Several domains from VAR2CSA can induce Plasmodium falciparum adhesion-blocking antibodies

<p>Abstract</p> <p>Background</p> <p>Malaria caused by <it>Plasmodium falciparum </it>can result in several different syndromes with severe clinical consequences for the about 200 million individuals infected each year. During pregnancy, women living in endemic areas become susceptible to malaria due to lack of antibodies against a unique <it>P. falciparum </it>membrane protein, named VAR2CSA. This antigen is not expressed in childhood infections, since it binds chondroitin sulphate A (CSA) expressed on the intervillous space in the placenta. A vaccine appears possible because women acquire protective antibodies hindering sequestration in the placenta as a function of parity. A challenge for vaccine development is to design small constructs of this large antigen, which can induce broadly protective antibodies. It has previously been shown that one domain of VAR2CSA, DBL4-FCR3, induces parasite adhesion-blocking antibodies. In this study, it is demonstrated that other domains of VAR2CSA also can induce antibodies with inhibitory activity.</p> <p>Methods</p> <p>All VAR2CSA domains from the 3D7 and HB3 parasites were produced in <it>Baculovirus</it>-transfected insect cells. Groups of three rats per protein were immunized and anti-sera were tested for surface reactivity against infected erythrocytes expressing FCR3 VAR2CSA and for the ability to inhibit FCR3CSA parasite adhesion to CSA. The fine specificity of the immune sera was analysed by VAR2CSA peptide arrays.</p> <p>Results</p> <p>Inhibitory antibodies were induced by immunization with DBL3-HB3 T1 and DBL1-3D7. However, unlike the previously characterised DBL4-FCR3 response the inhibitory response against DBL1-3D7 and DBL3-HB3 T1 was poorly reproduced in the second rounds of immunizations.</p> <p>Conclusion</p> <p>It is possible to induce parasite adhesion-blocking antibodies when immunizing with a number of different VAR2CSA domains. This indicates that the CSA binding site in VAR2CSA is comprised of epitopes from different domains.</p

Multiple var2csa-Type PfEMP1 Genes Located at Different Chromosomal Loci Occur in Many Plasmodium falciparum Isolates

BACKGROUND:The var2csa gene encodes a Plasmodium falciparum adhesion receptor which binds chondroitin sulfate A (CSA). This var gene is more conserved than other PfEMP1/var genes and is found in all P. falciparum isolates. In isolates 3D7, FCR3/It4 and HB3, var2csa is transcribed from a sub-telomeric position on the left arm of chromosome 12, but it is not known if this location is conserved in all parasites. Genome sequencing indicates that the var2csa gene is duplicated in HB3, but whether this is true in natural populations is uncertain. METHODOLOGY/PRINCIPAL FINDINGS:To assess global variation in the VAR2CSA protein, sequence variation in the DBL2X region of var2csa genes in 54 P.falciparum samples was analyzed. Chromosome mapping of var2csa loci was carried out and a quantitative PCR assay was developed to estimate the number of var2csa genes in P.falciparum isolates from the placenta of pregnant women and from the peripheral circulation of other malaria patients. Sequence analysis, gene mapping and copy number quantitation in P.falciparum isolates indicate that there are at least two loci and that both var2csa-like genes can be transcribed. All VAR2CSA DBL2X domains fall into one of two distinct phylogenetic groups possessing one or the other variant of a large (approximately 26 amino acid) dimorphic motif, but whether either motif variant is linked to a specific locus is not known. CONCLUSIONS/SIGNIFICANCE:Two or more related but distinct var2csa-type PfEMP1/var genes exist in many P. falciparum isolates. One gene is on chromosome 12 but additional var2csa-type genes are on different chromosomes in different isolates. Multiplicity of var2csa genes appears more common in infected placentae than in samples from non-pregnant donors indicating a possible advantage of this genotype in pregnancy associated malaria

Antibodies to a Full-Length VAR2CSA Immunogen Are Broadly Strain-Transcendent but Do Not Cross-Inhibit Different Placental-Type Parasite Isolates

The high molecular weight, multidomain VAR2CSA protein mediating adhesion of Plasmodium falciparum-infected erythrocytes in the placenta is the leading candidate for a pregnancy malaria vaccine. However, it has been difficult so far to generate strong and consistent adhesion blocking antibody responses against most single-domain VAR2CSA immunogens. Recent advances in expression of the full-length recombinant protein showed it binds with much greater specificity and affinity to chondroitin sulphate A (CSA) than individual VAR2CSA domains. This raises the possibility that a specific CSA binding pocket(s) is formed in the full length antigen and could be an important target for vaccine development. In this study, we compared the immunogenicity of a full-length VAR2CSA recombinant protein containing all six Duffy binding-like (DBL) domains to that of a three-domain construct (DBL4-6) in mice and rabbits. Animals immunized with either immunogen acquired antibodies reacting with several VAR2CSA individual domains by ELISA, but antibody responses against the highly conserved DBL4 domain were weaker in animals immunized with full-length DBL1-6 recombinant protein compared to DBL4-6 recombinant protein. Both immunogens induced cross-reactive antibodies to several heterologous CSA-binding parasite lines expressing different VAR2CSA orthologues. However, antibodies that inhibited adhesion of parasites to CSA were only elicited in rabbits immunized with full-length immunogen and inhibition was restricted to the homologous CSA-binding parasite. These findings demonstrate that partial and full-length VAR2CSA immunogens induce cross-reactive antibodies, but inhibitory antibody responses to full-length immunogen were highly allele-specific and variable between animal species

