Integrity of circulating cell-free DNA as a prognostic biomarker for vaccine therapy in patients with nonsmall cell lung cancer.

BACKGROUND: Many clinical trials of immune checkpoint blockade-based combination therapies are under way. Vaccine therapy is a promising partner of combination therapies. We have developed a personalized peptide vaccination and conducted clinical trials of it in patients with various cancers. At the present time, we have only a limited number of biomarkers related to the prognosis of vaccine-treated patients. Thus, new biomarkers are urgently needed. METHODS: In this study, we investigated the plasma cell-free DNA (cfDNA) integrity-a ratio of the necrotic tumor cell-derived long cfDNA fragments to the total dead cell-derived short cfDNA fragments from genomic Alu elements-in patients with advanced nonsmall cell lung cancer during treatment with the personalized peptide vaccination. RESULTS: We found that (1) the cfDNA integrity was decreased after the first cycle of vaccination, and (2) the patients with high prevaccination cfDNA integrity survived longer than those with low prevaccination integrity (median survival time (MST): 17.9 versus 9.0 months, respectively; hazard ratio (HR): 0.58, p = .0049). A similar tendency was observed in postvaccination cfDNA integrity (MST: 16.4 vs 9.4 months; HR: 0.65, p = .024). CONCLUSIONS: These results suggest that cfDNA integrity is a possible prognostic biomarker in patients treated with the personalized peptide vaccine.

Immunotherapy in Metastatic Castration-Resistant Prostate Cancer: Past and Future Strategies for Optimization.

PURPOSE OF REVIEW: To date, prostate cancer has been poorly responsive to immunotherapy. In the current review, we summarize and discuss the current literature on the use of vaccine therapy and checkpoint inhibitor immunotherapy in metastatic castration-resistant prostate cancer (mCRPC). RECENT FINDINGS: Sipuleucel-T currently remains the only FDA-approved immunotherapeutic agent for prostate cancer. Single-agent phase 3 vaccine trials with GVAX and PROSTVAC have failed to demonstrate survival benefit to date. Clinical trials using combination approaches, including combination PROSTVAC along with a neoantigen vaccine and checkpoint inhibitor immunotherapy, are ongoing. Checkpoint inhibitor monotherapy clinical trials have demonstrated limited efficacy in advanced prostate cancer, and combination approaches and molecular patient selection are currently under investigation. The optimal use of vaccine therapy and checkpoint inhibitor immunotherapy in metastatic castration-resistant prostate cancer remains to be determined. Ongoing clinical trials will continue to inform future clinical practice.

Advances in immunotherapy for acute myeloid leukemia.

Evasion of the host immune system is a key mechanism to promote malignant progression. Therapeutically targeting immune pathways has radically changed the treatment paradigm for solid and lymphoid tumors but has yet to be approved for myeloid malignancies. Here, we summarize the most recent advances in immunotherapy for acute myeloid leukemia. Topics reviewed here include adoptive cellular approaches (chimeric antigen receptor-T cells, natural killer and other immune cells), checkpoint inhibitors (anti-PD-1/PD-L1, anti-CTLA-4 and TIM-3) and vaccines (WT-1, HLA-A2 and hTERT). Emphasis is placed on agents with clear evidence of tumor-specific immune responses and/or clinical activity in early-phase trials. Despite concerns regarding heterogeneous antigen expression and cytokine release syndrome, immunotherapy remains a highly promising strategy for acute myeloid leukemia, particularly transplant-ineligible patients and minimal residual disease states.

mRNA: A Versatile Molecule for Cancer Vaccines.

mRNA vaccines are finally ready to assume their rightful place at the forefront of nucleic acid- based vaccines. Major achievements within the last two decades have turned this highly versatile molecule into a safe and very attractive pharmaceutical platform that combines many positive attributes able to address a broad range of diseases, including cancer. The simplicity of mRNA vaccines greatly reduces complications generally associated with the production of biological vaccines. Intrinsic costimulatory and inflammatory triggers in addition to the provision of the antigenic information makes mRNA an all- in-one molecule that does not need additional adjuvants and that does not pose the risk of genomic integration. Clinical studies in various cancer types are moving forward and promising results with favorable clinical outcome are awaited. This review will recapitulate conceptual, mechanistic and immune-related features of this highly versatile molecule, elucidate how these features have been addressed in the past, and how comprehensive understanding can foster further optimization for broad application possibilities in cancer treatment.

