The origins of the small DNA tumor viruses

Rhoptry antigens as Toxoplasma gondii vaccine target

Toxoplasmosis is a cosmopolitan zoonotic infection, caused by a unicellular protozoan parasite known as Toxoplasma gondii that belongs to the phylum Apicomplexa. It is estimated that over one-third of the world's population has been exposed and are latently infected with the parasite. In humans, toxoplasmosis is predominantly asymptomatic in immunocompetent persons, while among immunocompromised individuals may be cause severe and progressive complications with poor prognosis. Moreover, seronegative pregnant mothers are other risk groups for acquiring the infection. The life cycle of T. gondii is very complex, indicating the presence of a plurality of antigenic epitopes. Despite of great advances, recognize and construct novel vaccines for prevent and control of toxoplasmosis in both humans and animals is still remains a great challenge for researchers to select potential protein sequences as the ideal antigens. Notably, in several past years, constant efforts of researchers have made considerable advances to elucidate the different aspects of the cell and molecular biology of T. gondii mainly on microneme antigens, dense granule antigens, surface antigens, and rhoptry proteins (ROP). These attempts thereby provided great impetus to the present focus on vaccine development, according to the defined subcellular components of the parasite. Although, currently there is no commercial vaccine for use in humans. Among the main identified T. gondii antigens, ROPs appear as a putative vaccine candidate that are vital for invasion procedure as well as survival within host cells. Overall, it is estimated that they occupy about 1%–30% of the total parasite cell volume. In this review, we have summarized the recent progress of ROP-based vaccine development through various strategies from DNA vaccines, epitope or multi epitope-based vaccines, recombinant protein vaccines to vaccines based on live-attenuated vectors and prime-boost strategies in different mouse models.

FOXM1 (Forkhead box M1) in tumorigenesis: overexpression in human cancer, implication in tumorigenesis, oncogenic functions, tumor-suppressive properties, and target of anticancer therapy

FOXM1 (Forkhead box M1) is a typical proliferation-associated transcription factor and is also intimately involved in tumorigenesis. FOXM1 stimulates cell proliferation and cell cycle progression by promoting the entry into S-phase and M-phase. Additionally, FOXM1 is required for proper execution of mitosis. In accordance with its role in stimulation of cell proliferation, FOXM1 exhibits a proliferation-specific expression pattern and its expression is regulated by proliferation and anti-proliferation signals as well as by proto-oncoproteins and tumor suppressors. Since these factors are often mutated, overexpressed, or lost in human cancer, the normal control of the foxm1 expression by them provides the basis for deregulated FOXM1 expression in tumors. Accordingly, FOXM1 is overexpressed in many types of human cancer. FOXM1 is intimately involved in tumorigenesis, because it contributes to oncogenic transformation and participates in tumor initiation, growth, and progression, including positive effects on angiogenesis, migration, invasion, epithelial-mesenchymal transition, metastasis, recruitment of tumor-associated macrophages, tumor-associated lung inflammation, self-renewal capacity of cancer cells, prevention of premature cellular senescence, and chemotherapeutic drug resistance. However, in the context of urethane-induced lung tumorigenesis, FOXM1 has an unexpected tumor suppressor role in endothelial cells because it limits pulmonary inflammation and canonical Wnt signaling in epithelial lung cells, thereby restricting carcinogenesis. Accordingly, FOXM1 plays a role in homologous recombination repair of DNA double-strand breaks and maintenance of genomic stability, that is, prevention of polyploidy and aneuploidy. The implication of FOXM1 in tumorigenesis makes it an attractive target for anticancer therapy, and several antitumor drugs have been reported to decrease FOXM1 expression.

