Proposed method for agglutinating antibody titer analysis and its use as indicator of acquired immunity in pacu, Piaractus mesopotamicus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Acquired resistance of horses to Amblyomma cajennense (Fabricius, 1787) ticks

Acquired immunity of horses to larvae, nymphs and adults of the Amblyomma cajennense tick was evaluated through three consecutive experimental infestations of tick-bite naive hosts. Data from these infestations were compared to those from field-sensitized horses and donkeys. It was observed that tick-bite naive horses developed a low level of resistance after two infestations as shown by a significant decrease in larval yield and a tendency for lower engorged weight of nymphs during third infestation. Ticks fed on field-sensitized horses had a similar biological performance to that observed on the third infestation of tick-bite naive horses but the mean engorged nymph weight was significantly lower than that of the first infestation from tick-bite naive horses. Donkeys presented the strongest resistance with significantly lower engorged weights of all instars and of the egg mass compared to the first infestation of tick-bite naive horses. Donkeys also displayed a significantly higher resistance than field-sensitized horses as demonstrated by significantly lower egg mass weights. Overall these results indicate that donkeys but not horses maintain a strong resistance to A. cajennense ticks. The importance of these findings in relation to vectoring of tick-borne diseases is discussed. (C) 2003 Elsevier B.V. All rights reserved.

Humoral immune response of water buffalo monitored with three different antigens of Toxocara vitulorum

Humoral immune response of water buffalo naturally infected with Toxocara vitulorum was monitored using three different antigens of this parasite in serum and colostrum of buffalo cows and calves. Soluble extract (Ex) and excretory/secretory (ES) larval antigens and perienteric fluid antigen (Pe) of adult T vitulorum were used to measure the antibody levels by an indirect ELISA. Serum of 7-12 buffalo cows for the first 365 days and colostrum of the same number of buffalo cows for the first 60 days of parturition, and serum of 8-10 buffalo calves for the first 365 days afterbirth were assayed. The ELISA detected antibodies against all three T vitulorum antigens in the colostrum and serum of 100% of buffalo cows and calves examined. The highest antibody levels against Ex, ES and Pe antigens were detected in the buffalo cow sera during the perinatal period and were maintained at high levels through 300 days after parturition. on the other hand, colostrum antibody concentrations of all three antigens were highest on the first day post-parturition, but decreased sharply during the first 15 days. Concomitantly to the monitoring of immune response, the parasitic status of the calves was also evaluated. In calves, antibodies passively acquired were at the highest concentrations 24 h after birth and remained at high levels until 45 days coincidentally with the peak of T vitulorum infection. The rejection of the worms by the calves occurred simultaneously with the decline of antibody levels, which reached their lowest levels between 76 and 150 days. Thereafter, probably because of the presence of adults/larvae stimulation, the calves acquired active immunity and the antibodies started to increase slightly in the serum and plateaued between the days 211 and 365. All three antigens were detected by the serum antibodies of buffalo calves; however, the concentration of anti-Pe antibody was higher than anti-EX and anti-ES, particularly after 90 days of age. By conclusion, the buffalo cows develop immunity and keep high levels of antibodies against T vitulorum-Ex, ES and Pe antigens and these antibodies are transferred to their calves through the colostrum. This passively acquired immunity does not protect the calves against the acquisition of the infection, but these antibodies, passively or actively acquired, may have an important role during worm rejection by the calves and prevention of intestinal reinfection. (C) 2004 Elsevier B.V. All rights reserved.

Antigen-presenting cells in draining lymph nodes of goats repeatedly infested by the Cayenne tick Amblyomma cajennense nymphs

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Resposta imune-humoral de búfalos (Bubalus bubalis) contra Anaplasma marginale (Theiler, 1910)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização e validação de anticorpo monoclonal murino anti-Linfócitos B humanos para uso em citometria de fluxo e imunoquímica

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Imunomodulação por levamisol na imunidade inata e adquirida de pacu (Piaractus mesopotamicus)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparação da resistência natural a endoparasitas e ectoparasitas em bovinos das raças Criola Lageana e Angus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Resposta imune-humoral de búfalos (Bubalus bubalis) infectados naturalmente por Babesia bovis, B. bigemina e Anaplasma marginale

