mir-150-5p inhibits the osteogenic differentiation of bone marrow-derived mesenchymal stem cells by targeting irisin to regulate the p38/MAPK signaling pathway.

PURPOSE: To study the effect of miR-150-5p on the osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs), and further explore the relationship between its regulatory mechanism and irisin. METHODS: We isolated mouse BMSCs, and induced osteogenic differentiation by osteogenic induction medium. Using qPCR to detect the expression of osteogenic differentiation-related genes, western blot to detect the expression of osteogenic differentiation-related proteins, and luciferase reporter system to verify that FNDC5 is the target of miR-150-5p. Irisin intraperitoneal injection to treat osteoporosis in mice constructed by subcutaneous injection of dexamethasone. RESULTS: Up-regulation of miR-150-5p inhibited the proliferation of BMSCs, and decreased the content of osteocalcin, ALP activity, calcium deposition, the expression of osteogenic differentiation genes (Runx2, OSX, OCN, OPN, ALP and BMP2) and protein (BMP2, OCN, and Runx2). And down-regulation of miR-150-5p plays the opposite role of up-regulation of miR-150-5p on osteogenic differentiation of BMSCs. Results of luciferase reporter gene assay showed that FNDC5 gene was the target gene of miR-150-5p, and miR-150-5p inhibited the expression of FNDC5 in mouse BMSCs. The expression of osteogenic differentiation genes and protein, the content of osteocalcin, ALP activity and calcium deposition in BMSCs co-overexpressed by miR-150-5p and FNDC5 was significantly higher than that of miR-150-5p overexpressed alone. In addition, the overexpression of FNDC5 reversed the blocked of p38/MAPK pathway by the overexpression of miR-150-5p in BMSCs. Irisin, a protein encoded by FNDC5 gene, improved symptoms in osteoporosis mice through intraperitoneal injection, while the inhibitor of p38/MAPK pathway weakened this function of irisin. CONCLUSION: miR-150-5p inhibits the osteogenic differentiation of BMSCs by targeting irisin to regulate the/p38/MAPK signaling pathway, and miR-150-5p/irisin/p38 pathway is a potential target for treating osteoporosis.

[Comparison of effectiveness between unilateral biportal endoscopic and uniportal interlaminar endoscopic decompression in the treatment of lumbar spinal stenosis].

Objective: To compare the effectiveness between unilateral laminotomy and bilateral decompression (ULBD) with unilateral biportal endoscopy (UBE) and uniportal interlaminar endoscopy (UIE) in the treatment of lumbar spinal stenosis. Methods: A clinical data of 52 patients with lumbar spinal stenosis, who met the selection criteria and treated with ULBD between March 2021 and November 2022, was retrospectively analyzed. The patients were allocated into UBE group (23 cases) and UIE group (29 cases) according to the surgical methods. There was no significant difference ( P>0.05) in age, gender, body mass index, surgical segment, type of lumbar stenosis, and preoperative visual analogue scale (VAS) score of low back pain, VAS score of leg pain, Oswestry disability index (ODI), disc height, and dural sac area between the two groups. Perioperative indexes (incision length, operation time, hospital stay, and surgical complications), clinical indicators (VAS score of low back pain, VAS score of leg pain, and ODI before operation and at 3 days, 1 month, 6 months, and 12 months after operation), and imaging indicators (disc height and dural sac area before operation and at 1, 12 months after operation, and dural sac expansion area) were recorded and compared between the two group. Results: All operations in both groups were successfully completed. Compared with the UIE group, the UBE group had shorter operation time and longer incision length, with significant differences ( P<0.05). But there was no significant difference in hospital stay and incidence of complications between the two groups ( P>0.05). All patients were followed up 12-20 months (mean, 14 months). The VAS scores of low back pain and leg pain and ODI after operation significantly improved when compared with preoperative values ( P<0.05), and there was no significant difference in the above indicators between different time points after operation ( P>0.05). There was no significant difference between the two groups at different time points ( P>0.05). Imaging examination showed that there was no significant difference in disc height between the two groups at different time points after operation ( P>0.05). However, the dural sac area and dural sac expansion area were significantly larger in the UBE group than in the UIE group ( P<0.05). Conclusion: ULBD with UBE and UIE can achieve satisfactory effectiveness in the treatment of lumbar spinal stenosis. But the former has more thorough decompression and better dural sac expansion than the latter.