A review of guidance on immunization in persons with defective or deficient splenic function.

The spleen acts as a blood filter and lymphopoietic organ. Asplenic and hyposplenic individuals are more susceptible to serious infections caused by encapsulated bacteria but they can be protected by antibiotic prophylaxis and immunizations. Recent progress in vaccinology means prophylaxis is now successful in the vast majority of serious infections with pneumococci, meningococci and Haemophilus influenzae type b responsible for the majority of cases of overwhelming sepsis in asplenic patients. Current guidelines are coherent. Physicians treating patients with conditions associated with hyposplenism are ethically obliged to immunize their patients using the vaccines currently available to protect them from largely preventable, life-threatening infections.

Why has active immunotherapy not worked in lung cancer?

Vaccines that rely on active specific stimulation of the host immune system have the potential to trigger durable antitumor responses with minimal toxicity. However, in nonsmall-cell lung cancer (NSCLC), several large phase III trials of vaccines reported within the last year have yielded disappointing results. Compared with placebo, belagenpumatucel-L (an allogenic tumor cell vaccine), tecemotide (a peptide vaccine targeting MUC-1) and melanoma-associated antigen-A3 (a protein-based vaccine) did not improve outcomes in NSCLC. The lack of clinically significant outcomes, despite their ability to prime and expand tumor antigen-specific T cells could at least partly be attributed to the inability of vaccine-induced T-cell responses to overcome the tumoral mechanisms of immune escape which limit the clonal expansion of T cells following vaccination. A number of such mechanisms have been recognized including reduced antigen presentation, antigenic loss, cytokines, immunosuppressive cells and immune checkpoints. Strategies aimed at modulating the immune checkpoints have shown promise and are on the verge of revolutionizing the therapeutic landscape of metastatic NSCLC. Overcoming immune tolerance and improving the activation of antitumor T cells via combinatorial approaches may represent a new and more promising therapeutic application for active immunotherapies in NSCLC.

The flip side of immune surveillance: immune dependency.

The growths of many and perhaps all tumors may be stimulated rather than inhibited by a quantitatively low level of immunity. The reason tumors have antigens may be that tumors do not develop in vivo in the absence of at least a minimal immune reaction; in this sense, cancer may be considered an autoimmune disease. This review, based largely on the work of our own laboratory, outlines the data showing that the titration of anti-tumor immunity exhibits the phenomenon of hormesis, i.e. the dose-response curve is non-linear such that low levels of immunity are generally stimulatory but larger quantities of the same immune reactants may inhibit tumor growth. Evidence is also reviewed that suggests that the immune response may vary qualitatively and quantitatively during progression, such that there seems to be, during oncogenesis, a very low level of immune reaction that aids initial tumor growth, followed by a larger reaction that may cause remission of early neoplasms, followed, if the neoplasm survives, by a relative immunologic tolerance to the tumor that may be dependent, at least in part, on suppressor cells. This knowledge may help to explain some clinical observations concerning the relationships among tumor types and the organ distribution of metastases.

Targeting alpha-synuclein via the immune system in Parkinson's disease: Current vaccine therapies.

Parkinson's disease (PD) is the second most common neurodegenerative disorder and is defined pathologically by the abnormal accumulation of the presynaptic protein alpha-synuclein (aSyn) in the form of Lewy bodies and Lewy neurites and loss of midbrain dopaminergic neurons in the substantia nigra pars compacta. Because of aSyn's involvement in both sporadic and familial forms of PD, it has become a key target for the development of novel therapeutics. Aberrant aSyn is associated with multiple mechanisms of neuronal dysfunction and degeneration including inflammation, impaired mitochondrial function, altered protein degradation systems, and oxidative stress. Inflammation, in particular, has emerged as a potential significant contributor early in the disease making it an attractive target for disease modification and neuroprotection. Thus, immunotherapies targeting aSyn are currently being investigated in pre-clinical and clinical trials. The focus of this review is to highlight the role of aSyn in neuroinflammation and discuss the current status of aSyn-directed immunotherapies in pre-clinical and clinical trials for PD.

