Novel approaches to therapeutic cancer vaccines

Prediction and analysis of multi epitope based vaccine against Newcastle disease virus based on haemagglutinin neuraminidase protein

Newcastle disease virus (NDV), an avian orthoavulavirus, is a causative agent of Newcastle disease named (NDV), and can cause even the epidemics when disease is not treated. Previously several vaccines based on attenuated and inactivated viruses have been reported which are rendered useless with the passage of time due to versatile changes in viral genome. Therefore, we aimed to develop an effective multi-epitope vaccine against the haemagglutinin neuraminidase (HN) protein of 26 NDV strains from Pakistan through a modern immunoinformatic approaches. As a result, a vaccine chimaera was constructed by combining T-cell and B-cell epitopes with the appropriate linkers and adjuvant. The designed vaccine was highly immunogenic, non-allergen and antigenic; therefore, the potential 3D-structureof multi epitope vaccine was constructed, refined and validated. A molecular docking study of a multiepitope vaccine candidate with the chicken Toll-like receptor-4 indicated successful binding. An In silico immunological simulation was used to evaluate the candidate vaccine's ability to elicit an effective immune response. According to the computational studies, the proposed multiepitope vaccine is physically stable and may induce immune responses whichsuggested it a strong candidate against 26 Newcastle disease virus strains from Pakistan.

Predicting peptide vaccine candidates against H1N1 influenza virus through theoretical approaches

Identification of potential epitopes that might activate the immune system has been facilitated by the employment of algorithms that use experimental data as templates. However, in order to prove the affinity and the map of interactions between the receptor (major histocompatibility complex, MHC, or T-cell receptor) and the potential epitope, further computational studies are required. Docking and molecular dynamics (MDs) simulations have been an effective source of generating structural information at molecular level in immunology. Herein, in order to provide a detailed understanding of the origins of epitope recognition and to select the best peptide candidate to develop an epitope-based vaccine, docking and MDs simulations in combination with MMGBSA free energy calculations and per-residue free energy decomposition were performed, taking as starting complexes those formed between four designed epitopes (P1-P4) from hemagglutinin (HA) of the H1N1 influenza virus and MHC-II anchored in POPC membrane. Our results revealed that the energetic contributions of individual amino acids within the pMHC-II complexes are mainly dictated by van der Waals interactions and the nonpolar part of solvation energy, whereas the electrostatic interactions corresponding to hydrogen bonds and salt bridges determine the binding specificity, being the most favorable interactions formed between p4 and MHC-II. Then, P1-P4 epitopes were synthesized and tested experimentally to compare theoretical and experimental results. Experimental results show that P4 elicited the highest strong humoral immune response to HA of the H1N1 and may induce antibodies that are cross-reactive to other influenza subtypes, suggesting that it could be a good candidate for the development of a peptide-based vaccine.

Current trends in cancer vaccines--a bioinformatics perspective

Cancer vaccine development is in the process of becoming reality in future, due to successful phase II/III clinical trials. However, there are still problems due to the specificity of tumor antigens and weakness of tumor associated antigens in eliciting an effective immune response. Computational models to assess the vaccine efficacy have helped to improve and understand what is necessary for personalized treatment. Further research is needed to elucidate the mechanisms of activation of antigen specific cytotoxic T lymphocytes, decreased TREG number functionality and antigen cascade, so that overall improvement in vaccine efficacy and disease free survival can be attained. T cell epitomic based in sillico approaches might be very effective for the design and development of novel cancer vaccines.

T-cell epitope vaccine design by immunoinformatics

Vaccination is generally considered to be the most effective method of preventing infectious diseases. All vaccinations work by presenting a foreign antigen to the immune system in order to evoke an immune response. The active agent of a vaccine may be intact but inactivated ('attenuated') forms of the causative pathogens (bacteria or viruses), or purified components of the pathogen that have been found to be highly immunogenic. The increased understanding of antigen recognition at molecular level has resulted in the development of rationally designed peptide vaccines. The concept of peptide vaccines is based on identification and chemical synthesis of B-cell and T-cell epitopes which are immunodominant and can induce specific immune responses. The accelerating growth of bioinformatics techniques and applications along with the substantial amount of experimental data has given rise to a new field, called immunoinformatics. Immunoinformatics is a branch of bioinformatics dealing with in silico analysis and modelling of immunological data and problems. Different sequence- and structure-based immunoinformatics methods are reviewed in the paper.

