Innate immune recognition of flagellin limits systemic persistence of Brucella

Brucella are facultative intracellular bacteria that cause chronic infections by limiting innate immune recognition. It is currently unknown whether Brucella FliC flagellin, the monomeric subunit of flagellar filament, is sensed by the host during infection. Here, we used two mutants of Brucella melitensis, either lacking or overexpressing flagellin, to show that FliC hinders bacterial replication in vivo. The use of cells and mice genetically deficient for different components of inflammasomes suggested that FliC was a target of the cytosolic innate immune receptor NLRC4 in vivo but not in macrophages in vitro where the response to FliC was nevertheless dependent on the cytosolic adaptor ASC, therefore suggesting a new pathway of cytosolic flagellin sensing. However, our work also suggested that the lack of TLR5 activity of Brucella flagellin and the regulation of its synthesis and/or delivery into host cells are both part of the stealthy strategy of Brucella towards the innate immune system. Nevertheless, as a flagellin‐deficient mutant of B. melitensis wasfound to cause histologically demonstrable injuries in the spleen of infected mice, we suggested that recognition of FliC plays a role in the immunological stand‐off between Brucella and its host, which is characterized by a persistent infection with limited inflammatory pathology.     

Roadmap to determine the point mutations involved in cardiomyopathy disorder: A Bayesian approach

Determining the deleterious non-synonymous single nucleotide polymorphisms (nsSNPs), that might be involved in inducing disease-associated phenomena, is now among the most important field of computational genomic research. The rapid evolution in sequencing technologies has now outranged the limit of available sequence databases and has out-fledged the amount of SNP data that are yet to be characterized. In this article we have performed a comprehensive analysis of deleterious nsSNPs in MyH7 gene associated with cardiomyopathy cases using a set of computational platforms. We implemented a set of computational SNP analysis platforms along with the Bayesian calculations in order to filter the most likely mutation that might be associated with cardiomyopathy associated disorders. The Bayesian calculation depicted 27 fold rises in the likelihood score for causing cardiomyopathy disorder when MyH7 gene mutations were compiled. Furthermore, we reported E466Q mutation in MyH7 motor domain that showed increase in the amyloid propensity of protein, as well as a significant level of pathogenicity was also observed. The prediction roadmap followed in this article has showed a notable range of accuracy and can be used for determining cardiomyopathy associated nsSNPs for other candidate genes.     

Comparative analysis of serum zinc,copper, magnesium,calcium and iron level in acute and chronic patients of visceral leishmaniasis

ProjectChronic visceral leishmaniasis (VL) is an increasingly common problem in disease endemic states of India. Identification of prognosis risk factor in patients with VL may lead to preventive actions, toward decreasing its mortality in chronic individuals. Though serum Zinc levels are decreased in patients of VL, limited information is available regarding trace elements status in acute and chronic VL patients. The present study was undertaken to compare serum trace elements concentrations in acute and chronic VL patients.ProcedureAcute (mean age = 28.64 years), chronic (mean age = 23.68 years) VL patients and healthy controls (mean age = 23.05 years) who agreed to provide blood specimens for laboratory investigations participated in this study. Serum zinc (Zn), copper (Cu), iron (Fe), magnesium (Mg) and calcium (Ca) were measured spectrophotometrically using chemistry analyzer.ResultsSerum Zn concentration was comparatively much decreased in chronic VL than to acute ones (p = 0.007) while serum Mg was higher in chronic VL than acute (p = 0.002) ones. There was no statistically significant difference between acute and chronic VL in serum concentrations of Cu, Fe and Ca.ConclusionsSerum Zn levels were much decreased and serum Mg were increased in chronic VL as compared to acute cases. The serum concentrations of Fe and Ca did not show any difference between two groups. The serum Cu was increased in both groups but more in chronic ones. Serum Zn and Mg could be a potential prognosis factor for chronic VL patients. We hypothesize zinc supplementation as a chemo preventive agent for chronic VL cases, particularly in endemic areas.     

Protein oligomerization in the bacterial outer membrane (Review)

The formation of homo-oligomeric assemblies is a well-established characteristic of many soluble proteins and enzymes. Oligomerization has been shown to increase protein stability, allow allosteric cooperativity, shape reaction compartments and provide multivalent interaction sites in soluble proteins. In comparison, our understanding of the prevalence and reasons behind protein oligomerization in membrane proteins is relatively sparse. Recent progress in structural biology of bacterial outer membrane proteins has suggested that oligomerization may be as common and versatile as in soluble proteins. Here we review the current understanding of oligomerization in the bacterial outer membrane from a structural and functional point of view.     

Big Cats in Our Backyards: Persistence of Large Carnivores in a Human Dominated Landscape in India

Protected areas are extremely important for the long term viability of biodiversity in a densely populated country like India where land is a scarce resource. However, protected areas cover only 5% of the land area in India and in the case of large carnivores that range widely, human use landscapes will function as important habitats required for gene flow to occur between protected areas. In this study, we used photographic capture recapture analysis to assess the density of large carnivores in a human-dominated agricultural landscape with density >300 people/km² in western Maharashtra, India. We found evidence of a wide suite of wild carnivores inhabiting a cropland landscape devoid of wilderness and wild herbivore prey. Furthermore, the large carnivores; leopard (Panthera pardus) and striped hyaena (Hyaena hyaena) occurred at relatively high density of 4.8±1.2 (sd) adults/100 km² and 5.03±1.3 (sd) adults/100 km² respectively. This situation has never been reported before where 10 large carnivores/100 km² are sharing space with dense human populations in a completely modified landscape. Human attacks by leopards were rare despite a potentially volatile situation considering that the leopard has been involved in serious conflict, including human deaths in adjoining areas. The results of our work push the frontiers of our understanding of the adaptability of both, humans and wildlife to each other’s presence. The results also highlight the urgent need to shift from a PA centric to a landscape level conservation approach, where issues are more complex, and the potential for conflict is also very high. It also highlights the need for a serious rethink of conservation policy, law and practice where the current management focus is restricted to wildlife inside Protected Areas.     

