Biopanning the mimotopes of aflatoxin B1 and their immunogenicity / Panning de mimotopo aflatoxina B1 e sua imunogenicidade

Utilizando um anticorpo monoclonal contra a aflatoxina B1 (AFB1) como ligante, foi identificado um mimotopo específico de aflatoxina B1 após se realizarem quatro ciclos de seleção biológica de 7-peptídeos aleatórios em biblioteca de fago exibida. O mimotopo é denominado P10, e sua sequência de aminoácidos é YRRHEKD. O soro imunológico de ratos Balb/c imunizados com P10 foi especificamente ligado à aflatoxina B1-albumina, indicando que o anticorpo era específico ao AFB1. Esses resultados sugerem que é possível desenvolver a vacina baseada em mimotopo associado à toxina.(AU)

New insights on the development of fungal vaccines: from immunity to recent challenges

Fungal infections are emerging as a major problem in part due to high mortality associated with systemic infections, especially in the case of immunocompromised patients. With the development of new treatments for diseases such as cancer and the acquired immune deficiency syndrome pandemic, the number of immunosuppressed patients has increased and, as a consequence, also the number of invasive fungal infections has increased. Several studies have proposed new strategies for the development of effective fungal vaccines. In addition, better understanding of how the immune system works against fungal pathogens has improved the further development of these new vaccination strategies. As a result, some fungal vaccines have advanced through clinical trials. However, there are still many challenges that prevent the clinical development of fungal vaccines that can efficiently immunise subjects at risk of developing invasive fungal infections. In this review, we will discuss these new vaccination strategies and the challenges that they present. In the future with proper investments, fungal vaccines may soon become a reality.

Paracoccidioidoyycosis: challenges in the develpment of a vaccine against an eendemic mycosis in the americas / Paracoccidioidomicose: desafios no desenvolvimento de uma vacina contra micose endêmica nas Américas

SUMMARYParacoccidioidomycosis (PCM), caused by Paracoccidioides spp, is an important endemic mycosis in Latin America. There are two recognized Paracoccidioides species, P. brasiliensis and P. lutzii, based on phylogenetic differences; however, the pathogenesis and disease manifestations of both are indistinguishable at present. Approximately 1,853 (~51,2%) of 3,583 confirmed deaths in Brazil due to systemic mycoses from 1996-2006 were caused by PCM. Antifungal treatment is required for patients with PCM. The initial treatment lasts from two to six months and sulfa derivatives, amphotericin B, azoles and terbinafine are used in clinical practice; however, despite prolonged therapy, relapses are still a problem. An effective Th1-biased cellular immune response is essential to control the disease, which can be induced by exogenous antigens or modulated by prophylactic or therapeutic vaccines. Stimulation of B cells or passive transference of monoclonal antibodies are also important means that may be used to improve the efficacy of paracoccidioidomycosis treatment in the future. This review critically details major challenges facing the development of a vaccine to combat PCM.

RESUMOA paracoccidioidomicose (PCM), causada por Paracoccidioides spp, é importante micose endêmica na América Latina. Com base em diferenças filogenéticas, existem duas espécies reconhecidas de Paracoccidioides, P. brasiliensis e P. lutzii, no entanto, a patogênese e as manifestações clínicas de ambas são indistinguíveis atualmente. Aproximadamente 1853 (~51,2%) de 3583 mortes confirmadas, atribuídas a micoses sistêmicas de 1996-2006, no Brasil foram causadas por PCM. Tratamento antifúngico é necessário para pacientes com PCM. O tratamento inicial dura de dois a seis meses e derivados de sulfa, anfotericina B, azóis e terbinafina são utilizados na prática clínica; no entanto, apesar da terapêutica prolongada, as recaídas ainda são um problema. Uma resposta imune celular eficaz, tendendo a Th1, é essencial para controlar a doença que pode ser induzida por antígenos exógenos, ou moduladas por vacinas profiláticas ou terapêuticas. A estimulação de células B ou a transferência passiva de anticorpos monoclonais também são meios importantes que podem ser utilizados para melhorar a eficácia do tratamento da paracoccidioidomicose no futuro. Esta revisão detalha criticamente os principais desafios que o desenvolvimento de uma vacina para combater a PCM enfrenta.

