Vaccination of Melanoma Patients With Melan-A/Mart-1 Peptide and Klebsiella Outer Membrane Protein P40 as an Adjuvant

Tumour 63 protein (p63) in breast pathology: biology, immunohistochemistry, diagnostic applications, and pitfalls

Tumour protein 63 (p63) is a transcription factor of the p53 gene family, encoded by the TP63 gene located at chromosome 3q28, which regulates the activity of genes involved in growth and development of the ectoderm and derived tissues. p63 protein is normally expressed in the nuclei of the basal cell layer of glandular organs, including breast, in squamous epithelium and in urothelium. p63 immunohistochemical (IHC) staining has several applications in diagnostic breast pathology. It is commonly used to demonstrate myoepithelial cells at the epithelial stromal interface to differentiate benign and in situ lesions from invasive carcinoma and to characterize and classify papillary lesions including the distinction of breast intraduct papilloma from skin hidradenoma. p63 IHC is also used to identify and profile lesions showing myoepithelial cell and/or squamous differentiation, e.g. adenomyoepithelioma, salivary gland-like tumours including adenoid cystic carcinoma, and metaplastic breast carcinoma including low-grade adenosquamous carcinoma. This article reviews the applications of p63 IHC in diagnostic breast pathology and outlines a practical approach to the diagnosis and characterization of breast lesions through the identification of normal and abnormal p63 protein expression. The biology of p63, the range of available antibodies with emphasis on staining specificity and sensitivity, and pitfalls in interpretation are also discussed. The TP63 gene in humans, which shows a specific genomic structure, resulting in either TAp63 (p63) isoform or ΔNp63 (p40) isoform. As illustrated in the figure, both isoforms contain a DNA-binding domain (Orange box) and an oligomerization domain (Grey box). TAp63 contains an N-terminal transactivation (TA) domain (Green box), while ΔNp63 has an alternative terminus (Yellow box). Antibodies against conventional pan-p63 (TP63) bind to the DNA binding domain common to both isoforms (TAp63 and p40) and does not distinguish between them. Antibodies against TAp63 bind to the N-terminal TA domain, while antibodies specific to ΔNp63 (p40) bind to the alternative terminus. Each isoform has variant isotypes (α, β, γ, δ, and ε).

Bacteria and Bacterial Components as Natural Bio-Nanocarriers for Drug and Gene Delivery Systems in Cancer Therapy

Bacteria and bacterial components possess multifunctional properties, making them attractive natural bio-nanocarriers for cancer diagnosis and targeted treatment. The inherent tropic and motile nature of bacteria allows them to grow and colonize in hypoxic tumor microenvironments more readily than conventional therapeutic agents and other nanomedicines. However, concerns over biosafety, limited antitumor efficiency, and unclear tumor-targeting mechanisms have restricted the clinical translation and application of natural bio-nanocarriers based on bacteria and bacterial components. Fortunately, bacterial therapies combined with engineering strategies and nanotechnology may be able to reverse a number of challenges for bacterial/bacterial component-based cancer biotherapies. Meanwhile, the combined strategies tend to enhance the versatility of bionanoplasmic nanoplatforms to improve biosafety and inhibit tumorigenesis and metastasis. This review summarizes the advantages and challenges of bacteria and bacterial components in cancer therapy, outlines combinatorial strategies for nanocarriers and bacterial/bacterial components, and discusses their clinical applications.