The Effects of Functional Polymorphisms in the TGFβ1 Gene on Nasopharyngeal Carcinoma Susceptibility

Objective. Transforming growth factor β1 (TGFβ1) promotes tumor growth and metastasis in the later stage of cancer development. In this study, we explored whether TGFβ1 polymorphisms were associated with increased risk of nasopharyngeal carcinoma (NPC) in a Chinese population.

Design. Case-control study.

Setting. Hospitals of the Department of Otorhinolaryngology–Head and Neck Surgery.

Subjects and Methods. Two single nucleotide polymorphisms of TGFβ1 gene promoter -509C/T (rs1800469) and 869T/C (Leu 10 Pro, rs1800470) at exon 1 were analyzed in 522 NPC patients and 712 age- and sex-matched controls in a Chinese population, using polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) analysis. Functional relevance of the polymorphism was determined by biochemical assays.

Results. The -509T allele carriers were associated with a significantly reduced risk of NPC as compared with the noncarriers (odds ratio [OR], 0.67; 95% confidence interval [CI], 0.53-0.89 and OR, 0.50; 95% CI, 0.31-0.67, respectively). Moreover, -509C-containing TGFβ1 promoter drove an ~1.7-fold increase in reporter expression, compared with the -509T-containing counterpart in both CNE-1 and CNE-2 cell lines. The TGFβ1 -509 CC genotype carriers had a higher TGFβ1 mRNA level than the TGFβ1 -509TT genotype carriers did ( P < .01). However, no significant association was observed between the 869T/C polymorphism and risk of NPC.

Conclusion. These findings indicate that the -509C/T polymorphism in TGFβ1 may play a vital role in mediating individual susceptibility to NPC.

fTwo novel biomarkers, mesothelin and HE4, for diagnosis of ovarian carcinoma

INTRODUCTION: There is a need to improve the diagnosis and prognosis of ovarian carcinoma, particularly the serous type of cancer. Mesothelin and HE4 are two novel biomarkers which are expressed in serous ovarian carcinoma and can be measured in serum and other body fluids, including urine, by using ELISA. The measurement of antibodies to these markers can provide additional useful information. AREAS COVERED: A literature search was performed to as recent as December 1 2010, using the Internet (e.g. PubMed) on articles concerning mesothelin and HE4 for the diagnosis of ovarian carcinoma. The authors also included up to date recent information from the research performed in their own laboratory. EXPERT OPINION: The combination of CA125 with HE4 facilitates the triaging of women with a pelvic mass and detects more stage I/II tumors than CA125, the present 'gold standard', when used alone. Assaying urine for HE4 or mesothelin may detect early ovarian carcinoma more often than assaying serum. Antibodies to mesothelin and HE4 are more frequent in women with ovarian carcinoma or with certain types of infertility than in controls. No presently available biomarker or multi-marker panel lends itself to screening large populations of symptomless women to make possible detection of high grade serous ovarian carcinoma at stage I or II. The authors anticipate, within the next 5 years, that a greater emphasis will be given to the fact that the different subtypes of ovarian carcinoma represent different types of disease. Each different type of disease will require a different diagnostic approach and more efforts will focus on high grade serous ovarian carcinoma for which the clinical need is the greatest.

Vaccines to treat cancer--an old approach whose time has arrived

There are extensive DNA changes in tumor cells and the genes of tumor cells continuously mutate at a high rate. While this can provide therapeutic targets, it makes it unlikely that an agent that is selective for a single target will work against all cells in a tumor. However, it may be possible to use tumor epitopes as sentinels to engage adaptive and innate immunological mechanisms and create a tumor destructive environment effective also against variant cells that have lost a given antigen or their ability to present it. We hypothesize that therapeutic tumor vaccines, in combination with the targeting, to tumors, of costimulatory molecules such as anti-CD137scFv, or lymphokines such as GMCSF, will expand anti-tumor responses for therapeutic benefit when used as an adjunct to surgery and chemotherapy.

