Molecular and antigenic characterisation of ribosomal phosphoprotein P0 from Babesia bovis

Babesia bovis is a tick-borne pathogen that remains an important constraint for the development of cattle industries in tropical and subtropical regions of the world. Effective control can be achieved by vaccination with live attenuated phenotypes of the parasite. However, these phenotypes have a number of drawbacks, which justifies the search for new, more efficient immunogens based mainly on recombinant protein technology. In the present paper, ribosomal phosphoprotein P0 from a Brazilian isolate of B. bovis was produced and evaluated with regard to conservation and antigenicity. The protein sequence displayed high conservation between different Brazilian isolates of B. bovis and several Apicomplexa parasites such as Theileria, Neospora and Toxoplasma. IgG from cattle experimentally and naturally infected with B. bovisas well as IgG1 and IgG2 from naturally infected cattle reacted with the recombinant protein. IgG from cattle experimentally infected with Babesia bigemina cross-reacted with B. bovis recombinant P0. These characteristics suggest that P0 is a potential antigen for recombinant vaccine preparations against bovine babesiosis.

Immunogencity of HAS-L7/L12 [Brucella abortus ribosomal protein] in an animal model

The immunogenic Brucella abortus ribosomal protein L7/L12 is a promising candidate antigen for the development of subunit vaccines against brucellosis. This study was aimed to evaluate the protection of recombinant Human Serum Albumin [HAS]-L7/L12 fusion protein in Balb/c mice. The amplified L7/L12 gene was cloned in pYHSA5 vector, pYHSA5-L7/L12 construct was transformed in Saccharomyces cerevisiae and the expressed protein from supernatant was purified by affinity chromatography. Balb/c mice were immunized in five groups by tHSA-L7/L12 fusion protein [group 1], Brucella abortus S19 [group 2], HSA [group 3], recombinant L7/L12 [group 4], PBS [group 5]. ELISA to detect antibody production, LTT test to assess antigen specific lymphocyte response were conducted prior to virulent B. abortus strain 544 challenge two weeks after the last injection. Bacterial counts from spleens of immunized mice were done four weeks after challenge. In ELISA tests, the specific antibodies exhibited a dominance of immunoglobulin IgG1 over IgG2a. In addition, the tHSA-L7/L12 fusion protein and L7/L12 elicited a strong T-cell proliferative response upon restimulation in vitro with recombinant tHSA-L7/L12 and L7/L12, suggesting the induction of a cellular immunity response in vivo. However, there was no significant difference in proliferative response of L7/L12 and tHSA-L7/L12 fusion protein [p > 0.05]. The L7/L12 and tHSA-L7/L12 fusion protein vaccines could also induce significant protection against challenge with the virulent strain B. abortus 544 in Balb/c mice [p.0.05]. The tHSA-L7/L12 fusion protein, similar to L7/L12 has the ability to induce antigen specific lymphocyte proliferation, stimulate humoral immunity and engender protection

Trypanosoma cruzi ribosomal protein S4: characterization of its coding locus, analysis of transcripts, and antigenicity of the protein

Two allelic genomic fragments containing ribosomal protein S4 encoding genes (rpS4) from Trypanosoma cruzi (CL-Brener strain) were isolated and characterized. One allele comprises two complete tandem repeats of a sequence encoding an rpS4 gene. In the other, only one rpS4 gene is found. Sequence comparison to the accessed data in the genome project database reveals that our two-copy allele corresponds to a variant haplotype. However, the deduced aminoacid sequence of all the gene copies is identical. The rpS4 transcripts processing sites were determined by comparison of genomic sequences with published cDNA data. The obtained sequence data demonstrates that rpS4 genes are expressed in epimastigotes, amastigotes, and trypomastigotes. A recombinant version of rpS4 was found to be an antigenic: it was recognized by 62.5 percent of the individuals with positive serology for T. cruzi and by 93.3 percent of patients with proven chronic chagasic disease.

Effect of lead on immuno response to ribosomal antigen prepared from E. coli in rabbit

The function of immune system among lead exposure was evaluated in the present study using rabbits as experimental animals. Ribosomal antigen was prepared from E. coli and used as an immunogen. Animals were divided into three groups. Echgroup with 15 animals the first group was drenched with 5 mg/kg of lead acetate. The second group was given 10 mg/kg in triple distilled water for a period of 30 days. The third group served as experimental control. Immunization with the prepared ribosomes mixed with Freund's complete adjuvant was given at two doses. The first dose was injected 30 days after exposure. The second dose was given 15 days thereafter. Cellular and humoral immune responses were evaluated. Lead acetate used in these low doses for this period had little effect on the antibody level and also on the phagocytic activity. On the other hand, the effect was clear on cell-mediated immunity and resulted in a reduction in the number of T lymphocytes involved in this activity

Histo-pathological changes after exposure of rabbit to lead

Rabbits were immunized with ribosomal antigens prepared from E. coli and exposed to lead acetate. The histological picture of immunized animal showed immunological response to ribosomal antigens. Hyperplasia with the appearance of germinal centers was noted in lymph nodes and spleen in addition to infiltration of intestine with mononuclear cells. The pathological changes which appeared as a result of exposure to lead were represented by central venous and sinusoidal congestion in the capillary tuft of glomeruli and also in the vessels between proximal convoluted tubules. While in the brain, there was congestion and edema. It is concluded that the effect of lead on the body persists for long time after stoppage of lead exposure, and produced disturbances in immune system

Comparison of five methods for the detection of antiribosomal P protein antibody

1. We have compared the sensitivity and specificity of immunofluorescence, counterimmunoelectrophoresis, immunodiffusion, Western blotting and ELISA for the detection of antiribosomal P protein antibodies using 153 lupus sera. 2. Western blotting and ELISA were the 2 most sensitive and specific techniques for the detection of these antibodies. In contrast, cytoplasmic immunofluorescence was observed in only one third of the anti-P-positive patients. Immunodiffusion and counterimmunoelectrophoresis, although highly specific, detecting 14 per cent and 29 per cent of all anti-P-positive sera by Western blotting, were the least sensitive tests. 3. The frequency of anti-P in lupus patients, as detected by Western blotting analysis was 18 per cent . The most frequently observed antibody in anti-P sera was anti-Ro/SSA (39 per cent ). Anti-P antibodies were also detected in the sera of 3 patients with negative nuclear immunofluorescence. 4. Anti-P is an additional serological marker for systemic lupus erythematosus and Western blotting is the method of choice for detecting this antibody due to the limited availability of the fusion protein in Brazil

The chronic presence of the parasite, and anti-P autoimmunity in Chagas disease: the Trypanosoma cruzi ribosomal P proteins, and their recognition by the host immune system

Molecular expression cloning techniques revealed that patients with the severest clinical form of Chagas disease, chronic Chagas heart disease, presented a strong humoral response against the cloned C-terminal portion of a Trypanosoma cruzi ribosomal P protein. Parasite P antigens identification led to characterize the ribosomal P protein system in T. cruzi. Their exposed location on the ribosome, and the ®amplification® of their parasite specific, serine free C-terminal domain, generate a strong parasite specific anti-P response, that in certain cases may induce anti-P autoimmunity