Evaluation of autophagy induction on HEV 239 vaccine immune response in a mouse model.

Hepatitis E virus (HEV) infection remains a serious threat to life and productivity in developing world. Vaccine seems to be an effective, safe, and affordable approach to address HEV disease burden. The HEV genome consists of three open reading frames (ORFs). Of these, ORF2 encodes a single structural protein (pORF2) for the HEV capsid which has been studied extensively as vaccine candidates. Recently, it has been recognized that autophagy plays an important role in innate and adaptive immunity defense against intracellular pathogens. This mechanism could therefore promote a protective immune response by inducing CD4+ and CD8+ T cells. In this study, HEV 239 and Beclin1 proteins were expressed in prokaryotic host cell [Escherichia coli (BL21)]. HEV 239 protein with different formulations (+Alum, +Beclin1, and +Alum-Beclin1) were used as candidate vaccines and administrated subcutaneously in BALB/c mice on 0, 14, and 28 days. Finally, elicited cellular and humoral immunity were evaluated. Taken together, although our results indicated that mice immunized with HEV 239 protein formulated with Alum, Beclin1, and Alum + Beclin1 displayed humoral and cellular response that was not significant in comparison with each other (P > 0.05); whereas they were significant while compared with control groups (P < 0.05). A comprehensive understanding of the intricate interplay between autophagy and immune response remains to be unraveled. Further study will clear the detailed impact of autophagy manipulation to enhance vaccine efficacy and boost the immune responses against the disease. © 2018 IUBMB Life, 70(3):207-214, 2018.

Autophagy Modulation and Cancer Combination Therapy: A Smart Approach in Cancer Therapy.

The autophagy pathway is the process whereby cells keep cellular homeostasis and respond to stress via recycling their damaged cellular proteins, organelles, and other cellular components. In the context of cancer, autophagy is a dual-edge sword pro- and anti-tumorigenic role depending on the oncogenic context and stage of tumorigenesis. Cancer cells have a higher dependency on autophagy compared with normal cells because of cellular damages and high demands for energy. The carbon, nitrogen, and molecular oxygen are building blocks for highly proliferative cancer cells which extremely depend on glutaminolysis and aerobic glycolysis; when a cancer cell is restricted to glucose and glutamine, it initiates to activate a stress response pathway using autophagy. Oncogenic tyrosine kinases (OncTKs) and receptor tyrosine kinases (RTKs) activation result in autophagy modulation through activation of the PI3K/AKT/mTORC1 and RAS/MAPK signaling pathways. Targeted inhibition of tyrosine kinases (TKs) and RTKs have recently been considered as cancer therapy but drug resistance and cancer relapse continue to be a major limitation of tyrosine kinase inhibitors (TKIs). Manipulation of autophagy pathway along with TKIs may be a promising strategy to circumvent unknown existing drug-resistance mechanisms that may emerge in a treated patient. In this way, clinical trials are ongoing to modulate autophagy to treat cancer. This review aims to summarize the combination therapy of autophagy affecting compounds with anticancer drugs which target cell signaling pathways, metabolism mechanisms, and epigenetics modification to improve therapeutic efficacy against cancers.

Formulation of chitosan with the polyepitope HIV-1 protein candidate vaccine efficiently boosts cellular immune responses in mice.

Human immunodeficiency virus-1 (HIV-1) continues to be a major global public health issue and priority. Despite the variety of antiretroviral therapies, it seems that an effective vaccine against HIV-1 is still very necessary. An ideal HIV-1 vaccine should be able to elicit both humoral and cellular immunities. In this respect, polyepitope vaccines, incorporated from several conserved regions of HIV-1 proteins, have received much attention recently. Herein, the immunogenicity of the HIV-1 polyepitope protein-based candidate vaccines was evaluated in BALB/c mice. Following the plasmid (pET23a-HIV-1-tat/pol/gag/env) preparation and transformation, the recombinant protein expression was optimized in Escherichia coli BL21 (DE3) host cells. After the HIV-1-top4 protein purification, chitosan and alum adjuvants were added to the vaccines formulations to reinforce the immunogenicity of the candidate vaccines. Mice were subcutaneously immunized three times at 2-week intervals with the candidate vaccines and the elicitation of both humoral and cellular immune responses were investigated. Taken together, the results showed that chitosan adjuvanted candidate vaccine conferred a stronger immunogenicity and elicited higher cellular responses than other candidate vaccines (P < 0.05). Thereby, it seems that co-utilizing of potent adjuvants with the HIV-1 polyepitope protein vaccines can help to open new avenues for strategies for HIV/AIDS vaccine design.