A possible anticancer agent, type III interferon, activates cell death pathways and produces antitumor effects.

Recently identified interleukin-28 and -29 belong to a novel type III interferon (IFN) family, which could have distinct biological properties from type I and II IFNs. Type I IFNs, IFN-α/ß, have been clinically applied for treating a certain kind of malignancies for over 30 years, but a wide range of the adverse effects hampered the further clinical applications. Type III IFNs, IFN-λs, have similar signaling pathways as IFN-α/ß and inhibits proliferation of tumor cells through cell cycle arrest or apoptosis. Restricted patterns of type III IFN receptor expression in contrast to ubiquitously expressed IFN-α/ß receptors suggest that type III IFNs have limited cytotoxicity to normal cells and can be a possible anticancer agent. In this paper, we summarize the current knowledge on the IFN-λs-mediated tumor cell death and discuss the functional difference between type I and III IFNs.

[Advantages and prospects of the use of genetic vaccines for the protection from dangerous and socially significant infections].

High frequency of epidemiological threats (H5N1 influenza, SARS, etc.) in modern world calls for the development of new flexible technologies for manufacturing efficacious vaccines and rapid reorientation of their production as appropriate. Genetic vaccination is one of such technologies aimed at prophylaxis of dangerous and socially significant infections. The technology is based on administration of one or several functionally active genes encoding for antigens of pathogens which induces formation of both cellular and humoral immunity against the respective microorganism. This property of genetic vaccines is used for the development of prophylactic schemes. New vaccines are currently being designed to prevent a variety of infections. The aim of the present review is to outline major trends in genetic vaccination leading to the improvement of its efficacy.

Immunization therapy for Alzheimer disease: a comprehensive review of active immunization strategies.

Based on the amyloid cascade hypothesis, various strategies targeting amyloid beta protein (Abeta) have been invented for prevention and treatment of Alzheimer disease (AD). Active and passive immunizations with Abeta and Abeta antibodies successfully reduced AD pathology and improved cognitive functions in an AD mouse model. However, active immunization with AN-1792, a mixture of Abeta1-42 peptide and adjuvant QS21 induced autoimmune encephalitis in humans. Surprisingly, although AN-1792 cleared senile plaque amyloid, it showed no benefit in humans. It is speculated that AN-1792 failed in deleting more toxic forms of Abeta such as oligomers and intracellular Abeta, suggesting that newly developing vaccines should delete these toxic molecules. Since T cell epitopes exist mainly in the C-terminal portion of Abeta, vaccines using shorter N-terminal peptides are under development. In addition, since T helper 1 (Th1) immune responses activate encephalitogenic T cells and induce continuous inflammation in the central nervous system, vaccines inducing Th2 immune responses seem to be more promising. These are N-terminal short Abeta peptides with Th2 adjuvant or Th2-stimulating molecules, DNA vaccines, recombinant viral vector vaccines, recombinant vegetables and others. Improvement of vaccines will be also achieved by the administration method, because Th2 immune responses are mainly induced by mucosal or trans-cutaneous immunizations. Here I review recent progress in active immunization strategies for AD.

Engineering of bacterial strains and vectors for the production of plasmid DNA.

The demand for plasmid DNA (pDNA) is anticipated to increase significantly as DNA vaccines and non-viral gene therapies enter phase 3 clinical trials and are approved for use. This increased demand, along with renewed interest in pDNA as a therapeutic vector, has motivated research targeting the design of high-yield, cost-effective manufacturing processes. An important aspect of this research is engineering bacterial strains and plasmids that are specifically suited to the production of plasmid biopharmaceuticals. This review will survey recent innovations in strain and vector engineering that aim to improve plasmid stability, enhance product safety, increase yield, and facilitate downstream purification. While these innovations all seek to enhance pDNA production, they can vary in complexity from subtle alterations of the host genome or vector backbone to the investigation of non-traditional host strains for higher pDNA yields.

