IgG Fc Binding Protein Research Articles

Different Forms of TFF3 in the Human Endocervix, including a Complex with IgG Fc Binding Protein (FCGBP), and Further Aspects of the Cervico-Vaginal Innate Immune Barrier.

TFF3 is a typical secretory poplypeptide of mucous epithelia belonging to the trefoil factor family (TFF) of lectins. In the intestine, respiratory tract, and saliva, TFF3 mainly exists as a high-molecular-mass complex with IgG Fc binding protein (FCGBP), which is indicative of a role in mucosal innate immunity. For the first time, we identified different forms of TFF3 in the endocervix, i.e., monomeric and homodimeric TFF3, as well as a high-molecular-mass TFF3-FCGBP complex; the latter also exists in a hardly soluble form. Immunohistochemistry co-localized TFF3 and FCGBP. Expression analyses of endocervical and post-menopausal vaginal specimens revealed a lack of mucin and TFF3 transcripts in the vaginal specimens. In contrast, genes encoding other typical components of the innate immune defense were expressed in both the endocervix and vagina. Of note, FCGBP is possibly fucosylated. Endocervical specimens from transgender individuals after hormonal therapy showed diminished expression, particularly of FCGBP. Furthermore, mucus swabs from the endocervix and vagina were analyzed concerning TFF3, FCGBP, and lysozyme. It was the aim of this study to illuminate several aspects of the cervico-vaginal innate immune barrier, which is clinically relevant as bacterial and viral infections are also linked to infertility, pre-term birth and cervical cancer.

Multi-omics analysis of fecal samples in colorectal cancer Egyptians patients: a pilot study

BackgroundColorectal cancer (CRC) is a public health concern and the second most common disease worldwide. This is due to genetic coding and is influenced by environmental aspects, in which the gut microbiota plays a significant role. The purpose of this study was to compare the microbiota makeup of CRC patients with that of healthy control and to identify upregulated and downregulated proteins and metabolites in CRC patients. Using a next-generation sequencing approach, fecal samples of five females (4 CRC patients and one healthy control) were analyzed by BGI DNBSEQ-T7, Hong Kong, China. Furthermore, proteomics and metabolomics analysis were performed using LC-MS/MS technique.ResultsDysbiosis of gut microbiota has been observed in patients with CRC, with an increase in microbiota diversity at all taxonomic levels relative to healthy control. Where, at the functional level the bacterial species participate in many different pathways among them de novo nucleotide synthesis and amino acids pathways were aberrantly upregulated in CRC patients. Proteomics and metabolomics profiles of CRC patients showed different proteins and metabolites, a total of 360 and 158 proteins and metabolites, respectively were highly expressed compared to healthy control with fold change ≥ 1.2. Among the highly expressed proteins were transketolase, sushi domain-containing protein, sulfide quinone oxidoreductase protein, AAA family ATPase protein, carbonic anhydrase, IgG Fc-binding protein, nucleoside diphosphate kinase protein, arylsulfatase, alkaline phosphatase protein, phosphoglycerate kinase, protein kinase domain-containing protein, non-specific serine/threonine protein kinase, Acyl-CoA synthetase and EF-hand domain-containing protein. Some of the differential metabolites, Taurine, Taurocholic acid, 7-ketodeoxycholic acid, Glycochenodeoxycholic acid, Glycocholic acid, and Taurochenodeoxycholic acid that belong to bile acids metabolites.ConclusionsSome bacterial species, proteins, and metabolites could be used as diagnostic biomarkers for CRC. Our study paves an insight into using multi-omics technology to address the relationship between gut microbiota and CRC.

IgGFc-binding protein and MUC2 mucin produced by colonic goblet-like cells spatially interact non-covalently and regulate wound healing.

The colonic mucus bilayer is the first line of innate host defense that at the same time houses and nourishes the commensal microbiota. The major components of mucus secreted by goblet cells are MUC2 mucin and the mucus-associated protein, FCGBP (IgGFc-binding protein). In this study, we determine if FCGBP and MUC2 mucin were biosynthesized and interacted together to spatially enhance the structural integrity of secreted mucus and its role in epithelial barrier function. MUC2 and FCGBP were coordinately regulated temporally in goblet-like cells and in response to a mucus secretagogue but not in CRISPR-Cas9 gene-edited MUC2 KO cells. Whereas ~85% of MUC2 was colocalized with FCGBP in mucin granules, ~50% of FCGBP was diffusely distributed in the cytoplasm of goblet-like cells. STRING-db v11 analysis of the mucin granule proteome revealed no protein-protein interaction between MUC2 and FCGBP. However, FCGBP interacted with other mucus-associated proteins. FCGBP and MUC2 interacted via N-linked glycans and were non-covalently bound in secreted mucus with cleaved low molecular weight FCGBP fragments. In MUC2 KO, cytoplasmic FCGBP was significantly increased and diffusely distributed in wounded cells that healed by enhanced proliferation and migration within 2 days, whereas, in WT cells, MUC2 and FCGBP were highly polarized at the wound margin which impeded wound closure by 6 days. In DSS colitis, restitution and healed lesions in Muc2+/+ but not Muc2-/- littermates, were accompanied by a rapid increase in Fcgbp mRNA and delayed protein expression at 12- and 15-days post DSS, implicating a potential novel endogenous protective role for FCGBP in wound healing to maintain epithelial barrier function.

