Gelatin Zymography of Major Proteases in Exosomes of Leishmania major Promastigotes.

Background: Enzymatic digestion of extra cellular matrix proteins by proteinases of Leishmania promastigotes is a complex process. Hence, studies on functional proteomics of these enzymes can help select these enzymes as possible vaccine candidates or selecting candidates for chemotherapy and immunotherapy. Several proteolytic enzymes are involved in virulence of Leishmania spp. These enzymes are mostly serine, cysteine and metalloproteases. We aimed to detect proteases in Leishmania promastigote exosomes. Methods: Serine, cysteine and metalloproteases were investigated in exosomes and lysate of L. major promastigote using gelatin zymography. The study was carried out in the Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran, in 2021. Results: Zymography findings of metalloproteinases showed transparent bands, including a 63-kDa glycoprotein (GP63). This glycoprotein is a major surface metalloproteinase. In addition, transparent bands belonged to serin proteases and cathepsin were demonstrated in gels associated to Leishmania promastigote lysate and exosomes. Conclusion: Several metalloproteases, serin proteases and cathepsins were shown in promastigote lysate and exosomes of L. major, which could purified and used as fractions for immunodiagnostic.

Rational Design of a Hybrid Peptide against Severe Acute Respiratory Syndrome Coronavirus 2 Using Melittin and Angiotensin-Converting Enzyme 2 as Pharmaceutical Agents.

Background: Management of severe acute respiratory syndrome coronavirus 2 in humans depends on the availability of vaccines or effective drugs. Studies have shown that angiotensin-converting enzyme 2 (ACE2) is responsible for binding the viral spike glycoproteins to human cells. Melittin from the bee venom of Apis melifera is a peptide with antimicrobial activities. Materials and Methods: In this study, important amino acid residues of ACE2 interacting with spike glycoproteins of the virus were described based on the ACE2-spike-glycoprotein interface. This has been previously analyzed by Robson in crystal structures of the receptors and ligands. Flexible linkers and 31 amino acid residues from N-terminal of ACE2 as coronavirus spike binding domains (SBDs) were added to 17 N-terminal amino acids of melittin (the hydrophobic motif) to construct a hybrid peptide or M-ACE2SBD. Then, secondary and tertiary structures of the peptide were predicted. Results: Docking of the hybrid peptide and coronavirus SBDs was carried out as well. Previous studies showed that toxicity and hemolytic activity of the melittin hydrophobic motif decreased in comparison to native melittin due to the lack of peptide binding to the exposed anionic lipids of the human cell membranes and hence the novel peptide can be recommended as an appropriate drug for clinical uses. Conclusion: This study has hypothesized that 17 N-terminal amino acids of the mutant melittin used in M-ACE2SBD design are potentially hydrophobic and attached coronavirus-2 through lipid envelope of the virus.

Designing of RNA Molecule Translating for Activitable Melittin as Selective Targeting of Leishmania Infected Cells.

BACKGROUND: Leishmaniasis is characterized by strong inflammatory responses with high levels of inflammatory cytokines that induce microRNA 21 and matrix metalloproteinases. Melittin has inhibitory effects on proliferation of various cells via induction of apoptosis. Melittin can be integrated in cell membranes and induce apoptosis. Thus, designation of biomolecules for the selective destroy of the infected cells is a treatment option. One approach is the precise engineering of constructs for the selective expression of melittin in the infected cells. METHODS: For this aim we designed a construct composing melittin nucleotide sequence and nucleotide sequence coding for polyanionic peptide function inhibitory element to further guarantee the selective function of melittin in inflamed tissues and infected cells, were included in a construct as melittin inhibitor via matrix metalloproteinase degradable linker. RESULTS: Reverse complementary sequences were designed so melittin sequences for the selective targeting of Leishmania could be expressed in infected cells using cell microRNA machinery. CONCLUSION: Translation machinery in infected cells with increased miR-21 could translate melittin, MMP linker and polyanionic inhibitor through a non-canonical pathway. Then, the MMP linker is degraded and selective killing of Leishmania infected cells would happen.