Oil-in-water emulsion formulated with eucalyptus leaves extract inhibit influenza virus binding and replication in vitro.

Throughout human history, the human-beings have been used different types of plants as antimicrobial agents in fight against infectious diseases. Influenza virus is one of the most common causes of respiratory infection and transmitted through direct contact with flu infected individuals and contaminated substances or droplets. In the current study, both oil-in-water and water-in-oil emulsions with hydroalcoholic extract of eucalyptus leaves (OLHE) were developed and their antiviral efficiency was evaluated. To doing so, Madin-Darbey Canine Kidney (MDCK) cells were treated with effective minimal cytotoxic concentration of the formulated emulsions. The treated cells were then infected with 50% cell culture infectious dose (100 CCID50) of the A/H1N1 virus (the swine flu). The viral titers were measured by hemagglutination (HA) and cell culture infectious dose 50% (CCID50) assays. Also, to check the virus binding inhibition via the formulated extract, the viruses were incubated with the formulated extracts. Our study showed that the oil-in-water emulsions formulated with 2% eucalyptus leaves extract inhibited virus replication completely when the cells were infected by 100 CCID50 and decreased HA titer up to four fold. Therefore, this formulation, may hold promising application to prevent influenza virus transmission through direct contact among children and passengers.

Autophagy induction reduces telomerase activity in HeLa cells.

Autophagy is a cellular homeostatic process whereby damaged proteins and organelles are encapsulated into double membrane vesicles, called autophagosomes, for lysosomal digestion. Beclin1 plays a key role in the initial steps of autophagosome formation. In this study, we evaluated the effect of Beclin 1 overexpression in induction of autophagy and the relationship between autophagy induction and telomerase activity in HeLa cells. We found that overexpression of Beclin 1 in HeLa cells leads to autophagosome formation as shown by intracellular autophagosomal marker LC3-II staining. Expression of Beclin1 reduced telomerase activity for about 100 fold compared with the control while it did not affect TERT expression level. The results of cell cycle analysis indicated that the cell cycle and proliferation progressed normally up to 48h post-transfection. Understanding the role of autophagy induction and telomerase in the pathophysiology of aging and human cancer reveal new strategies that hold much promise for intervention and therapeutic uses.

Autophagy induction regulates influenza virus replication in a time-dependent manner.

PURPOSE: Autophagy plays a key role in host defence responses against microbial infections by promoting degradation of pathogens and participating in acquired immunity. The interaction between autophagy and viruses is complex, and this pathway is hijacked by several viruses. Influenza virus (IV) interferes with autophagy through its replication and increases the accumulation of autophagosomes by blocking lysosome fusion. Thus, autophagy could be an effective area for antiviral research. METHODOLOGY: In this study, we evaluated the effect of autophagy on IV replication. Two cell lines were transfected with Beclin-1 expression plasmid before (prophylactic approach) and after (therapeutic approach) IV inoculation.Results/Key findings. Beclin-1 overexpression in the cells infected by virus induced autophagy to 26 %. The log10haemagglutinin titre and TCID50 (tissue culture infective dose giving 50 % infection) of replicating virus were measured at 24 and 48 h post-infection. In the prophylactic approach, the virus titre was enhanced significantly at 24 h post-infection (P≤0.01), but it was not significantly different from the control at 48 h post-infection. In contrast, the therapeutic approach of autophagy induction inhibited the virus replication at 24 and 48 h post-infection. Additionally, we showed that inhibition of autophagy using 3-methyladenine reduced viral replication. CONCLUSION: This study revealed that the virus (H1N1) titre was controlled in a time-dependent manner following autophagy induction in host cells. Manipulation of autophagy during the IV life cycle can be targeted both for antiviral aims and for increasing viral yield for virus production.