Transcriptome Analysis Describing New Immunity and Defense Genes in Peripheral Blood Mononuclear Cells of Rheumatoid Arthritis Patients

Background: Large-scale gene expression profiling of peripheral blood mononuclear cells from Rheumatoid Arthritis (RA) patients could provide a molecular description that reflects the contribution of diverse cellular responses associated with this disease. The aim of our study was to identify peripheral blood gene expression profiles for RA patients, using Illumina technology, to gain insights into RA molecular mechanisms. Methodology/Principal Findings: The Illumina Human-6v2 Expression BeadChips were used for a complete genome-wide transcript profiling of peripheral blood mononuclear cells (PBMCs) from 18 RA patients and 15 controls. Differential analysis per gene was performed with one-way analysis of variance (ANOVA) and P values were adjusted to control the False Discovery Rate (FDR < 5%). Genes differentially expressed at significant level between patients and controls were analyzed using Gene Ontology (GO) in the PANTHER database to identify biological processes. A differentially expression of 339 Reference Sequence genes (238 down-regulated and 101 up-regulated) between the two groups was observed. We identified a remarkably elevated expression of a spectrum of genes involved in Immunity and Defense in PBMCs of RA patients compared to controls. This result is confirmed by GO analysis, suggesting that these genes could be activated systemically in RA. No significant down-regulated ontology groups were found. Microarray data were validated by real time PCR in a set of nine genes showing a high degree of correlation. Conclusions/Significance: Our study highlighted several new genes that could contribute in the identification of innovative clinical biomarkers for diagnostic procedures and therapeutic interventions

Avaliação da qualidade de vida com o instrumento SF-36 em lombalgia crônica

OBJETIVO: Avaliar a qualidade de vida através dos domínios do Instrumento SF-36 em portadores de lombalgia crônica inespecífica. MÉTODOS: Trinta portadores de lombalgia crônica inespecífica foram aleatorizados para três grupos (grupo Iso (Isostretching), grupo RPG (Reeducação Postural Global) e Iso+RPG), e avaliados quanto à dor e qualidade de vida antes e após as intervenções fisioterápicas e reavaliados novamente após 2 meses de acompanhamento. Após a aceitação do Termo de Consentimento Livre e Esclarecido os pacientes foram submetidos a procedimentos como: avaliação fisioterápica através do Instrumento de Avaliação da Coluna Vertebral, Escala Visual Analógica de Dor (EVA), Questionário de Qualidade de Vida através do Instrumento SF-36, antes da 1ª sessão e após três meses de tratamento, e reavaliados 2 meses após o tratamento. RESULTADOS: Mostraram que ambas as técnicas fisioterápicas diminuíram a dor (p<0,001), porém quando foram associadas as duas técnicas (Iso + RPG) a melhora da dor foi significativamente maior, e na avaliação após dois meses de acompanhamento o método de RPG foi mais eficaz. Quanto à avaliação da qualidade de vida, as técnicas fisioterápicas foram eficazes após as intervenções (P<0,001), porém o método do Iso foi mais eficaz quando os pacientes foram reavaliados no acompanhamento. CONCLUSÃO: As técnicas fisioterápicas utilizadas neste estudo foram eficazes para tratar a lombalgia crônica inespecífica apresentada pelos pacientes, pois diminuíram a algia que os mesmos apresentavam e melhoraram a qualidade de vida segundo os domínios do Instrumento SF-36. Nível de Evidência II, Ensaio Clínico Controlado e Randomizado. ____________________________________________________________________________________ ABSTRACTThe objective of this study was to evaluate the quality of life (QL) with the use of the SF-36 Questionnaire in patients with chronic nonspecific low back pain (CNLBP). Thirty patients with CNLBP were randomly assigned to one of three groups (Iso group (Isostretching), GPR group (Global Postural Reeducation), and the Iso+GPR group. Patients underwent physical therapy assessment with the use of the Vertebral Spine Assessment, the Visual Analog Scale of Pain (VASP), and the SF-36 life quality questionnaire before the first session (first assessment), after three months of treatment (second assessment) and reassessed two months after the final session in the follow-up (third assessment). The results indicated that both physical therapy techniques reduced pain (p<0.001); when the techniques (Iso+GPR) were combined, the reduction in pain was significantly greater; and, in the follow-up assessment, the GPR method was more efficient. As for the QL, physical therapy techniques were effective after the interventions (p<0.001), and the Iso method was more effective when patients were reassessed in the follow-up. We conclude that the physical therapy techniques used in this study were efficient to treat CNLBP in the patients since they reduced pain and increased QL according to the results of the SF-36 questionnaire. Level of Evidence II, Randomized Controlled Clinical Trial

Reproductive biology of the pampas deer (Ozotoceros bezoarticus): a review

The pampas deer (Ozotoceros bezoarticus) is a South American grazing deer which is in extreme danger of extinction. Very little is known about the biology of the pampas deer. Moreover, most information has not been published in peer-reviewed scientific journals, and is only available in local publications, theses, etc. Therefore, our aim was to update and summarize the available information regarding the reproductive biology of the pampas deer. Moreover, in most sections, we have also included new, unpublished information. Detailed descriptions are provided of the anatomy of both the female and the male reproductive tract, puberty onset, the oestrous cycle and gestational length. Birthing and the early postpartum period are described, as are maternal behaviour and early fawn development, seasonal distribution of births, seasonal changes in male reproduction and antler cycle, reproductive behaviour, semen collection, and cryopreservation. Finally, an overview is given and future directions of research are proposed