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Modulation of cell proliferation, survival and gene expression by RAGE and TLR signaling in cells of the innate and adaptive immune response: role of p38 MAPK and NF-KB

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Immunity in plants and animals: common ends through different means using similar tools

A comparative approach is potentially useful for understanding the role of mammal innate immunity role in stimulating adaptive immunity as well as the relationship between these two types of immune strategies. Considerable progress has been made in the elucidation of the co-ordinated events involved in plant perception of infection and their mobilisation of defence responses. Although lacking immunoglobulin molecules, circulating cells, and phagocytic processes, plants successfully use pre-formed physical and chemical innate defences, as well as inducible adaptive immune strategies. In the present paper, we review some shared and divergent immune aspects present in both animals and plants. (C) 2002 Elsevier B.V. All rights reserved.

Paracoccidioidomycosis associated with acquired immunodificiency syndrome: report of seven cases

São apresentadas as características clínicas e evolutivas de sete pacientes (cinco masculinos e dois do sexo feminino), a maioria dos quais usuários de drogas ilícitas endovenosa, com paracoccidioidomicose associada à Síndrome da Imunodeficiência Adquirida (SIDA/AIDS). em quatro pacientes a paracoccidioidomicose comprometia os pulmões isoladamente, nos demais a doença era generalizada com envolvimento cutâneo. Apenas dois pacientes eram procedentes recentes da zona rural. O que nos faz presumir que nos demais a paracoccidioidomicose doença resultou da reativação de focos latentes da infecção. Dado o papel da imunidade medida por células na defesa do hospedeiro contra o Paracoccidioides brasiliensis, é de se prever crescente ocorrência da associação paracoccidioidomicose -SIDA/AIDS nas áreas endêmicas para ambas as enfermidades.

Lack of acquired resistance in dogs to successive infestations of Rhipicephalus sanguineus ticks from Brazil and Argentina

Comparative studies between brown dog tick Rhipicephalus sanguineus populations from Brazil (Jaboticabal, São Paulo) and Argentina (Rafaela, Santa Fé) showed significant biological, morphological and genetic differences between them. This work aimed to study, in a comparative way, the acquisition of resistance in domestic dogs to R. sanguineus from Jaboticabal and Rafaela, after successive and controlled infestations. Ticks were kept in a BOD incubator under controlled conditions (27 °C, 80 % relative humidity, 12-h photoperiod). Ten dogs, Dachshund breed, males and females, 6 months old, short- or long-haired, without prior contact with ticks, were used as hosts. They were distributed into two experimental groups composed of five animals each: G1 infested with ten adult couples of R. sanguineus (Jaboticabal) per animal, and G2 infested with ten adult couples of R. sanguineus (Rafaela) per animal. Ticks' biological parameters and titration of antibodies from the dogs' sera by ELISA test were used for comparison between the strains. Results of the biological parameters showed that the dogs did not acquire immunity to either of the R. sanguineus strains after repeated infestations. The ELISA test showed low antibody titers in sera of dogs from G2, in successive infestations, and higher antibody responses post second and third infestations in G1. It also demonstrated cross-reactivity between sera of dogs infested with R. sanguineus (Jaboticabal) and antigens from R. sanguineus (Rafaela) and vice versa. We conclude that Dachshund dogs did not develop resistance against neither Jaboticabal nor Rafaela strains of R. sanguineus.

Hemolytic activity of alternative complement pathway as an indicator of innate immunity in pacu (Piaractus mesopotamicus)

The objective of this study was to evaluate the methodology to establish the hemolytic activity of alternative complement pathway as an indicator of the innate immunity in Brazilian fish pacu (Piaractus mesopotamicus), in addition to verifying the influence of β-glucan as an immunostimulant. Fish were fed with diets containing 0, 0.1 and 1% β-glucan, during seven days, and then inoculated with Aeromonas hydrophila. Seven days after the challenge, they were bled for serum extraction. The methodology consisted of a kinetic assay that allows calculating the required time for serum proteins of the complement to promote 50% lysis of a rabbit red blood cell suspension. The method developed in mammals was successfully applied for pacu and determined that the hemolytic activity of the proteins of the complement system (alternative pathway) increased after the pathogen challenge, but was not influenced by the β-glucan treatment.

Passive immunity transfer and serum constituents of crossbred calves

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)