primary USC tumors and clinical-pathological features. CRISPR/Cas9-mediated Gal3-knockout (KO) and GB1107, inhibitor of Gal3, were employed to evaluate Gal3's impact on cell function. RESULTS: TCGA analysis revealed a worse prognosis for USC patients with high LGALS3. Patients with no-to-low Gal3 expression in primary tumors exhibited reduced clinical-pathological tumor progression. Gal3-KO and GB1107 reduced cell proliferation, stemness, adhesion, migration, and or invasion properties of USC lines. Furthermore, Gal3-positive conditioned media (CM) stimulated vascular tubal formation and branching and transition of fibroblast to cancer-associated fibroblast compared to Gal3-negative CM. Xenograft models emphasized the significance of Gal3 loss with fewer and smaller tumors compared to controls. Moreover, GB1107 impeded the growth of USC patient-derived organoids. CONCLUSION: These findings suggest inhibiting Gal3 may benefit USC patients.

Interplay in galectin expression predicts patient outcomes in a spatially restricted manner in PDAC.

BACKGROUND: Galectins (Gal's) are a family of carbohydrate-binding proteins that are known to support the tumour microenvironment through their immunosuppressive activity and ability to promote metastasis. As such they are attractive therapeutic targets, but little is known about the cellular expression pattern of galectins within the tumour and its neighbouring stromal microenvironment. Here we investigated the cellular expression pattern of Gals within pancreatic ductal adenocarcinoma (PDAC). METHODS: Galectin gene and protein expression were analysed by scRNAseq (n=4) and immunofluorescence imaging (n=19) in fibroblasts and epithelial cells of pancreatic biopsies from PDAC patients. Galectin surface expression was also assessed on tumour adjacent normal fibroblasts and cancer associated primary fibroblasts from PDAC biopsies using flow cytometry. RESULTS: scRNAseq revealed higher Gal-1 expression in fibroblasts and higher Gal-3 and -4 expression in epithelial cells. Both podoplanin (PDPN+, stromal/fibroblast) cells and EpCAM+ epithelial cells expressed Gal-1 protein, with highest expression seen in the stromal compartment. By contrast, significantly more Gal-3 and -4 protein was expressed in ductal cells expressing either EpCAM or PDPN, when compared to the stroma. Ductal Gal-4 cellular expression negatively correlated with ductal Gal-1, but not Gal-3 expression. Higher ductal cellular expression of Gal-1 correlated with smaller tumour size and better patient survival. CONCLUSIONS: In summary, the intricate interplay and cell-specific expression patterns of galectins within the PDAC tissue, particularly the inverse correlation between Gal-1 and Gal-4 in ducts and its significant association with patient survival, highlights the complex molecular landscape underlying PDAC and provides valuable insights for future therapeutic interventions.

Galectin-8 modulates human osteoclast activity partly through isoform-specific interactions.

In overactive human osteoclasts, we previously identified an alternative splicing event in LGALS8, encoding galectin-8, resulting in decreased expression of the long isoform. Galectin-8, which modulates cell-matrix interactions and functions intracellularly as a danger recognition receptor, has never been associated with osteoclast biology. In human osteoclasts, inhibition of galectin-8 expression revealed its roles in bone resorption, osteoclast nuclearity, and mTORC1 signaling regulation. Galectin-8 isoform-specific inhibition asserted a predominant role for the short isoform in bone resorption. Moreover, a liquid chromatography with tandem mass spectrometry (LC-MS/MS) proteomic analysis of galectin-8 isoforms performed in HEK293T cells identified 22 proteins shared by both isoforms. Meanwhile, nine interacting partners were specific for the short isoform, and none were unique to the long isoform. Interactors specific for the galectin-8 short isoform included cell adhesion proteins and lysosomal proteins. We confirmed the interactions of galectin-8 with CLCN3, CLCN7, LAMP1, and LAMP2, all known to localize to secretory vesicles, in human osteoclasts. Altogether, our study reveals direct roles of galectin-8 in osteoclast activity, mostly attributable to the short isoform.

