In silico analysis for development of epitopes-based peptide vaccine against Alkhurma hemorrhagic fever virus

Abstract

Alkhurma hemorrhagic fever virus (ALKV) causes a fatal clinical disease in human beings of different tropical and sub-tropical regions. Recently, the ALKV epidemics have raised a great public health concern with the room for improvement in the essential therapeutic interventions. Despite increased realistic clinical cases of ALKV infection, the efficient vaccine or immunotherapy is not yet available to-date. Therefore, the current study aimed to analyze the envelope glycoprotein of ALKV for the development of B-cells and T-cells epitope-based peptide vaccine using the computational in silico method. Utilizing various immunoinformatics approaches, a total of 5 B-cells and 25 T-cells (MHC-I?=?17, MHC-II?=?8) epitope-based peptides were predicted in the current study. All predicted peptides had highest antigenicity and immunogenicity scores along with high binding affinity to human leukocyte antigen (HLA) class II alleles. Among 25T-cell epitopes, three peptides were found alike to have affinity to bind both MHC-I and MHC-II alleles. These outcomes suggested that these predicted epitopes could potentially be used in the development of an efficient vaccine against ALKV, which may enable to elicit both humoral and cell-mediated immunity. Although, these predicted peptides could be useful in designing a candidate vaccine for the prevention of ALKV; however, it’s in vitro and in vivo assessments are prerequisite.

Communicated by Ramaswamy H. Sarma     

Oral immunisation of wild boar against classical swine fever in Baden-Württemberg: development of the seroprevalences based on the hunting bag

Oral immunisation of wild boar against classical swine fever (CSF) in the German federal state of Baden-Württemberg has been evaluated on the basis of the seroprevalence rates after application of an improved immunisation procedure consisting of three double vaccinations per year (in spring, summer and autumn). The seroprevalence in the vaccination area increased continuously until the third immunisation campaign (72.4% seropositive animals). Later, a decrease of the seroprevalence rates was detected, especially in young boars. Although in the infected area the seroprevalences were higher, in principle, the same trend could be found in the surveillance zone. The development of the monthly seroprevalence rates of young boars during the first year of their life showed that the new immunisation procedure had a positive effect on their immunisation rate. Fifty percent and more of the wild boar shot at the age of 6–12 months were antibody positive. Neutralising antibody titre levels were the same in young boars (on average 812 ND₅₀) and in sub-adults (on average 997 ND₅₀). Individual antibody positive animals may be detected for more than 2 years after completion of the vaccination programme.     

Lessons of Aedes aegypti control in Thailand

Abstract. The incidence of dengue haemorrhagic fever (DHF) in Thailand has increased cyclically since the first recognized outbreak in 1958. Without an effective vaccine against dengue, and considering the clinical difficulty of treating DHF cases, vector control is needed to prevent dengue transmission. Since the establishment of the WHO Aedes Research Unit in 1964, continued since 1973 as the WHO Collaborating Centre at the Department of Medical Research in Bangkok, much operational research has been carried out in Thailand on the bionomics and control of dengue vectors: Aedes aegypti and Ae.albopictus. This review shows that, as in most other countries, dengue vector control programmes in Thailand make little use of the procedures arising from research, nor have they reduced the upward trend of dengue or prevented DHF outbreaks. Implications of the reluctance to use results of operational research on vector control are considered and remedial suggestions made.     

Experimental Argentine hemorrhagic fever: myocardial involvement in Cebus monkey

Four Cebus apella monkeys, to test a recently proposed model for testing neurovirulence of Junín virus (JV) strains, were intracerebrally infected with 10(5) LD50 of the XJ clone 3 strain of JV. There were no significant electrocardiographic abnormalities or gross lesions, but all infected monkeys exhibited a varying degree of histologic myocardial lesions including focal lymphoblastic infiltrates, vascular ruptures, and mild interstitial reactive change. One Cebus showed lymphocytic infiltrates in the caudal portion of the A-V node without specific cell involvement. These preliminary results demonstrate cardiac involvement in experimental infection of the Cebus monkey with Junín virus.     

Plant species from Brazilian Caatinga: a control alternative for Aedes aegypti

The mosquito Aedes aegypti is the main vector for the virus dengue, chikungunya and Zika. For its control, it is essential to search for natural products with insecticidal effects. The climatic singularity of Caatinga, an exclusive Brazilian biome, aids the survival of plants that produce secondary metabolites, which could be toxic to insects. Therefore, this review discusses the insecticidal potential of Caatinga plants on Aedes aegypti mosquitoes. The meta-analysis was performed using Review Manager Software 5.4.1®. Several studies have demonstrated the insecticidal efficacy of Caatinga plants on the egg, larvae, pupae and adult phases of Ae. aegypti, with a predominance of the plant activity in the larval stage. The leaves were the most utilized part of the plant. The essential oils from Caatinga plants were significantly active against Ae. aegypti (RR = 0.21, 95 % CI = 0.07 – 0.68, p = 0.009). The most promising botanical genera as an insecticide are: Abarema, Myracrodruon, Croton, Lippia and Syagrus. Among chemical compounds from these insecticidal plants has been identified and isolated flavonoids and fatty acids. Therefore, the Caatinga plant is a promising plant that contain bioactive compounds that are useful in the control of vector insects. This could contribute to the characterisation and valorisation of flora of this biome, as well as the production of environmentally friendly insecticides with specific action on target insects.     