IgG Fc-binding protein positively regulates the assembly of pore-forming protein complex βγ-CAT evolved to drive cell vesicular delivery and transport

Cell membranes form barriers for molecule exchange between the cytosol and the extracellular environments. βγ-CAT, a complex of pore-forming protein BmALP1 (two βγ-crystallin domains with an aerolysin pore-forming domain) and the trefoil factor BmTFF3, has been identified in toad Bombina maxima. It plays pivotal roles, via inducing channel formation in various intracellular or extracellular vesicles, as well as in nutrient acquisition, maintaining water balance, and antigen presentation. Thus, such a protein machine should be tightly regulated. Indeed, BmALP3 (a paralog of BmALP1) oxidizes BmALP1 to form a water-soluble polymer, leading to dissociation of the βγ-CAT complex and loss of biological activity. Here, we found that the B.maxima IgG Fc-binding protein (FCGBP), a well-conserved vertebrate mucin-like protein with unknown functions, acted as a positive regulator for βγ-CAT complex assembly. The interactions among FCGBP, BmALP1, and BmTFF3 were revealed by co-immunoprecipitation assays. Interestingly, FCGBP reversed the inhibitory effect of BmALP3 on the βγ-CAT complex. Furthermore, FCGBP reduced BmALP1 polymers and facilitated the assembly of βγ-CAT with the biological pore-forming activity in the presence of BmTFF3. Our findings define the role of FCGBP in mediating the assembly of a pore-forming protein machine evolved to drive cell vesicular delivery and transport.

Serum Proteomic Analysis by Nanoflow LC-MS/MS-Based Proteomics in IgA Chronic Kidney Disease.

IgA nephropathy (IgAN) is the most frequently occurring primary glomerulonephritis. A lack of specific biomarkers hinders the early diagnosis and treatment of this disease. This study analyzes and validates potential serum biomarkers using mass spectrometry proteomics. Global proteomics profiles of serum from 60 patients with IgAN and 43 healthy control subjects were compared to identify significantly changed proteins. These proteins were validated with targeted proteomics using parallel reaction monitoring (PRM) in an independent validation set consisting of samples from 67 different stage IgAN patients and 60 healthy controls. A total of 37 significantly changed proteins were found in the discovery set, among which 18 proteins were identified as potential biomarkers for IgAN through PRM assays in the validation set. Of these 18 proteins, IgGFc-binding protein, MS-A1 light chain variable region, transthyretin, ficolin-3, and myosin-reactive immunoglobulin light chain variable region were up-regulated in different IgAN stages, B cell receptor heavy chain variable region, rheumatoid factor RF-ET6, heavy chain Fab, cryocrystalglobulin CC1 heavy chain variable region, FLJ94213, lumican, and Q68CN4 (uncharacterized protein) were down-regulated in different IgAN stages. These proteins support previous findings that CKD is accompanied by altered immune response. This study lays the groundwork for additional research using biomarkers to clinically diagnose IgAN. These proteins are potential molecular markers that could help us understand the potential molecular mechanism of IgAN.

Different Molecular Forms of TFF3 in the Human Respiratory Tract: Heterodimerization with IgG Fc Binding Protein (FCGBP) and Proteolytic Cleavage in Bronchial Secretions

The polypeptide TFF3 belongs to the trefoil factor family (TFF) of lectins. TFF3 is typically secreted from mucous epithelia together with mucins. Both intestinal and salivary TFF3 mainly exist as disulfide-linked heterodimers with IgG Fc binding protein (FCGBP). Here, we investigated bronchial tissue specimens, bronchial secretions, and bronchoalveolar lavage (BAL) fluid from patients with a chronic obstructive pulmonary disease (COPD) background by fast protein liquid chromatography and proteomics. For the first time, we identified different molecular forms of TFF3 in the lung. The high-molecular mass form represents TFF3-FCGBP oligomers, whereas the low-molecular mass forms are homodimeric and monomeric TFF3 with possibly anti-apoptotic activities. In addition, disulfide-linked TFF3 heterodimers with an Mr of about 60k and 30k were detected in both bronchial secretions and BAL fluid. In these liquids, TFF3 is partly N-terminally truncated probably by neutrophil elastase cleavage. TFF3-FCGBP is likely involved in the mucosal innate immune defense against microbial infections. We discuss a hypothetical model how TFF3 might control FCGBP oligomerization. Furthermore, we did not find indications for interactions of TFF3-FCGBP with DMBT1gp340 or the mucin MUC5AC, glycoproteins involved in mucosal innate immunity. Surprisingly, bronchial MUC5AC appeared to be degraded when compared with gastric MUC5AC.