Largemouth bass galectin, MsGal-9: Mediating various functions as a pattern recognition receptor and a potential damage-associated molecular pattern.

Galectins are lectins that bind to ß-galactose and are widely expressed in immune system tissues, playing pivotal roles in innate immunity through their conserved carbohydrate-recognition domains (CRDs). In this present investigation, a tandem-repeat galectin was discovered in the largemouth bass, Micropterus salmoides (designated as MsGal-9). The open reading frame of MsGal-9 encodes two CRDs, each containing two consensus motifs that are essential for ligand binding. MsGal-9 is expressed in various tissues of the largemouth bass, with particularly high expression levels in the liver and spleen. The full-length form of MsGal-9, as well as the N-terminal (MsGal-9-N) and C-terminal (MsGal-9-C) CRDs, were individually recombined. Their ability for nonself recognition was studied. The three recombinant proteins were able to bind to glucan (GLU), peptidoglycan (PGN), and lipopolysaccharide (LPS), with MsGal-9 displaying the highest binding activity. Furthermore, rMsGal-9-N exhibited higher binding activity towards GLU in comparison to rMsGal-9-C. Further investigations revealed that the full-length rMsGal-9 could significantly bind to Gram-positive bacteria, Gram-negative bacteria, and fungi, while rMsGal-9-C specifically bound to Escherichia coli. However, rMsGal-9-N did not exhibit significant binding activity towards any microbes. These findings indicate that MsGal-9 requires both CRDs to cooperate in order to fulfill its nonself recognition function. All three recombinant proteins demonstrated agglutination activity towards various microbes, with MsGal-9 and MsGal-9-N displaying a similar broad binding spectrum, while MsGal-9-C agglutinated three types of bacteria. Moreover, both MsGal-9 and MsGal-9-N were capable of coagulating largemouth bass red blood cells, whereas MsGal-9-C lacked this ability. However, MsGal-9-C played a significant role in enhancing the encapsulation of leukocytes in comparison to MsGal-9-N. All three proteins acted as potential damage-associated molecular patterns (DAMPs), inducing apoptosis in leukocytes.

Galectin-7 Induction by EHMT2 Inhibition Enhances Immunity in Microsatellite Stability Colorectal Cancer.

BACKGROUND & AIMS: Although immunotherapy shows substantial advancement in colorectal cancer (CRC) with microsatellite instability high, it has limited efficacy for CRC with microsatellite stability (MSS). Identifying combinations that reverse immune suppression and prime MSS tumors for current immunotherapy approaches remains an urgent need. METHODS: An in vitro CRISPR screen was performed using coculture models of primary tumor cells and autologous immune cells from MSS CRC patients to identify epigenetic targets that could enhance immunotherapy efficacy in MSS tumors. RESULTS: We revealed EHMT2, a histone methyltransferase, as a potential target for MSS CRC. EHMT2 inhibition transformed the immunosuppressive microenvironment of MSS tumors into an immunomodulatory one by altering cytokine expression, leading to T-cell-mediated cytotoxicity activation and improved responsiveness to anti-PD1 treatment. We observed galectin-7 up-regulation upon EHMT2 inhibition, which converted a "cold" MSS tumor environment into a T-cell-inflamed one. Mechanistically, CHD4 repressed galectin-7 expression by recruiting EHMT2 to form a cotranscriptional silencing complex. Galectin-7 administration enhanced anti-PD1 efficacy in MSS CRC, serving as a potent adjunct cytokine therapy. CONCLUSIONS: Our findings suggest that targeting the EHMT2/galectin-7 axis could provide a novel combination strategy for immunotherapy in MSS CRC.

The elevation of plasma galectin-9 levels in patients with psoriasis and its associations with inflammatory and immune checkpoint molecules in skin tissues.

