Identification of L10e/L12e ribosomal protein genes in Babesia bovis

Molecular screening of piroplasms and Anaplasmataceae agents in Hyalomma dromedarii ticks from camels over different seasons in Egypt

Piroplasmosis, a disease of domestic and wild animals, is caused by tick-borne protozoa of the genera Babesia and Theileria, while anaplasmosis is caused by tick-borne bacteria of genera Anaplasma. Hyalomma dromedarii is the most dominant tick species infesting camels in Egypt and act as a vector of piroplasms, Anaplasma, Rickettsia and Ehrlichia spp. The available information concerning the detection of these pathogens in H. dromedarii infesting camels is limited. The present study aimed to evaluate the status of these pathogens in H. dromedarii ticks over four seasons of a year, in addition to investigate the infections of piroplasms and Anaplasmataceae besides their genetic diversity starting from June 2021 till April 2022. A total of 275 semi-engorged females of H. dromedarii were collected from different slaughtered camels, Toukh city slaughterhouse then investigated by Polymerase Chain Reaction (PCR) to detect piroplasms (Babesia spp., Theileria spp.) and Anaplasmataceae DNA targeting 18 S rRNA and 16 S rRNA genes, respectively followed by sequencing and phylogenetic analyses. Overall, piroplasms were detected in 38 ticks (13.8%), Babesia spp. was detected in 35 ticks (12.7%), while Theileria spp. was detected in one tick (0.4%). Anaplasmataceae was detected in 57 ticks (20.7%). Mixed infections of piroplasms and Anaplasmataceae were detected in 13 ticks (5%). Single infection either with piroplasms or Anaplasmataceae was detected in 25 (9%) and 44 (16%) ticks, respectively. The highest monthly rate of piroplasms was in April (spring) and Anaplasmataceae was in July (summer). Sequence analysis revealed that Babesia bigemina, Wolbachia spp. and Anaplasma marginale are the most dominant species in the examined tick samples. To the best of our knowledge, this study confirms the presence of B. bigemina, Wolbachia spp. and A. marginale in H. dromedarii in Egypt by sequencing.

Evaluation of DNA encoding acidic ribosomal protein P2 of Cryptosporidium parvum as a potential vaccine candidate for cryptosporidiosis

The Cryptosporidium parvum acidic ribosomal protein P2 (CpP2) is an important immunodominant marker in C. parvum infection. In this study, the CpP2 antigen was evaluated as a vaccine candidate using a DNA vaccine model in adult C57BL/6 IL-12 knockout (KO) mice, which are susceptible to C. parvum infection. Our data show that subcutaneous immunization in the ear with DNA encoding CpP2 (CpP2-DNA) cloned into the pUMVC4b vector induced a significant anti-CpP2 IgG antibody response that was predominantly of the IgG1 isotype. Compared to control KO mice immunized with plasmid alone, CpP2-immunized mice demonstrated specific in vitro spleen cell proliferation as well as enhanced IFN-γ production to recombinant CpP2. Further, parasite loads in CpP2 DNA-immunized mice were compared to control mice challenged with C. parvum oocysts. Although a trend in reduction of infection was observed in the CpP2 DNA-immunized mice, differences between groups were not statistically significant. These results suggest that a DNA vaccine encoding the C. parvum P2 antigen is able to provide an effective means of eliciting humoral and cellular responses and has the potential to generate protective immunity against C. parvum infection but may require using alternative vectors or adjuvant to generate a more potent and balanced response.

Cloning and characterization of the acidic ribosomal protein P2 of Cryptosporidium parvum, a new 17-kilodalton antigen

Cryptosporidium infection is commonly observed among children and immunocompromised individuals in developing countries, but large-scale outbreaks of disease among adults have not been reported. In contrast, outbreaks of cryptosporidiosis in the United States and Canada are increasingly common among patients of all ages. Thus, it seems likely that residents of regions where Cryptosporidium is highly endemic acquire some level of immunity, while residents of the developed world do not. A new immunodominant Cryptosporidium parvum antigen in the 15- to 17-kDa size range was identified as the Cryptosporidium parvum 60S acidic ribosomal protein P2 (CpP2). We developed a recombinant protein-based enzyme-linked immunosorbent assay for serologic population surveillance for antibodies that was 89% sensitive and 92% specific relative to the results of the large-format Western blot assay. The human IgG response is directed almost exclusively toward the highly conserved, carboxy-terminal 15 amino acids of the protein. Although IgG antibody cross-reactivity was documented with sera from patients with acute babesiosis, the development of an anti-CpP2 antibody response in our Peru study population correlated better with Cryptosporidium infection than with infection by any other parasitic protozoan. In Haiti, the prevalence of antibodies to CpP2 plateaus at 11 to 20 years of age. Because anti-CpP2 IgG antibodies were found only among residents of countries in the developing world where Cryptosporidium infection occurs early and often, we propose that this response may be a proxy for the intensity of infection and for acquired immunity.