Lovastatin/SN38 co-loaded liposomes amplified ICB therapeutic effect via remodeling the immunologically-cold colon tumor and synergized stimulation of cGAS-STING pathway.

Current immune checkpoint blockade (ICB) immunotherapeutics have revolutionized cancer treatment. However, many cancers especially the "immunologically cold" tumors, do not respond to ICB, prompting the search for additional strategies to achieve durable responses. The cGAS-STING pathway, as an essential immune response pathway, has been demonstrated for a potent target to sensitize ICB immunotherapy. However, the low efficiency of conventional STING agonists limits their clinical application. Recent studies have shown that DNA topoisomerase I (TOPI) inhibitor chemodrug SN38 can activate the cGAS-STING pathway and induce an immune response through DNA damage, while the traditional statins medication lovastatin was found to inhibit DNA damage repair, which may in turn upregulate the damaged DNA level. Herein, we have developed a liposomal carrier co-loaded with SN38 and lovastatin (SL@Lip), which can be accumulated in tumors and efficiently released SN38 and lovastatin, addressing the problem of weak solubility of these two drugs. Importantly, lovastatin can increase DNA damage and enhance the activation of cGAS-STING pathway, coordinating with SN38 chemotherapy and exhibiting the enhanced combinational immunotherapy of PD-1 antibody by remodeling the tumor microenvironment in mouse colorectal cancer of both subcutaneous and orthotopic xenograft models. Overall, this study demonstrates that lovastatin-assisted cGAS-STING stimulation mediated by liposomal delivery system significantly strengthened both chemotherapy and immunotherapy of colorectal cancer, providing a clinically translational strategy for combinational ICB therapy in the "immunologically cold" tumors.

Cocrystallization of Gefitinib Potentiate Single-Dose Oral Administration for Lung Tumor Eradication via Unbalancing the DNA Damage/Repair.

Gefitinib (GEF) is a clinical medication for the treatment of lung cancer targeting the epidermal growth factor receptor (EGFR). However, its efficacy is remarkably limited by low solubility and dissolution rates. In this study, two cocrystals of GEF with co-formers were successfully synthesized using the recrystallization method characterized via Powder X-ray Diffraction, Fourier Transform Infrared Spectroscopy, and 2D Nuclear Overhauser Effect Spectroscopy. The solubility and dissolution rates of cocrystals were found to be two times higher than those of free GEF. In vitro cytotoxicity studies revealed that the cocrystals enhanced the inhibition of cell proliferation and apoptosis in A549 and H1299 cells compared to free GEF. In mouse models, GEF@TSBO demonstrated targeted, safe, and effective antitumor activity with only one-dose administration. Mechanistically, the GEF cocrystals were shown to increase the cellular levels of damaged DNA, while potentially downregulating PARP, thereby impairing the DNA repair machinery and leading to an imbalance between DNA damage and restoration. These findings suggest that the cocrystallization of GEF could serve as a promising adjunct to significantly enhance the physicochemical and biopharmaceutical performance for lung cancer treatment, providing a facial strategy to improve GEF anticancer efficiency with high bioavailability that can be orally administrated with only one dose.

High-Salt-Diet (HSD) aggravates the progression of Inflammatory Bowel Disease (IBD) via regulating epithelial necroptosis.

Due to its unclear etiology, there is no specific medicine to cure the recurrent and incurable inflammatory bowel disease (IBD). Unhealthy dietary habits unconsciously contributed to the progression of IBD, for example a High-Salt-Diet (HSD) is the most neglected and frequently adopted habit. However, the molecular mechanism of how HSD aggravates the progression of IBD has yet to remain uncovered. Herein, we focus on the hypothesis that necroptosis pathway may be involved in the process of IBD exacerbated by HSD. To this end, different gene expression (DEGs) profiles of human epithelia under hypertonic culture conditions were applied to screen candidate pathways. What's more, gene expression manipulation, immune microenvironment detection, RIPK3/MLKL gene knockout (KO), and wild-type (WT) mice were carried out to research the promotion of IBD progression under treatments of high salt intake. Based on our present results, gene expression profiles in human normal colon epithelia cell NCM460 were significantly changed under salt- or sucrose-induced hypertonic culture conditions. RIPK3 was significantly up-regulated under both conditions. Furthermore, mice colon epithelia cell CT26 growth was inhibited in a time- and dose-dependent manner by extra NaCl incubation. Autophagy, and Necroptosis pathways were activated and enhanced by LPS pretreatment. HSD significantly exacerbated DSS-induced IBD symptoms in vivo in a dose-dependent manner. Moreover, RIPK3-/- and MLKL-/- mice presented severe IBD symptoms in vivo. Overall, the results demonstrated that HSD aggravated the IBD progression via necroptosis activation, providing novel strategies and promising targets for the clinical treatment of IBD.

