Anti-tumor Effects of Cisplatin Synergist in Combined Treatment with Clostridium novyi-NT Spores Against Hypoxic Microenvironments in a Mouse Model of Cervical Cancer Caused by TC-1 Cell Line

Purpose

Despite the development of anti-human papillomavirus (HPV) vaccines, cervical cancer is still a common disease in women, especially in developing countries. The presence of a hypoxic microenvironment causes traditional treatments to fail. In this study, we presented a combined treatment method based on the chemotherapeutic agent cisplatin and Clostridium novyi-NT spores to treat normoxic and hypoxic areas of the tumor.

Methods

TC-1 Cell line capable of expressing HPV-16 E6/7 oncoproteins was subcutaneously transplanted into female 6-8 week old C57/BL6 mice. The tumor-bearing mice were randomly divided into four groups and treated with different methods after selecting a control group. Group 1: Control without treatment (0.1 mL sterile PBS intratumorally), Group: C. novyi-NT (107 C. novyi-NT). Group 3: Receives cisplatin intraperitoneally (10 mg/kg). Fourth group: Intratumoral administration of C. novyi-NT spores + intraperitoneal cisplatin. Western blot analysis was used to examine the effects of anti-hypoxia treatment and expression of hypoxia-inducible factor 1 (HIF-1) and vascular endothelial growth factor (VEGF) proteins.

Results

The results clearly showed that combined treatment based on C. novyi-NT and cisplatin significantly reduced the expression of HIF-1 alpha and VEGF proteins compared to cisplatin alone. At the same time, the amount of necrosis of tumor cells in the combined treatment increased significantly compared to the single treatment and the control. At the same time, the mitotic count decreased significantly.

Conclusion

Our research showed that developing a combined treatment method based on C. novyi-NT and cisplatin against HPV-positive cervical cancer could overcome the treatment limitations caused by the existence of hypoxic areas of the tumor.

Effect of formalin percentage, incubation time and temperature on Clostridium chauvoei culture inactivation and immunogenicity

OBJECTIVES

In order to find the optimal inactivation conditions for Clostridium chauvoei culture, different factors were investigated and the immunogenicity of inactivated cultures was studied.

METHODS

C. chauvoei was cultured with different formalin percentages (0.3, 0.5 or 0.7% V/V), inactivation temperatures (37 °C or room temperature) and incubation times (one or two weeks). Sterility tests were performed and residual formaldehyde and pH were measured. Rabbits were immunized twice with inactivated cultures and sera were used for detection of immune response.

RESULTS

In the one-week experiment, 0.5 and 0.7% formalin inactivated the bacteria after one week, and the percentage of 0.3 inactivated after three weeks. The residual formaldehyde at weeks 1 and 8 was not significantly different. In the two-week experiment, cultures treated with 0.3 and 0.5% formalin were inactivated after four weeks, and those with 0.7% formalin were inactivated after three weeks. Residual formaldehyde at week 8 differed significantly from that of week 1. Residual formaldehyde was affected by incubation temperature since it was lower at 37 °C than in room temperature. Also, a significant effect was observed for formalin on pH, as higher formalin contents led to lower pH values of the cultures. ELISA showed the lowest antibody titer achieved by 0.7% formalin group. Antibody titer was not different between 0.3 and 0.5% formalin.

CONCLUSIONS

The best condition for inactivation of C. chauvoei was considered as one-week incubation with 0.5% formalin at 37 °C, leading to a high antibody response.

Evaluation of humoral immune responses against C. perfringens epsilon toxin in Iranian sheep and goats after vaccination

Clostridium perfringens is a common cause of death in domestic animals worldwide. However, vaccination on a regular basis is an economically beneficial means for controlling clostridial contamination.The objective of the current investigation was to evaluate the humoral immune responses using iELISA in Iranian sheep and goats following the vaccination programs administered by the bacterin-toxoid polyvalent entrotoxemia vaccine. A total of one-hundred-and-twenty animals, consisting of sixty sheep and sixty goats, were randomly divided into three groups. These animals were vaccinated with clostridial vaccine on days 0 and 14 using two different dosages. Blood samples were collected on day zero, 15, 30, 45, 60, 75, and 90 following vaccination. The sera samples were then separated and antibody titers were measured using an in-house enzyme-linked immunosorbent assay (ELISA) against C. perfringens epsilon toxin. The titers of antibodies in sheep were notably higher than those in goats, particularly after receiving the booster dose. No statistically significant variations were identified in the immune responses of Iranian sheep and goat breeds. (p>0.05). Overall, the duration of the humoral immune response in goats upon administration of the clostridial vaccine was relatively brief, requiring multiple booster injections.