Introducing a new anti-Rhipicephalus (Boophilus) microplus tick recombinant vaccine candidate using cathepsin and tropomyosin multi-epitope gene.

Rhipicephalus (Boophilus) spp. are important vectors for Babesia and Anaplasma species causing severe economic losses in livestock. Chemical compounds are commonly used to control tick infestation; however, acaricides resistance in tick has led to move toward alternative strategies such as vaccination. In this study, we introduced a vaccine candidate, namely CaTro against Rh. microplus tick composing of immunogenic B-cell epitopes derived from Rh. microplus cathepsin L and tropomyosin proteins. To evaluate this vaccine candidate, firstly the CaTro sequence was inserted into the prokaryotic expression vector and the recombinant protein CaTro was expressed in Bl21 bacteria. Afterward, purification was performed by Ni-NTA affinity chromatography. The quality of purified recombinant CaTro was also analyzed using sodium dodecyl sulfate-gel electrophoresis and western blotting. Moreover, to evaluate the induction of immune response, the rabbits were immunized with purified recombinant protein combined with Freund's adjuvant. The findings of this study revealed molecular weight of expressed protein (CaTro) as 38.00 kDa. Furthermore, anti-CaTro antibody was detected in immunized rabbit's sera through dot blotting; while, there was not any response to the control rabbit's sera. The results suggest that CaTro is a potential candidate to develop an anti- Rh. microplus tick.

Molecular Epidemiology and Phylogeny of Crimean-Congo Haemorrhagic Fever (CCHF) Virus of Ixodid Ticks in Khorasan Razavi Province of Iran.

BACKGROUND: Crimean-Congo hemorrhagic fever (CCHF) is a fatal disease caused by Nairovirus classified within the Bunyaviridae family. The virus is transmitted to humans through the bites of infected ticks or direct contact with viremic animals or humans. The current study aimed to detect the virus genome in ticks from Khorasan Razavi Province. METHODS: One hundred hard ticks were collected randomly from 100 sheep in four different areas of the province. Collected ticks were kept alive and identified. All the ticks were analyzed for the presence of CCHF virus genome using reverse transcriptase polymerase chain reactions (RT-PCR). RESULTS: The identified ticks were belonging to Hyalomma marginatum (16% female and 6% male), Rhipicephalus turanicus (52% female and 25% male), and Dermacentor raskemensis (1%). The CCHF virus genome was found in Hyalomma marginatum (5% male from Taibad and Sabzevar region and 1% female from Taibad). Genetic analysis of the virus genome isolated from two regions (Sabzevar and Taibad) showed 100% identity. CONCLUSION: This study indicated that CCHF should be regarded as a risk-borne infection in this province. Therefore, special health management is needed to control this disease.

Morphometric Analysis of the Intestine in Experimental Coccidiosis in Broilers Treated with Anticoccidial Drugs.

BACKGROUND: Coccidiosis causes morphologic alteration in intestinal mucosa resulting in reduction of absorptive surface. Anticoccidials used as feed additives may induce changes in the intestinal mucosa. This study was designed to assess intestinal morphometry in broilers infected with Eimeria under different anticoccidial treatments. METHODS: To evaluate the effect of salinomycin and amprolium+ethopabate on intestinal morphometry in broilers experimental coccidiosis, in Tehran, Iran in May 2015, fifty-four Ross 308 birds were randomly divided into two challenged and unchallenged groups at the age of 12 days. The birds were challenged with Eimeria field isolate at day 14. Different growth and parasitological parameters including weight gain, feed consumption, FCR, macroscopic lesion score and oocyst score were recorded 7 d post-inoculation. Histological sections from four main parts of intestine (anterior, middle, lower intestines and cecum) were prepared and analyzed. Villus width and length and total mucosal thickness were measured microscopically. RESULTS: Amprolium+ethopabate and salinomycin significantly reduced coccidiosis gross lesions in infected birds. Microscopically anticoccidial administration in the presence of infection has significantly increased the villus length while the presence of amprolium+ethopabate in the absence of infection has greatly increased the mucosal thickness and villi height in comparison to the control group. CONCLUSION: Anticoccidials may induce some histological changes in the mucosa when there is no parasite to be affected. Some of these effects may be advantageous for the intestinal epithelium integrity and hence the birds' performance.