Targeting Lymph Nodes for Systemic Immunosuppression Using Cell-Free-DNA-Scavenging And cGAS-Inhibiting Nanomedicine-In-Hydrogel for Rheumatoid Arthritis Immunotherapy.

Rheumatoid arthritis (RA) is a systemic autoimmune disease with pathogenic inflammation caused partly by excessive cell-free DNA (cfDNA). Specifically, cfDNA is internalized into immune cells, such as macrophages in lymphoid tissues and joints, and activates pattern recognition receptors, including cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS), resulting in overly strong proinflammation. Here, nanomedicine-in-hydrogel (NiH) is reported that co-delivers cGAS inhibitor RU.521 (RU) and cfDNA-scavenging cationic nanoparticles (cNPs) to draining lymph nodes (LNs) for systemic immunosuppression in RA therapy. Upon subcutaneous injection, NiH prolongs LN retention of RU and cNPs, which pharmacologically inhibit cGAS and scavenged cfDNA, respectively, to inhibit proinflammation. NiH elicits systemic immunosuppression, repolarizes macrophages, increases fractions of immunosuppressive cells, and decreases fractions of CD4+ T cells and T helper 17 cells. Such skewed immune milieu allows NiH to significantly inhibit RA progression in collagen-induced arthritis mice. These studies underscore the great potential of NiH for RA immunotherapy.

Pretreatment with 3-methyladenine ameliorated Pseudomonas aeruginosa-induced acute pneumonia by inhibiting cell death of neutrophils in a mouse infection model.

Pseudomonas aeruginosa is one of the leading causes of nosocomial infections worldwide. Clinical isolates that are resistant to multiple antimicrobials make it intractable. The interactions between P. aeruginosa and host cell death have multiple effects on bacterial clearance and inflammation; however, the potential intervention effects remain to be defined. Herein, we demonstrated that intravenous administration of 3-methyladenine before, but not after, P. aeruginosa infection enhanced autophagy-independent survival, which was accompanied by a decrease in the bacterial load, alleviation of pathology and reduction in inflammatory cytokines, in an acute pneumonia mouse model. Interestingly, these beneficial effects were not dependent on neutrophil recruitment or phagocytosis, but on the enhanced killing capacity induced by inhibiting the cell death of 3-MA pretreated neutrophils. These findings demonstrate a novel protective role of 3-MA pretreatment in P. aeruginosa-induced acute pneumonia.

Predictors of the Spontaneous Resolution of Central Diabetes Insipidus Following Endoscopic Endonasal Surgery for Craniopharyngioma.

OBJECTIVE: Central diabetes insipidus (CDI) is the most common complication of endoscopic endonasal surgery (EES) for craniopharyngioma. However, some cases of CDI could spontaneously resolve during the follow-up period. Hence, this study aimed to determine the predictive factors for the spontaneous resolution of CDI. METHODS: Data of patients with CDI who underwent EES for craniopharyngioma between February 2009 and June 2021 were retrospectively reviewed. All patients were divided into 2 groups based on the resolution of CDI during follow-up: the recovery and no recovery groups. The baseline characteristic, surgical, and follow-up results of patients were compared. RESULTS: We identified 84 patients with CDI (35 in the recovery group and 49 in the no recovery group). A direct comparison showed that retaining the pituitary stalk (57.1% vs. 14.3%, P = 0.000) and no-hypothalamic injury (HI) (68.6% vs. 20.4%, P = 0.000) were more common in the recovery group, whereas hydrocephalus at diagnosis (8.6% vs. 46.9%, P = 0.000) was significantly more common in the no recovery group. Subsequently, we found through univariate and multivariate analysis that the spontaneous resolution of CDI was associated with hydrocephalus at diagnosis (yes vs. no: odds ratio [OR], 0.198; P = 0.045), pituitary stalk injury (retaining vs. sectioning: OR, 7.055; P = 0.004), and the Hong et al HI pattern (mild-HI vs. no-HI: OR, 0.183; P = 0.038; unilateral-HI vs. no-HI: OR, 0.147; P = 0.017; bilateral-HI vs. no-HI: OR, 0.154; P = 0.044). CONCLUSIONS: Hydrocephalus at diagnosis, pituitary stalk injury, and the Hong et al HI pattern might be predictors of the spontaneous resolution of CDI following EES for craniopharyngioma.