Current Stage in the Development of Klebsiella pneumoniae Vaccines

Klebsiella pneumoniae is a bacterium capable of colonizing mucous membranes, causing serious infections. Widespread antibiotic resistance in K. pneumoniae—either through intrinsic mechanisms or via acquisition from different species, especially in hospital environments—limits the therapeutic options against this pathogen, further aggravating the disease burden. To date, there are no vaccines available against K. pneumoniae infection. Although formulations based on capsular polysaccharides have been proposed, the high variability in capsular serotypes limits vaccine coverage. Recombinant vaccines based on surface exposed bacterial antigens are a promising alternative owing to their conservation among different serotypes and accessibility to the immune system. Many vaccine candidates have been proposed, some of which have reached clinical trials. The present review summarizes the current status of K. pneumoniae vaccine development. Different strategies including whole cell vaccines, outer membrane vesicles (OMVs), ribosome, polysaccharide, lipopolysaccharide (LPS), and protein-based formulations are discussed. The contribution of antibody and cell-mediated responses is also presented. In summary, K. pneumoniae vaccines are feasible and a promising strategy to prevent infections and to reduce the antimicrobial resistance burden worldwide.

Trial watch: Peptide vaccines in cancer therapy

Prophylactic vaccination constitutes one of the most prominent medical achievements of history. This concept was first demonstrated by the pioneer work of Edward Jenner, dating back to the late 1790s, after which an array of preparations that confer life-long protective immunity against several infectious agents has been developed. The ensuing implementation of nation-wide vaccination programs has de facto abated the incidence of dreadful diseases including rabies, typhoid, cholera and many others. Among all, the most impressive result of vaccination campaigns is surely represented by the eradication of natural smallpox infection, which was definitively certified by the WHO in 1980. The idea of employing vaccines as anticancer interventions was first theorized in the 1890s by Paul Ehrlich and William Coley. However, it soon became clear that while vaccination could be efficiently employed as a preventive measure against infectious agents, anticancer vaccines would have to (1) operate as therapeutic, rather than preventive, interventions (at least in the vast majority of settings), and (2) circumvent the fact that tumor cells often fail to elicit immune responses. During the past 30 y, along with the recognition that the immune system is not irresponsive to tumors (as it was initially thought) and that malignant cells express tumor-associated antigens whereby they can be discriminated from normal cells, considerable efforts have been dedicated to the development of anticancer vaccines. Some of these approaches, encompassing cell-based, DNA-based and purified component-based preparations, have already been shown to exert conspicuous anticancer effects in cohorts of patients affected by both hematological and solid malignancies. In this Trial Watch, we will summarize the results of recent clinical trials that have evaluated/are evaluating purified peptides or full-length proteins as therapeutic interventions against cancer.

Construction, immune protection and innate immune response of shuffled polyvalent ompAs vaccines

Our previous studies demonstrated that molecular breeding via DNA shuffling directs the evolution of polyvalent vaccines with desired traits, which leads to generation of polyvalent ompA vaccines using Vibrio alginolyticus VA0764 primers. Here, we replaced VA0764 primers with Edwardsiella tarda ompA primers to generate new polyvalent ompA vaccines by DNA shuffling of the same five ompA genes from four species of bacteria E. tarda, V. parahaemolyticus, V. alginolyticus and Escherichia coli. We identified four polyvalent vaccine candidates from a eukaryotic expressing library EompAs-FE containing 82 ompAs using active immune protection against V. alginolyticus and E. tarda. Furthermore, we explored mechanisms of polyvalent vaccine candidates by investigation of the innate immune response to these ompAs, and found that expression of IL-1β, IL-8, IL-15, COX-2, IFN-γ, TLR-1, TLR-3 and C3b genes was elevated as a characteristic feature of these polyvalent vaccine candidates. These results indicate that use of different primers to construct a DNA library selects new evolution of polyvalent vaccines with desired traits, and polyvalent ompA vaccines elicit high innate immune response.

