In Situ Synthesis and Self-Assembly of Peptide-PEG Conjugates: A Facile Method for the Construction of Fibrous Hydrogels.

Peptide-based hydrogels have gained considerable attention as a compelling platform for various biomedical applications in recent years. Their attractiveness stems from their ability to seamlessly integrate diverse properties, such as biocompatibility, biodegradability, easily adjustable hydrophilicity/hydrophobicity, and other functionalities. However, a significant drawback is that most of the functional self-assembling peptides cannot form robust hydrogels suitable for biological applications. In this study, we present the synthesis of novel peptide-PEG conjugates and explore their comprehensive hydrogel properties. The hydrogel comprises double networks, with the first network formed through the self-assembly of peptides to create a ß-sheet secondary structure. The second network is established through covalent bond formation via N-hydroxysuccinimide chemistry between peptides and a 4-arm PEG to form a covalently linked network. Importantly, our findings reveal that this hydrogel formation method can be applied to other peptides containing lysine-rich sequences. Upon encapsulation of the hydrogel with antimicrobial peptides, the hydrogel retained high bacterial killing efficiency while showing minimum cytotoxicity toward mammalian cells. We hope that this method opens new avenues for the development of a novel class of peptide-polymer hydrogel materials with enhanced performance in biomedical contexts, particularly in reducing the potential for infection in applications of tissue regeneration and drug delivery.

Antipodoplanin antibody enhances the antitumor effects of CTLA-4 blockade against malignant mesothelioma by natural killer cells.

Combination immunotherapy with multiple immune checkpoint inhibitors (ICIs) has been approved for various types of malignancies, including malignant pleural mesothelioma (MPM). Podoplanin (PDPN), a transmembrane sialomucin-like glycoprotein, has been investigated as a diagnostic marker and therapeutic target for MPM. We previously generated and developed a PDPN-targeting Ab reagent with high Ab-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). However, the effects of anti-PDPN Abs on various tumor-infiltrating immune cells and their synergistic effects with ICIs have remained unclear. In the present study, we established a novel rat-mouse chimeric anti-mouse PDPN IgG2a mAb (PMab-1-mG2a ) and its core-fucose-deficient Ab (PMab-1-mG2a -f) to address these limitations. We identified the ADCC and CDC activity of PMab-1-mG2a -f against the PDPN-expressing mesothelioma cell line AB1-HA. The antitumor effect of monotherapy with PMab-1-mG2a -f was not sufficient to overcome tumor progression in AB1-HA-bearing immunocompetent mice. However, PMab-1-mG2a -f enhanced the antitumor effects of CTLA-4 blockade. Combination therapy with anti-PDPN Ab and anti-CTLA-4 Ab increased tumor-infiltrating natural killer (NK) cells. The depletion of NK cells inhibited the synergistic effects of PMab-1-mG2a -f and CTLA-4 blockade in vivo. These findings indicated the essential role of NK cells in novel combination immunotherapy targeting PDPN and shed light on the therapeutic strategy in advanced MPM.

Potential of fluoropyrimidine to be an immunologically optimal partner of immune checkpoint inhibitors through inducing immunogenic cell death for thoracic malignancies.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are a revolutionary paradigm in the treatment of thoracic malignancies and chemoimmunotherapy is a current standard care in this field. Chemotherapeutic agents are known to induce not only direct cytotoxic effects on tumor cells but also immune modulating effects, such as stimulating immunogenic cell death (ICD). Currently, either pemetrexed (PEM) or taxane plus platinum are combined with ICIs for patients with non-small cell lung cancer (NSCLC); however, it is still unknown whether these agents are immunologically optimal partners for ICIs. METHODS: To determine the immunologically optimal chemotherapeutic agent, we first evaluated the ability of several chemotherapeutic agents, including platinum, PEM, taxane, and 5-fluorouracil (5-FU) to induce ICD using several thoracic tumor cell lines in vitro. ICD was evaluated by the cell surface expression of calreticulin (CRT) and adenosine-triphosphate (ATP) secretion. We further performed an antitumor vaccination assay in vivo. RESULTS: 5-FU induced cell surface expression of CRT and ATP secretion most efficiently among the several chemotherapeutic agents. This effect was enhanced when it was combined with platinum. In the antitumor vaccination assay in vivo, we found that vaccination with dying-AB1-HA (a murine malignant mesothelioma cell line) cells treated with 5-FU, but neither PEM nor PTX, reduced the tumor growth of living-AB1-HA cells inoculated 1 week after vaccination by recruiting CD3+ CD8+ T cells into the tumor microenvironment. CONCLUSION: Our findings indicate that fluoropyrimidine can be an immunologically optimal partner of ICIs through the induction of ICD for thoracic malignancies.

