Broadly neutralizing antibodies (bnAb) have been clinically proven to be an excellent choice for HIV-1 prevention. However, the relative effectiveness of best-in-class bnAbs against regionally relevant circulating HIV-1 forms is not clear. In the present study, we compared the degree of neutralization sensitivity of contemporary HIV-1 Indian clade C with that of South African origin. Phylogenetic analysis revealed that these clade C viruses continue to evolve distinctly from one another. Env-pseudotyped viruses prepared using contemporary HIV-1 clade C env genes (N=115) obtained from nine geographically distinct sites in India (between 2020-2023) were found to be most sensitive to V3-directed bnAbs 10-1074 and BG18, and second generation CD4 binding site (CD4bs) directed bnAbs (VRC07, N6 and 1-18), however they were found to be significantly resistant to V1/V2 apex directed bnAbs. Moreover, we observed that the degree of sensitivity varied between contemporary Indian and South African clade C viruses. Differences in degree of neutralization susceptibility were associated with differences observed in key residues that form bnAb contact sites, gp120 loop lengths and the number of N-linked glycans in the V4 hypervariable region. Interestingly, the second generation CD4bs bnAbs (VRC07, N6, 1-18) showed neutralization of VRC01 and 3BNC117 resistant viruses but with 2-7-fold reduced potency compared to the VRC01 sensitive counterparts, likely due to the enrichment of resistance associated residues observed in loop D. Predictive analysis indicated that combination of BG18, N6 and PGDM1400 can provide over 95% neutralization coverage at 1mg/mL of contemporary India clade C, an observation found to be distinct to that reported for the Africa clade C viruses. Taken together, we found distinct neutralization patterns and env signatures associated with resistance to key bnAbs. Our study highlights that towards achieving clinical effectiveness, both the complementarity of bnAb classes and the regionally relevant HIV forms need to be considered. ### Competing Interest Statement The authors have declared no competing interest.

Introduction: Several factors influence transmission of 2019-nCoV from mother to fetus during pregnancy, thus the dynamics of vertical transmission is unclear. The role of cellular protective factors, namely a 90 KDa glycoprotein, Early pregnancy-associated protein (Epap-1), expressed by placental endothelial cells in women during early pregnancy would provide an insight into role of placental factors in virus transmission. Since viral spike protein binding to the ACE2 receptors of the host cells promotes virus invasion in placental tissue, an analysis of effects of Epap-1 on the Spike-ACE2 protein binding was studied. Methods: Epap-1 was isolated from MTP placental tissue. Molecular interaction of Epap-1 and variants of the spike was analyzed in silco. The interaction of Epap-1 with Spike and RBD were analyzed using ELISA and immunofluorescence studies. Results: The results in silico showed an interaction of Epap-1 with S-protein at RBD region involving K417, Y449, Y453, Y456, Y473, Q474, F486, Q498, N501 residues of spike with Y61, F287, I302, N303, N305, S334, N465, G467, N468 residues of Epap-1 leading to interference of S-protein and ACE2 interaction [1]. Further, the interaction is conserved among the variants. The studies in vitro confirm that Epap-1 affects S protein-ACE2 and RBD- ACE2 binding, thus suggesting that during early pregnancy, SARS CoV-2 infection may be protected by Epap-1 protein present in placental tissue. The results were further confirmed by pseudovirus expressing Spike and RBD in an infection assay. Discussion: Epap-1 interferes with Spike and RBD interaction with ACE2, suggesting a possible mechanism of the antiviral environment during pregnancy.

Topoisomerase II (TopoII) is a critical component of HIV-1 integration, proviral DNA synthesis, and reverse transcription. During HIV-1 infection, the TopoIIβkinase (TopoIIβKHIV-1) phosphorylates TopoIIβ. Our earlier research demonstrated that the pyridine scaffold has potent anti-HIV-1 activity by specifically inhibiting TopoIIβKHIV-1 activity. 3D QSAR results showed the presence of molecular features for interaction with TopoIIβKHIV-1 requiring chemically induced proximity for potential interaction. In this study, the chalcone and methyl groups were added to the pyridine scaffold's core to achieve the desired proximity length between the pyridine scaffold and charged centers, which resulted in an inhibitory activity against TopoIIβKHIV-1 and viral replication. According to the findings, the TopoIIβKHIV-1activity was inhibited by the inclusion of the pyridine scaffold with the chalcone group, leading to better anti-HIV-1 activity. The water-soluble methylated pyridinium chalcones' showed significant TopoIIβKHIV-1 antagonism, anti-HIV-1 activity (from IC50 > 500 nM to ID50 25 nM), and reduced cytotoxicity (CC50 = 2 mM). These activities could be associated with the charge on the pyridine and extended proximity. Therefore, it is clear that within the scope of this work, altering the proximity length and charge centers of pyridine molecules are critical for the design and development of effective anti-HIV-1 leads, specifically targeting TopoIIβKHIV-1.