Rhipicephalus rossicus,a neglected tick at the margin of Europe: a review of its distribution,ecology and medical importance

Rhipicephalus rossicus (Ixodida: Ixodidae) is a three‐host tick with a broad host spectrum that includes wild animals, pets, livestock and humans. Despite its local abundance in certain areas, most of the available information on R. rossicus was published decades ago, mainly by former soviet authors. Its distribution largely overlaps the Eurasian steppe. However, its range may be more extensive than is currently known because this species may have been misidentified as Rhipicephalus sanguineus, principally in areas where the latter species is present. Although R. rossicus has been occasionally reported to feed on people, little attention has been given to its medical importance. It has been shown to have a vectorial role in the transmission of Francisella tularensis, Crimean–Congo haemorrhagic fever virus and West Nile virus. However, the vectorial importance of R. rossicus may be significantly greater, mainly as the closely related species R. sanguineus s.l. is known to transmit a very wide spectrum of pathogens. The probably underestimated vectorial role of R. rossicus may represent a hidden public health threat.     

A mathematical model for Crimean-Congo haemorrhagic fever: tick-borne dynamics with conferred host immunity

Crimean-Congo haemorrhagic fever (CCHF) is a highly contagious tick-borne disease that impacts many countries in parts of Africa, Europe, Asia, and the Middle East. Outbreaks are episodic, but deadly. Due to the highly contagious nature of this disease, suspected cases are taken extremely serious, with very strong control measures implemented almost immediately. It is primarily those living on farms, livestock workers, and medical workers who are at risk. The virus responsible for CCHF is transmitted asymptomatically and transiently to livestock, and symptomatically to humans. The fatality rate in human cases can be very high. The number of methods and directions of viral transmission is large, including tick-to-tick, tick-to-livestock, tick-to-human, livestock-to-tick, livestock-to-human, and human-to-human. We model CCHF using a deterministic system of nonlinear differential equations. This compartment model allows us to analyse threshold parameters and equilibria describing the magnitude and progression of cases of the disease in a hypothetical outbreak.     

Association study involving polymorphisms in IL-6, IL-1RA,and CTLA4 genes and rheumatic heart disease in New Zealand population of Māori and Pacific ancestry

IntroductionRheumatic fever (RF) incidence among New Zealand (NZ) individuals of Polynesian (Māori and Pacific) ancestry remains among the highest in the world. Polymorphisms in the IL-6, IL1RN, and CTLA4 genes have been associated with RF, and their products are modulated by new medications. Confirmation of these previous associations could help guide clinical approaches. We aimed to test IL-6, IL-1RA (IL1RN), and CTLA4 functional SNPs in 204 rheumatic heart disease (RHD) patients and 116 controls of Māori and Pacific ancestry.Material and methodSelf-reported ancestry of the eight great-grandparents defined ancestry of participants. Severity of carditis was classified according to the 2012 World Heart Federation guideline for the echocardiographic diagnosis of RHD. The IL-6 promoter rs1800797, IL1RN rs447713 and CTLA4 rs3087243 SNPs were genotyped by Taqman. Correlations were assessed by logistic regression analysis adjusting for gender and ancestry.ResultsThe IL-6 rs1800797 variant was significantly associated with RHD with carriers of the GG genotype 6.09 (CI 1.23; 30.23) times more likely to develop RHD than the carriers of the AA genotype (P = 0.027). No significant associations with RHD were found for the IL1RN rs447713 and CTLA4 rs3087243 SNPs. Patients carrying the G allele (GG plus AG genotype) for the IL1RN rs447713 SNP had 2.36 times (CI 1.00; 5.56) more severe carditis than those without this allele (the AA genotype) (P = 0.049).ConclusionThe IL-6 promoter rs1800797 (−597G/A) SNP may influence susceptibility to RHD of people of Māori and Pacific ancestry living in NZ. The IL1RN rs447713 SNP may influence the severity of carditis in this population.     

Differentiation of Coxiella burnetii by Sequence Analysis of the Gene (com1) Encoding a 27-kDa Outer Membrane Protein

The gene (com1) encoding a 27-kDa outer membrane protein in 21 strains of Coxiella burnetii from a variety of clinical and geographical sources was sequenced for strain differentiation. The com1 gene was highly conserved among all the strains tested but there were several differences in nucleotide and deduced amino acid sequences. Based on the com1 gene-specific nucleotides and deduced amino acids, the 21 strains were divided into four groups. Group 1 contained 14 strains originating from ticks, cattle and human cases of acute Q fever. Groups 2 and 3 included 2 and 3 strains, respectively, originating from human cases of chronic Q fever. Group 4 contained 2 strains originating from a human case of acute Q fever and a goat with abortion. The results indicated that the strains originating from ticks, cattle and human cases of acute Q fever differed at the molecular level from those of human chronic Q fever. This study suggests that a sequence analysis of the com1 gene can be used for strain differentiation of C. burnetii.