Identification of fibrocyte cluster in tumors reveals the role in antitumor immunity by PD-L1 blockade.

Recent clinical trials revealed that immune checkpoint inhibitors and antiangiogenic reagent combination therapy improved the prognosis of various cancers. We investigated the roles of fibrocytes, collagen-producing monocyte-derived cells, in combination immunotherapy. Anti-VEGF (vascular endothelial growth factor) antibody increases tumor-infiltrating fibrocytes and enhances the antitumor effects of anti-PD-L1 (programmed death ligand 1) antibody in vivo. Single-cell RNA sequencing of tumor-infiltrating CD45+ cells identifies a distinct "fibrocyte cluster" from "macrophage clusters" in vivo and in lung adenocarcinoma patients. A sub-clustering analysis reveals a fibrocyte sub-cluster that highly expresses co-stimulatory molecules. CD8+ T cell-costimulatory activity of tumor-infiltrating CD45+CD34+ fibrocytes is enhanced by anti-PD-L1 antibody. Peritumoral implantation of fibrocytes enhances the antitumor effect of PD-L1 blockade in vivo; CD86-/- fibrocytes do not. Tumor-infiltrating fibrocytes acquire myofibroblast-like phenotypes through transforming growth factor ß (TGF-ß)/small mothers against decapentaplegic (SMAD) signaling. Thus, TGF-ßR/SMAD inhibitor enhances the antitumor effects of dual VEGF and PD-L1 blockade by regulating fibrocyte differentiation. Fibrocytes are highlighted as regulators of the response to programmed death 1 (PD-1)/PD-L1 blockade.

S-1 eliminates MDSCs and enhances the efficacy of PD-1 blockade via regulation of tumor-derived Bv8 and S100A8 in thoracic tumor.

Myeloid-derived suppressor cells (MDSCs) have been known to play a pivotal role in the induction of immune tolerance, which limits the benefits of immune checkpoint inhibitors (ICIs). Recent studies revealed that several chemotherapeutic agents decreased tumor-infiltrating MDSCs. Therefore, combination therapy with cytotoxic chemotherapeutic agents and ICIs was approved for first-line treatment for lung cancer. However, the impact of chemotherapeutic agents on MDSCs and an optimal partner of ICIs has not been fully investigated in thoracic tumors, including lung cancer and malignant pleural mesothelioma. In the present study, we found that treatment with 5-FU and its oral formulation, S-1, suppressed tumor progression and inhibited the accumulation of MDSCs in thoracic tumor-bearing mice. Tumor-infiltrating T cells and dendritic cells were significantly expanded in S-1-treated mice. 5-FU suppressed the ability of tumor cells to recruit MDSCs, while it did not suppress the survival and differentiation of mouse MDSCs in vitro. We also revealed that 5-FU or S-1 significantly downregulated the expression of tumor-derived Bv8 and S100A8. The knockdown of Bv8 or S100A8 in tumor cells suppressed tumor growth and MDSC recruitment in vivo. Furthermore, in comparison with pemetrexed, administration of S-1 improved the synergistic therapeutic efficacy of anti-PD-1 antibodies with or without carboplatin. Our findings revealed a novel mechanism wherein S-1 primed a favorable tumor microenvironment to provide the rationale for combination therapy with S-1 and ICIs as the optimal therapy for thoracic cancer.

Aerobic vaginitis in the third trimester and its impact on pregnancy outcomes.

