Cytokine fusion protein that modulates the immune response holds great potential for cancer immunotherapy. IL-2 is an effective treatment against advanced cancers. However, the therapeutic efficacy of IL-2 is limited by severe systemic toxicity. Several mutants recombinant IL-2 can increase antitumor activity and minimize systemic toxicity. Melittin is an attractive anticancer candidate because of its wide-spectrum lytic properties. We previously generated a bifunctional fusion protein melittin-MIL-2, composed of melittin and a mutant IL-2. The melittin-MIL-2 inhibited the growth of human ovarian cancer SKOV3 cells in vitro and in vivo tumor growth. However, whether this antitumor effect could also be used in cancer immunotherapy was unknown. To assess its cancer immunotherapy potential, we further investigated its more effective antitumor immune response and antitumor effect against cancers of different tissue origins in vitro and in vivo. The specific IL-2 activity of the melittin-MIL-2 fusion protein was tested on the cytokine growth dependent cell line CTLL-2. The cytolytic activity was detected by standard 4-h 51Cr-release assays. PBMC stimulation in response to the melittin-MIL-2 was determined by IFN-γ release assay. We observed the cancer cell proliferation of different tissue origins by MTT assay. The ability of melittin-MIL-2 to inhibit tumor growth in vivo was evaluated by using human liver (SMMC-7721 cancer cells), lung (A549 cancer cells) and ovarian (SKOV3 cancer cells) cancer xenograft models. To assess the immunity within the tumor microenvironment, the level of some cytokines including IFN-γ, TNF-α, IL-12 and IL-4 was analyzed by ELISA. We injected the MDA-MB-231 cells and the melittin-MIL-2 into mice, and the anti-metastatic effect was examined by counting nodules in the lung. The melittin-MIL-2 was more effective in inducing T cell and NK-cell cytotoxicity. The fusion protein significantly increased IFN-γ production in PBMCs. In vitro, the melittin-MIL-2 mediated immune cells killing or directly killed the cancer cell lines of different tissue origins. In vivo, the fusion protein exhibited stronger inhibition on the growth of transplanted human tumors compared to rIL-2. The melittin-MIL-2 treatment promoted the IFN-γ secretion in tumor tissues and decreased the immunosuppressive cells in vivo. Furthermore, the fusion protein reduced lung metastasis of breast cancer. This study provides the evidence that the melittin-MIL-2 can produce stronger immune stimulation and antitumor effects, and the fusion protein is a potent candidate for cancer immunotherapy.
21 August 2019 in Archives of Gynecology and Obstetrics
Objective: The aim of this study was to explore the signatures of oral microbiome associated with OSCC using a random forest (RF) model. Patients and Methods: A total of 24 patients with OSCC were enrolled in the study. The oral microbiome was assessed in cancerous lesions and matched paracancerous tissues from each patient using 16S rRNA gene sequencing. Signatures of mucosal microbiome in OSCC were identified using a RF model. Results: Significant differences were found between OSCC lesions and matched paracancerous tissues with respect to the microbial profile and composition. Linear discriminant analysis effect size analyses (LEfSe) identified 15 bacteria genera associated with cancerous lesions. Fusobacterium, Treponema, Streptococcus, Peptostreptococcus, Carnobacterium, Tannerella, Parvimonas and Filifactor were enriched. A classifier based on RF model identified a microbial signature comprising 12 bacteria, which was capable of distinguishing cancerous lesions and paracancerous tissues (AUC = 0.82). The network of the oral microbiome in cancerous lesions appeared to be simplified and fragmented. Functional analyses of oral microbiome showed altered functions in amino acid metabolism and increased capacity of glucose utilization in OSCC. Conclusion: The identified microbial signatures may potentially be used as a biomarker for predicting OSCC or for clinical assessment of oral cancer risk.
Purpose: The incidence and severity of Clostridium difficile infection (CDI) have markedly increased over the past decade. However, there is very limited epidemiological data on CDI in China so far, specifically no data in Shandong Province. The aim of this study was to evaluate diagnostic algorithm for CDI and to gain data on molecular epidemiology of CDI in the Shandong Province of China. Materials and methods: Nonrepetitive unformed fecal specimens (n=504) were investigated by the glutamate dehydrogenase (GDH), C. difficile toxin A&B (CDAB) tests and toxigenic culture. Furthermore, 85 isolates were characterized by toxin gene detection, multilocus sequence typing, ribotyping and antimicrobial susceptibility testing. Results: The algorithm of combining GDH and CDAB tests could define diagnosis of 54.2% CDI cases and excluded 90% of non-CDI. Further adding the toxigenic culture to the algorithm enhanced the detection sensitivity to 100%. Toxigenic strains comprised 84.7% of isolates, including A+B+CDT- (71.8%, 61/85), A-B+CDT- (11.8%, 10/85) and A+B+CDT+ (1.2%, 1/85) isolates. RT046/ST35 (13.9%, 10/72), RT014/ST2 (12.5%, 9/72) and RT017/ST37 (12.5%, 9/72) were the more common genotypes among toxigenic C. difficile strains. The clinical severity score of A-B+CDT- toxin genes genotype (3.50 +/- 0.85) was significantly higher than the A+B+CDT- type (2.59 +/- 0.93) (P<0.05). RT046/ST35 isolates were highly prevalent and had high clinical severity scores (3.80 +/- 0.92). Variations in resistance from different sequence types (STs) were observed. Toxigenic strains showed higher resistance rates to erythromycin, clindamycin and ciprofloxacin compared to nontoxigenic strains (P<0.05). Conclusion: The epidemiology of C. difficile in Shandong Province differed from other regions in China. Comprehensive optimized diagnosis strategy and continuous surveillance should be established and applied in order to curb the spread of toxigenic C. difficile strains, especially for hospitalized patients.
27 February 2013 in Cancer Immunology, Immunotherapy
Preeclampsia (PE) is an excessive systemic inflammation response with dysfunction of endothelial. As a stress protein, heat shock protein 70(HSP70) plays a pivotal role in protecting cells against apoptosis, oxidative damage and genetic damage. In humans, three genes encode members of the HSP70 class: HSPA1A, HSPA1B and HSPA1L[1]. Our study was to investigate the association between genetic variations of HSPA1L and the susceptibility for PE in Chinese Han population. The polymorphisms of rs2227956, rs1043618 and rs1061581 in HSPA1L were genotyped by TaqMan allelic discrimination real time polymerase chain reaction (PCR) in 929 PE patients and 1024 healthy pregnant women. Statistic difference of the genotypic and allelic frequencies were found in HSPA1L rs1061581 between PE patients and controls (χ2=29.863, PHSPA1L rs1061581 A alleles occurred more frequently in PE patients compared to healthy controls (PE vs. controls 10.28% vs. 5.76%). Furthermore, we divided the PE cases into early-onset/late-onset PE and mild/severe PE subgroups and found statistical differences in genotypic and allelic frequencies of the HSPA1L rs1061581 between early-onset PE , late-onset PE, mild PE, severe PE and controls respectively. Moreover, HSPA1L rs1061581 A alleles were more frequent in early-onset PE , late-onset PE, mild PE and severe PE than controls respectively. Therefore, we concluded that HSPA1L rs1061581 polymorphism is associated with the risk of PE in Han Chinese women and A alleles may play a role in the susceptibility for PE.