Psoriasis is a chronic, immune-mediated disorder that mainly affects the skin, with an estimated global prevalence of 2-3%. Galectin-9 (Gal-9) is a ß-galactoside-binding lectin capable of promoting or suppressing the progression of infectious and immune-mediated diseases. Here, we determined if the expression of Gal-9 is observed in psoriasis. Gal-9 levels were measured in plasma of psoriasis (n = 62) and healthy control (HC) (n = 31) using an enzyme-linked immunosorbent assay. In addition, skin samples from seven patients were screened for RNA transcriptomes and the expression of Gal-9 was compared with inflammatory, immune checkpoint molecules (ICMs) and Foxp3. The plasma Gal-9 levels in patients with psoriasis were significantly higher (841 pg/mL) than in HCs (617 pg/mL) (P < 0.0001) and were associated with white blood cell numbers, eosinophils (%) and alanine transaminase. The levels of inflammatory molecules IL-36B, IL-17RA, IL-6R, IL-10, IRF8, TGFb1, and IL-37, and those of ICMs of Tim-3, CTLA-4, CD86, CD80, PD-1LG2, CLEC4G, and Foxp3 were significantly correlated with Gal-9 (LGALS9) in skin. However, HMGB1, CD44, CEACAM1 and PDL1-known to be associated with a variety of Gal-9 biological functions were not correlated with LGALS9. Thus, it is likely that Gal-9 expression affects the disease state of PS.

Identification of antimicrobial peptide genes from transcriptomes in Mandarin fish (Siniperca chuatsi) and their response to infection with Aeromonas hydrophila.

Mandarin fish (Siniperca chuatsi) is a valuable freshwater fish species widely cultured in China. Its aquaculture production is challenged by bacterial septicaemia, which is one of the most common bacterial diseases. Antimicrobial peptides (AMPs) play a critical role in the innate immune system of fish, exhibiting defensive and inhibitory effects against a wide range of pathogens. This study aimed to identify the antimicrobial peptide genes in mandarin fish using transcriptomes data obtained from 17 tissue in our laboratory. Through nucleotide sequence alignment and protein structural domain analysis, 15 antimicrobial peptide genes (moronecidin, pleurocidin, lysozyme g, thymosin ß12, hepcidin, leap 2, ß-defensin, galectin 8, galectin 9, apoB, apoD, apoE, apoF, apoM, and nk-lysin) were identified, of which 9 antimicrobial peptide genes were identified for the first time. In addition, 15 AMPs were subjected to sequence characterization and protein structure analysis. After injection with Aeromonas hydrophila, the number of red blood cells, hemoglobin concentration, and platelet counts in mandarin fish showed a decreasing trend, indicating partial hemolysis. The expression change patterns of 15 AMP genes in the intestine after A. hydrophila infection were examined by using qRT-PCR. The results revealed, marked up-regulation (approximately 116.04) of the hepcidin gene, down-regulation of the piscidin family genes expression. Moreover, most AMP genes were responded in the early stages after A. hydrophila challenge. This study provides fundamental information for investigating the role of the different antimicrobial peptide genes in mandarin fish in defense against A. hydrophila infection.

Activated Tim-3/Galectin-9 participated in the development of multiple myeloma by negatively regulating CD4 T cells.

The interaction between Tim-3 on T cells and its ligand Galectin-9 negatively regulates the cellular immune response. However, the regulation of Tim-3/Galectin-9 on CD4 T cell subsets in multiple myeloma (MM) remains unclear. The aim of this study was to investigate the relationship between the regulation of CD4 T cell subsets by the Tim-3/Galectin-9 pathway and clinical prognostic indicators in MM. Tim-3/Galectin-9 were detected by flow cytometry, PCR and ELISA in 60 MM patients and 40 healthy controls, and its correlation with clinical prognostic parameters was analyzed. The expressions of Tim-3 on CD4 T cells, Galectin-9 mRNA in PBMC and level of Galectin-9 protein in serum were significantly elevated in MM patients, especially those with poor prognostic indicators. In MM patients, Tim-3 was highly expressed on the surfaces of Th1, Th2, and Th17 cells, but lowly expressed on Treg. Moreover, level of cytokine IFN-γ in serum was negatively correlated with Tim-3+Th1 cell and Galectin-9mRNA, Galectin-9 protein level. In addition, cell culture experiments showed that the anti-tumor effect and the ability to secrete IFN-γ were restored by blocking the Tim-3/Galectin-9 pathway. In MM patients, Tim-3/Galectin-9 is elevated and associated with disease progression, by inhibiting the cytotoxic function of Th1, and also promoting Th2 and Th17 to be involved in immune escape of MM. Therefore, Tim-3/Galectin-9 may serve as a new immunotherapeutic target for MM patients.