Tumor metastasis is promoted by an immunosuppressive environment. Lactoferrin (Lf) is known to regulate immunological activity in tumor cells and inhibit processes associated with tumor metastasis. A delivery of lactoferrin with docetaxel (DTX) in prostate cancer cells in the form of DTX-loaded lactoferrin nanoparticles (DTX-LfNPs) would provide a dual activity wherein the lactoferrin affects metastasis and DTX chemotherapeutically inhibits mitosis and cell division. DTX-LfNPs were prepared using sol–oil chemistry, and particles were characterized using transmission electron microscopy. Antiproliferation activity was analyzed in prostate cancer Mat Ly Lu cells. The target localization and efficacy of DTX-LfNPs were studied in an orthotopic prostate cancer induced by Mat Ly Lu cells in a rat model. Biomarkers were estimated using ELISA and biochemical reactions. DTX was loaded in pure Lf nanoparticles without involving any chemical modification and conjugation, thus when these nanoparticles are delivered in cancer cells both DTX and Lf will be present in biologically active forms. DTX-LfNps exhibit a spherical morphology of dimension of 60 ± 10 nm with DTX Encapsulation Efficiency of 62.06 ± 4.07

Against the backdrop of the second wave of COVID-19 pandemic in India that started in March 2021, we have monitored the spike (S) protein mutations in all the reported (GISAID portal) whole genome sequences of SARS CoV-2 circulating in India from 1 January 2021 to 31 August 2021. In the 43,102 SARS-CoV-2 genomic sequences analysed, we have identified 24, 260 mutations in the S protein, based on which 265 pango lineages could be categorised. The dominant lineage in most of the 28 states of India and its 8 union territories was B.1.617.2 (the delta variant). However, the states Madhya Pradesh, Jammu & Kashmir, and Punjab had B.1.1.7 (alpha variant) as the major lineage, while the Himachal Pradesh state reported B.1.36 as the dominating lineage. A detailed analysis of various domains of S protein was carried out for detecting mutations having a prevalence of >1%; 70, 18, 7, 3, 9, 4, and 1 (N=112) such mutations were observed in the N -terminal domain, receptor binding domain, C -terminal domain, fusion peptide region, heptapeptide repeat (HR)-1 domains, signal peptide domain, and transmembrane region, respectively. However, no mutations were recorded in the HR-2, and cytoplasmic domains of the S protein. Interestingly, 13.39% (N=15) of these mutations were reported to increase the infectivity and pathogenicity of the virus; 2%(N=3) were known to be vaccine breakthrough mutations; and 0.89%(N=1) were known to escape neutralising antibodies. Biological significance of 82% (N=92) of the reported mutations is yet unknown. As SARS-CoV-2 variants are emerging rapidly, it is critical to continuously monitor local viral mutations to understand national trends of virus circulation. This can tremendously help in designing better preventive regimens in the country, and avoid vaccine breakthrough infections.

We report clinical profile of hundred and nine patients with SARS CoV-2 infection, and whole genome sequences (WGS) of seven virus isolates from the first reported cases in India, with various international travel histories. Comorbidities such as diabetes, hypertension, and cardiovascular disease were frequently associated with severity of the disease. WBC and neutrophil counts showed an increase, while lymphocyte counts decreased in patients with severe infection suggesting a possible neutrophil mediated organ damage, while immune activity may be diminished with decrease in lymphocytes leading to disease severity. Increase in SGOT, SGPT and blood urea suggests the functional deficiencies of liver, heart, and kidney in patients who succumbed to the disease when compared to the group of recovered patients. The WGS analysis showed that these isolates were classified into two clades: I/A3i, and A2a (four according to GISAID: O, L, GR, and GH). Further, WGS phylogeny and travel history together indicate possible transmission from Middle East and Europe. Three S protein variants: Wuhan reference, D614G, and Y28H were identified predicted to possess different binding affinities to host ACE2.

The third variable loop region (V3 loop) on gp120 plays an important role in cellular entry of HIV-1. Its interaction with the cellular CD4 and coreceptors is an important hallmark in facilitating the bridging by gp41 and subsequent fusion of membranes for transfer of viral genetic material. Further, the virus phenotype determines the cell tropism via respective co-receptor binding. Thus, coreceptor binding motif of envelope is considered to be a potent anti-viral drug target for viral entry inhibition. However, its high variability in sequence is the major hurdle for developing inhibitors targeting the region. In this study, we have used an in silico Virtual Screening and "Fragment-based" method to design small molecules based on the gp120 V3 loop interactions with a potent broadly neutralizing human monoclonal antibody, 447-52D. From the in silico analysis a potent scaffold, 1,3,5-triazine was identified for further development. Derivatives of 1,3,5-triazine with specific functional groups were designed and synthesized keeping the interaction with co-receptor intact. Finally, preliminary evaluation of molecules for HIV-1 inhibition on two different virus strains (clade C, clade B) yielded IC50 < 5.0 mu M. The approach used to design molecules based on broadly neutralizing antibody, was useful for development of target specific potent antiviral agents to prevent HIV entry. The study reported promising inhibitors that could be further developed and studied.

