A Live Vector Expressing HPV16 L1 Generates an Adjuvant-Induced Antibody Response In-vivo

Leishmania tarentolae as a platform for the production of vaccines against viral pathogens

Infectious diseases remain a persistent public health problem and a leading cause of morbidity and mortality in both humans and animals. The most effective method of combating viral infections is the widespread use of prophylactic vaccinations, which are administered to both people at risk of disease and animals that may serve as significant sources of infection. Therefore, it is crucial to develop technologies for the production of vaccines that are highly effective, easy to transport and store, and cost-effective. The protein expression system based on the protozoan Leishmania tarentolae offers several advantages, validated by numerous studies, making it a good platform for producing vaccine antigens. This review provides a comprehensive overview into the potential applications of L. tarentolae for the safe production of effective viral antigens.

Design and antiviral assessment of a panel of fusion proteins targeting human papillomavirus type 16

Cervical cancer ranks as the third most prevalent malignancy in women worldwide. The persistence of Human papillomavirus (HPV) infection stands out as the foremost risk factor for cervical cancer development. Among the numerous HPV subtypes, HPV16 infection emerges as the primary pathogenic determinant of cervical cancer. To date, no specific drugs have been approved. In this study, we engineered two high-affinity fusion protein targeting HPV16 L1 protein based on the alpaca-derived single-domain antibody 2C12 previously obtained in our laboratory. These two fusion proteins exhibited potent neutralizing activity against HPV16 pseudovirus with IC50 values of 7.8 nM and 6.5 nM, respectively. Molecular docking analysis revealed that 2C12 formed ten pairs of hydrogen bonds with HPV16 L1, among which Arg39 and Thr100 established multiple pairs of hydrogen bonds with HPV16 L1, indicating their crucial roles in antigen-antibody binding process. These structural and biological findings underscore the effective binding capacity of these fusion proteins to HPV16, leading to reduced viral load and providing valuable insights into therapeutic antibody and vaccine development against HPV 16 infection.

Current status and future directions for the development of human papillomavirus vaccines

The development of human papillomavirus (HPV) vaccines has made substantive progress, as represented by the approval of five prophylactic vaccines since 2006. Generally, the deployment of prophylactic HPV vaccines is effective in preventing newly acquired infections and incidences of HPV-related malignancies. However, there is still a long way to go regarding the prevention of all HPV infections and the eradication of established HPV infections, as well as the subsequent progression to cancer. Optimizing prophylactic HPV vaccines by incorporating L1 proteins from more HPV subtypes, exploring adjuvants that reinforce cellular immune responses to eradicate HPV-infected cells, and developing therapeutic HPV vaccines used either alone or in combination with other cancer therapeutic modalities might bring about a new era getting closer to the vision to get rid of HPV infection and related diseases. Herein, we summarize strategies for the development of HPV vaccines, both prophylactic and therapeutic, with an emphasis on the selection of antigens and adjuvants, as well as implications for vaccine efficacy based on preclinical studies and clinical trials. Additionally, we outline current cutting-edge insights on formulation strategies, dosing schedules, and age expansion among HPV vaccine recipients, which might play important roles in addressing barriers to vaccine uptake, such as vaccine hesitancy and vaccine availability.

Leishmania tarentolae: a vaccine platform to target dendritic cells and a surrogate pathogen for next generation vaccine research in leishmaniases and viral infections

Parasites of the genus Leishmania are unusual unicellular microorganisms in that they are characterized by the capability to subvert in their favor the immune response of mammalian phagocytes, including dendritic cells. Thus, in overt leishmaniasis, dendritic cells and macrophages are converted into a niche for Leishmania spp. in which the parasite, rather than being inactivated and disassembled, survives and replicates. In addition, Leishmania parasites hitchhike onto phagocytic cells, exploiting them as a mode of transport to lymphoid tissues where other phagocytic cells are potentially amenable to parasite colonization. This propensity of Leishmania spp. to target dendritic cells has led some researchers to consider the possibility that the non-pathogenic, reptile-associated Leishmania tarentolae could be exploited as a vaccine platform and vehicle for the production of antigens from different viruses and for the delivery of the antigens to dendritic cells and lymph nodes. In addition, as L. tarentolae can also be regarded as a surrogate of pathogenic Leishmania parasites, this parasite of reptiles could possibly be developed into a vaccine against human and canine leishmaniases, exploiting its immunological cross-reactivity with other Leishmania species, or, after its engineering, for the expression of antigens from pathogenic species. In this article we review published studies on the use of L. tarentolae as a vaccine platform and vehicle, mainly in the areas of leishmaniases and viral infections. In addition, a short summary of available knowledge on the biology of L. tarentolae is presented, together with information on the use of this microorganism as a micro-factory to produce antigens suitable for the serodiagnosis of viral and parasitic infections.