Molecular and morphological description of Isospora sp. from the common mynah (Acridotheres tristis) and a preliminary survey of two anticoccidial drugs in natural infection.

Coccidian parasites, especially Isospora, are prevalent parasites in Passeriformes. Isosporan oocysts from common mynahs (Acridotheres tristis) are incompletely described. Detailed knowledge on biology, prevalence, pathogenesis and treatment of avian isosporiasis is scant. In this study, isosporan oocysts isolated from common mynahs were morphologically and molecularly characterized. The medication efficiencies of diclazuril and sulfadiazine-trimethoprim in isosporiasis in naturally infected mynahs were evaluated. Isosporan oocysts from common mynahs were described morphologically by microscopic imaging. The 18S rRNA and COI genes were amplified using PCR and the resultant products were sequenced and analysed phylogenetically. To evaluate the efficiencies of diclazuril and sulfadiazine-trimethoprim, two experimental treatment groups and a null control were assigned. General health status, weight and oocysts per gram of faeces were evaluated. Oocysts from all birds contained isosporan oocysts that were morphologically and dimensionally similar (P < 0.05). The oocysts were spherical; with no oocyst residuum, micropyle or polar granules. At both loci, phylogenetic analyses placed the Isospora isolate in the same clade with Isospora spp. from other Passeriformes. Both of the anticoccidials were well tolerated by the birds, a rapid reduction in oocyst excretion was noted at the commencement of treatment and 72 h after drug administration, oocyst excretion zeroed in all treated birds. Based on morphological and molecular data, this isolate does not resemble any previously described isosporas, hence Isospora tristum n. sp. is proposed for the current species. Both evaluated anticoccidials seemed to be efficient in reduction of oocyst production and can be recommended for the treatment of mynah isosporiasis.

The first comprehensive molecular detection of six honey bee viruses in Iran in 2015-2016.

At least 18 viruses have been reported in the honey bee (Apis mellifera L.). However, severe diseases in honey bees are mainly caused by six viruses, and these are the most important in beekeeping. These viruses include: deformed wing virus (DWV), acute bee paralysis virus (ABPV), chronic bee paralysis virus (CBPV), sacbrood virus (SBV), kashmir bee virus (KBV), and black queen cell virus (BQCV). In this study, we evaluated 89 Iranian honey bee apiaries (during the period 2015-2016) suffering from symptoms of depopulation, sudden collapse, paralysis, or dark coloring, by employing reverse transcription-PCR. Samples were collected from four regions (Mazandaran, Hormozgan, Kurdistan, and Khorasan Razavi) of Iran. Of the 89 apiaries examined, 16 (17.97%), three (3.37%), and three (3.37%) were infected by DWV, ABPV, and CBPV, respectively. The study results for the other viruses (SBV, KBV, and BQCV) were negative. The present study evaluated the presence of the six most important honey bee viruses in bee colonies with suspected infections, and identified remarkable differences in the distribution patterns of the viruses in different geographic regions of Iran.

Transmission of Leishmania infantum by Rhipicephalus sanguineus (Acari: Ixodidae) in Dogs.