Evaluation of the Fecal Proteome in Healthy and Diseased Cheetahs (Acinonyx jubatus) Suffering from Gastrointestinal Disorders.

Simple SummaryThe cheetah (genus Acinonyx), which is considered vulnerable by the IUCN Red List, suffers quite frequently from chronic gastrointestinal (GI) diseases, often associated with Helicobacter spp., with a significant mortality, especially in captive animals. The study of the fecal proteome aims to investigate possible new markers of disease that could be useful in diagnosing and/or monitoring, when performed in feces, gastrointestinal disorders. Considering the invasiveness of some diagnostic investigations (e.g., GI endoscopy) in general and the difficulties of carrying out even simple blood sampling in animals such as the cheetah, the possibility of deriving clinical-diagnostic information from fecal samples is extremely interesting. Herein, a fecal proteomic evaluation from healthy and diseased cheetahs suffering from GI disorders is performed.Fecal proteomics allows for the identification of proteins and peptides present in stools and is useful in finding possible new biomarkers for diagnosing and/or monitoring gastrointestinal (GI) disorders. In the present study, we investigated the fecal proteome in healthy and diseased cheetahs (Acinonyx jubatus). Captive individuals of this species frequently show gastrointestinal disorders characterized by recurrent episodes of diarrhea, rare episodes of vomiting and weight loss, associated with Helicobacter spp. infection. Fecal proteomic evaluation has been performed by two-dimensional electrophoresis followed by liquid chromatography-tandem mass spectrometry. In healthy cheetahs, the results showed the presence of the following proteins: collagen alpha-1 (II) chain, transthyretin, IgG Fc-binding protein, titin, dystonin, isopentenyl-diphosphate Delta-isomerase 1, sodium/potassium-transporting ATPase subunit alpha-1 and protein disulfide-isomerase A6. The presence of albumin isoforms was found only in diseased cheetahs. The present paper reports the study of the fecal proteome in the cheetah, evidences some differences between healthy and diseased patients and confirms, once again, the potential of fecal proteomics for the study of the GI environment, with promising developments regarding the identification of new diagnostic/monitoring markers.

Role of the mucin-like glycoprotein FCGBP in mucosal immunity and cancer.

IgGFc-binding protein (FCGBP) is a mucin first detected in the intestinal epithelium. It plays an important role in innate mucosal epithelial defense, tumor metastasis, and tumor immunity. FCGBP forms disulfide-linked heterodimers with mucin-2 and members of the trefoil factor family. These formed complexes inhibit bacterial attachment to mucosal surfaces, affect the motility of pathogens, and support their clearance. Altered FCGBP expression levels may be important in the pathologic processes of Crohn’s disease and ulcerative colitis. FCGBP is also involved in regulating the infiltration of immune cells into tumor microenvironments. Thus, the molecule is a valuable marker of tumor prognosis. This review summarizes the functional relevance and role of FCGBP in immune responses and disease development, and highlights the potential role in diagnosis and predicting tumor prognosis.

FCGBP Is a Promising Prognostic Biomarker and Correlates with Immunotherapy Efficacy in Oral Squamous Cell Carcinoma.

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies of the head and neck. In OSCC patients, the prognosis was dramatically different. In this research, we aimed to study the expressions and prognostic values of IgG Fc binding protein (FCGBP) in OSCC patients. The expression of FCGBP was analyzed using TCGA datasets and GEO datasets. FCGBP was evaluated for its predictive significance in OSCC patients by the use of a Kaplan-Meier and Cox regression model. Enrichment analysis for the GO and KEGG databases were conducted. CIBERSORT used TCGA datasets to show immune cell infiltration. In addition, researchers looked into the relationships between FCGBP and immune cells. The levels of FCGBP in OSCC cells was examined through the use of RT-PCR. FCGBP overexpression was tested for its effects on OSCC cell proliferation and invasion using CCK-8 and Transwell assays. We observed that FCGBP expressions were distinctly downregulated in OSCC specimens compared with nontumor tissues in both TCGA and GEO datasets, which was further confirmed by RT-PCR. OSCC patients with advanced clinical stages and poor prognoses had lower levels of FCGBP expression. Many immune-related biological activities and signaling pathways were found to be considerably abundant in KEGG tests and GO analysis results. The correlation analysis indicated that FCGBP was associated with a number of immune cells in a positive way. We found that FCGBP expressions were strongly and distinctly linked to the expressions of known immunological checkpoints, and FCGBP expression had significant positive connections with tumor mutational burden. FCGBP upregulation distinctly slowed the growth and invasion of OSCC cells in functional experiments. FCGBP has the potential to be a therapeutic target for OSCC and a biomarker for OSCC patients' prognosis.