Aim: We report here the development of tenofovir- and curcumin-loaded lactoferrin nanoparticles (TCNPs) as an HIV-microbicide. Materials & methods: TCNPs were subjected to various physicochemical characterization experiments, followed by in vitro and in vivo experiments to assess their efficacy. Results: TCNPs had a diameter of 74.31 ± 2.56 nm with a gross encapsulation of more than 61% for each drug. Nanoparticles were effective against HIV-1 replication, with an IC50 of 1.75 μM for curcumin and 2.8 μM for tenofovir. TCNPs provided drug release at the application site for up to 8-12 h, with minimal leakage into the systemic circulation. TCNPs showed spermicidal activity at ≥200 μM and induced minimal cytotoxicity and inflammation in the vaginal epithelium as revealed by histopathological and ELISA studies. Conclusion: We demonstrated that TCNPs could serve as a novel anti-HIV microbicidal agent in rats. [Formula: see text].

Toll-like receptors (TLRs) activate host innate immunity by recognizing microbial ligands and viral nucleic acids. Of late, TLR8 has emerged as an attractive target for antiviral activity, antitumor activity and vaccine development owing to its ability to recognize small synthetic molecules that induce pro-inflammatory cytokines, type 1 interferons and chemokines. Of the many synthetic and natural ligands researched so far, ligands derived from coumarin have been known to have enhanced antiviral and immunomodulatory properties. Thus, the coumarin scaffold plays an important role through the modulation of cytokines by noncovalent interactions with various enzymes and receptors. The present study aims to identify a coumarin derivative that binds to the TLR8 receptor and induce NF-kappa B activity. In silico screening and chemical synthesis were performed to realize novel coumarin leads with potential TLR8 agonistic activity. HEK-Blue (TM) hTLR8 cell line was used to validate the TLR8 agonist evaluation In vitro. The key finding of this study brings out strong evidence supporting the binding of the 3,3(1)-(4(11)-N,N-dimethylaminophenylmethylene)-4,4(1)-epoxydicoumarin to TLR8 receptor in comparison to the co-crystallized R848 ligand.

The HIV-1 invasion is initiated with the interaction of viral glycoprotein gp120 and cellular receptor CD4. The binding mechanism reveals two major hotspots involved in gp120-CD4 interaction. The first one is a hydrophobic cavity (Phe43 cavity) on gp120 capped with phenyl ring of phe43CD4 and the second is the electrostatic interaction between positive charge of Arg59CD4 and negative charge of Asp368gp120. Targeting these hotspots, small molecules for entry inhibition and HIV-1 neutralization were designed and tested. In the process, pyrimidine derivatives were identified as potent molecules to intercept gp120-CD4 binding by targeting both the hotspots. Herein, the synthesis, characterization of 1,2,3,4-Tetrahydropyrimidine derivatives, and biological evaluation on 93IN101, a clade C virus are presented. The paper presents a novel set of entry inhibitors to target dual hotspots on gp120 to inhibit protein-protein interactions.

Biosurfactants are important macromolecular frameworks that provide capsular microenvironment mimicking cellular compartment for molecular reactivity and stability. Physico-chemical features like polar, non-polar, charged interacting side chains of biosurfactant promote interaction of gene, drugs, and intermediates for stabilization and biotransformation of reactive intermediates. Surface modified biosurfactant conjugates are useful for providing target recognition and thus facilitate an efficient delivery of bioactive agents to the site of action. This chapter discusses structural as well as compositional aspects of surfactants and biosurfactants along with current advances in development of surfactant and biosurfactant formulations as therapeutic and drug delivery systems.

Topoisomerase II beta (Topo IIβ) is one of the two isoforms of type II topoisomerases present in higher eukaryotes. This 180 kDa nuclear protein involves in different cellular processes like transcription, recombination, etc., apart from its normal topological functions. Previously, we have reported the association of this isoform along with the other isoform topoisomerase II alpha (Topo IIα) with HIV-1 reverse transcription complex and the downregulation of Topo IIβ expression resulted in incomplete reverse transcription. In this study, we have tested the Topo IIβ specific siRNA delivery using protein nanoparticles prepared with c-terminal domine of transferrin (c-ter) for the first time. Results show that, c-ter nanoparticles resemble apotransferrin nanoparticles in drug holding capability and drug delivery but with small in size. Topo IIβ specific siRNA delivered in the form of c-ter nanoformulation resulted in knockdown of Topo IIβ expression for the prolonged periods and which intern resulted in decreased viral replication of HIV-1.