Molecular characterization and functional study of a galectin-9 from a teleost fish, Boleophthalmus pectinirostris.

Galectin-9, a tandem-repeat galectin, plays an important role in the regulation of innate immune response against various microbial infections. Here, galectin-9 from mudskipper (Boleophthalmus pectinirostris) was identified and named as BpGal-9. Putative BpGal-9 contains two conserved carbohydrate recognition domains (CRDs), one CRD within N-terminal (N-CRD) and the other one within C-terminal (C-CRD). Multi-alignment analysis indicated that BpGal-9 shared the highest amino acid sequence identity of 64.3 % with that of Southern platyfish (Xiphophorus maculatus). Phylogenetic analysis showed that BpGal-9 grouped tightly with other teleosts galectin-9 and was most closely related to that of Southern platyfish. BpGal-9 transcripts were more abundant in the intestine, and its expression upregulated significantly in the intestine, kidney, spleen, gills, and skin after Edwardsiella tarda infection. Meanwhile, BpGal-9 expression significantly increased in hemocytes and serum of mudskipper infected by E. tarda. The recombinant BpGal-9 (rBpGal-9) and rBpGal-9C-CRD could agglutinate all tested bacteria, whereas rBpGal-9N-CRD could only agglutinate three kinds of bacteria. When targeting the same bacteria, rBpGal-9 showed stronger agglutinating activities than rBpGal-9C-CRD or rBpGal-9N-CRD. In addition, the induction effect of three recombinant proteins on the mRNA expression of anti-inflammatory cytokines (BpIL-10 and BpTGF-ß) was better than that on the pro-inflammatory cytokines (BpIL-1ß and BpTNF-α). Our result suggested that the N-CRD and C-CRD of galectin-9 contribute differently to its multiple functions in innate immunity in teleosts.

A prototype galectin-1 (also known as galecin-2) from large yellow croaker (Larimichthys crocea): Molecular and function study.

Galectin-1 (also known as galecin-2), one member of galectins family, has multiple functions as a pattern recognition receptor (PRR) in innate immune defense system. In the present study, LcGal-1, a prototype galectin, was identified and function investigated in large yellow croaker (Larimichthys crocea). LcGal-1 consists of one carbohydrate recognition domain (CRD), which contains two carbohydrate binding motifs HFNPR and WG-E-R. LcGal-1 had a ubiquitous tissues profile with the highest and lowest expression in spleen and muscle, respectively. Moreover, it was in cytoplasm and nucleus of head-kidney cells in large yellow croaker. RT-qRCR showed that P. plecoglossicida induced LcGal-1 up-regulated expression in liver and gills, and the results were validated by immunohistochemistry analysis. Additionally, the recombinant LcGal-1 (rLcGal-1) showed agglutinate activity on erythrocytes, and the histidine (His) in the HFNPR motif was a key locus to the activity. The agglutination effect of rLcGal-1 on erythrocytes could be inhibited by LPS, α-lactase and d-galactose. The rLcGal-1 was able to bind and agglutinate Gram+ and Gram-bacteria, and damage bacterial membrane as confirmed by PI staining and SEM observation. Transcriptome analysis showed that the overexpressed LcGal-1 in HEK 293T cells could induce 176 DGEs, including 172 boosting genes and 4 falling genes. Collectively, LcGal-1 was a key immune gene involved in the recognition, conjunction, and elimination of pathogens in L. crocea, as well as multiple physiological and pathological regulatory processes.