A new personalized vaccine strategy based on inducing the pyroptosis of tumor cells in vivo by transgenic expression of a truncated GSDMD N-terminus.

The variability and heterogeneity of tumor antigens and the tumor-driven development of immunosuppressive mechanisms leading to tumor escape from established immunological surveillance. Here, the tumor cells were genetically modified to achieve an inducible overexpression of the N-terminal domain of gasdermin D (GSDMD-NT) and effectively cause pyroptosis under a strict control. Pyroptotic tumor cells release damage-associated molecular patterns (DAMPs) and inflammatory cytokines to promote the maturation and migration of bone marrow-derived dendritic cells (BMDCs). Furthermore, local tumor delivery, and preventive or therapeutic subcutaneous immunization of the modified cells, followed by the induction of GSDMD-NT expression, significantly stimulated both the systemic and local responses of antitumor immunity, and reprogrammed the tumor microenvironment, leading to the dramatic suppression of tumor growth in mice. This study has explored the application potency of inducing the pyroptosis of tumor cells in the field of tumor immunotherapy, especially for developing a new and promising personalized tumor vaccine.

Risk Factors Associated with Postoperative Obesity in Childhood-Onset Craniopharyngioma Patients: A Case-Control Study.

OBJECTIVE: Identifying risk factors associated with obesity after craniopharyngioma (CP) resection is pivotal for the prediction and prevention of postoperative obesity. Although multiple elegant studies have investigated this issue, studies focusing on Asian pediatric patients are missing. Herein, we retrospectively analyzed the risk factors associated with obesity after childhood-onset CP surgery in our center, aiming to provide insights into approaches reducing the occurrence of postoperative obesity. METHODS: The clinical data of 53 children with CP who met the inclusion criteria from July 2011 to August 2020 in our center were collected for retrospective analysis. Univariate and multivariate logistic retrospective analyses were used to identify independent risk factors contributing to postoperative obesity. A review of the available literature reporting the risk factors associated with obesity after CP surgery over the past two decades was performed for comparison. RESULTS: The median age at diagnosis of this cohort was 11.0 years, with a median follow-up of 44.0 months (range = 8-119 months). Eighteen (34.0%) experienced obesity at the last follow-up. Multivariate logistic regression analysis showed preoperative body mass index standard deviation score (odds ratio [OR], 1.71; 95% confidence interval [CI]: 1.01-2.90; P = 0.046), preoperative hypothalamic involvement (OR, 29.38; 95% CI: 1.76-490.66; P = 0.019), and age at diagnosis (OR, 0.76; 95% CI: 0.61-0.95; P = 0.016) were independent risk factors for obesity after childhood-onset CP resection. CONCLUSIONS: Our results combined with previous literature support preoperative body mass index standard deviation score, preoperative hypothalamic involvement, and age at diagnosis are the independent risk factors associated with obesity after childhood-onset CP resection.

SQSTM1/p62 regulate breast cancer progression and metastasis by inducing cell cycle arrest and regulating immune cell infiltration.

The autophagy adaptor protein SQSTM1/p62 is overexpressed in breast cancer and has been identified as a metastasis-related protein. However, the mechanism by which SQSTM1/p62 contributes to breast cancer progression and tumor microenvironment remains unclear. This study revealed that silencing SQSTM1/p62 expression suppressed breast cancer progression via regulating cell proliferation and reshaping the tumor microenvironment (TME). Here, we found that SQSTM1/p62 was overexpressed in multiple human cancer tissue types and that was correlated with poor patient overall survival (OS) and disease-free survival (DFS). Moreover, we found that short-hairpin RNA (shRNA)-mediated knockdown of p62 expression significantly inhibited cell proliferation, migration, and invasion, and promoted cell death in vitro, as well as suppressed breast cancer growth and lung metastasis in vivo. In addition, flow cytometry analysis of splenocytes and tumor infiltrating lymphocytes (TILs) indicated that the numbers of CD8α+ interferon (IFN)-γ+ cells (CTLs) and CD4+IFN-γ+ (Th1) cells were increased while those of CD4+IL-4+ (Th2) cells, tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs) were decreased. RT-PCR analyses showed that the gene expression of Th1/Th2 cytokines changed in the tumor microenvironment. Silencing SQSTM1/p62 suppressed tumor cell lung metastasis. Together, our results provide strong evidence that silencing tumor cell SQSTM1/p62 inhibited tumor growth and metastasis through cell cycle arrest and TME regulation. This finding provides a novel molecular therapeutic strategy for breast cancer progression and metastasis treatment.