Exploring the Molecular Pathogenesis, Pathogen Association, and Therapeutic Strategies against HPV Infection

The human papillomavirus (HPV), commonly documented as the cause of warts, has gained much interest recently due to its possible links to several types of cancer. HPV infection is discussed in this review from multiple angles, including its virology, epidemiology, etiology, immunology, clinical symptoms, and treatment. Recent breakthroughs in molecular biology have led to the development of new methods for detecting and treating HPV in tissue. There is no cure for HPV, and although vaccines are available to prevent infection with the most common HPV viruses, their utilization is limited. Destruction and excision are the primary treatment modalities. This review sheds light on the epidemiology, molecular pathogenesis, the association of several other pathogens with HPV, the latest treatment strategies available to treat the same, and an overview of the progress made and the obstacles still to be overcome in the fight against HPV infection.

Antiviral therapy for the sexually transmitted viruses: recent updates on vaccine development

INTRODUCTION

The sexually transmitted infections (STIs) caused by viruses including human T cell leukemia virus type-1 (HTLV-1), human immunodeficiency virus-1 (HIV-1), human simplex virus-2 (HSV-2), hepatitis C virus (HCV), hepatitis B virus (HBV), and human papillomavirus (HPV) are major public health issues. These infections can cause cancer or result in long-term health problems. Due to high prevalence of STIs, a safe and effective vaccine is required to overcome these fatal viruses.

AREAS COVERED

This review includes a comprehensive overview of the literatures relevant to vaccine development against the sexually transmitted viruses (STVs) using PubMed and Sciencedirect electronic search engines. Herein, we discuss the efforts directed toward development of effective vaccines using different laboratory animal models including mice, guinea pig or non-human primates in preclinical trials, and human in clinical trials with different phases.

EXPERT OPINION

There is no effective FDA approved vaccine against the sexually transmitted viruses (STVs) except for HBV and HPV as prophylactic vaccines. Many attempts are underway to develop vaccines against these viruses. There are several approaches for improving prophylactic or therapeutic vaccines such as heterologous prime/boost immunization, delivery system, administration route, adjuvants, etc. In this line, further studies can be helpful for understanding the immunobiology of STVs in human. Moreover, development of more relevant animal models is a worthy goal to induce effective immune responses in humans.

Satureja hortensis induces cell death and inhibited cell cycle progression in K562 myelogenous and Jurkat T cell leukemia cell lines

Several plants of Satureja genus have shown anti-tumor activity. We investigated the antileukemia effects of different fractions of Satureja hortensis (Summer savory). The growth inhibitory effect of S. hortensis fractions on K562 and Jurkat leukemia cells were determined by MTT assay. The most effective fractions were analyzed by flow cytometry and colorimetric assay for apoptosis induction and cell cycle changes. Various fractions from S. hortensis showed growth inhibitory effects on leukemia cells, among them two hexane and dichloromethane fractions with IC₅₀ values of 32.1-47.8 μg/ml (K562) and 44.3-45.7 μg/ml (Jurkat) were the most effective. According to annexin V staining, both of these fractions significantly induced apoptosis at 50μg/ml in K562 (hexane; 73.06 ± 5.11% and dichloromethane; 96.14 ± 2.33%) and Jurkat cells (hexane; 78.85 ± 11.9% and dichloromethane; 94.05 ± 2.47%) 48 h after treatment. They increased cell accumulation in sub-G1 phase (>50%, p < .001) and decreased number of cells in G0-G1, S and G2M phases. The fractions significantly increased the caspase-3 activity in both cell lines (≈2.5-3.5 fold of untreated cells). Hexane and dichloromethane fractions of S. hortensis had the capacity to induce death and change the cell cycle distribution in leukemia cells; therefore they might be good candidates for more studies in regard to their possible therapeutic usefulness in leukemia.