Molecular cloning, expression, and functional analysis of a putative lectin from the pearl oyster (Pinctada fucata, Gould 1850).

Marine lectins are a group of proteins that possess specific carbohydrate recognition and binding domains. They exhibit various activities, including antimicrobial, antitumor, antiviral, and immunomodulatory effects. In this study, a novel galectin-binding lectin gene named PFL-96 (GenBank: OQ561753.1) was cloned from Pinctada fucata. The PFL-96 gene has an open reading frame of 324 base pairs (bp) and encodes a protein comprising 107 amino acids. The protein has a molecular weight of 11.95 kDa and an isoelectric point of 9.27. It contains an N-terminal signal peptide and a galactose-binding lectin domain. The sequence identity to lectin proteins from fish, echinoderms, coelenterates, and shellfish ranges from 31.90 to 40.00 %. In the phylogenetic analysis, it was found that the PFL-96 protein is closely related to the lectin from Pteria penguin. The PFL-96 recombinant protein exhibited coagulation activity on 2 % rabbit red blood cells at a concentration of ≥8 µg/mL. Additionally, it showed significant hemolytic activity at a concentration of ≥32 µg/mL. The PFL-96 recombinant protein exhibited significant antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Candida albicans, and Vibrio alginolyticus, with minimum inhibitory concentrations (MIC) of 4, 8, 16, and 16 µg/mL, respectively. The minimum bactericidal concentrations (MBC) were determined to be 8, 16, 32, and 32 µg/mL, respectively. Furthermore, the PFL-96 recombinant protein exhibited inhibitory effects on the proliferation of Hela tumor cells, HepG2 tumor cells, and C666-1 tumor cells, with IC50 values of 7.962, 8.007, and 9.502 µg/mL, respectively. These findings suggest that the recombinant protein PFL-96 exhibits significant bioactivity in vitro, contributing to a better understanding of the active compounds found in P. fucata. The present study establishes a fundamental basis for further investigation into the mechanism of action and structural optimization of the recombinant protein PFL-96. The aim is to develop potential candidates for antibacterial and anti-tumor agents.

Evaluation of the Relationship Between miRNA-22-3p and Gal-9 Levels in Glioblastoma.

BACKGROUND/AIM: Glioblastoma, the most prevalent primary malignant brain tumor, is significantly impacted by molecular mechanisms, including the function of microRNAs and galectins. The interplay between miRNA-22-3p and Galectin-9, a galactoside-binding lectin, is particularly notable. This study aimed to further investigate their roles in glioblastoma pathogenesis by analyzing the serum levels of these molecules in patients with glioblastoma. PATIENTS AND METHODS: This investigation included 50 subjects, consisting of 25 patients with glioblastoma and an equal number of healthy controls. Blood serum specimens were obtained for miRNA isolation and subsequent cDNA synthesis. The expression of the miRNA-22-3p gene was assessed using polymerase chain reaction (PCR), and a sandwich enzyme-linked immunosorbent assay (ELISA) was utilized to quantify serum Gal-9 concentrations. RESULTS: In patients diagnosed with glioblastoma, there was a significant elevation in miRNA-22-3p expression compared to healthy controls. However, despite a trend towards increased serum Gal-9 levels in the glioblastoma group, the difference did not reach statistical significance. CONCLUSION: Glioblastoma patients are characterized by increased Gal-9 serum levels and reduced miRNA-22-3p expression. These results indicate their potential as diagnostic and prognostic markers as well as therapeutic targets.

Galectin 9 restricts viral replication in teleost via autophagy-antiviral pathway and polarizes M2 macrophages for anti-inflammatory response: New insights into functional properties of fish Galectin-9 from Planiliza haematocheilus.