Research Progress of Feasibility of Dendritic Cell Antifungal Vaccines / 生物医学工程学杂志

Fungal infection is an important clinical problem for patients with immune deficiency or immunosuppression. With deadly fungus infection case increasing, the development of antifungal vaccine attracts the attention of researchers. Dendritic cell (DC) is the unique antigen presenting cell (APC) to trigger the antifungal immune reaction, and recent studies indicate that the targeted vaccination strategy based on DC have prospective antifungal potentials. In this paper, we review the antifungal immunity mechanism and recent development of the targeted DC antifungal strategy.

Generation and Immunity Testing of a Recombinant Adenovirus Expressing NcSRS2-NcGRA7 Fusion Protein of Bovine Neospora caninum

Neospora caninum is the etiologic agent of bovine neosporosis, which affects the reproductive performance of cattle worldwide. The transmembrane protein, NcSRS2, and dense-granule protein, NcGRA7, were identified as protective antigens based on their ability to induce significant protective immune responses in murine neosporosis models. In the current study, NcSRS2 and NcGRA7 genes were spliced by overlap-extension PCR in a recombinant adenovirus termed Ad5-NcSRS2-NcGRA 7, expressing the NcSRS2-NcGRA7 gene, and the efficacy was evaluated in mice. The results showed that the titer of the recombinant adenovirus was 10(9)TCID50/ml. Three weeks post-boost immunization (w.p.b.i.), the IgG antibody titer in sera was as high as 1:4,096. IFN-gamma and IL-4 levels were significantly different from the control group (P<0.01). This research established a solid foundation for the development of a recombinant adenovirus vaccine against bovine N. caninum.

Vaccines against Coccidioides

Vaccines against fungal diseases are gaining attention because of their growing impact on modern medicine. Development of these vaccines should incorporate immunological tools that integrate with or replace chemotherapy to minimize antibiotic use and consequent resistance. In this review, we evaluate the current developmental status of fungal vaccines against coccidioidomycosis. There is a need for a vaccine that sufficiently prevents disease, without eradicating the fungus, by neutralizing adhesions and enzymes or other low penetrance virulence traits.

Antifungal and antitumor models of bioactive protective peptides

Peptides are remarkably reactive molecules produced by a great variety of species and able to display a number of functions in uni-and multicellular organisms as mediators, agonists and regulating substances. Some of them exert cytotoxic effects on cells other than those that produced them, and may have a role in controlling subpopulations and protecting certain species or cell types. Presently, we focus on antifungal and antitumor peptides and discuss a few models in which specific sequences and structures exerted direct inhibitory effects or stimulated a protective immune response. The killer peptide, deduced from an antiidiotypic antibody, with several antimicrobial activities and other Ig-derived peptides with cytotoxic activities including antitumor effects, are models studied in vitro and in vivo. Peptide 10 from gp43 of P. brasiliensis (P10) and the vaccine perspective against paracoccidioidomycosis is another topic illustrating the protective effect in vivo against a pathogenic fungus. The cationic antimicrobial peptides with antitumor activities are mostly reviewed here. Local treatment of murine melanoma by the peptide gomesin is another model studied at the Experimental Oncology Unit of UNIFESP.

Peptídeos são moléculas particularmente reativas produzidas por uma grande variedade de espécies, aptos a exercer um número de funções em organismos uni-e multicelulares como mediadores, agonistas e substâncias regulatórias. Alguns deles exercem efeitos citotóxicos em células outras das que os produzem, e podem ter um papel controlando subpopulações e protegendo certas espécies ou tipos celulares. No presente, focalizamos peptídeos antifúngicos e antitumorais e discutimos alguns modelos nos quais seqüências específicas e estruturas exercem efeitos inibitórios diretos ou estimulam uma resposta imune protetora. O peptídeo letal ("killer"), deduzido de um anticorpo anti-idiotípico, com várias atividades antimicrobianas bem como outros peptídeos derivados de imunoglobulinas com atividades citotóxicas incluindo efeitos antitumorais são modelos estudados in vitro e in vivo. O peptídeo P10 da gp43 de P. brasiliensis e a perspectiva de vacina contra a paracoccidioidomicose é outro tópico ilustrando o efeito protetor in vivo contra um fungo patogênico. Peptídeos antimicrobianos catiônicos com atividades antitumorais são os principais revistos aqui. O tratamento local do melanoma murino com o peptídeo gomesina é outro modelo estudado na Unidade de Oncologia Experimental (UNONEX) da UNIFESP.