BACKGROUND: Aerobic vaginitis (AV) is a vaginal inflammation characterized by disruption of the lactobacillus microbiota and increased counts of different aerobic bacteria. AV may result in severe complications, especially during pregnancy, including preterm delivery, neonatal and maternal infections. This study aimed to determine the prevalence of AV in the third trimester of pregnancy, and the relationship between AV and pregnancy outcomes.  METHODS: A cross-sectional descriptive study included 323 pregnant women attending for routine antenatal care in the Hue University Hospital. Vaginal samples collected at the third trimester of pregnancy were evaluated for AV according to the scoring system of Donders and cultured for identification of predominant bacteria. Pregnancy was followed to its end, and pregnancy outcomes were recorded for both mothers and infants. RESULTS: The proportion of pregnant women diagnosed with AV in the third trimester was found to be 15.5%, with the vast majority of the cases (84%) displaying the light AV and 16% the moderate AV. The vaginal cultures in the women with AV revealed most frequently Streptococcus agalactiae (6%), followed by Enterococcus spp (4%), Staphylococcus aureus (4%), and Acinetobacter baumannii (2%). In addition, AV during the last trimester of pregnancy was associated with an increased risk of puerperal sepsis (OR 8.65, 95% CI: 1.41-53.16, p = 0.020) and there was a slightly increased risk for neonatal infections, which was statistically insignificant. CONCLUSIONS: The proportion of AV is relatively high in Vietnamese pregnant women. Since it is associated with an increased risk of puerperal sepsis, it needs to be diagnosed and treated before delivery.

Programmed death (PD)-1/PD-ligand 1 blockade mediates antiangiogenic effects by tumor-derived CXCL10/11 as a potential predictive biomarker.

Immune checkpoint inhibitor (ICI) programmed death (PD)-1/PD-ligand 1 (PD-L1) blockade has been approved for various cancers. However, the underlying antitumor mechanisms mediated by ICIs and the predictive biomarkers remain unclear. We report the effects of anti-PD-L1/PD-1 Ab in tumor angiogenesis. In syngeneic mouse models, anti-PD-L1 Ab inhibited tumor angiogenesis and induces net-like hypoxia only in ICI-sensitive cell lines. In tumor tissue and serum of ICI-sensitive cell line-bearing mice, interferon-γ (IFN-γ) inducible angiostatic chemokines CXCL10/11 were upregulated by PD-L1 blockade. In vitro, CXCL10/11 gene upregulation by IFN-γ stimulation in tumor cell lines correlated with the sensitivity of PD-L1 blockade. The CXCL10/11 receptor CXCR3-neutralizing Ab or CXCL11 silencing in tumor cells inhibited the antiangiogenic effect of PD-L1 blockade in vivo. In pretreatment serum of lung carcinoma patients receiving anti-PD-1 Ab, the concentration of CXCL10/11 significantly correlated with the clinical outcome. Our results indicate the antiangiogenic function of PD-1/PD-L1 blockade and identify tumor-derived CXCL10/11 as a potential circulating biomarker of therapeutic sensitivity.

CD137 Signaling Is Critical in Fungal Clearance during Systemic Candida albicans Infection.

Invasive fungal infections by Candida albicans frequently cause mortality in immunocompromised patients. Neutrophils are particularly important for fungal clearance during systemic C. albican infection, yet little has been known regarding which surface receptor controls neutrophils' antifungal activities. CD137, which is encoded by Tnfrsf9, belongs to the tumor necrosis receptor superfamily and has been shown to regulate neutrophils in Gram-positive bacterial infection. Here, we used genetic and immunological tools to probe the involvement of neutrophil CD137 signaling in innate defense mechanisms against systemic C. albicans infection. We first found that Tnfrsf9-/- mice were susceptible to C. albicans infection, whereas injection of anti-CD137 agonistic antibody protected the host from infection, suggesting that CD137 signaling is indispensable for innate immunity against C. albicans infection. Priming of isolated neutrophils with anti-CD137 antibody promoted their phagocytic and fungicidal activities through phospholipase C. In addition, injection of anti-CD137 antibody significantly augmented restriction of fungal growth in Tnfrsf9-/- mice that received wild-type (WT) neutrophils. In conclusion, our results demonstrate that CD137 signaling contributes to defense mechanisms against systemic C. albicans infection by promoting rapid fungal clearance.

Blockade of PD-1/PD-L1 Pathway Enhances the Antigen-Presenting Capacity of Fibrocytes.