Galectin 9 (Gal9) is a tandem repeat type ß-galactoside-binding galectin that mediates various cellular biochemical and immunological functions. Many studies have investigated the functional properties of Gal9 in mammals; however, knowledge of fish Gal9 is limited to antibacterial studies. In this context, our aim was to clone Gal9 from Planiliza haematocheilus (PhGal9) and investigate its structural and functional characteristics. We discovered the PhGal9 open reading frame, which was 969 base pairs long and encoded a 322 amino acid protein. PhGal9 had a projected molecular weight of 35.385 kDa but no signal peptide sequence. PhGal9 mRNA was ubiquitously produced in all investigated tissues but was predominant in the intestine, spleen, and brain. Its mRNA expression was increased in response to stimulation by Poly(I:C), LPS, and L. garvieae. The rPhGal9 exhibited a dose-dependent agglutination potential toward gram-positive and gram-negative bacteria at a minimum concentration of 50 µg/mL. Overexpression of PhGal9 promoted M2-like phenotype changes in mouse macrophages, and RT-qPCR analysis of M1 and M2 marker genes confirmed M2 polarization with upregulation of M2 marker genes. In the antiviral assay, the expression levels of Viral Hemorrhagic Septicemia Virus (VHSV) glycoproteins, phosphoproteins, nucleoproteins, non-virion proteins, matrix proteins, and RNA polymerase were significantly reduced in PhGal9-overexpressed cells. Furthermore, the mRNA expression of autophagic genes (sqstm1, tax1bp1b, rnf13, lc3, and atg5) and antiviral genes (viperin) were upregulated in PhGal9 overexpressed cells. For the first time in teleosts, our study demonstrated that PhGal9 promotes M2 macrophage polarization by upregulating M2-associated genes (egr2 and cmyc) and suppressing M1-associated genes (iNOS and IL-6). Furthermore, our results show that exogenous and endogenous PhGal9 prevented VHSV attachment and replication by neutralizing virion and autophagy, respectively. Gal9 may be a potent modulator of the antimicrobial immune response in teleost fish.

The ligation between ERMAP, galectin-9 and dectin-2 promotes Kupffer cell phagocytosis and antitumor immunity.

Kupffer cells, the liver tissue resident macrophages, are critical in the detection and clearance of cancer cells. However, the molecular mechanisms underlying their detection and phagocytosis of cancer cells are still unclear. Using in vivo genome-wide CRISPR-Cas9 knockout screening, we found that the cell-surface transmembrane protein ERMAP expressed on various cancer cells signaled to activate phagocytosis in Kupffer cells and to control of liver metastasis. ERMAP interacted with ß-galactoside binding lectin galectin-9 expressed on the surface of Kupffer cells in a manner dependent on glycosylation. Galectin-9 formed a bridging complex with ERMAP and the transmembrane receptor dectin-2, expressed on Kupffer cells, to induce the detection and phagocytosis of cancer cells by Kupffer cells. Patients with low expression of ERMAP on tumors had more liver metastases. Thus, our study identified the ERMAP-galectin-9-dectin-2 axis as an 'eat me' signal for Kupffer cells.

Expression of Tim-3/Galectin-9 pathway and CD8+T cells and related factors in patients with cystic echinococcosis.