Global N6-methyladenosine methylation analysis reveals the positive correlation between m6A modification and mRNA abundance during Apostichopus japonicus disease development

N6-methyladenosine (m6A), the most abundant epitranscriptomic modification in eukaryotic messenger RNA (mRNA), plays important roles in regulation of gene expression for fundamental biological processes and diverse physiological functions, including combating with pathogen infection. Here, we were first profile transcriptome-wide m6A sequencing in four stages of skin ulceration syndrome-diseased Apostichopus japonicus following Vibrio splendidus infection, including Control (healthy), Early (small ulcer), Later (extensive ulcer), and Resistant (no ulcer) groups. Our results revealed that three experimental groups were all extensively methylated by m6A and the proportion of the m6A modified genes were also significantly increased to 28.90% (Early), 27.97% (Later), and 29.98% (Resistant) when compared with Control group (15.15%), indicating m6A modification could be induced by V. splendidus infection. Intriguingly, we discovered a positive correlation between the m6A methylation level and mRNA abundance, indicating a positive regulatory role of m6A in sea cucumber gene expression during V. splendidus infection. Moreover, genes with specific and differentially expressed m6A methylation in Later group were both enriched in cell adhesion, while Early and Resistant groups were both mainly involved in DNA conformation change and chromosome organization when compared with Control, suggesting the higher-methylated m6A might serve as “conformational marker” and associated to the initiation of related anti-disease genes transcription in order to improve disease resistance of sea cucumber. Subsequently, we selected the pivotal genes enriched in cell adhesion pathway and found that the IggFc-binding protein (FcGBP) and Fibrocystin-L both had higher levels of m6A methylation and higher level of mRNA expressions in Later group. Conversely, Fibrinogen C domain-containing protein 1 (F1BCD1) gene presented as an antibacterial role in sea cucumber and showed higher mRNA expression and higher m6A methylation in Resistant group and lower mRNA level in Later group. The levels of m6A methylation and mRNA abundance of FcGBP and F1BCD1 genes indicates disease occurrence or disease resistant were also verified by MeRIP-qPCR. Overall, our study presents the first comprehensive characterize of dynamic m6A methylation modification in the different stages of disease in sea cucumber. These data provide an invaluable resource for future studies of function and biological significance of m6A in mRNA in marine invertebrates.

Multi-Omics Analyses to Identify FCGBP as a Potential Predictor in Head and Neck Squamous Cell Carcinoma

(Purpose) Previous studies have pointed out the significance of IgG Fc binding protein (FCGBP) in carcinogenesis, cancer progression, and tumor immunity in certain malignancies. However, its prognostic values, molecular interaction, and immune characteristics in the head and neck squamous cell carcinoma (HNSC) remained unclear. (Methods) To evaluate the potential role of the FCGBP gene, we used GEPIA2 and UALCAN platforms to explore the differential levels, survivals, and genetic alteration through cBioPortal (based on The Cancer Genome Atlas dataset). STRING, GeneMania, and TIMER2.0 identified the interacting networks. LinkedOmics performed Gene enrichment analysis, and TISIDB and TIMER2.0 evaluated the role of FCGBP in the tumor microenvironment. (Results) The expression level of FCGBP is lower in cancer tissues. A high FCGBP level is significantly associated with better overall- and disease-specific-survivals, regardless of human papillomavirus infection. Low FCGBP levels correlated to a higher tumor protein p53 (TP53) mutation rate (p = 0.018). FCGBP alteration significantly co-occurred with that of TP53 (q = 0.037). Interacting networks revealed a significant association between FGFBP and trefoil factor 3 (TFF3), a novel prognostic marker in various cancers, at transcriptional and translational levels. Enrichment analyses identified that the top gene sets predominantly related to immune and inflammatory responses. Further investigation found that the FCGBP mRNA level positively correlated to the infiltration rates of B cells, Th17/CD8+ T lymphocytes, T helper follicular cells, mast cells, and expression levels of various immune molecules and immune checkpoints in HNSC. (Conclusions) We found that the FCGBP mRNA level negatively correlated to TP53 mutation status while positively correlated to the TFF3 level. Additionally, FCGBP may regulate the tumor microenvironment. These findings support the FCGBP as a potential biomarker to estimate HNSC prognoses.