Responsive Multivesicular Polymeric Nanovaccines that Codeliver STING Agonists and Neoantigens for Combination Tumor Immunotherapy.

Immune checkpoint blockade (ICB) has significantly advanced cancer immunotherapy, yet its patient response rates are generally low. Vaccines, including immunostimulant-adjuvanted peptide antigens, can improve ICB. The emerging neoantigens generated by cancer somatic mutations elicit cancer-specific immunity for personalized immunotherapy; the novel cyclic dinucleotide (CDN) adjuvants activate stimulator of interferon genes (STING) for antitumor type I interferon (IFN-I) responses. However, CDN/neoantigen vaccine development has been limited by the poor antigen/adjuvant codelivery. Here, pH-responsive CDN/neoantigen codelivering nanovaccines (NVs) for ICB combination tumor immunotherapy are reported. pH-responsive polymers are synthesized to be self-assembled into multivesicular nanoparticles (NPs) at physiological pH and disassembled at acidic conditions. NPs with high CDN/antigen coloading are selected as NVs for CDN/antigen codelivery to antigen presenting cells (APCs) in immunomodulatory lymph nodes (LNs). In the acidic endosome of APCs, pH-responsive NVs facilitate the vaccine release and escape into cytosol, where CDNs activate STING for IFN-I responses and antigens are presented by major histocompatibility complex (MHC) for T-cell priming. In mice, NVs elicit potent antigen-specific CD8+ T-cell responses with immune memory, and reduce multifaceted tumor immunosuppression. In syngeneic murine tumors, NVs show robust ICB combination therapeutic efficacy. Overall, these CDN/neoantigen-codelivering NVs hold the potential for ICB combination tumor immunotherapy.

Circ-Ctnnb1 Regulates Neuronal Injury in Spinal Cord Injury through the Wnt/ß-Catenin Signaling Pathway.

STUDY DESIGN: Spinal cord injury (SCI) rat model and cell model were established for in vivo and in vitro experiments. Functional assays were utilized to explore the role of the circRNAs derived from catenin beta 1 (mmu_circ_0001859, circ-Ctnnb1 herein) in regulating neuronal cell viability and apoptosis. Bioinformatics analysis and mechanism experiments were conducted to assess the underlying molecular mechanism of circ-Ctnnb1. OBJECTIVE: We aimed to probe into the biological function of circ-Ctnnb1 in neuronal cells of SCI. METHODS: The rat model of SCI and hypoxia-induced cell model were constructed to examine circ-Ctnnb1 expression in SCI through quantitative reverse transcription real-time polymerase chain reaction. The Basso, Beattie, and Bresnahan score was utilized for evaluating the neurological function. Terminal-deoxynucleotidyl transferase mediated nick end labeling assays were performed to assess the apoptosis of neuronal cells. RNase R and actinomycin D were used to treat cells to evaluate the stability of circ-Ctnnb1. RESULTS: Circ-Ctnnb1 was highly expressed in SCI rat models and hypoxia-induced neuronal cells, and its deletion elevated the apoptosis rate of hypoxia-induced neuronal cells. Furthermore, circ-Ctnnb1 activated the Wnt/ß-catenin signaling pathway via sponging mircoRNA-205-5p (miR-205-5p) to upregulate Ctnnb1 and Wnt family member 2B (Wnt2b). CONCLUSION: Circ-Ctnnb1 promotes SCI through regulating Wnt/ß-catenin signaling via modulating the miR-205-5p/Ctnnb1/Wnt2b axis.

Inappropriate use of antibiotics exacerbates inflammation through OMV-induced pyroptosis in MDR Klebsiella pneumoniae infection.