OBJECTIVE: One of the primary reasons for the successful patriotization of Echinococcus multilocularis in patients is its ability to induce host immune tolerance. This study examined the expression of the immunosuppressive Tim-3/Galectin-9 pathway, CD8+T cells, and related factors in AE patients. The aim was to analyze the relationship between the Tim-3/Galectin-9 pathway and CD8+T cells in this disease and further understand the mechanism of immune tolerance induced by cystic echinococcosis. METHODS: Using flow cytometry, we evaluated the expression of CTL, CD8+CD28-T cells, CD8+CD28 + IFN-γ + T cells, CD8+CD28+perforin + T cells, CD8+CD28+granzyme B + T cells, CD8+CD28-IL-10 + T cells, CD8+CD28-TGF-ß+T cells, and Tim-3 expression on CD8+T cells in the peripheral blood of control (n = 30) and AE patients (n = 33). qRT-PCR was used to measure CD107a and Tim-3/Galectin-9 mRNA levels in PBMCs from the control and AE groups. Immunohistochemistry was employed to detect IL-10, TGF-ß, and Tim-3/Galectin-9 expressions in the infected livers of AE patients. RESULTS: AE patients exhibited a significant decrease in peripheral blood CTL ratio (P < 0.001) and an increase in CD8+CD28+IFN-γ+T cell ratio (P < 0.001). No significant changes were observed in the ratios of CD8+CD28+perforin + T cells (P = 0.720) and CD8+CD28+granzyme B + T cells (P = 0.051). The proportions of CD8+CD28-T cells (P < 0.001), CD8+CD28-IL-10 + T cells (P < 0.001), and CD8+CD28-TGF-ß+T cells (P < 0.001) were notably higher than in the control group. The expression of Tim-3 on CTL and CD8+CD28-T cells in AE patients was significantly upregulated (P < 0.001, P < 0.001). AE patients displayed a substantial decrease in peripheral blood PBMC CD107a mRNA levels (P < 0.001) and significant elevations in Tim-3/Galectin-9 mRNA levels (P < 0.001, P < 0.001). A negative correlation was observed between CD107a mRNA levels and both Tim-3 (r^2 = 0.411, P < 0.001) and Galectin-9 (r2 = 0.180, P = 0.019) mRNA levels. Expressions of IL-10 (P < 0.001), TGF-ß (P < 0.001), and Tim-3/Galectin-9 (P < 0.001, P < 0.001) in AE patient-infected livers were significantly higher than in uninfected regions. IL-10 and TGF-ß expressions showed a positive correlation with Tim-3/Galectin-9. CONCLUSION: This study suggests that the high expression of Tim-3 on CD8+T cell surfaces in AE patients might promote an increase in CD8+CD28-T cells and related factors, while suppressing CTL and related factor expressions. This potentially induces the onset of immune tolerance, which is unfavorable for the clearance of Echinococcus multilocularis in patients, leading to the exacerbation of persistent infections.

Epithelial Galectin-3 Induced the Mitochondrial Complex Inhibition and Cell Cycle Arrest of CD8+ T Cells in Severe/Critical COVID-19.

Previous research suggested that the dramatical decrease in CD8+ T cells is a contributing factor in the poor prognosis and disease progression of COVID-19 patients. However, the underlying mechanisms are not fully understood. In this study, we conducted Single-cell RNA sequencing (scRNA-seq) and single-cell T cell receptor sequencing (scTCR-seq) analysis, which revealed a proliferative-exhausted MCM+FASLGlow CD8+ T cell phenotype in severe/critical COVID-19 patients. These CD8+ T cells were characterized by G2/M cell cycle arrest, downregulation of respiratory chain complex genes, and inhibition of mitochondrial biogenesis. CellChat analysis of infected lung epithelial cells and CD8+ T cells found that the galectin signaling pathway played a crucial role in CD8+ T cell reduction and dysfunction. To further elucidate the mechanisms, we established SARS-CoV-2 ORF3a-transfected A549 cells, and co-cultured them with CD8+ T cells for ex vivo experiments. Our results showed that epithelial galectin-3 inhibited the transcription of the mitochondrial respiratory chain complex III/IV genes of CD8+ T cells by suppressing the nuclear translocation of nuclear respiratory factor 1 (NRF1). Further findings showed that the suppression of NRF1 translocation was associated with ERK-related and Akt-related signaling pathways. Importantly, the galectin-3 inhibitor, TD-139, promoted nuclear translocation of NRF1, thus enhancing the expression of the mitochondrial respiratory chain complex III/IV genes and the mitochondrial biogenesis of CD8+ T cells. Our study provided new insights into the immunopathogenesis of COVID-19 and identified potential therapeutic targets for the prevention and treatment of severe/critical COVID-19 patients.