Galactoxyloglucan Endowed Biogenic Nanoimmunobiotics Arrests Microbial Growth and Elicits Antitumor Immunity.

A straightforward investigation with a surfactant-free green method mediated orchestration of a nanocomposite, where immunotherapy was fused with antimicrobial ability in a biogenic amalgamation, resulted in a nanoimmunobiotics (NIB). Consequently, a galactoxyloglucan (PST001) isolated from Tamarindus indica seed kernel was utilized in a sustainable approach to endow copper nanoparticles (CuNP@PST) with high stability and broad pH tolerance. The biocompatible nature of the CuNP@PST was demonstrated by toxicity studies on BALB/c mice. The nanoparticles exhibited immunomodulatory features by stimulating both humoral and cell-mediated immunity. As remarkable aftermath, we observed promising wound healing capacity on normal human keratinocytes along with the excellent antibacterial and antifungal activity by the NIB. The unique potential of CuNP@PST as a chemopreventive agent by eliciting antitumor immunity was illustrated on syngeneic murine tumor models. The outstanding capacity to reduce tumor burden with a significant increase in lifespan and a peculiar cytokine activation pattern could materialize these nanoparticles as an adjuvant for cancer management. The intrinsically bioeliminable, well-tolerated, and systemically available NIB promises to enter clinical testing as an antimicrobial-immunotherapy agent. Appreciable biodistribution pattern, along with the cost-effective fabrication strategies for scale-up, presents a futuristic biomedical scenario for fast promoting the translational potential of our NIB to combat antibiotic resistance and neoplasia effectively.

Heterologous Expression, Purification and Characterization of an Oligopeptidase A from the Pathogen Leptospira interrogans.

Oligopeptidases are enzymes involved in the degradation of short peptides (generally less than 30 amino acids in size) which help pathogens evade the host defence mechanisms. Leptospira is a zoonotic pathogen and causes leptospirosis in mammals. Proteome analysis of Leptospira revealed the presence of oligopeptidase A (OpdA) among other membrane proteins. To study the role of oligopeptidase in leptospirosis, the OpdA of L. interrogans was cloned and expressed in Escherichia coli with a histidine tag (His-tag). The protein showed maximum expression at 37 °C with 0.5 mM of IPTG after 2 h of induction. Recombinant OpdA protein was purified to homogeneity using Ni-affinity chromatography. The purified OpdA showed more than 80% inhibition with a serine protease inhibitor but the activity was reduced to 30% with the cysteine protease inhibitor. The peptidase activity was increased significantly in the presence of Zn2+ at a neutral pH. Inhibitor assay indicate the presence of more than one active sites for peptidase activity as reported with the OpdA of E. coli and Salmonella. Over-expression of OpdA in E. coli BL21 (DE3) did not cause any negative effects on normal cell growth and viability. The role of OpdA as virulence factor in Leptospira and its potential as a therapeutic and diagnostic target in leptospirosis is yet to be identified.

Expression of Leptospira membrane proteins Signal Peptidase (SP) and Leptospira Endostatin like A (Len A) in BL-21(DE3) is toxic to the host cells.

Heterologous expression of Integral Membrane Proteins (IMPs) is reported to be toxic to the host system in many studies. Even though there are reports on various concerns like transformation efficiency, growth properties, protein toxicity, inefficient expression and protein degradation in IMP overexpression, no studies so far addressed these issues in a comprehensive way. In the present study, two transmembrane proteins of the pathogen Leptospira interrogans, namely Signal peptidase (SP), and Leptospira Endostatin like A (Len-A) were taken along with a cytosolic protein Hydrolase (HYD) to assess the differences in transformation efficiency, protein toxicity, and protein stability when over expressed in Escherichia coli (E. coli). Bioinformatics analysis to predict the transmembrane localization indicated that both SP and Len are targeted to the membrane. The three proteins were expressed in full length in the E. coli expression strain, BL 21 (DE3). Significant changes were observed for the strains transformed with IMP genes under the parameters analysed such as, the transformation efficiency, survival of colonies on IPTG-plate, culture growth kinetics and protein expression compared to the strain harbouring the cytosolic protein gene.

Exploration of Biogenic Nano-chemobiotics Fabricated by Silver Nanoparticle and Galactoxyloglucan with an Efficient Biodistribution in Solid Tumor Investigated by SERS Fingerprinting.

An incredible exploration ensued of a dual modality nanocomposite wherein chemotherapy in fusion with antibacterial efficacy is obtained in a biogenic fabrication, which transformed as a novel nano-chemobiotics (NCB) prevailing fundamental molecular level investigation by surface-enhanced Raman scattering (SERS) platform. The nanocomposite is a facile, robust, and ecofriendly constitution between silver nanoparticles (SNPs) and a naturally occurring galactoxyloglucan (PST001) denoted as SNP@PST, which displayed biocompatibility with an upgraded selective cytotoxicity toward cancer cells. The relatively nontoxic nature of the SNP@PST on normal cells and red blood cells was further proved by detailed toxicological profiling on BALB/c mice. As a unique outcome, we observed excellent antibacterial activity, which is complementary to the greater cytotoxicity by the NCB. In diagnostic aspect, SNP@PST was revealed to be a superior SERS substrate with multiscale Raman signal enhancement contributed by homogeneous hot-spot distribution. Finally, the inherent SERS feature enabled us to investigate the biodistribution of the NCB in tumor-challenged mice using Raman fingerprinting and mapping analysis. Hence, the unrevealed SNP@PST orchestrated with the surfactant-free green method resembled a potential theransonstic NCB construct with synergistic anticancer and antibacterial potential in a single platform.