The development of an effective immune response can help decrease mortality from malaria and its clinical symptoms. However, this mechanism is complex and has significant inter-individual variation, most likely owing to the genetic contribution of the human host. Therefore, this study aimed to investigate the influence of polymorphisms in genes involved in the costimulation of B-lymphocytes in the naturally acquired humoral immune response against proteins of the asexual stage of Plasmodium vivax. A total of 319 individuals living in an area of malaria transmission in the Brazilian Amazon were genotyped for four SNPs in the genes CD40, CD40L, BLYS and CD86. In addition, IgG antibodies against P. vivax apical membrane antigen 1 (PvAMA–1), Duffy binding protein (PvDBP) and merozoite surface protein 1 (PvMSP–119) were detected by ELISA. The SNP BLYS –871C>T was associated with the frequency of IgG responders to PvAMA–1 and PvMSP–119. The SNP CD40 –1C>T was associated with the IgG response against PvDBP, whereas IgG antibody titers against PvMSP–119 were influenced by the polymorphism CD86 +1057G>A. These data may help to elucidate the immunological aspects of vivax malaria and consequently assist in the design of malaria vaccines.

Background Humoral immune responses against proteins of asexual blood-stage malaria parasites have been associated with clinical immunity. However, variations in the antibody-driven responses may be associated with a genetic component of the human host. The objective of the present study was to evaluate the influence of co-stimulatory molecule gene polymorphisms of the immune system on the magnitude of the humoral immune response against a Plasmodium vivax vaccine candidate antigen.MethodsPolymorphisms in the CD28, CTLA4, ICOS, CD40, CD86 and BLYS genes of 178 subjects infected with P. vivax in an endemic area of the Brazilian Amazon were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The levels of IgM, total IgG and IgG subclasses specific for ICB2-5, i.e., the N-terminal portion of P. vivax merozoite surface protein 1 (PvMSP-1), were determined by enzyme-linked immuno assay. The associations between the polymorphisms and the antibody response were assessed by means of logistic regression models.ResultsAfter correcting for multiple testing, the IgG1 levels were significantly higher in individuals recessive for the single nucleotide polymorphism rs3116496 in CD28 (p = 0.00004). Furthermore, the interaction between CD28 rs35593994 and BLYS rs9514828 had an influence on the IgM levels (p = 0.0009).ConclusionsThe results of the present study support the hypothesis that polymorphisms in the genes of co-stimulatory components of the immune system can contribute to a natural antibody-driven response against P. vivax antigens.Electronic supplementary materialThe online version of this article (doi:10.1186/s12936-016-1350-2) contains supplementary material, which is available to authorized users.

The results of this study show that, although the investigated CD40, CD40L and BLYS alleles differ functionally, this variation does not alter the functionality of the molecules in a way that would interfere in susceptibility to the disease. The variants of these genes may influence the clinical course rather than simply increase or decrease susceptibility.

a. MSc -Curso de Medicina Veterinária RESUMO -As Infecções do Trato Urinário (ITUs), ocorrem em aproximadamente 14% dos cães, e estão entre as mais comuns indicações de antibioticoterapia. A etiologia é variável, com maior predomínio de bactérias. Realizamos um levantamento sobre a prevalência de uropatógenos em ITUs de uma população canina, atendida no Hospital Veterinário "Dr. Halim Atique", entre janeiro de 2006 e abril de 2012. Foi realizada a análise de prontuário para coleta de dados dos animais. Dos 358 avaliados, em 44,72% as culturas foram positivas ao crescimento de microrganismos. Quanto ao isolamento, a frequência de Escherichia coli foi de 37,64%; Staphylococcus spp. de 19,66%, entre outros. O maior isolamento bacteriano foi descrito na faixa etária acima de 84 meses, sendo a mais prevalente entre machos (n=37) e fêmeas (n=50). Essa faixa etária também foi estatisticamente significante tanto para a presença de infecção urinária em animais Sem Raça Definida (p=0,009). Houve uma maior resistência da Escherichia coli para Clindamicina (100%); Staphylococcus spp a Ampicilina (82,14%). Os resultados obtidos apontam para a importância do diagnóstico laboratorial com definição do agente etiológico, e assim para realização de melhores condutas terapêuticas. Palavras-chave:Cães, Infecção do Trato Urinário, Escherichia coli.ABSTRACT -Urinary tract infections (ITUs), occur in approximately 14% of dogs, and are among the most common indications for antibiotictherapy. ITUs have variable etiology, with a higher prevalence of bacteria. The aim of this study was to estimate the prevalence of uropathogens in ITUs in a canine population, assisted at the Veterinary Hospital "Dr. Halim Atique", between January 2006 and April 2012. The analysis was performed based on paper and electronic records, such as gender, age and race of affected animals. Later, a test for susceptibility to antimicrobial agents and description of etiologic agents was performed. Of the 358 evaluated (44.72 %) cultures were positive for the growth of microorganisms. In relation to the insulation, the frequency of Escherichia coli was 37.64 %; Staphylococcus spp. of 19.66 % among others. The largest bacterial isolation was described in the age group above 84 months, being the most prevalent among males (n= 37) and female (n= 50), the age group above 84 months was also statistically significant for both the presence of urinary infection in animals Breed (p=0.009). There was a higher resistance of Escherichia coli to Clindamycin (100 %), Staphylococcus spp to Ampicillin (82.14 %). The results point to the importance of laboratory diagnostic to definition of the etiologic agent, and thus for the realization of better therapeutic approaches.