Daniel Carlos Ferreira Lanza

Macrophage Migration Inhibitory Factor (MIF): Biological Activities and Relation with Cancer.

Macrophage migration inhibitory factor (MIF) emerged in recent years as an important inflammation mediator, playing a prominent role in the pathogenesis of various types of malignant neoplasm. MIF is a glycoprotein that presents a wide spectrum of biological activities and exerts a complex interaction with various cellular signaling pathways, causing imbalance of homeostasis. Experimental and clinical studies show that high levels of MIF are found in almost all types of human cancers and are implicated in seemingly all stages of development of the tumors. The production of MIF is triggered through an autocrine signal emitted by tumor cells, and stimulates the production of cytokines, chemokines, and growth as well as angiogenic factors that lead to growth of the tumor, increasing its aggressiveness and metastatic potential. MIF is produced by virtually all types of human body cells, in response to stress caused by different factors, leading to pathological conditions such as chronic inflammation and immunomodulation with suppression of immune surveillance and of immune response against tumors, angiogenesis, and carcinogenesis. In this review, we present recent advances on the biological activity of MIF, the signaling pathways with which it is involved and their role in tumorigenesis.

New insights about ORF1 coding regions support the proposition of a new genus comprising arthropod viruses in the family Totiviridae

Analyzing the positions of 2A-like polypeptide cleavage sites in all available genomes of arthropod totiviruses we propose the limits of all ORF1 coding sequences and observed that two proteins previously predicted in infectious myonecrosis virus genome are unique in the arthropod totiviruses group. A putative protein cleavage site upstream the major capsid protein was also identified only in these genomes. In addition, protein models generated using ab initio and threading approaches revealed conserved structures possibly related to formation of viral protrusions and RNA packaging, clarifying the mechanisms involved in the extracellular transmission. These data appoints that the group formed by arthropod totiviruses are sufficient distinctive to be clustered in new genus belonging to the Totiviridae family, in agreement with previous phylogenetic analysis.

In silico single strand melting curve: a new approach to identify nucleic acid polymorphisms in Totiviridae

BackgroundThe PCR technique and its variations have been increasingly used in the clinical laboratory and recent advances in this field generated new higher resolution techniques based on nucleic acid denaturation dynamics. The principle of these new molecular tools is based on the comparison of melting profiles, after denaturation of a DNA double strand. Until now, the secondary structure of single-stranded nucleic acids has not been exploited to develop identification systems based on PCR. To test the potential of single-strand RNA denaturation as a new alternative to detect specific nucleic acid variations, sequences from viruses of the Totiviridae family were compared using a new in silico melting curve approach. This family comprises double-stranded RNA virus, with a genome constituted by two ORFs, ORF1 and ORF2, which encodes the capsid/RNA binding proteins and an RNA-dependent RNA polymerase (RdRp), respectively.ResultsA phylogenetic tree based on RdRp amino acid sequences was constructed, and eight monophyletic groups were defined. Alignments of RdRp RNA sequences from each group were screened to identify RNA regions with conserved secondary structure. One region in the second half of ORF2 was identified and individually modeled using the RNAfold tool. Afterwards, each DNA or RNA sequence was denatured in silico using the softwares MELTSIM and RNAheat that generate melting curves considering the denaturation of a double stranded DNA and single stranded RNA, respectively. The same groups identified in the RdRp phylogenetic tree were retrieved by a clustering analysis of the melting curves data obtained from RNAheat. Moreover, the same approach was used to successfully discriminate different variants of Trichomonas vaginalis virus, which was not possible by the visual comparison of the double stranded melting curves generated by MELTSIM.ConclusionIn silico analysis indicate that ssRNA melting curves are more informative than dsDNA melting curves. Furthermore, conserved RNA structures may be determined from analysis of individuals that are phylogenetically related, and these regions may be used to support the reconstitution of their phylogenetic groups. These findings are a robust basis for the development of in vitro systems to ssRNA melting curves detection.

Pathogenicity and phenotypic sulfadiazine resistance of Toxoplasma gondii isolates obtained from livestock in northeastern Brazil

Toxoplasma gondii is the causative protozoan agent of toxoplasmosis, which is a common infection that is widely distributed worldwide. Studies revealed stronger clonal strains in North America and Europe and genetic diversity in South American strains. Our study aimed to differentiate the pathogenicity and sulfadiazine resistance of three T. gondiiisolates obtained from livestock intended for human consumption. The cytopathic effects of the T. gondii isolates were evaluated. The pathogenicity was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using a CS3 marker and in a rodent model in vivo. Phenotypic sulfadiazine resistance was measured using a kinetic curve of drug activity in Swiss mice. IgM and IgG were measured by ELISA, and the dihydropteroate synthase (DHPS) gene sequence was analysed. The cytopathic effects and the PCR-RFLP profiles from chickens indicated a different infection source. The Ck3 isolate displayed more cytopathic effects in vitro than the Ck2 and ME49 strains. Additionally, the Ck2 isolate induced a differential humoral immune response compared to ME49. The Ck3 and Pg1 isolates, but not the Ck2 isolate, showed sulfadiazine resistance in the sensitivity assay. We did not find any DHPS gene polymorphisms in the mouse samples. These atypical pathogenicity and sulfadiazine resistance profiles were not previously reported and served as a warning to local health authorities.

An alternative nested-PCR assay for the detection of Toxoplasma gondii strains based on GRA7 gene sequences.