Tumor cells expressing anti-CD137 scFv induce a tumor-destructive environment

For immunotherapy to become more effective, there is a need to maximize the antitumor response at the tumor site as well as to eliminate tumor cell variants that lack a given tumor antigen or the ability to present it. We have previously shown that wild-type (WT) cells from the K1735 melanoma (K1735-WT) are rejected following vaccination with cells (K1735-1D8) transfected to express scFv from the anti-CD137 monoclonal antibody 1D8, and that CD4(+) T cells and natural killer (NK) cells are needed for this rejection. We now show that tumors harvested 4 to 10 days after mice had been transplanted with K1735-1D8 cells or a mixture of K1735-1D8 and K1735-WT cells contained more NK cells and that they had an increased percentage of CD4(+) T lymphocytes producing IFNgamma or tumor necrosis factor-alpha. We further show that the percentage of NK cells was higher in B16-1D8 melanomas expressing anti-CD137 scFv than in the WT tumors and that the percentage of FoxP3(+) cells was lower. Admixture of 10% K1735-1D8 cells prevented the progressive growth of transplanted K1735-WT cells in syngeneic mice and also of cells from the antigenically different sarcoma Ag104. Inhibition of WT tumor cells by tumor cells transfected to express anti-CD137 scFv was shown also with the TC1 carcinoma and B16 melanoma. Furthermore, injection of an adenovirus vector, Ad-1D8, which encodes anti-CD137 scFv into established B16 melanomas, significantly prolonged the survival of tumor-bearing mice and could induce regression. Our data suggest that targeting of anti-CD137 scFv to tumors should be explored for therapy for some human cancers.

Modulation of prostaglandin activity, part 1: prostaglandin inhibition in the management of nonrheumatologic diseases: immunologic and hematologic aspects

Prostaglandins (PGs) are active biologic substances that are involved in a wide range of physiologic processes; when their production is out of balance, they are factors in the pathogenesis of illness. Modulation of PGs by inhibition or stimulation is promising for the management of various conditions. PG inhibitors are widely used to relieve pain and inflammation in patients with rheumatologic disease. Interest in the use of PG inhibitors to prevent cancer and cardiovascular events is growing. More than 27 y ago, investigators found that PG depresses antibody production in vivo; reduces serum iron, hemoglobin, and leukoid series in bone marrow during acute and chronic blood loss; reduces albumin during antigenic stimulation; suppresses hypercalcemia after bleeding; and reduces fasting blood sugar and hyperglycemia after ether anesthesia and bleeding. Chronic conditions that produce large quantities of PGs are associated with immunosuppression and secondary anemia. Investigators in the present study hypothesized (1) that the overproduction of PGs is responsible for immunosuppression and secondary anemia in conditions associated with increased PG synthesis, such as pathologic inflammation, malignancy, trauma, and injury, and (2) that PG inhibitors reverse immunosuppression and secondary anemia, thereby enhancing the immune response. This is supported by many reports that show the immunosuppressive effects of PGs and their role in the immunosuppression associated with pathologic inflammation, burns, trauma, and tumors. Inhibition of PGs can be achieved through the use of synthetic medicines and natural products. This article reviews the effects of PGs and inhibition of increased synthesis of PGs on the lymphoid system, hematologic indices, and bone marrow elements in trauma, injury, burns, and tumors. The Medline database (1966-2006) was used in this study. Investigators in the present study and others have provided evidence that shows the involvement of PGs in immunosuppression and secondary anemia, as well as the efficacy of inhibited overproduction of PGs in many pathologic conditions other than rheumatologic disease.

B7-H4 expression identifies a novel suppressive macrophage population in human ovarian carcinoma

Tumor-associated macrophages are a prominent component of ovarian cancer stroma and contribute to tumor progression. B7-H4 is a recently identified B7 family molecule. We show that primary ovarian tumor cells express intracellular B7-H4, whereas a fraction of tumor macrophages expresses surface B7-H4. B7-H4+ tumor macrophages, but not primary ovarian tumor cells, suppress tumor-associated antigen-specific T cell immunity. Blocking B7-H4-, but not arginase-, inducible nitric oxide synthase or B7-H1 restored the T cell stimulating capacity of the macrophages and contributes to tumor regression in vivo. Interleukin (IL)-6 and IL-10 are found in high concentrations in the tumor microenvironment. These cytokines stimulate macrophage B7-H4 expression. In contrast, granulocyte/macrophage colony-stimulating factor and IL-4, which are limited in the tumor microenvironment, inhibit B7-H4 expression. Ectopic expression of B7-H4 makes normal macrophages suppressive. Thus, B7-H4+ tumor macrophages constitute a novel suppressor cell population in ovarian cancer. B7-H4 expression represents a critical checkpoint in determining host responses to dysfunctional cytokines in ovarian cancer. Blocking B7-H4 or depleting B7-H4+ tumor macrophages may represent novel strategies to enhance T cell tumor immunity in cancer.

The rationale for prophylactic cancer vaccines and need for a paradigm shift

This review summarizes clinical experience with infectious disease vaccines and data from animal tumor models that support a paradigm shift for cancer vaccines from therapeutic to prevention applications.