DNA shuffling approach for recombinant polyvalent OmpAs against V. alginolyticus and E. tarda infections

Molecular breeding via DNA shuffling directs the evolution of vaccines with desired traits. In the present study, polyvalent OmpA vaccines were generated by DNA shuffling of five ompA genes from four species of bacteria Vibrio parahaemolyticus, V. alginolyticus, Edwardsiella tarda and Escherichia coli. First, a new hybrid OmpA was constructed using VA0764 primers and used for construction of a prokaryotic expressing library PompAs-FV containing 84 ompAs, which were validated by PCR and SDS/PAGE. Then, the 84 ompAs were used to construct a eukaryotic expressing library EompAs-FV for preparing DNA vaccines. Third, extracellular bacterium V. alginolyticus challenge post active immunization using these DNA vaccines was carried out to identify genes with high immunoprotection. Among the 84 ompAs, 17 showed higher or equal immune protection against infection caused by V. alginolyticus than control VA0764. Finally, immune protection against infection caused by intracellular bacterium Edwardsiella tarda was assessed further using the top seven out of the 17 ompAs. This led to identification of three efficient polyvalent vaccines against infections caused by the extracellular bacterium V. alginolyticus and intracellular bacterium E. tarda. In addition, we sequenced genes for understanding mechanisms of the polyvalent vaccines, but association of immune protection with mutation of gene and amino acids is not determined. These results indicate that DNA shuffling is an efficient way to develop polyvalent vaccines against microbial infections.

Construction and immune protection evaluation of recombinant polyvalent OmpAs derived from genetically divergent ompA by DNA shuffling

A wide variety of bacterial infections is a major challenge in aquaculture. Development of polyvalent vaccines that can fight against as many pathogens as possible is especially necessary. The present study uses DNA shuffling to create a new hybrid OmpA with improved cross-protection against Vibrio alginolyticus and Edwardsiella tarda through the recombination of six OmpA genes from Vibrio parahaemolyticus, V. alginolyticus, E. tarda and Escherichia coli. Out of the 43 recombinant chimeras genes constructed using VA0764 primers, EompAs-19 was demonstrated as an ideal polyvalent vaccine against infections caused V. alginolyticus and E. tarda. Compared with VA0764, OmpAs-19 had three mutations, which may be a molecular basis of EompAs-19 as an efficient polyvalent vaccine against both V. alginolyticus and E. tarda infections. These results develop a polyvalent vaccine that prevents the infections caused by extracellular and intracellular bacteria. Thus, the present study highlights the way to develop polyvalent vaccines against microbial infections by DNA shuffling.

Vitiligo-like depigmentation in patients with stage III-IV melanoma receiving immunotherapy and its association with survival: a systematic review and meta-analysis

PURPOSE

Vitiligo-like depigmentation in patients with melanoma may be associated with more favorable clinical outcome. We conducted a systematic review of patients with stage III to IV melanoma treated with immunotherapy to determine the cumulative incidence of vitiligo-like depigmentation and the prognostic value of vitiligo development on survival.

METHODS

We systemically searched and selected all studies on melanoma immunotherapy that reported on autoimmune toxicity and/or vitiligo between 1995 and 2013. Methodologic quality of each study was appraised using adapted criteria for systematic reviews in prognostic studies. Random-effect models were used to calculate summary estimates of the cumulative incidence of vitiligo-like depigmentation across studies. The prognostic value of vitiligo-like depigmentation on survival outcome was assessed using random-effects Cox regression survival analyses.

RESULTS

One hundred thirty-seven studies were identified comprising 139 treatment arms (11 general immune stimulation, 84 vaccine, 28 antibody-based, and 16 adoptive transfer) including a total of 5,737 patients. The overall cumulative incidence of vitiligo was 3.4% (95% CI, 2.5% to 4.5%). In 27 studies reporting individual patient data, vitiligo development was significantly associated with both progression-free-survival (hazard ratio [HR], 0.51; 95% CI, 0.32 to 0.82; P < .005) and overall survival (HR, 0.25; 95% CI, 0.10 to 0.61; P < .003), indicating that these patients have two to four times less risk of disease progression and death, respectively, compared with patients without vitiligo development.