Toxoplasma gondii is a widespread parasite able to infect virtually any nucleated cells of warm-blooded hosts. In some cases, T. gondii detection using already developed PCR primers can be inefficient in routine laboratory tests, especially to detect atypical strains. Here we report a new nested-PCR protocol able to detect virtually all T. gondii isolates. Analyzing 685 sequences available in GenBank, we determine that GRA7 is one of the most conserved genes of T. gondii genome. Based on an alignment of 85 GRA7 sequences new primer sets that anneal in the highly conserved regions of this gene were designed. The new GRA7 nested-PCR assay providing sensitivity and specificity equal to or greater than the gold standard PCR assays for T. gondii detection, that amplify the B1 sequence or the repetitive 529bp element.

Panorama de oportunidades para os egressos do ensino superior no Brasil: o papel da inovação na criação de novos mercados de trabalho

O numero de egressos do ensino superior aumentou de cerca de 480 mil, em 2002, para mais de um milhao, em 2012. O panorama do mercado de trabalho para o profissional formado nas instituicoes de Ensino Superior brasileiras, gerado a partir da consulta a dados publicos no periodo de 2002 a 2012, indica desvalorizacao da mao de obra qualificada, decrescimo no numero de empregos de maior remuneracao, e um deficit de mais de 450 mil empregos de nivel superior. Esses dados deixam claro que o nivel de profissionalizacao dos trabalhadores deve crescer concomitantemente a acoes que permitam o acesso desses profissionais ao mercado de trabalho. Nesse contexto, a importância dos projetos do governo e da universidade sao inquestionaveis, sendo necessario o aprimoramento dos mecanismos de interacao entre universidade, empresa e governo, de forma a viabilizar o sucesso dos programas do governo que ja estao em andamento, e possibilitar o desenvolvimento economico e social.

Direct sequencing of the white spot syndrome virus from Brazil: Genome assembly and new insights on phylogeny

White spot syndrome virus (WSSV) has been the cause of great economic losses in world shrimp farming. In this work the genome of a Brazilian WSSV isolate was determined from direct sequencing of total DNA extracted from an infected whiteleg shrimp, and assembled based on a chimera template approach. Comparisons between WSSV-BR and other isolates revealed that the Brazilian virus has a relatively small genome, and is very similar to isolates from Thailand and Mexico. A phylogenetic relationship using different approaches has demonstrated that these isolates share a common evolutionary history. An analysis of conflicting phylogenetic signals also considering genomes of other isolates revealed that the evolutionary history of WSSV may be related to recombination events. We observed that these events can also be traced at some level by analyzing the homologous regions in the WSSV genome. The existence of recombination events introduces a new point of view that must be considered in the evolutionary history of WSSV.

Chikungunya fever: a threat to global public health

ABSTRACT Chikungunya fever is an emerging arbovirus infection, representing a serious public health problem. Its etiological agent is the Chikungunya virus (CHIKV). Transmission of this virus is mainly vector by mosquitoes of the genus Aedes, although transmission by blood transfusions and vertical transmission has also been reported. The disease presents high morbidity caused mainly by the arthralgia and arthritis generated. Cardiovascular and neurological manifestations have also been reported. The severity of the infection seems to be directly associated with the action of the virus, but also with the decompensation of preexisting comorbidities. Currently, there are no therapeutic products neither vaccines licensed to the infection CHIKV control, although several vaccine candidates are being evaluated and human polyvalent immunoglobulins anti-CHIKV had been tested. Antibodies can protect against the infection, but in sub-neutralizing concentrations can augment virus infection and exacerbate disease severity. So, the prevention still depends on the use of personal protection measures and vector control, which are only minimally effective.

Th17 response in patients with cervical cancer (Review)

Persistent infection by high-risk human papillomavirus (HR-HPV) is the main risk factor for uterine cervical cancer (UCC). However, viral infection alone is not sufficient for the development and progression of premalignant cervical lesions for cancer. In previous years it has been suggested that the adaptive immune response triggered by the differentiation of naïve helper T cells in Th17 cells may serve an important role in disease development. It has been hypothesized that Th17 cells may be involved in the promotion of UCC, as high levels of interleukin 17 (IL17) expression have been detected in the mucosa of the uterine cervix of patients affected by the disease. However, the role of Th17 cells in the tumor development and progression remains unclear. It is believed that the immune response of the Th17 type during persistent infection of the genital tract with HR-HPV triggers chronic inflammation with a long duration with the production of IL17 and other pro-inflammatory cytokines, creating a favorable environment for tumor development. These cytokines are produced by immune system cells in addition to tumor cells and appear to function by modulating the host immune system, resulting in an immunosuppressive response as opposed to inducing an effective protective immune response, thus contributing to the growth and progression of the tumor. In the present review, the latest advances are presented about the function of Th17 cells and the cytokines produced by them in the development and progression of UCC.

A seminested PCR assay for detection and typing of human papillomavirus based on E1 gene sequences

HPV infection is considered one of the leading causes of cervical cancer in the world. To date, more than 180 types of HPV have been described and viral typing is critical for defining the prognosis of cancer. In this work, a seminested PCR which allow fast and inexpensively detection and typing of HPV is presented. The system is based on the amplification of a variable length region within the viral gene E1, using three primers that potentially anneal in all HPV genomes. The amplicons produced in the first step can be identified by high resolution electrophoresis or direct sequencing. The seminested step includes nine specific primers which can be used in multiplex or individual reactions to discriminate the main types of HPV by amplicon size differentiation using agarose electrophoresis, reducing the time spent and cost per analysis.