Oral Vaccination with Hepatitis E Virus Capsid Protein and Immunobiotic Bacterium-Like Particles Induce Intestinal and Systemic Immunity in Mice.

The hepatitis E virus (HEV) genotype 3 (GT3) is an emergent pathogen in industrialized countries. It is transmitted zoonotically and may lead to chronic hepatitis in immunocompromised individuals. We evaluated if the major antigen of HEV, the capsid protein, can be used in combination with immunobiotic bacterium-like particles (IBLP) for oral vaccination in a mouse model. We have cloned and expressed the RGS-His5-tagged HEV GT3 capsid protein (ORF2) in E. coli and purified it by NiNTA. IBLP were obtained from two immunobiotic Lactobacillus rhamnosus strains acid- and heat-treated. ORF2 and the IBLP were orally administered to Balb/c mice. After three oral immunizations (14-day intervals), blood, intestinal fluid, Peyer´s patches, and spleen samples were drawn. IgA- and IgG-specific antibodies were determined by ELISA. Mononuclear cell populations from Peyer's patches and spleen were analyzed by flow cytometry, and the cytokine profiles were determined by ELISA to study cellular immunity. Orally administered recombinant ORF2 and IBLP from two L. rhamnosus strains (CRL1505 and IBL027) induced both antigen-specific humoral and cellular immune responses in mice. IBLP027 was more effective in inducing specific secretory IgA in the gut. IFN-γ, TNF-α, and IL-4 were produced by Peyer's plaques lymphocytes stimulated with ORF2 ex vivo suggesting a mixed Th1/Th2-type adaptive immune response in immunized mice. Oral vaccines are not invasive, do not need to be administered by specialized personal, and elicit both systemic and local immune responses at the port of entry. Here, we present an experimental oral vaccine for HEV GT3, which could be further developed for human and/or veterinary use.

Occurrence of TRGV-BJ hybrid gene in SV40-transformed fibroblast cell lines.

Illegitimate V(D)J-recombination in lymphoid malignancies involves rearrangements in immunoglobulin or T-cell receptor genes, and these rearrangements may play a role in oncogenic events. High frequencies of TRGV-BJ hybrid gene (rearrangement between the TRB and TRG loci at 7q35 and 7p14-15, respectively) have been detected in lymphocytes from patients with ataxia telangiectasia (AT), and also in patients with lymphoid malignancies. Although the TRGV-BJ gene has been described only in T-lymphocytes, we previously detected the presence of TRGV-BJ hybrid gene in the genomic DNA extracted from SV40-transformed AT5BIVA fibroblasts from an AT patient. Aiming to determine whether the AT phenotype or the SV40 transformation could be responsible for the production of the hybrid gene by illegitimate V(D)J-recombination, DNA samples were extracted from primary and SV40-transformed (normal and AT) cell lines, following Nested-PCR with TRGV- and TRBJ-specific primers. The hybrid gene was only detected in SV40-transformed fibroblasts (AT-5BIVA and MRC-5). Sequence alignment of the cloned PCR products using the BLAST program confirmed that the fragments corresponded to the TRGV-BJ hybrid gene. The present results indicate that the rearrangement can be produced in nonlymphoid cells, probably as a consequence of the genomic instability caused by the SV40-transformation, and independently of ATM gene mutation.

Cytogenetic and molecular biomonitoring of agricultural workers exposed to pesticides in Brazil.

The use of agricultural chemicals without correct protection may lead to alterations in the genetic material of cells and the possible development of several types of tumors. The individual genetic variability in the enzymes which metabolize agricultural chemicals is also involved in this process, such as when the enzymes are not efficient in the detoxifying process of the organism, the metabolic subproducts accumulate, contributing to the tumorigenic process. Cytogenetic monitoring was carried out on a group of 20 male workers occupationally exposed to a mixture of pesticides in the town of São Jerônimo da Serra, PR (Brazil). Student's t = test and Wilcoxon's test showed, respectively, that there was no significant difference between the chromosome aberration frequencies between the exposed and control groups and between the paired individuals. However, there was a significant difference in the two analyses regarding the mitotic index of the sampled individuals. Smoking and time of exposure to agricultural chemicals did not influence the cytogenetic responses obtained, but the mitotic index of the control individuals was higher than that of the exposed individuals from the different age groups. The GSTM1 gene polymorphism was 33% null. When statistical tests were carried out to assess the relationship of the GSTM1 genotypes with the chromosome aberrations and mitotic indexes, there was no significant difference. The CA frequencies found in this study were low, making it difficult to associate it with the GSTM1 gene polymorphism. Teratogenesis Carcinog. Mutagen. 20:161-170, 2000.