CONCLUSION

Although vitiligo occurs only in a low percentage of patients with melanoma treated with immunotherapy, our findings suggest clear survival benefit in these patients. Awareness of vitiligo induction in patients with melanoma is important as an indicator of robust antimelanoma immunity and associated improved survival.

Process development and production of cGMP grade Melan-A for cancer vaccine clinical trials

Melan-A is a cancer testis antigen commonly found in melanoma, and has been shown to stimulate the body's immune response against cancerous cells. We have developed and executed a process utilizing current good manufacturing practices (cGMP) to produce the 6 times-His tagged protein in C41DE3 Escherichia coli for use in Phase I clinical trials. Approximately 11 g of purified Melan-A were produced from a 20 L fed-batch fermentation. Purification was achieved through a three column process utilizing immobilized metal affinity, anion exchange, and cation exchange chromatography with a buffer system optimized for low-solubility, high LPS binding capacity proteins. The host cell proteins, residual DNA, and endotoxin concentration were well below limits for a prescribed dose with a final purity level of 91%.

The immune system--a hidden treasure for biomarker discovery in cutaneous melanoma

This chapter describes how skin immune system (SIS) is specifically involved in the development of cutaneous melanoma. Local immune surveillance is presented as a complex process that comprises markers to be monitored in disease's evolution and in therapy. The ranking of tissue or soluble immune markers in a future panel of diagnostic/prognostic panel are evaluated. Taking into account the difficulties of cutaneous melanoma patients' management, this chapter shows the immune surveillance at the skin level, the conditions that favor the tumor escape from the immunological arm, the immune pattern of skin melanoma with diagnostic/prognostic relevance, the circulatory immune markers, and, last but not least, how immune markers are used in immune-therapy monitoring. The chapter cannot be exhaustive but will give the reader a glimpse of the complex immune network that lies within tumor escape and where to search for immune-therapeutical targets in skin melanoma.

Identification of plasma-responsive outer membrane proteins and their vaccine potential in Edwardsiella tarda using proteomic approach

We have used differential sub-proteomic methodologies to detect Edwardsiella tarda outer membrane (OM) protein expression regulation during interaction with fish and human plasma, which is the critical step of the bacterial invasion internal organs via blood circulation. Seven and nine OM proteins were differentially expressed in response to fish and human plasma stress, respectively. Six proteins, TolB2, ETAE_2935, ETAE_0245, EvpA, ETAE_2675 and OmpA, were the shared proteins with the similar changes between the two plasma treatments. Except for EvpA, which was a known protein involved in bacterial pathogenesis and stress sensing, the others were first reported here to be related to bacterial invasion and infection. Out of them, four, upregulated ETAE_0245 and OmpA and downregulated ETAE_2675 and ETAE_2935, were selected for investigation of immune protection. The upregulated OmpA and ETAE_0245 were able to induce bactericidal antibodies in mice. These findings demonstrate that differential proteomic methodologies following protein expression regulation to interaction between host and pathogen with bacterial challenge post immunization of these altered proteins is a valid approach for identifying new vaccine candidates and nicely complements other high throughput mining strategies used for vaccine discovery.

Immune-related biomarkers for diagnosis/prognosis and therapy monitoring of cutaneous melanoma

Skin melanoma, a life-threatening disease, has a recently reported worldwide increase in incidence, despite primary prevention. Skin melanoma statistics emphasize the need for finding markers related to the immune response of the host. The mechanisms that are able to over-power the local immune surveillance comprise molecules that can be valuable markers for diagnosis and prognosis. This article summarizes the immune markers that can monitor the disease stage and evaluate the efficacy of therapeutic interventions. Recent data regarding immunotherapy are presented in the context of tumor escape from immune surveillance and the immune molecules that are both targets and a means of monitoring. Perspectives for developing immune interventions for skin melanoma management and the position of tissue or soluble immune markers as a diagnostic/prognostic panel are evaluated. State-of-the-art technology is emphasized for developing immune molecular signatures for a complex characterization of the patient's immunological status.