Amyloid-beta immunisation for Alzheimer's disease.

Alzheimer's disease is the main cause of dementia in elderly people and is becoming an ever greater problem as societies worldwide age. Treatments that stop or at least effectively modify disease course do not yet exist. In Alzheimer's disease, the conversion of the amyloid-beta peptide (Abeta) from a physiological water-soluble monomeric form into neurotoxic oligomeric and fibrillar forms rich in stable beta-sheet conformations is an important event. The most toxic forms of Abeta are thought to be oligomers, and dimers might be the smallest neurotoxic species. Numerous immunological approaches that prevent the conversion of the normal precursor protein into pathological forms or that accelerate clearance are in development. More than ten new approaches to active and passive immunotherapy are under investigation in clinical trials with the aim of producing safe methods for immunological therapy and prevention. A delicate balance between immunological clearance of an endogenous protein with acquired toxic properties and the induction of an autoimmune reaction must be found.

Molecular evolution of Salmonella enterica serovar Typhimurium and pathogenic Escherichia coli: from pathogenesis to therapeutics.

Salmonella enterica serovar Typhimurium (S. Typhimurium) and certain Escherichia coli are human pathogens that have evolved through the acquisition of multiple virulence determinants by horizontal gene transfer. Similar genetic elements, as pathogenicity islands and virulence plasmids, have driven molecular evolution of virulence in both species. In addition, the contribution of prophages has been recently highlighted as a reservoir for pathogenic diversity. Characterization of horizontally acquired virulence genes has several clinical implications. First, identification of virulence determinants that have a sporadic distribution and are specifically associated with a pathotype and/or a pathology can be useful markers for risk assessment and diagnosis. Secondly, virulence factors widely distributed in pathogenic strains, but absent from non-pathogenic bacteria, are interesting targets for the development of novel antimicrobial chemotherapies and vaccines. Here, we summarize the horizontally acquired virulence factors of S. Typhimurium, enterohemorrhagic E. coli O157:H7 and uropathogenic E. coli, and we describe their use in novel therapeutic approaches.

DNA vaccine therapy for Alzheimer's disease: present status and future direction.

Alzheimer's disease is the most common cause of dementia characterized by progressive neurodegeneration. Based on the amyloid cascade hypothesis, a vaccine therapy for Alzheimer's disease (AD) was developed as a curative treatment. In 1999, the amyloid beta (Abeta) reduction in AD model transgenic mice with active vaccination with Abeta peptide was first reported. Although the clinical trials of active vaccination for AD patients were halted due to the development of meningoencephalitis in some patients, from the analysis of the clinical and pathological findings of treated patients, the vaccine therapy is thought to be effective. Based on such information, the vaccines for clinical application of human AD have been improved to control excessive immune reaction. Recently, we have developed non-viral DNA vaccines and obtained substantial Abeta reduction in transgenic mice without side effects. DNA vaccines have many advantages over conventional active or passive immunization. In this article, we review conventional vaccine therapies and further explain our non-viral DNA vaccine therapy. Finally, we show some data regarding the mechanisms of Abeta reduction after administration of DNA vaccines. DNA vaccination may open up new avenues of vaccine therapy for AD.

Vaccination for treatment and prevention of cancer in animal models.