Fibrocytes, a distinct population of collagen-producing, monocyte-derived cells, are involved in wound healing as well as fibrotic diseases. Recently, fibrocytes have been revealed to play a role in the tumor microenvironment, particularly under antiangiogenic therapy. In addition, combination cancer immunotherapy with immune checkpoint inhibitor and antiangiogenic agents have been developed for various cancers in the clinical setting, although the immunological background is not clear. In the current study, we aimed to determine the function of fibrocytes in tumor immunity induced by immune checkpoint inhibitor therapy. Human and murine fibrocytes were generated from PBMCs and lungs, respectively. The expression of costimulatory and inhibitory molecules on fibrocytes was examined by flow cytometry. The stimulation of CD8+ T cells by fibrocytes was examined in MLRs with a 3H-thymidine incorporation assay. Fibrocytes expressed CD80low and CD86high as a costimulatory molecule, and expressed PD-L1high, but not PD-L2, as a coinhibitory molecule. Without any stimulation, fibrocytes strongly enhanced the proliferation of CD8+ T cells in mice and humans. Treatment with anti-CD86 and -CD54 Abs inhibited the growth of CD8+ T cells induced by fibrocytes. Anti-PD-L1 Ab further enhanced the proliferation of CD8+ T cells, even in the OVA-specific MLR with OT-1Rag-/- mice. Importantly, fibrocytes derived from PBMCs of patients with lung adenocarcinoma or murine MC38 tumors augmented the proliferation of CD8+ T cells with PD-L1 blockade. These results suggest that fibrocytes infiltrating tumor sites may play a role in the antitumor immunity mediated by CD8+ T cells when the activity is further enhanced by PD-L1/PD-1 blockade.

Soybean TIP Gene Family Analysis and Characterization of GmTIP1;5 and GmTIP2;5 Water Transport Activity.

Soybean, one of the most important crops worldwide, is severely affected by abiotic stress. Drought and flooding are the major abiotic stresses impacting soybean yield. In this regard, understanding water uptake by plants, its utilization and transport has great importance. In plants, water transport is mainly governed by channel forming aquaporin proteins (AQPs). Tonoplast intrinsic proteins (TIPs) belong to the plant-specific AQP subfamily and are known to have a role in abiotic stress tolerance. In this study, 23 soybean TIP genes were identified based on the latest soybean genome annotation. TIPs were characterized based on conserved structural features and phylogenetic distribution. Expression analysis of soybean TIP genes in various tissues and under abiotic stress conditions demonstrated tissue/stress-response specific differential expression. The natural variations for TIP genes were analyzed using whole genome re-sequencing data available for a set of 106 diverse soybean genotypes including wild types, landraces and elite lines. Results revealed 81 single-nucleotide polymorphisms (SNPs) and several large insertions/deletions in the coding region of TIPs. Among these, non-synonymous SNPs are most likely to have a greater impact on protein function and are candidates for molecular studies as well as for the development of functional markers to assist breeding. The solute transport function of two TIPs was further validated by expression in Xenopus laevis oocytes. GmTIP1;5 was shown to facilitate the rapid movement of water across the oocyte membrane, while GmTIP2;5 facilitated the movement of water and boric acid. The present study provides an initial insight into the possible roles of soybean TIP genes under abiotic stress conditions. Our results will facilitate elucidation of their precise functions during abiotic stress responses and plant development, and will provide potential breeding targets for modifying water movement in soybean.

Evaluation of high yielding soybean germplasm under water limitation.

Limited information is available for soybean root traits and their plasticity under drought stress. To date, no studies have focused on examining diverse soybean germplasm for regulation of shoot and root response under water limited conditions across varying soil types. In this study, 17 genetically diverse soybean germplasm lines were selected to study root response to water limited conditions in clay (trial 1) and sandy soil (trial 2) in two target environments. Physiological data on shoot traits was measured at multiple crop stages ranging from early vegetative to pod filling. The phenotypic root traits, and biomass accumulation data are collected at pod filling stage. In trial 1, the number of lateral roots and forks were positively correlated with plot yield under water limitation and in trial 2, lateral root thickness was positively correlated with the hill plot yield. Plant Introduction (PI) 578477A and 088444 were found to have higher later root number and forks in clay soil with higher yield under water limitation. In sandy soil, PI458020 was found to have a thicker lateral root system and higher yield under water limitation. The genotypes identified in this study could be used to enhance drought tolerance of elite soybean cultivars through improved root traits specific to target environments.