Face up to challenge of virology world

Welcome to the World Journal of Virology (WJV), a new member of the World Journal Series. The World Journal Series was first launched as a peer-reviewed scientific journal covering aspects of research, diagnostics and clinical practice in biomedicine in 1995. WJV is an online and open-access peer-reviewed periodical focusing on virology. WJV covers a variety of topics in different areas of virology, including advances in basic research, updates in nomenclature, the development of novel diagnostic assays, the epidemiology of viral disorders and, new developments in the clinical management of viral diseases, including new vaccines and antiviral therapeutics. The purpose in launching the WJV is to promote knowledge exchange related to the classic human viruses as well as newly emerging viruses and their associated clinical disorders. Continually updating knowledge in a timely manner in this field where information related to the unceasing evolution of viruses is becoming available at a rapid pace is challenging. Thanks to the World-Wide-Web we are able to provide a podium for all authors and readers of WJV to address this challenge. I would like to acknowledge the Baishideng publisher, the members of the editorial board, and all contributing authors involved in this inaugural issue of the WJV. I sincerely hope all readers, i.e. future contributing authors, will like WJV and we look forward to your input in assisting WJV to grow and mature.

Hamster polyomavirus infection in a pet Syrian hamster (Mesocricetus auratus)

An approximately 8-week-old pet Syrian hamster (Mesocricetus auratus) with a 1-week history of dyspnea, hyporexia, and ataxia was submitted for necropsy. On gross examination, the hamster had multiple abdominal adhesions and enlargement of the mesenteric lymph node. Histologic evaluation revealed multicentric lymphoma of the liver, jejunum, mesenteric lymph node, testicular fat pad, and epididymis. Based on the hamster's age and the type and distribution of the lymphoma, a presumptive diagnosis of hamster polyomavirus-induced lymphoma was made. A specific polymerase chain reaction (PCR) was developed, which confirmed the diagnosis. An in situ PCR demonstrated hamster polyomavirus DNA within lymphocytes of the multicentric lymphoma and renal tubular epithelial cells and within clusters of enterocytes in the jejunum. These data are consistent with environmental dissemination of hamster polyomavirus virions through the renal tubular epithelium and into the urine and with fecal shedding of hamster polyomavirus virions; however, additional studies will be needed to confirm these observations.

Personal historical chronicle of six decades of basic and applied research in virology, immunology, and vaccinology

The sciences of vaccinology and of immunology were created just two centuries ago by Jenner's studies of prevention of smallpox by inoculation with cowpox virus. This rudimentary beginning was expanded greatly by the giants of late 19th and early 20th centuries biomedical sciences. The period from 1930 to 1950 was a transitional era with the introduction of chick embryos and minced tissues for propagating viruses and rickettsiae in vitro for vaccines. Modern era vaccinology began about 1950 as a continuum of notable advances made during the 1940s and World War II. Present vaccinology is based largely on breakthroughs in cell culture, bacterial polysaccharide chemistry, molecular biology, and immunology. By invitation, the author, who is a microbe hunter in fact, was asked to chronicle his six decades of pioneering achievements in basic and applied virology, bacteriology, immunology, molecular biology, epidemiology, and cancer, with special reference to the pioneering creation of most of the present day vaccines. Knowledge of the past may guide the present and future. This chronicle will have achieved its legacy if it helps others to understand the why and how of the past that may help to create the substance of the future.

Overview of viruses, cancer, and vaccines in concept and in reality

Cancer is a consequence of malfunction of the replicative cell cycle caused by acquisition of independence from proliferative and restrictive controls in the process. Such alteration may be driven by unrepaired mutations in proto-oncogenes and anti-oncogenes or by genetic insults of environmental, infectious, or spontaneous origin. The consequence of mutations may be reflected at any of a number of locations in the transductive pathways from receptor to nucleus which upset normal homeostatic balance between the opposing forces for promotion or restraint of cell proliferation. About 15% of human cancers are caused primarily by viruses that bring about aberrations in gene structure and function or that express proteins that bind to cell regulatory proteins. The means for achieving immunoprophylaxis of viral cancers, such as hepatitis B or Marek's disease, are based on prior specific perturbation of the immune system, causing it to respond rapidly and effectively in preventing infection on subsequent contact with the corresponding agent. Existing cancers of viral origin and those of nonviral causation come together in attempted immunotherapy. Cure is far more difficult to achieve than prevention and relies on the principle that tumor cells can display abnormal markers on the cell surface that are capable of being detected and engaged by an effective immune response. Efforts to prevent and cure cancer of viral, spontaneous, or environmental origin are a worthy pursuit and must take account of the most advanced information relating to the chemistry of the cell cycle and to the function of the immune system.