BACKGROUND: Rhipicephalus sanguineus is the most widely distributed tick in the world, which is partly due to its biological flexibility and the global distribution of its major host, the domestic dog. In Mediterranean region it could be principal reservoir host for Leishmania infantum, usually transmitted by the phlebotomine sand flies. In this study, we evaluated the vector potential of R. sanguineus in transmitting L. infantum to uninfected dogs. METHODS: During 2014, five dogs with clinical manifestations of canine visceral leishmaniasis (CVL), high anti-Leishmania antibody titers and tick infestation, were selected from CVL endemic areas (Tehran and Alborz provinces). At least, twenty live ticks were removed from each infected dog. After morphological identification, the ticks were divided into two groups; ticks belonging to the first group were dissected for parasitological examinations and semi-nested PCR assay, and those of the second group were selected for the transmission of CVL caused by L. infantum to uninfected dogs. Following tick infestation, all uninfected dogs were kept for 9 months and examined monthly for clinical and serological tests. RESULTS: Nearly, 67% of ticks were infected by L. infantum using the semi-nested PCR. All other parasitological tests of ticks were negative. Clinical examinations and serological tests of the investigated dogs revealed negative results. Nested-PCR test results performed on splenic biopsy samples of dogs were also negative. CONCLUSION: L. infantum-positive R. sanguineus ticks were unable to transfer L. infantum from infected dogs to healthy ones. The detection of L. infantum DNA in ticks collected from naturally infected dogs by semi-nested PCR does not prove their vectorial competence.

Molecular identification and phylogenetic analysis of chronic bee paralysis virus in Iran.

Chronic bee paralysis virus (CBPV) is an unclassified polymorphic single-stranded RNA virus. Among the viruses infecting honeybees, CBPV is known to induce significant losses in honeybee colonies. In this study, a total number of eighty-nine suspected apiaries from four regions of Iran (including Mazandaran, Khorasan Razavi, Hormozgan, and Kurdistan) were sampled and submitted for molecular identification. Three positive samples were detected by RT-PCR. All positive samples were confirmed by sequencing. The phylogenetic tree which displays the molecular relationship between the viruses of different Iranian geographic regions and references isolates was constructed. The Iranian isolates formed two distinct phylogenetic groups (Group 1 and Group 2). The IR-CPV-GMG-1, IR-CPV-GMG-2, IR-CPV-GMG-4, and IR-CPV-GMG-6 formed Group 1 and IR-CPV-GMG-3, IR-CPV-GMG-5, and IR-CPV-GMG-7 were in Group 2 as a distinct group. Iranian isolates in group 1 were similar to European and East Asian CBPVs. This research was the first phylogenetic analysis of CBPV in Iran. Further researches are needed to study the other aspects of this virus-like genetic characteristics and pathogenesis in Iran.

Immunization of Cattle with Tick Salivary Gland Extracts.

BACKGROUND: Rhipicephalus (Boophilus) annulatus tick is one of the most important ectoparasite of cattle. Recently, several laboratories in the world have been concentrated on immunizing cattle against tick using various types of tissue extracts of ticks. The aim of this study was to evaluate the effect of immunization of cattle with tick salivary gland extract on biological parameters of ticks and humoral immune responses of cattle. METHODS: Fourteen more dominant protein bands identified as immunogenic by Western-blot analysis were eluted from polyacrylamide gel. Test and control groups were injected three times with eluted proteins and sterile PBS (pH= 7.2) respectively with equivalent amount of adjuvant. After four weeks a tick challenge was performed. Finally, biological parameters of collected engorged female ticks were recorded and humoral immune responses to immunization measured by ELISA. RESULTS: The results indicated immunization of cattle resulted in reduction in mean tick counts, attachment, engorgement weights, feeding index, egg mass weight, hatchability and fertility index (respectively 63.1%, 62.6%, 30.2%, 36.4%, 40%, 78.7% and 13.3%) and increased duration of feeding, preoviposition and incubation period of eggs (respectively 8.6%, 45 and 31.34%). All changes were statistically significant (P< 0.05). Results showed an increase in antibody production of test group from the first week after immunization. The antibody level was boosted following tick infestation. CONCLUSION: This investigation indicates that immunization of cattle with these antigens could induce a protective immune response against Rh. (B.) annulatus tick that would be expected to provide a safe non-chemical means of tick control.

Designing and modeling of complex DNA vaccine based on tropomyosin protein of Boophilus genus tick.