Comparative Transcriptomic Analysis Reveals the Regulated Expression Profiles in Oreochromis niloticus in Response to Coinfection of Streptococcus agalactiae and Streptococcus iniae.

Tilapia (Oreochromis sp.) is one of the important economical fishes in the world. Streptococcosis is commonly found in tilapia, causing severe and devastating effects in tilapia cultures. Streptococcus agalactiae and Streptococcus iniae are the predominant pathogens causing tilapia streptococcosis. To understand the molecular mechanisms underlying differential streptococcal infection patterns, Nile tilapias (Oreochromis niloticus) were infected by 1 × 107 CFU/mL S. agalactiae, 1 × 107 CFU/mL S. iniae, and 1 × 107 CFU/mL S. agalactiae and S. iniae (1:1), respectively, and transcriptome analysis was conducted to the intestine samples of Nile tilapia (Oreochromis niloticus) at 6, 12, 24 h, and 7 days post-infection. A total of 6,185 genes that differentially expressed among groups were identified. Eight differentially expressed genes (DEGs) including E3 ubiquitin-protein ligase TRIM39-like, C-X-C motif chemokine 10-like(CXCL 10), C-C motif chemokine 19-like, interleukin-1 beta-like, IgM heavy chain VH region, partial, IgG Fc-binding protein, proteasome subunit beta type-8 (PSMB8), and ATP synthase F(0) complex subunit B1, mitochondrial that involved in the immune system were selected, and their expression levels in the coinfection group were significantly higher than those in either of the single infection groups. These genes were associated with four different KEGG pathways. Additionally, the differential expression of eight DEGs was validated by using the RT-qPCR approach, and their immunological importance was discussed. The results provided insights into the responses of tilapia against S. agalactiae and S. iniae at the transcriptome level, promoting our better understanding of immune responses for aquatic animal against Streptococcus.

Abstract P4-11-34: An integrated clinical, behavioral and biological model to predict the risk of weight gain among breast cancer survivors (BCS)

