Natural Infection with Rabies Virus: A Histopathological and Immunohistochemical Study of Human Brains

OBJECTIVES: Despite all the efforts and increased knowledge of rabies, the exact mechanisms of infection and mortality from the rabies virus are not well understood. To understand the mechanisms underlying the pathogenicity of rabies virus infection, it is crucial to study the tissue that the rabies virus naturally infects in humans. METHODS: Cerebellum brain tissue from 9 human post mortem cases from Iran, who had been infected with rabies virus, were examined histopathologically and immunohistochemically to evaluate the innate immune responses against the rabies virus. RESULTS: Histopathological examination revealed inflammation of the infected cerebellum and immunohistochemical analyses showed an increased immunoreactivity of heat shock protein 70, interleukin-6, interleukin-1, tumor necrosis factor-alpha, caspase-3, caspase-9, toll-like receptor3 and toll-like receptor4 in the infected brain tissue. CONCLUSION: These results indicated the involvement of innate immunity in rabies infected human brain tissue, which may aggravate the progression of this deadly disease.

Hippocampal serotonin-2A receptor-immunoreactive neurons density increases after testosterone therapy in the gonadectomized male mice / 대한해부학회지

The change of steroid levels may also exert different modulatory effects on the number and class of serotonin receptors present in the plasma membrane. The effects of chronic treatment of testosterone for anxiety were examined and expression of 5-HT(2A) serotonergic receptor, neuron, astrocyte, and dark neuron density in the hippocampus of gonadectomized male mice was determined. Thirty-six adult male NMRI mice were randomly divided into six groups: intact-no testosterone treatment (No T), gonadectomy (GDX)-No T, GDX-Vehicle, GDX-6.25 mg/kg testosterone (T), GDX-12.5 mg/kg T, and GDX-25 mg/kg T. Anxiety-related behavior was evaluated using elevated plus maze apparatus. The animals were anesthetized after 48 hours after behavioral testing, and decapitated and micron slices were prepared for immunohistochemical as well as histopathological assessment. Subcutaneous injection of testosterone (25 mg/kg) may induce anxiogenic-like behavior in male mice. In addition, immunohistochemical data reveal reduced expression of 5-HT(2A) serotonergic receptor after gonadectomy in all areas of the hippocampus. However, treatment with testosterone could increase the mean number of dark neurons as well as immunoreactive neurons in CA1 and CA3 area, dose dependently. The density of 5-HT(2A) receptor-immunoreactive neurons may play a crucial role in the induction of anxiety like behavior. As reduction in such receptor expression have shown to significantly enhance anxiety behaviors. However, replacement of testosterone dose dependently enhances the number of 5-HT(2A) receptor-immunoreactive neurons and interestingly also reduced anxiety like behaviors.

Immunogenicity evaluation of a DNA vaccine expressing the hepatitis C virus non-structural protein 2 gene in C57BL/6 mice

Most of the hepatitis C virus [HCV] infections elicit poor immune responses and 75% to 85% of cases become chronic; therefore, the development of an effective vaccine against HCV is of paramount importance. In this study, we aimed to evaluate co-administration of HCV non-Structural Protein 2 and IL-12 DNA vaccines in C57BL/6 mice A plasmid encoding full-length HCV NS2 protein [non-structural protein 2] was generated and used to vaccinate mice. Negative control [an empty expression vector] was also employed to evaluate the background response. To investigate immune responses against vaccine, C57BL/6 mice received three doses of the vaccine with a two-week interval. Cellular immunity was assessed using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay for lymphocyte proliferation, lactate dehydrogenase release for cytotoxic T lymphocyte [CTL] activity and cytokine assay. The findings demonstrated that immunization of mice with plasmid expressing HCV NS2 induced CTL response, interferon gamma production, and lymphocyte proliferation compared to negative control. The results also demonstrated that co-administration of IL-12 with the HCV NS2 plasmid induced significantly better immune response in C57BL/6 mice. DNA vaccine encoding HCV NS2 is an effective candidate that can trigger CTL-based immune response against HCV. In addition, the results suggested that combining the DNA vaccine approach with immune stimulatory cytokines may significantly enhance antigen-specific immune responses