Boophilus tick is a bloodsucking ectoparasite that transfers some pathogens, reducing production and thus leading to economical losses in the cattle industry. Tropomyosin (TPM) protein is a salivary protein, has actin regulator activity, and plays an important role in immune reactions against parasites. In the current study, besides developing a safe, effective, and broad spectrum protective measure against Boophilus genus tick based on TPM protein, we attempted to minimize possible problems occurring in the design of polytopic vaccines. Briefly, the steps that were followed in the present study were as follows: retrieving sequences and finding the mutational/conservative regions, selecting consensus and high immunogenic epitopes of B and CD4(+) T cells by different approaches, three-dimensional structure (3D structure) prediction and representation of epitopes and highly variable/conserve regions, designing vaccinal construct by fusion of B and T cell epitopes by special patterns and improving immunogenicity, evaluation of the constructs' primary structure and posttranslational modification, calculation of hydrophobic regions, reverse translation, codon optimization, open reading frame checking, insertion of start/end codon, Kozak sequence, and finally constructing the DNA vaccine. Variation plot showed some shared epitopes among the ticks' and mites' species that some might be effective only in some species. Finally, by following the steps mentioned above, two constructs for B and T cells were achieved. Checking constructs revealed their reliability and efficacy for in vitro production and utilization. Successful in silico modeling is an essential step of designing vigorous vaccines. We developed a novel protective and therapeutic vaccine against Boophilus genus (based on TPM protein). At the next step, constructed DNA vaccine would be produced in vitro and administrated to cattle, and its potency to induction of immune response and protection against Boophilus genus as well as other ticks and mites will be evaluated.

Assessment and partial purification of serine protease inhibitors from Rhipicephalus (Boophilus) annulatus larvae.

Ticks are rich sources of serine protease inhibitors, particularly those that prevent blood clotting and inflammatory responses during blood feeding. The tick Rhipicephalus (Boophlus) annulatus is an important ectoparasite of cattle. The aims of this study were to characterize and purify the serine protease inhibitors present in R. (B.) annulatus larval extract. The inhibitors were characterized by means of one and two-dimensional reverse zymography, and purified using affinity chromatography on a trypsin-Sepharose column. The analysis on one and two-dimensional reverse zymography of the larval extract showed trypsin inhibitory activity at between 13 and 40 kDa. Through non-reducing SDS-PAGE and reverse zymography for proteins purified by trypsin-Sepharose affinity chromatography, some protein bands with molecular weights between 13 and 34 kDa were detected. Western blotting showed that five protein bands at 48, 70, 110, 130 and 250 kDa reacted positively with immune serum, whereas there was no positive reaction in the range of 13-40 kDa. Serine protease inhibitors from R. (B.) annulatus have anti-trypsin activity similar to inhibitors belonging to several other hard tick species, thus suggesting that these proteins may be useful as targets in anti-tick vaccines.

Assessment and partial purification of serine protease inhibitors from Rhipicephalus (Boophilus) annulatus larvae / Avaliação e purificação parcial dos inibidores da serina protease de larvas do Rhipicephalus (Boophilus) annulatus

Ticks are rich sources of serine protease inhibitors, particularly those that prevent blood clotting and inflammatory responses during blood feeding. The tick Rhipicephalus (Boophlus) annulatus is an important ectoparasite of cattle. The aims of this study were to characterize and purify the serine protease inhibitors present in R. (B.) annulatus larval extract. The inhibitors were characterized by means of one and two-dimensional reverse zymography, and purified using affinity chromatography on a trypsin-Sepharose column. The analysis on one and two-dimensional reverse zymography of the larval extract showed trypsin inhibitory activity at between 13 and 40 kDa. Through non-reducing SDS-PAGE and reverse zymography for proteins purified by trypsin-Sepharose affinity chromatography, some protein bands with molecular weights between 13 and 34 kDa were detected. Western blotting showed that five protein bands at 48, 70, 110, 130 and 250 kDa reacted positively with immune serum, whereas there was no positive reaction in the range of 13-40 kDa. Serine protease inhibitors from R. (B.) annulatus have anti-trypsin activity similar to inhibitors belonging to several other hard tick species, thus suggesting that these proteins may be useful as targets in anti-tick vaccines.