Two approaches to immunological intervention in tumor-host interactions in mouse models are discussed in this review. The first is described with reference to experiments in which CD8(+) T lymphocytes are used to kill established transplantable tumors. Peptides and their optimal presentation by dendritic cells and intervention in immune regulatory mechanisms are the key issues for efficient induction of T-killer cell-mediated tumor eradication. The time frame of tumor therapy and the threat imposed by tumor growth in transplantable models and cancer patients require the induction of a robust T-cell reaction. Prevention of the progression of small preneoplastic lesions, on the other hand, requires the significant and prolonged immune protection sought in the second approach. This is based on antibody production and the coordinated activation of multiple low-avidity cell-mediated mechanisms elicited by DNA vaccination in genetically modified cancer-prone mice, transgenic for a mutant Her-2/neu growth factor receptor expressed at the plasma membrane surface of preneoplastic mammary gland epithelial cells. Vaccination with appropriate DNA formulations results in prolonged immune inhibition of the progression of preneoplastic mammary lesions but is ineffective against established tumors. The use of molecularly defined adjuvants and intervention in immune regulatory mechanisms are critical in both the elicitation of an effective T-cell mediated reaction required for tumor debulking in the first set of models and the induction by vaccination of a sustained immune memory able to prevent the expansion of preneoplastic lesions in genetically cancer-prone mice.

Human natural killer cell subsets and acute exercise: a brief review.

Natural killer (NK) cells are the most responsive immune cell to acute exercise. This sensitivity to physiological stress combined with their role in innate immune defences suggests that these cells may be a link between regular physical activity and overall health status. NK cells are a heterogeneous population consisting of at least two distinct subsets based on the expression intensity of CD56. CD56(bright) and CD56(dim) cells exhibit different phenotypical and functional characteristics. In this review, we examine the effects of acute exercise on NK cell subsets, with special reference to potential health implications of the findings. The available evidence suggests a differential mobilization of NK cell subsets in response to acute exercise; CD56(bright) NK cells are less responsive than their CD56(dim) counterparts. During the post-exercise recovery period (up to 1 h), the ratio of CD56(bright):CD56(dim) cells favours the CD56(bright) subset. The potential significance of these findings is discussed in the context of normal physiological adaptation to exercise. We also discuss the potential role of exercise in certain clinical conditions (e.g., multiple sclerosis) as an adjunct therapy to mobilize the CD56(bright) subset. Further investigation into the biology of NK cell subsets and exercise should prove to be a fruitful area for years to come.

The future of cancer vaccines for non-small-cell lung cancer: ongoing trials.

Lung cancer represents one of the malignancies in which the 3 elements of conventional therapy (ie, surgery, radiotherapy, and chemotherapy) have limited effectiveness in curbing progressive disease. In this context, there is burgeoning interest in the use of vaccine therapy as a nontoxic adjunct to increase the treatment success rates over those obtained with traditional regimens alone. Several clinical trials using a variety of vaccination strategies have been reported or are ongoing. In this review, we have provided an overview of these trials, with a special focus on the clinical efficacy of the vaccines. The future prospects and challenges of vaccine therapy in lung cancer have also been discussed.

Melioidosis.

Burkholderia pseudomallei is a Gram-negative environmental bacterium and the aetiological agent of melioidosis, a life-threatening infection that is estimated to account for ∼89,000 deaths per year worldwide. Diabetes mellitus is a major risk factor for melioidosis, and the global diabetes pandemic could increase the number of fatalities caused by melioidosis. Melioidosis is endemic across tropical areas, especially in southeast Asia and northern Australia. Disease manifestations can range from acute septicaemia to chronic infection, as the facultative intracellular lifestyle and virulence factors of B. pseudomallei promote survival and persistence of the pathogen within a broad range of cells, and the bacteria can manipulate the host's immune responses and signalling pathways to escape surveillance. The majority of patients present with sepsis, but specific clinical presentations and their severity vary depending on the route of bacterial entry (skin penetration, inhalation or ingestion), host immune function and bacterial strain and load. Diagnosis is based on clinical and epidemiological features as well as bacterial culture. Treatment requires long-term intravenous and oral antibiotic courses. Delays in treatment due to difficulties in clinical recognition and laboratory diagnosis often lead to poor outcomes and mortality can exceed 40% in some regions. Research into B. pseudomallei is increasing, owing to the biothreat potential of this pathogen and increasing awareness of the disease and its burden; however, better diagnostic tests are needed to improve early confirmation of diagnosis, which would enable better therapeutic efficacy and survival.