Exploratory algorithm to devise multi-epitope subunit vaccine by investigating Leishmania donovani membrane proteins

Visceral leishmaniasis (VL) is a deadly parasitic infection which affects poorest to poor population living in the endemic countries. Increasing resistant to existing drugs, disease burden and a significant number of deaths, necessitates the need for an effective vaccine to prevent the VL infection. This study employed a combinatorial approach to develop a multi-epitope subunit vaccine by exploiting Leishmania donovani membrane proteins. Cytotoxic T- and helper T-lymphocyte binding epitopes along with suitable adjuvant and linkers were joined together in a sequential manner to design the subunit vaccine. The occurrence of B-cell and IFN-γ inducing epitopes approves the ability of subunit vaccine to develop humoral and cell-mediated immune response. Physiochemical parameters of vaccine protein were also assessed followed by homology modeling, model refinement and validation. Moreover, disulfide engineering was performed for the increasing stability of the designed vaccine and molecular dynamics simulation was performed for the comparative stability purposes and to conform the geometric conformations. Further, molecular docking and molecular dynamics simulation study of a mutated and non-mutated subunit vaccine against TLR-4 immune receptor were performed and respective complex stability was determined. In silico cloning ensures the expression of designed vaccine in pET28a(+) expression vector. This study offers a cost-effective and time-saving way to design a novel immunogenic vaccine that could be used to prevent VL infection.

Communicated by Ramaswamy H. Sarma     

Phylogeographical Structure in Mitochondrial DNA of Legume Pod Borer (Maruca vitrata) Population in Tropical Asia and Sub-Saharan Africa

This study was undertaken to assess the genetic diversity and host plant races of M. vitrata population in South and Southeast Asia and sub-Saharan Africa. The cytochrome c oxidase subunit 1 (cox1) gene was used to understand the phylogenetic relationship of geographically different M. vitrata population, but previous studies did not include population from Southeast Asia, the probable center of origin for Maruca, and from east Africa. Extensive sampling was done from different host plant species in target countries. Reference populations from Oceania and Latin America were used. An amplicon of 658 bp was produced by polymerase chain reaction, and 64 haplotypes were identified in 686 M. vitrata individuals. Phylogenetic analysis showed no difference among the M. vitrata population from different host plants. However, the results suggested that M. vitrata has formed two putative subspecies (which cannot be differentiated based on morphological characters) in Asia and sub-Saharan Africa, as indicated by the high pairwise F_ST values (0.44–0.85). The extremely high F_ST values (≥0.93) of Maruca population in Latin America and Oceania compared to Asian and African population seem to indicate a different species. On the continental or larger geographical region basis, the genetic differentiation is significantly correlated with the geographical distance. In addition, two putative species of Maruca, including M. vitrata occur in Australia, Indonesia and Papua New Guinea. The negative Tajima’s D and Fu’s F_S values showed the recent demographic expansion of Maruca population. The haplotype network and Automatic Barcode Gap Discovery analyses confirmed the results of phylogenetic analysis. Thus, this study confirmed the presence of three putative Maruca species, including one in Latin America, one in Oceania (including Indonesia) and M. vitrata in Asia, Africa and Oceania. Hence, the genetic differences in Maruca population should be carefully considered while designing the pest management strategies in different regions.     

EFFECT OF TOURISM ON THE DISTRIBUTION OF LARVAL BLACKFLIES (DIPTERA: SIMULIUM) IN PALNI HILLS OF SOUTH INDIA

The effect of tourism on the distribution of larval blackflies during three different seasons of Palni hills was investigated.Six streams were selected(Kumbakkarai,Moolayar,Kurusedi,Silver cascade Pampar and Guntar) for this study,of which,three streams(Silver cascade Pampar and Guntar) were in peak of Palni hills(Kodaikanal town areas) and easy access to the tourists.The remaining three streams(Kumbakkarai,Moolayar and Kurusedi) were in downhill areas.The physico-chemical and stream parameters analyses indicated that the most tourist accessible site of Silver cas-cade stream had poor water quality and the predominant of larval blackfly population when compared to other sampling streams.The highest population of larval blackflies was observed during winter followed by summer and northeast monsoon.Since the effect of tourism causes pollution to streams,which in turn to promote the population of blackfly larvae and affect the other insect community in streams.       

Modes of cell death in the pupal perivisceral fat body tissue of the silkworm Bombyx mori L.

Cell death is a scheduled event during animal development and tissue turnover. Here, we affirm the presence of two major pathways of programmed cell death (PCD), viz. apoptotic and autophagic cell death, in the disintegrated pupal perivisceral (PV) fat body during pupal-adult metamorphosis. The acridine orange (a vital stain for apoptosis) staining pattern and DNA fragmentation assay have revealed the exact day (6th day of the pupal stage) of disintegration in the PV fat body as represented by chromatin condensation and DNA laddering. Electron microscopy and scanning electron microscopy have demonstrated the presence of cytoplasmic budding and giant autophagic vacuoles and the low numbers of mitochondria, all of which are attributes of autophagic cell death. Immunoblot analysis of proteosomal subunits 20S and 26S has established the involvement of proteolytic activity during PCD of PV tissue. Lysosomal participation during the PCD of PV tissues has been confirmed by the elevated level of the marker enzyme, acid phosphatase, which is distinct on day 6 of the pupal period. The results of the present study have thus ascertained the co-existence of both autophagic and apoptotic cell death in PV fat body tissue.     