The inappropriate use of antibiotics is a severe public health problem worldwide, contributing to the emergence of multidrug-resistant (MDR) bacteria. To explore the possible impacts of the inappropriate use of antibiotics on the immune system, we use Klebsiella pneumoniae (K. pneumoniae) infection as an example and show that imipenem increases the mortality of mice infected by MDR K. pneumoniae. Further studies demonstrate that imipenem enhances the secretion of outer membrane vesicles (OMVs) with significantly elevated presentation of GroEL, which promotes the phagocytosis of OMVs by macrophages that depends on the interaction between GroEL and its receptor, lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1). OMVs cause the pyroptosis of macrophages and the release of proinflammatory cytokines, which contribute to exacerbated inflammatory responses. We propose that the inappropriate use of antibiotics in the cases of infection by MDR bacteria such as K. pneumoniae might cause damaging inflammatory responses, which underlines the pernicious effects of inappropriate use of antibiotics.

Immune Responses to Varicella-Zoster Virus Glycoprotein E Formulated with Poly(Lactic-co-Glycolic Acid) Nanoparticles and Nucleic Acid Adjuvants in Mice.

The subunit herpes zoster vaccine Shingrix is superior to attenuated vaccine Zostavax in both safety and efficacy, yet its unlyophilizable liposome delivery system and the limited supply of naturally sourced immunological adjuvant QS-21 still need to be improved. Based on poly(lactic-co-glycolic acid) (PLGA) delivery systems that are stable during the lyophilization and rehydration process and using a double-emulsion (w/o/w) solvent evaporation method, we designed a series of nanoparticles with varicella-zoster virus antigen glycoprotein E (VZV-gE) as an antigen and nucleic acids including polyinosinic-polycytidylic acid (Poly I:C) and phosphodiester CpG oligodeoxynucleotide (CpG ODN), encapsulated as immune stimulators. While cationic lipids (DOTAP) have more potential than neutral lipids (DOPC) for activating gE-specific cell-mediated immunity (CMI) in immunized mice, especially when gE is encapsulated in and presented on the surface of nanoparticles, PLGA particles without lipids have the greatest potential to induce not only the highest gE-specific IgG titers but also the strongest gE-specific CMI responses, including the highest proportions of interferon-γ (IFN-γ)- and interleukin-2 (IL-2)-producing CD4+/CD8+ T cells according to a flow cytometry assay and the greatest numbers of IFN-γ- and IL-2-producing splenocytes according to an enzyme-linked immunospot (ELISPOT) assay. These results showed that immune-stimulating nucleic acids together with the PLGA delivery system showed promise as a safe and economical varicella and zoster vaccine candidate.

A therapeutic HPV16 E7 vaccine in combination with active anti-FGF-2 immunization synergistically elicits robust antitumor immunity in mice.

FGF-2 accumulates in many tumor tissues and is closely related to the development of tumor angiogenesis and the immunosuppressive microenvironment. This study aimed to investigate whether active immunization against FGF-2 could modify antitumor immunity and enhance the efficacy of an HPV16 E7-specific therapeutic vaccine. Combined immunization targeting both FGF-2 and E7 significantly suppressed tumor growth, which was accompanied by significantly increased levels of IFN-γ-expressing splenocytes and effector CD8 T cells and decreased levels of immunosuppressive cells such as regulatory T cells (Tregs) and myeloid-derived suppressor cells(MDSCs) in both the spleen and tumor; in addition, the levels of FGF-2 and neovascularization in tumors were decreased in the mice receiving the combined immunization, and tumor cell apoptosis was promoted. The combination of an HPV16 E7-specific vaccine and active immunization against FGF-2 significantly enhances antitumor immune responses in mice with TC-1 tumors, indicating a promising strategy for tumor immunotherapy.

Virus-Like Particles Presenting the FGF-2 Protein or Identified Antigenic Peptides Promoted Antitumor Immune Responses in Mice.