Human, monoclonal and recombinant candidacidal, pneumocysticidal and mycobactericidal antibodies.

Antiidiotypic antibodies (antiIds) representing the internal image of some antigenic deteminants have been proposed as surrogate vaccines or, conjugated with toxins, in the immunotherapy of cancer. Experimental studies on antiidiotypic vaccination against fungal infections have been lacking. A conceptually new model of idiotypic vaccination against fungal infection has been recently developed. The vaccine used is monoclonal antibody that in vitro neutralizes the activity of killer toxin from the yeast, Pichia anomala (KT). This is effective against a wide range of fungal pathogens including Candida albicans and Pneumocystis carinii, and is also active against Mycobacterium tuberculosis. In an experimental mouse model, this vaccination was found to confer significant protection against systemic and mucosal infection with C. albicans. Human recombinant killer toxin antibodies and its synthetic derivatives hold promise of a potentially powerful tool against fungal and mycobacterial infections.

Vacinaçäo de camundongos BALB/c com o gene da GP43 de Paracoccidioides brasiliensis: estudo da resposta imune / BALB/c mice vaccination with GP43 gene from Paracocidioides brasiliensis: study of imune response

Ácidos nucléicos têm sido utilizados como a terceira geração de vacinas, e têm sido utilizados em ensaios de imunoproteção contra infecções virais, bacterianas e parasitárias. Resultados prévios mostraram que a imunização com a gp43 nativa ou com um peptídeo de 15 aminoácidos (P1O) contido neste antígeno protegeu camundongos contra o desafio de leveduras virulentas de P. brasiliensis. Para determinar se similar imunidade protetora poderia ser conseguida pela imunização com DNA, a ORF da gp43 foi subclonada em um vetor de expressão para células de mamíferos denominado VR-1012 (Vical Inc.), criando assim o plasmídeo VR-gp43. Grupos de camundongos BALB/c foram imunizados com lOOmg de VR-gp43 ou VR-1012, num total de 4 doses, com intervalos de 2 semanas, por 2 meses. A resposta humoral contra a gp43 aumentou durante a imunização com VR-gp43, sendo IgG1, IgG2a, IgG2b e IgE os principais isótipos produzidos. Resposta imune celular também foi induzida, como medido pela estimulação ín vitro com gp43 de células de linfonodos dos animais imunizados com VR-gp43, com alta produção de IL-2 e IFN-Y. Estes resultados sugerem que uma resposta imune celular mista THllTH2, modulada por IFN-Y, foi induzida pela imunização com DNA neste modelo murino. A imunidade induzida foi duradoura e capaz de proteger camundongos BALB/c infectados com leveduras virulentas de P. brasiliensis, levando à significante diminuição dos UFCs nos pulmões e' redução ou não disseminação para baço e fígado dos camundongos, quando comparado com os animais controles. Estes resultados indicam que a imunização gênica e uma alternativa viável para induzir imunidade protetora também contra infecções fúngicas

Evaluation of the role of cell-mediated immunity in dermatophytosis

For demonstration of cell-mediated immunity and its role in the process of dermatophytosis, 98 patients with acute dermatophytosis [group 1] and 131 chronic dermatophytosis patients [group 2] were chosen. In all patients, lymphocyte transformation and skin test were used. 96 members of group 1 [98%] had positive delayed-type hypersensitivity [DTH] responses to trichophytin, whereas only 43 subjects [32.8%] of group 2 had positive DTH responses. In group 1, positive lymphocyte blastogenic responses to trichophytin and phytohemagglutinin were seen in 95 [96.9%] and 98 [100%] patients, respectively, but in group 2 the positive results were observed in 49 [34.4%] and 127 [94.9%] subjects, respectively. Patients with chronic dermatophytosis had histories of a number of systemic disorders such as: atopy 64 patients; diabetes, seven patients; contact dermatitis, four patients; and tuberculosis, three patients