Carrapatos são uma rica fonte de inibidores da serina protease, particularmente aqueles que previnem coagulação e respostas inflamatórias durante a alimentação com sangue. O carrapato Rhipicephalus (B.) annulatus é um ectoparasita importante de bovinos. O objetivo deste estudo foi caracterizar e purificar os inibidores da serina protease presentes no extrato de larva do R. (B.) annulatus. Os inibidores foram caracterizados através de zimografia reversa uni e bidimensional e purificados com cromatografia de afinidade em uma coluna de sepharose-tripsina. A análise do extrato de larva pela zimografia reversa uni e bidimensional mostrou atividade inibitória de tripsina entre 13 e 40 kDa. Através de SDS-PAGE e zimografia reversa para proteínas purificadas pela cromatografia por sepharose-tripsina, algumas bandas de proteínas com pesos moleculares entre 13 e 34 kDa foram detectadas. Western blotting mostrou que cinco bandas de proteínas a 48, 70, 110, 130 e 250 kDa reagiram positivamente com o soro imune, enquanto não houve reação positiva nas bandas 13-40 kDa. Inibidores da serina protease do R. (B.) annulatus têm atividade antitripsina semelhante àquelas dos inibidores de outras espécies de carrapatos duros, sugerindo, assim, que essas proteínas podem ser úteis como alvo de vacinas contra carrapatos.

Sarcoptic mange of gazelle (Gazella subguttarosa) and its medical importance in Iran.

Sarcoptes scabiei infestation was diagnosed in four freshly dead and three net-captured gazelle while ranging freely. The captured animals presented with an alopecic pruritic skin disease with signs of crusted skin lesions, numerous small nodules which first appeared on the lips or nostrils and then it also extended towards the eyelids, around the ears, and, in some cases, over entire face, neck, trunk, and legs. Skin over the affected area gradually became bald, thick and hard, being dry and doughy to the touch, and serous fluid or sometimes blood oozes from the lesions which had a severe malodor. Skin scrapings confirmed the presence of the mite S. scabiei. Histopathology of lesions demonstrated marked acanthosis, hyperkeratosis, and parakeratosis. Microscopical examination also revealed all stages of S. scabiei, which were located mainly in the stratum corneum and also in the stratum granulosum. During the capture and sampling of the animals, four persons ranging in age from 25 to 62 years were exposed to scabies. Two relatives of one of them have been also affected by familiar contact. Clinical signs appeared within 9 days of exposure. They developed several pruretic erythematous papules with intense itching.

Status of Haemaphysalis tick infestation in domestic ruminants in Iran.

The geographical distribution and ecological preferences of Haemaphysalis in domestic animals in Iran were studied 4 times a year from April 2003 to March 2005. A total of 1,622 ixodid tick specimens were collected from 3 different zones. Among them, 108 (6.7%) Haemaphysalis ticks, consisting of 6 species, were identified; H. punctata (3.4%), H. parva (0.5%), H. sulcata (0.6%), H. choldokovskyi (1.7%), H. concinna (0.06%) and Haemaphysalis sp. (0.6%). H. punctata was the most abundant species, whereas H. concinna was the rarest species collected in humid and sub-humid zones on cattle, sheep and goats. H. choldokovskyi was principally collected from sheep and goats grazed in cold mountainous areas. The infested areas consisted of Caspian Sea (Guilan, Mazandaran, Golestan, and central provinces), mountainous (Azarbaiejan, Ardebil, Kohgilouyeh, and Kordestan) and semi-dessert (Khorasan, Semnan, Kerman, Sistan, and Baluchestan) zones. The Caspian Sea zone (23.6%) was the most highly infested region. The results show that various species of Haemaphysalis ticks infest domestic ruminants in Iran and each tick species show characteristic geographical distributions.