Cloning and sequence analysis of a cDNA encoding bovine ribosomal protein P2: predicted alpha-helices and potential phosphorylation sites

A cDNA corresponding to bovine acidic ribosomal P2 was cloned and sequenced. It encodes a polypeptide 115 amino acids long. The secondary structure prediction shows that bovine P2 contains a large part of the protein domain as alpha helices. Alignment and analysis of 16 eukaryotic P2 proteins of 12 species reveal that there are three predicted alpha-helical regions conserved in almost all P2 proteins; helix 1 and helix 2 may be part of a helix-turn-helix structure. Sequence analysis indicates that there are seven serine residues in bovine P2 protein which are potential phosphorylation sites for a variety of Ser/Thr kinases. A few such sites appear at similar positions in many P2 proteins. The antigenic region is predicted to be located in the stretch of acidic amino acids in the vicinity of the C-terminus of P2. The predicted alpha-helical structures, potential phosphorylation sites and antigenic regions of the P2 protein provide some insights into the structure of P2 protein and deserve further experimental study.

Characterization of a maize ribosomal P2 protein cDNA and phylogenetic analysis of the P1/P2 family of ribosomal proteins

The nucleotide sequence of a full-length ribosomal P2 protein cDNA from maize was determined and used for a sequence comparison with the P2 and P1 proteins from other organisms. The integration of these data into a phylogenetic tree shows that the P proteins separated into the subspecies P1 and P2 before the eukaryotic kingdoms including plants developed from their ancestor.

During active viscerocutaneous leishmaniasis the anti-P2 humoral response is specifically triggered by the parasite P proteins

In this work we show that in the sera from dogs naturally infected with the protozoan parasite Leishmania infantum there are antibodies that react specifically against the parasite acidic ribosomal proteins LiP2a and LiP2b, and that each one of the Leishmania P proteins elicits a specific humoral immune response. Using synthetic peptides, the antigenic epitope of these proteins has been mapped in a single region located adjacent to the C-terminal domain highly conserved among the eukaryotic P proteins. The anti-P antibodies elicited during the Leishmania infection do not recognize the conserved C-terminal domain of the parasite P proteins, in contrast with the findings reported in Chagas' disease or systemic lupus erythematosus. The antigenic epitopes of the LiP2a and LiP2b are almost identical in amino acid sequence. No reactivity against Trypanosoma cruzi and human P proteins was found in sera from L. infantum-infected dogs.

The Trypanosoma cruzi ribosomal P protein family: Classification and antigenicity

The multi-copy ribosomal P proteins have been identified on the ribosomes of prokaryotic and eukaryotic cells, and their antigenicity is an important feature of human Trypanosoma cruzi infection. In this review, Mariano Levin, Martin Vazquez, Dan Kaplan and Alejandro Schijman give a rational basis for the classification of these proteins, and discuss their inter-relationship.

Molecular variation and diversity in candidate vaccine antigens from Babesia

Recombinant vaccines are being developed against a number of species of protozoan parasites in the genus Babesia. Protozoan parasites are notorious for their diversity of strains and their ability to express families of equivalent, but antigenically distinct, surface proteins. In order to reduce the likelihood of evasion of the immune response induced by a recombinant vaccine, ideal components should be essential proteins encoded by single copy genes. The proteins should also have a limited ability to tolerate polymorphism in amino acid sequence, especially in critical epitopes. While little is known about the function of the candidate protective antigens, there is now considerable information concerning the variation of a number of candidate vaccine antigens from several species of Babesia. Four of the well studied antigens are all members of multi-gene families. The members of the VMSA gene family of Babesia bovis are also highly polymorphic in sequence. The members of the Bv60/p58 family of rhoptry protein homologues exhibit more limited polymorphism within a single species of Babesia. However, comparison of the sequences of the equivalent proteins and the organisation of the corresponding genes from B. bovis, Babesia bigemina, Babesia canis and Babesia ovis suggests that members of this family have the potential to acquire and to tolerate substantial polymorphism in amino acid sequence. The choice of protein, and particular region of the protein, suitable for incorporation in a recombinant vaccine may require extensive analysis of the genetic systems encoding the candidate antigens.