Abstract Background: Weight management is an integral part of survivorship care. Excess weight in BCS is associated with worse clinical outcomes and quality of life. Early identification of BCS at risk of gaining substantial weight could lead to prompt and tailored interventions. We aimed at developing a predictive model of weight gain that integrates clinical, behavioral and biological data. Methods: We included patients with stage I-III BC from the CANTO cohort (NCT01993498). CANTO collects longitudinal data, including objective anthropometric measures, at diagnosis (dx), 1 (T1), 2 (T2) and 4 (T3) years after dx. In addition, profiling of blood samples obtained at dx was performed for two sub-cohorts with HR+/HER2- BC for quantification of: (1) inflammatory and metabolic biomarkers (IL6, TNFα, IL1RA, CRP, IL2, IL1β, IFNγ, IL10, IL1A, IL4, IL8, ADPN, LEPT, INS, RETN) and (2) detectable proteins using hyper reaction mass spectrometry (Biognosys). Our outcome of interest was weight gain (increase ≥ 5%) compared to dx. First, multivariable logistic regression with bootstrapped Augmented Backwards Elimination (ABE) retained associations between weight gain and clinico-behavioral covariates. To assess contribution of biologic data, ABE retained associations between weight gain and biomarkers, correcting for significant covariates. Models were validated using internal cross-validation and overoptimism-correction. For proteomics, proteins relative intensity was calculated, and a bootstrapped differential protein expression analysis identified proteins associated with weight gain that were then included in logistic regression. Models performance was assessed in terms of Area Under the Curve (AUC). Results: In the overall cohort (N=9541) mean age was 56.8 (SD 11.4), mean BMI was 25.9 Kg/m2 (SD 5.4), 48.9% of pts were overweight or obese, and 52.9% received chemotherapy (CT). Overall, 16.9% (T1), 23.4% (T2), and 27.2% (T3) BCS gained weight (absolute mean change (95% CI): 6.1 kg (5.9-6.2), 6.7 kg (6.5-6.9) and 7.2 kg (6.9-7.3) at T1, T2, T3, respectively). In clinico-behavioral models, younger age, current smoking, lower income and education, receipt of CT and radiotherapy were associated with increased risk of weight gain (Table). Among 1261 BCS with biomarkers data, higher levels of IL1α (OR for 1-unit log increase [95%CI] 0.11 [0.02 - 0.65]) and of ADPN (1.36 [1.01 - 1.85]) were associated with lower and higher risk of weight gain at T2 and T3, respectively. Performance of models integrating these biomarkers was similar to clinico-behavioral models. Among 462 BCS with proteomic profiling, preliminary data showed that higher relative abundance of IgG Fc Binding Protein (OR 0.44, p<.05) and Tubulin-1 (OR 0.73, p<.05) was associated with lower risk of weight gain at T1. AUC of model integrating clinical and proteomics data was 0.74 (0.58-0.90). Conclusions: Over one-in-four BCS in the CANTO cohort experienced meaningful weight gain 4 years after dx. This large, multidimensional study confirms the role of clinico-behavioral risk factors for weight gain. However, the predictive ability of clinico-behavioral models seems suboptimal. The exploitation of additional data dimensions, including serum proteins and proteomic data, may help improve predictive ability and inform underlying biological processes implicated in weight gain after BC. Further studies will aim at improving model stability, particularly for proteomics analyses. Table. Models of weight gain in the overall cohort.T1 (N= 8397)T2 (N= 7663)T3 (N= 5802)Clinical predictors OR* (95% CI)OR* (95% CI)OR* (95% CI)Age, 1-year increase0.96 (0.94 - 0.97)0.96 (0.95 - 0.97)0.96 (0.95 - 0.97)BMI, 1-unit increaseNRNS0.97 (0.94 - 0.99)Education, primary vs collegeNS1.57 (1.04 - 2.39)NREducation, high school vs college1.38 (1.04 - 1.83)1.54 (1.21 - 1.98)NRIncome, ≥ 1500 and <3000 vs >3000NRNR1.29 (1.00 - 1.66)Smoke, current vs never1.70 (1.24 - 2.33)NR1.53 (1.12 - 2.08)Chemotherapy, yes vs no1.40 (1.07 - 1.82)1.31 (1.01 - 1.69)NRRadiotherapy, yes vs no2.10 (1.10 - 3.99)NR1.83 (1.08 - 3.12)AUC (95% CI) - clinical models0.65 (0.63 - 0.68)0.64 (0.61 - 0.67)0.65 (0.63 - 0.68)AUC (95% CI) - clinical + inflammatory and metabolic biomarkers models, [N]0.65 (0.60 - 0.70), [1179]0.66 (0.62 - 0.70), [948]0.67 (0.63 - 0.71), [1017]AUC (95% CI) - clinical and proteomics models, [N]0.74 (0.58 - 0.90), [462]0.65 (0.50 - 0.81), [462]NEOR= Odds Ratio, CI= Confidence Interval, NR= Not Retained, NS= Not significant, NE= Not evaluated *Adjusted by age, menopause, smoke, socioeconomic, psychological, tumor and treatments **Significant covariates from previous models were forced and ABE selected significant variables among all circulating biomarkers. Citation Format: Davide Soldato, Antonio Di Meglio, Caroline Pradon, Antonin Della Noce, Daniele Presti, Julie Havas, Florine Dubuisson, Barbara Pistilli, Valerie Camara-Clayette, Fabrice André, Alexandra Jacquet, Sibille Everhard, Sandrine Boyault, Paul-Henry Cournede, Stefan Michiels, Ines Vaz-Luis, Stergios Christodoulidis. An integrated clinical, behavioral and biological model to predict the risk of weight gain among breast cancer survivors (BCS) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-11-34.

Salivary Trefoil Factor Family (TFF) Peptides and Their Roles in Oral and Esophageal Protection: Therapeutic Potential.

Human saliva is a complex body fluid with more than 3000 different identified proteins. Besides rheological and lubricating properties, saliva supports wound healing and acts as an antimicrobial barrier. TFF peptides are secreted from the mucous acini of the major and minor salivary glands and are typical constituents of normal saliva; TFF3 being the predominant peptide compared with TFF1 and TFF2. Only TFF3 is easily detectable by Western blotting. It occurs in two forms, a disulfide-linked homodimer (Mr: 13k) and a high-molecular-mass heterodimer with IgG Fc binding protein (FCGBP). TFF peptides are secretory lectins known for their protective effects in mucous epithelia; the TFF3 dimer probably has wound-healing properties due to its weak motogenic effect. There are multiple indications that FCGBP and TFF3-FCGBP play a key role in the innate immune defense of mucous epithelia. In addition, homodimeric TFF3 interacts in vitro with the salivary agglutinin DMBT1gp340. Here, the protective roles of TFF peptides, FCGBP, and DMBT1gp340 in saliva are discussed. TFF peptides are also used to reduce radiotherapy- or chemotherapy-induced oral mucositis. Thus, TFF peptides, FCGBP, and DMBT1gp340 are promising candidates for better formulations of artificial saliva, particularly improving wound healing and antimicrobial effects even in the esophagus.