BACKGROUND: Fibroblast growth factor (FGF)-2 is overexpressed in various tumor tissues. It affects tumor cell proliferation, invasion and survival, promotes tumor angiogenesis and is tightly involved in the development of systemic and local immunosuppressive tumor mechanisms. PURPOSE: This study aimed to develop an effective vaccine against FGF-2 and to investigate the effects of anti-FGF-2 immunization on tumor growth and antitumor immune responses. METHODS: A set of thirteen synthesized overlapping peptides covering all possible linear B-cell epitopes of murine FGF-2 and a recombinant FGF-2 protein were conjugated to virus-like particles (VLPs) of recombinant hepatitis B core antigen (HBcAg). The VLPs were immunized through a preventive or therapeutic strategy in a TC-1 or 4T1 grafted tumor model. RESULTS: Immunization with FGF-2 peptides or full-length protein-coupled VLPs produced FGF-2-specific antibodies with a high titer. Peptide 12, which is located in the heparin-binding site of FGF-2, or protein-conjugated VLPs presented the most significant effects on the suppression of TC-1 tumor growth. The levels of IFN-γ-expressing splenocytes and serum IFN-γ were significantly elevated; further, the immune effector cells CD8+ IFN-γ+ cytotoxic T lymphocytes (CTLs) and CD4+ IFN-γ+ Th1 cells were significantly increased, whereas the immunosuppressive cells CD4+ CD25+ FOXP3+ Treg cells and Gr-1+ CD11b+ myeloid-derived suppressor cells (MDSCs) were decreased in the immunized mice. In addition, VLP immunization significantly suppressed tumor vascularization and promoted tumor cell apoptosis. In mice bearing 4T1 breast tumor, preventive immunization with FGF-2-conjugated VLPs suppressed tumor growth and lung metastasis, and increased effector cell responses. CONCLUSION: Active immunization against FGF-2 is a new possible strategy for tumor immunotherapy.

Modified bacterial outer membrane vesicles induce autoantibodies for tumor therapy.

Using monoclonal antibodies to block tumor angiogenesis has yielded effective antitumor effects. However, this treatment method has long cycles and is very expensive; therefore, its long-term and extensive application is limited. In this study, we developed a nanovaccine using bacterial biomembranes as carriers for antitumor therapy. The whole basic fibroblast growth factor (BFGF) molecule (154 amino acids (aa)) was loaded onto bacterial outer membrane vesicles (OMVs) using gene recombination technology. The strong adjuvant effect of OMVs was used to induce the host to produce anti-BFGF autoantibodies. We proved that persistent anti-BFGF autoantibodies can be induced in mice after only 3 immunizations to antagonize BFGF functions. The effects included multiple tumor suppression functions, including inhibition of tumor angiogenesis, induction of tumor cell apoptosis, reversal of tumor immune barriers, and promotion of tumor-specific cytotoxic T lymphocytes (CTLs), eventually causing tumor regression. We confirmed that bacterial biomembranes can be used as a vaccine delivery system to induce the production of antibodies against autoantigens, which may be used for tumor therapy. This study expands the application fields of bacterial biomembrane systems and provides insight for tumor immunotherapy other than monoclonal antibody technology. STATEMENT OF SIGNIFICANCE: In this study, we proved that bacteria-released outer membrane vesicles (OMVs) modified via genetic engineering can be used as a vaccine carrier to break autoimmune tolerance and induce the body to produce autoantibodies to antagonize pathological molecules and block pathological signaling pathways for tumor therapy. OMVs naturally released by bacteria were used to successfully load the full-length BFGF protein (154 aa). We proved that persistent anti-BFGF autoantibodies can be induced in tumor-bearing mice after only 3 immunizations to effectively inhibit tumors. Furthermore, the production of these antibodies successfully inhibited tumor angiogenesis, promoted tumor cell apoptosis, reversed the tumor immunosuppressive microenvironment, increased the cytotoxic T lymphocyte (CTL) reaction, and eventually inhibited tumor growth.

P. aeruginosa Mediated Necroptosis in Mouse Tumor Cells Induces Long-Lasting Systemic Antitumor Immunity.

Necroptosis is a form of programmed cell death (PCD) characterized by RIP3 mediated MLKL activation and increased membrane permeability via MLKL oligomerization. Tumor cell immunogenic cell death (ICD) has been considered to be essential for the anti-tumor response, which is associated with DC recruitment, activation, and maturation. In this study, we found that P. aeruginosa showed its potential to suppress tumor growth and enable long-lasting anti-tumor immunity in vivo. What's more, phosphorylation- RIP3 and MLKL activation induced by P. aeruginosa infection resulted in tumor cell necrotic cell death and HMGB1 production, indicating that P. aeruginosa can cause immunogenic cell death. The necrotic cell death can further drive a robust anti-tumor response via promoting tumor cell death, inhibiting tumor cell proliferation, and modulating systemic immune responses and local immune microenvironment in tumor. Moreover, dying tumor cells killed by P. aeruginosa can catalyze DC maturation, which enhanced the antigen-presenting ability of DC cells. These findings demonstrate that P. aeruginosa can induce immunogenic cell death and trigger a robust long-lasting anti-tumor response along with reshaping tumor microenvironment.