Lipophorin transport of hydrocarbon during early vitellogenesis in the silkworm,Bombyx mori

Lipophorin transports the hydrophobic molecule from origin to destination in time specific manner. Here, we investigate the hydrocarbon composition in the lipophorin during day 2 of pupal silkworm, Bombyx mori. Lipophorin was isolated from hemolymph by immunoprecipitation; lipid extracted and analyzed in GC-MS, resulting in seventeen compounds including eight hydrocarbons. Which were searched with the Pherobase (Pheromone database) and functional roles analysed. All hydrocarbons denoted as a pheromone except pentatriacontane in lepidopteron insects. Other hand, hydrocarbons such as hexadecane, nonadecane, undecane and hexacosane specifically refer as an attractant, additionally heptacosane, octacosane and docosane indicate as an allomone in non-lepidopteron insects. As well as, docosane and undecane perform as kairomone. Identified pheromone interaction with lipophorin was analysed by molecular docking and shows the best binding score. All hydrocarbons bound in a lipid binding pocket, most of these sharing the same binding sites for hydrophobic interaction and hydrogen bonding. Overall findings elucidated that lipophorin associated with different hydrocarbons by hydrogen bonds and hydrophobic interactions, and each of the hydrocarbon having various functional roles.     

Antimicrobial Substance Produced by Pseudomonas aeruginosa Isolated from Slaughterhouse Sediment: Physicochemical Characterization,Purification, and Identification

International Journal of Peptide Research and Therapeutics - This study aimed to produce the novel bacteriocin from Pseudomonas aeruginosa 43. The bacteriocin was purified through 80% ammonium...     

Two new black fly species of Simulium (Simulium) (Diptera: Simuliidae) from South India

Two new black fly species, Simulium (Simulium) pothigaiense sp. n. and Simulium (Simulium) valparaiense sp. n., are described based on females, males, pupae and larvae. Simulium (Simulium) pothigaiense sp. n. is characterized by a claw simple without subbasal tooth and the base of radial vein with hair tuft in the females, maxillary palp with small sensory vesicle in the males, pupal gill with 10 short slender filaments and very short common basal stalk in the pupae and 5 hypostomal bristles per side lying parallel to lateral margin in the larvae. Simulium (Simulium) valparaiense sp. n. is characterized by hind basitarsus 6.6 times as long as its greatest width and claw with small distinct subbasal tooth in the females, gonostyle in medial view 2.3 times longer than coxite in the males, common basal stalk of pupal gill 0.31 times as long as interspiracular trunk, and larval thoracic and abdominal cuticle with pair of dorsolateral protuberances. Taxonomic notes are given to distinguish these two new species from closely related species. www.zoobank.org/urn:lsid:zoobank.org:pub:7285F6BC-607D-4F76-B6EE-9CAC67CDE651     

Assessment of bacterial community composition in response to uranium levels in sediment samples of sacred Cauvery River

Applied Microbiology and Biotechnology - Global industrialization is a major cause of effluent discharge from industries up to alarming concentrations. Especially, uranium concentrations in water...     

Effect of RH-2485 on development, metamorphosis and synthesis of major proteins in female silkworm Bombyx mori

Toxicological data on silkworm Bombyx mori are quite comparable to those of other lepidopteran pest insects, therefore, it is considered as a suitable model for exploring effects of any new synthetic formulations. In this study, female V instar larvae of silk moth B. mori were chosen to evaluate the lethal and sublethal toxicity effects of RH-2485 (methoxyfenozide), a non-steroidal ecdysteroid agonist and to substantiate the ecdysteroid mimicking action of RH-2485 on ovary development, vitellogenin incorporation and egg production in isolated pupal abdomen (IPA). Probit analysis was carried out to find the median lethal dose (LD₅₀) from 96 h cumulative mortality percent. Protein profile of haemolymph, fat body, ovary and eggs were separated in SDS-PAGE. Western blot analysis was carried out to confirm vitellogenin in the ovary. Sublethal effects on feeding, cocoon spinning, pupation, adult emergence and egg production were studied at doses of 1/5^th, 1/10^th and 1/20^th of LD₅₀. Significant changes were observed in all these parameters at all three sublethal doses. The morphological effects were related to underlying biochemical changes by finding the changes in haemolymph, fat body, ovary and egg protein profile. Marked changes were observed in storage proteins (80 kDa) and 30 kDa proteins in the haemolymph at all three sublethal doses. The larvae that escaped the sublethal effects at a dose of 1/20 of LD₅₀ and emerged as adults with malformed wings produced significantly lower number of eggs. The isolated pupal abdomen (IPA) treated with RH-2485 did not metamorphose into adult but the oocyte development and vitellogenesis were normal but the egg precursor processing was incomplete leading to failure in choriogenesis.