Therapeutic Potential of Clostridium novyi NT in Cancer: Current Knowledge and Future Perspectives

Resistance to conventional antitumour therapies and Hypoxia in patients with advanced solid tumours are two major reasons for the failure of conventional anti-tumour therapies. Therefore, it is important to find a new therapeutic method that can overcome these problems. An attenuated anaerobic bacterium, Clostridium novyi- NT, could target Hypoxic and Necrotic areas of tumours causing tumour lysis and stimulating a host anti-tumour immune response. To the best of our knowledge, the combination of bacterial anti-tumour therapy, chemotherapy, radiotherapy and immunotherapy may promote tumour regression, inhibit metastasis and develop a new strategy for the treatment of solid tumours. However, the possible molecular mechanisms of the combined therapies are still the biggest challenge. This review provides an overview of the history of bacterial cancer therapy and the development of a non-lethal strain of Clostridium novyi. Below is a precise definition of Hypoxic conditions in solid tumour tissue. To understand the anticancer effect of Clostridium novyi- NT spores, possible cell death mechanisms were summarised by the enzyme phospholipase C (nt01cx0979), which is secreted by Clostridium novyi- NT spores after germination in tumour tissue. The function of Clostridium novyi- NT spores in stimulating the host immune system to elicit anti-tumour responses was reviewed. Then, the results of anti-tumour combination therapies based on Clostridium novyi- NT spores were compiled. Identifying the molecular mechanisms of Clostridium novyi- NT in treating tumours and inducing cell death in invasive cancer cells, ultimately leading to tumour regression, may develop promising clinical strategies in the combined treatment of solid tumours.

Major pathogenic Clostridia in human and progress toward the clostridial vaccines

The Clostridium genus is composed of a large spectrum of heterogeneous bacteria. They are Gram-positive, mostly mesophilic, and anaerobic spore-forming strains. Clostridia are widely distributed in oxygen-free habitats. They are found principally in the soil and intestines of ruminants as normal flora, but also are the cause of several infections in humans. The infections produced by important species in humans include botulism, tetanus, pseudomembranous colitis, antibiotics-associated diarrhea, and gas gangrene. Immunization with toxoid or bacterin-toxoid or genetically modified or other vaccines is a protective way against clostridial infection. Several experimental or commercial vaccines have been developed worldwide. Although conventional vaccines including toxoid vaccines are very important, the new generation of vaccines is an effective alternative to conventional vaccines. Recent advances have made it possible for new vaccines to increase immunogenicity. This review discusses briefly the important species of clostridia in humans, their toxins structure, and vaccine development and usage throughout the world.

Development of an in-house Indirect ELISA for detection of bovine viral diarrhoea virus antibodies in bovine sera

Bovine viral diarrhoea virus (BVDV) infection is a worldwide distributed animal disease. BVDV is the causal agent of congenital defects, diarrhea, reproductive failure, and contaminating biological products. Virus Neutralization test (VNT) as a gold standard method is used for detection of BVDV. Although this assay is very sensitive and specific, it has disadvantages including requires to an experienced person and cell culture facilities. VNT is time-consuming. It is important to design a method that does not have the mentioned disadvantages. So, in-house indirect enzyme linked immunosorbent assay (i-ELISA) was developed for laboratories where it is not possible to perform VNT. The system was made using NADL strain of BVDV and MDBK cell line. This ELISA system was compared with a commercial ELISA kit using 99 bovine sera. Coefficient of variation (CV) was calculated 3.9% and 4.8% for the positive and negative control, respectively for the designed i-ELISA system. The sensitivity, specificity, and accuracy of i-ELISA system was 88%, 53.6%, and 70.7% respectively. Based on our result correlation between in- house and commercial ELISA kit for detection of antibody against BVDV in bovine sera was significant (Kappa coefficient =0.41, p < 0.05). Results of the present study suggested that an in-house ELISA as an affordable and confident system for primary screening of the sera used for biological product.

Genotyping analysis of bovine, ovine, and caprine paratuberculosis in Iran: An IS900-RFLP study

OBJECTIVE/BACKGROUND

Mycobacterium avium subspecies paratuberculosis (MAP) has been reported in Iranian cattle since 1965. Little is known on the population genetics of MAP in this Middle-Eastern State. A principle scope of this study was therefore genetic characterization of MAP isolates collected from farm animals in Iran.

METHODS

Sixteen field isolates of MAP collected from bovine (n=8), ovine (n=3), and caprine (n=2) hosts in Alborz, Fars, Isfahan, Qazvin, Tehran, and Zanjan provinces were subcultured on mycobactin J-supplemented Herrold's egg slopes in order to provide the required genomic material. The laboratory strain MAP III & V was included as the reference strain. IS900-RFLP (Restriction Fragment length Polymorphism) was conducted using BsteII restriction enzyme. Application of IS900-RFLP genotyping on 16 Iranian MAP isolates in the present study classified them into six observable but similar types represented by two clustered and four orphan types. The laboratory strain MAP III & V displayed a totally different pattern easily distinguishable from that of Iranians.

RESULTS

Detection of six genotypes among 16 wild isolates is an indication of a population with a potentially high level of diversity. We assume that, with inclusion of more field isolates, it is very likely that even higher diversity may be observed within the studied isolates. The different patterns displayed by the Iranians and the laboratory strain in this work might explain the independent evolutionary pathways these have gone through to evolve from their ancestral clones.

CONCLUSION

Further description on population genetic of MAP in Iran urges for more epidemiological work using similar and alternative standard genotyping system.