Perpetuation of immunological memory through common MHC-I binding modes of peptidomimic and antigenic peptides

Understanding the molecular mechanisms of immunological memory assumes importance in vaccine design. We had earlier hypothesized a mechanism for the maintenance of immunological memory through the operation of a network of idiotypic and anti-idiotypic antibodies (Ab2). Peptides derived from an internal image carrying anti-idiotypic antibody are hypothesized to facilitate the perpetuation of antigen specific T cell memory through similarity in peptide-MHC binding as that of the antigenic peptide. In the present work, the existence of such peptidomimics of the antigen in the Ab2 variable region and their similarity of MHC-I binding was examined by bioinformatics approaches. The analysis employing three known viral antigens and one tumor-associated antigen shows that peptidomimics from Ab2 variable regions have structurally similar MHC-I binding patterns as compared to antigenic peptides, indicating a structural basis for memory perpetuation.     

Diverse forms of Pin-II family proteinase inhibitors from Capsicum annuum adversely affect the growth and development of Helicoverpa armigera

Novel forms of Pin-II type proteinase inhibitor (PIs) cDNAs (CanPIs) having three or four inhibitory repeat domains (IRD) were isolated from the developing green fruits of Capsicum annuum. Deduced amino acid (aa) sequences of the CanPIs showed up to 15% sequence divergence among each other or reported inhibitors (CanPI-1AF039398, CanPI-2AF221097). Amino acid sequence analysis of these CanPIs revealed that three IRD PIs have trypsin inhibitory sites, while four IRD CanPIs have both trypsin and chymotrypsin inhibitory sites. Four CanPIs, two having three IRD (CanPI-3AY986465 and CanPI-5DQ005912) and two having four IRD (CanPI-7DQ005913 and CanPI-9DQ005915), were cloned in Pichia pastoris to express recombinant CanPIs. Recombinant CanPIs inhibited 90% of bovine trypsin (TI), while chymotrypsin inhibition (CI) varied with the number of chymotrypsin inhibitory sites in the CanPIs. Recombinant inhibitors inhibited over 70% of the gut proteinase activity of Helicoverpa armigera. H. armigera larvae fed on recombinant CanPIs individually incorporated into artificial diet, showed 35% mortality; in addition, weight gain in H. armigera larvae and pupae was severely reduced compared to controls. Of the four CanPIs, CanPI-7, which has two sites for TI and CI, was the only one to have a consistently antagonistic effect on H. armigera growth and development. We conclude that among the four recombinant PIs tested, CanPIs containing diverse IRDs are best suited for developing insect-resistant transgenic plants.     

EMG activity of the muscular and stromal layer of the cervix in relation to EMG activity of the myometrium and cervical dilatation in PGF2alpha induced parturition in the cow

The goal of this study was to quantify and characterize the electromyographic (EMG) activities in the cervical outer muscular layer and in the cervical stromal layer, and to characterize their relationship with myometrial EMG activity and cervical dilatation during PGF2alpha-induced parturition in term pregnant cows. We continuously measured the EMG activity of the uterine myometrium and cervical outer muscular layer as well as the cervical stromal layer in five cows using bipolar electrodes while at the same time measuring changes in the cervical diameter with ultrasound cervimetry. This we did from the moment a prostaglandin analogue was injected until the expulsion of the calf. In contrast to the cervical stromal layer, the cervical outer muscular layer showed distinct EMG activity, which began to increase at about the same time as the EMG activity of the myometrium, i.e. some 12 h before the start of cervical dilatation. However, the rate of this increase was lower than in the myometrium and it was not characterized, like in the myometrium, by an increase in maximum EMG amplitude. Although the cervical outer muscular layer showed contracture and contraction like EMG activity in unison with in the myometrium, it was also characterized by a more irregular EMG activity, which occurred independently from the myometrium. These data suggest that while the outer muscular layer of the cervix may be considered to be a caudal continuation of the myometrium, it also displays activity independently from the myometrium. The physiological relevance of this activity remains to be explored.     

Cytoskeletal elements and intracellular transport

Recent advances in the understanding of the functions of various components of the cytoskeleton indicate that, besides serving a structural role, the cytoskeletal elements may regulate the transport of several proteins in the cell. Studies reveal that there are co-operative interactions between the actin and microtubule cytoskeletons including functional overlap in the transport influenced by different motor families. Multiple motors are probably involved in the control of the dynamics of many proteins and intriguing hints about how these motors are co-ordinated are appearing. It has been shown that some of the intermediate elements also participate in selected intracellular transport mechanisms. In view of the author's preoccupation with the steroid receptor systems, special attention has been given to the role of the cytoskeletal elements, particularly actin, in the intracellular transport of steroid receptors and receptor-related proteins.