Genistein induces a protective immunomodulatory effect in a mouse model of cervical cancer

Genistein [GEN], a naturally occurring flavonoid present in soy bean, has attracted scientific interest for its possible benefits in cancer. The potential immunomodulatory effects of genistein on the immune system and against TC-1 tumor cell line were evaluated in adult female C57BL/6 mice. Mice were treated with GEN 10 days before to 10 days after the tumor induction. Thirty days after the last GEN treatment, lymphocyte proliferation, Lactase Dehydrogenase [LDH] cytolytic activity and cytokine secretion were analyzed in GEN and control groups. The results showed that ingestion of genistein significantly increased lymphocyte proliferation and LDH release. Furthermore, the treatment with genistein also caused a significant increment in interferon gamma [IFN-alpha]. In addition, the treatment achieved significant therapeutic effect in tumor models compared to the control group. These results indicated that the effect of GEN on tumor growth may be attributed to its effect on lymphocyte proliferation, cytolytic activity and IFN-alpha production. These results demonstrate that GEN exerts an immunomodulatory effect in a mouse model of Human Papillomavirus [HPV] associated-cervical cancer

Efficacy of HPV-16 E7 based vaccine in a TC-1 tumoric animal model of cervical cancer

The human papillomavirus as an etiological agent of cervical cancer does not grow adequately in tissue culture systems. The tumor cell line TC-1 continuously expresses the E6 and E7 oncogenic proteins of HPV, and is considered a suitable tool in laboratory investigations and vaccine researches against cervical cancer The TC-1 cell line was grown in RPMI 1650 supplemented with 10% FBS, glutamine and antibiotics, and was used for tumor development in mice. Six to seven week-old tumor bearing C57BL/6 mice were divided into 3 groups consisting of 7 mice per group. The first group received pcDNA-E7, the second group received pcDNAS, and the third group received phosphate buffered saline [PBS]. The treated animals were monitored for their tumor size progression and survival. At last, the tumoric tissues from autopsied animals were fixed and examined with Mayer's hematoxylin and eosin [H and E]. All experiments were done in accordance with guidelines of the Laboratory Animal Ethical Commission of Tarbiat Modares University. Data analysis was performed using the oneway ANOVA followed by Tukey's test in both experimental and control groups. A p-value <0.05 was considered significant. There were significant decreases in tumor growth; there were also improvements in survival among mice in the treated groups [p<0.041]. H and E stained sections from untreated mice were studied independently in a blinded fashion by two observers and showed malignant neoplasms composed of severely pleomorphic tumor cells with nuclear enlargement, high nuclear-cytoplasmic [N/C] ratios, and prominent nucleoli in solid and fascicular patterns of growth. High mitotic activity with extensive necrosis was also noted in both test and control groups. The TC-1 lung metastatic model can be used to test the efficacy of various E7-based therapeutic cancer vaccine strategies for cervical cancer and the prevention of HPV-related neoplasia

Localization of herpes simplex virus type 1 DNA in latently infected BALB/c mice neurons using in situ polymerase chain reaction

Herpes simplex virus type-1 [HSV-1] establishes a lifelong latent infection in neurons following primary infection. The existence of latent HSV-1 DNA in the trigeminal ganglia of infected BALB/c mice was examined using a direct in situ PCR technique, based on Digoxigenin-11-dUTP detection system with anti-digoxigenin-peroxidase and 3,3f-diaminobenzidine [DAB] substrate. Eight-week-old male BALB/c mice were inoculated via the eye by 10[4] plaque forming unit of wild type Iranian isolates of HSV-1. After establishment of latency, trigeminal ganglia were removed and examined using in situ PCR to detect HSV-1 genome. Finally, the results of in situ PCR were verified by a two-round PCR method, using amplification cocktail of in situ reaction, as a template for a conventional gel base PCR. The results suggest that a direct in situ PCR method using a peroxidase and DAB detection system is a useful means for detection of latent HSV-1 DNA in the latently infected ganglia