Trefoil Factor Family (TFF) Peptides

Trefoil factor family (TFF) peptides mainly consist of characteristic TFF domains, which contain about 40 amino acid residues, including 6 conserved cysteine residues. TFF peptides possess a single (mammalian TFF1 and TFF3), two (mammalian TFF2, Xenopus laevis xP2) or four TFF domains (X. laevis xP4). They exhibit lectin activities and are characteristic exocrine products of the mucous epithelia. Here, they play different roles for mucosal protection and the innate immune defense: TFF1 is a gastric tumor suppressor; TFF2 builds a lectin complex with the mucin MUC6, physically stabilizing the inner gastric mucus layer; and TFF3 forms a disulfide-linked heterodimer with IgG Fc binding protein (FCGBP), probably preventing the infiltration of microorganisms. Minor amounts of TFF peptides are endocrine products of the immune and nervous systems. Pathologically, TFF peptides are linked to inflammation. There are increasing indications that TFF peptides can antagonize cytokine receptors, such as receptors for IL-1β, IL-6, and TNFα (thereby acting as anti-inflammatory peptides). TFF peptides can probably also activate a variety of receptors, such as CXCR4. The TFF domain is a unique shuffled module which is also present in a number of mosaic proteins, such as zona pellucida proteins, sugar degrading enzymes and frog skin mucins. Here, their function seems to be defined by a lectin activity, which might even allow a role in fertilization.

Directional immobilization of antibody onto magnetic nanoparticles by Fc-binding protein-assisted photo-conjugation for high sensitivity detection of antigen

Immobilized antibodies with site-specific, oriented, and covalent pattern are of great significance to improve the sensitivity of solid-phase immunoassay. Here, we developed a novel antibody conjugation strategy that can immobilize antibodies in a directional and covalent manner. In this study, an IgG-Fc binding protein (Z domain) carrying a site-specific photo-crosslinker, p-benzoyl-L-phenylalanine, and a single C-terminal cysteine (Cys) handle was genetically engineered. Upon UV irradiation, the chimeric protein enables the Cys handle to couple with the native antibody in Fc-specific and covalent conjugation pattern, resulting in a novel thiolated antibody. Thus, an approach for the covalent, directional immobilization of antibodies to maleimide-modified magnetic nanoparticles (MNPs) was developed on the basis of the crosslinking between sulfhydryl and maleimide groups. The antibody-conjugated MNPs were applied in MNP-based enzyme-linked immunosorbent assay (ELISA) for the detection of carcinoembryonic antigen. The MNP-based ELISA presented a quantification linear range of 0.1–100 ng mL−1 and detection limit of 0.02 ng mL−1, which was approximately 100 times more sensitive than the traditional microplate ELISA (2.0 ng mL−1). Thus, the proposed antibody immobilization approach can be used in surface functionalization for the sensitive detection of various biomarkers.

Gel-forming Mucins in Oviductus Ranae Contribute to Swelling Capacity by iTRAQ Proteomics Analysis

Abstract: Introduction: Oviductus Ranae (OR) is the dried oviduct of female Rana temporaria chensinensis David, which is one of the best-known and highly valued oriental foods and medicines in China. OR has a unique physiological phenomenon that is high swelling capacity. Objectives: We aimed to study which components are associated with high swelling capacity in OR. Materials and Methods: isobaric tags for relative and absolute quantification (iTRAQ) proteomic methods were used to identify differentially expressed proteins between the OR and three counterfeit oviducts, including Rana nigromaculata, Bufo bufogargarizans and Rana catesbeiana to explore the mechanism of swelling capacity. Results: We found that a total of 1220 proteins were identified from 2149 unique peptide sequences. Comparing with three counterfeit oviducts, 11 differentially expressed proteins were identified in OR, including 9 up-regulated proteins, such as mucins (MUC2, MUC5AC, MUC5AC-like, MUC5B), PREDICTED: a-kinase anchor protein 13-like (AKAP13-like), PREDICTED: IgGFc-binding protein (FcγBP), PREDICTED: IgGFcbinding protein-like (FcγBP-like), et al. and 2 down-regulated proteins. Bioinformatics results found that these up-regulated proteins were involved in biological processes, including metabolic process, cellular process, responses to stimulus and biological regulation. Conclusion: Mucins, AKAP13-like, FcγBP and FcγBP-like may act as a positive regulator for the innate immune response in oviduct of Chinese brown frog and exceptional swelling capacity of OR is closely related to gel-forming mucins. Taken together, our results provide the basis for further understanding of the unique physiological phenomenon of OR. Key words: Oviductus Ranae, Swelling capacity, Gel-forming mucins, Counterfeit oviducts, Differentially expressed proteins.

Neglected roles of IgG Fc-binding protein secreted from airway mucin-producing cells in protecting against SARS-CoV-2 infection.

Both innate immunity and acquired immunity are involved in severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. The induction of Abs that neutralize the virus has been described, and certain Abs against endemic coronaviruses may cross-react with SARS-CoV-2. Detailed mechanisms to protect against the pandemic of SARS-CoV-2 remain unresolved. We previously reported that IgG Fc-binding protein (Fcγbp), a unique, large molecular weight, and mucin-like secretory Fc receptor protein, secreted from goblet cells of human small and large intestine, mediates the transportation of serum IgG onto the mucosal surface. In this review, we show that mucous bronchial gland cells and some goblet cells are immunoreactive for Fcγbp. Fcγbp traps the cross-reactive (both neutralizing and non-neutralizing) IgG bound to the virus and can consequently eliminate the virus from the mucosal surface to decrease viral loads. Fcγbp can also suppress immune overreaction by interfering with Fc-binding by macrophages and competing with complement fixation. Fcγbp secreted from mucin-producing cells of the airway functions as an important anti-infection mucosal defense. The Fcγbp-mediated mechanism can be a key factor in explaining why SARS-CoV-2 is less infective/lethal in children, and may also be involved in the unique Ab response, recurrent infection, and effects of serum therapy and vaccination.

Fecal multi-omics analysis reveals diverse molecular alterations of gut ecosystem in COVID-19 patients

Gut ecosystem has profound effects on host physiology and health. Gastrointestinal (GI) symptoms were frequently observed in patients with COVID-19. Compared with other organs, gut antiviral response can result in more complicated immune responses because of the interactions between the gut microbiota and host immunity. However, there are still large knowledge gaps in the impact of COVID-19 on gut molecular profiles and commensal microbiome, hindering our comprehensive understanding of the pathogenesis of SARS-CoV-2 and the treatment of COVID-19. We performed longitudinal stool multi-omics profiling to systemically investigate the molecular phenomics alterations of gut ecosystem in COVID-19. Gut proteomes of COVID-19 were characterized by disturbed immune, proteolysis and redox homeostasis. The expression and glycosylation of proteins involved in neutrophil degranulation and migration were suppressed, while those of proteases were upregulated. The variable domains of Ig heavy chains were downregulated and the overall glycosylation of IgA heavy chain constant regions, IgGFc-binding protein, and J chain were suppressed with glycan-specific variations. There was a reduction of beneficial gut bacteria and an enrichment of bacteria derived deleterious metabolites potentially associated with multiple types of diseases (such as ethyl glucuronide). The reduction of Ig heave chain variable domains may contribute to the increase of some Bacteroidetes species. Many bacteria ceramide lipids with a C17-sphingoid based were downregulated in COVID-19. In many cases, the gut phenome did not restore two months after symptom onset. Our study indicates widely disturbed gut molecular profiles which may play a role in the development of symptoms in COVID-19. Our findings also emphasis the need for ongoing investigation of the long-term gut molecular and microbial alterations during COVID-19 recovery process. Considering the gut ecosystem as a potential target could offer a valuable approach in managing the disease.

The IgGFc-binding protein FCGBP is secreted with all GDPH sequences cleaved but maintained by interfragment disulfide bonds

Mucus forms an important protective barrier that minimizes bacterial contact with the colonic epithelium. Intestinal mucus is organized in a complex network with several specific proteins, including the mucin-2 (MUC2) and the abundant IgGFc-binding protein, FCGBP. FCGBP is expressed in all intestinal goblet cells and is secreted into the mucus. It is comprised of repeated von Willebrand D (vWD) domain assemblies, most of which have a GDPH amino acid sequence that can be autocatalytically cleaved, as previously observed in the mucins MUC2 and mucin-5AC. However, the functions of FCGBP in the mucus are not understood. We show that all vWD domains of FCGBP with a GDPH sequence are cleaved and that these cleavages occur early during biosynthesis in the endoplasmic reticulum. All cleaved fragments, however, remain connected via a disulfide bond within each vWD domain. This cleavage generates a C-terminal-reactive Asp-anhydride that could react with other molecules, such as MUC2, but this was not observed. Quantitative analyses by MS showed that FCGBP was mainly soluble in chaotropic solutions, whereas MUC2 was insoluble, and most of the secreted FCGBP was not covalently bound to MUC2. Although FCGBP has been suggested to bind immunoglobulin G, we were unable to reproduce this binding in vitro using purified proteins. In conclusion, while the function of FCGBP is still unknown, our results suggest that it does not contribute to covalent crosslinking in the mucus, nor incorporate immunoglobulin G into mucus, instead the single disulfide bond linking each fragment could mediate controlled dissociation.