Purpose: Cancer stem cells (CSCs) are known to contribute to tumor relapses by virtue of their chemoresistance. With the knowledge that nanoformulations can overcome drug resistance, we evaluated the efficacy and cytotoxicity of clinical-grade carboplatin (CPT)– and etoposide (ETP)–loaded lactoferrin nanoparticles (Lf-Nps) on total, CD133-enriched (non-CSC), and CD133-depleted (CSC) populations of retinoblastoma (Rb) Y79 cells. Methods: Physicochemical properties of drug-loaded Lf-Nps were measured with transmission electron microscopy and attenuated total reflectance–Fourier transform infrared. The encapsulation efficiency, uptake, and release of drug-loaded Lf-Nps were measured using high-performance liquid chromatography and a UV-visible spectrophotometer. Cytotoxicity of the standard and drug-loaded Lf-Nps was evaluated by the MTT assay. Results: The mean (SD) size and encapsulation efficiency of Lf-CPT and Lf-ETP were 61.2 (3.94) nm, 60% and 45.15 (5.85) nm, 38%, respectively, and the drug release efficiency was highest at pH 6. The increased drug uptake and lower release of drug-loaded Lf-Nps were observed in CSC and non-CSC populations compared to their standard forms. The relative increase of drug uptake and sustained intracellular retention of the drug-loaded Lf-Nps compared to standard drugs showed an enhanced cytotoxicity up to 50%, especially in Rb Y79 CSCs (IC50: CPT, 230.3; Lf-CPT, 118.2; ETP, 198.1; and Lf-ETP, 129) compared to non-CSCs. Conclusions: Our study documents an increase in drug uptake, retention, and cytotoxicity of Lf-CPT and Lf-ETP on Y79 CSCs and non-CSCs as compared to their standard drugs in vitro. The reversal of chemoresistance in the CSC population by nanoformulation appears promising with the potential to pave the way for improved targeted therapy and better clinical outcomes.

Of biologically active B-complex vitamins, vitamins B6, B9 and B12 has been reported to influence maintenance of red blood cells, stem cells, nervous and immune systems, tissue regeneration and wound healing. However, the collective effects of restrictions/supplementations of vitamins B6, B9 and B12 on growth, vasculogenesis and senescence of BG01V human embryonic stem cell (hESC) derived human embryoid bodies (hEBs) is not understood. This study was proposed to understand the collective effects of restrictions/supplementations of vitamins B6, B9 and B12 on growth, vasculogenesis and senescence of hEBs. The collective effect of four different media conditions like deficient (0%), marginal (30%), adequate (70%) and supraphysiological levels of vitamins B6, B9 and B12 restrictions/supplementations on growth and viability of hEB derived vasculogenesis were studied by photometric analysis. Morphology and senescence of hEB derivatives were examined and compared using inverted microscopy and scanning electron microscopy. Out of four different media conditions like 0%, 30%, 70% and supraphysiological levels of vitamins B6, B9 and B12, media supplied with adequate level of vitamins B6, B9 and B12 to hESCs grown on 100% restriction were able to resume all activities at normal. The BG01V hESC-hEBs grown without vitamins B6, B9 and B12 showed cell disintegration, cell floating, SA-β-gal expression, cell lose, decrease size, number and metabolic activity. The hEB derived vascular cell like structures grown on similar conditions showed compromised self-renewal capacity, vulnerable growth and early senescence. The initial damages due to restrictions may be reversed by adequate (70%) supply of vitamins B6, B9 and B12; however reversal of damage may not be 100%.

Intriguing properties and structural dynamics of Lactoferrin have been exploited in numerous applications, including its use as self-assembling, pH sensitive nanoparticles to deliver intended cargo at the disease site. In this study, we explore the possibility of surface modification of Lactoferrin nanoparticles to hone its specificity to target HIV-1 infected cells. Existence of free cysteine groups on Lactoferrin nanoparticles available for reaction with external molecules facilitates conjugation on the surface with Sodium 2-mercaptoethanesulfonate (MES). Conjugation with MES is used to edge a negative charge that can mimic CCR5 and Heparan sulfate (initial point of contact of HIV-1 env to host cell surface) electrostatic charge (Sulfate group). A simple sono-chemical irradiation method was employed for self-assembly of Nanoparticles and for surface modification. The nanoparticles serve dual purpose to abrogate extracellular entry and to target viral enzymes, when loaded with ART drugs. The morphology and size distribution of the formed particles were explored using Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM) and Dynamic Light Scattering. Raman SERS was employed to understand the difference in the protein upon surface modification. The anti-HIV property of the particles was confirmed in-vitro. The modified device demonstrated acceptable nanoparticle properties with controlled release and higher effective concentration in the area of infection.

Lactoferrin, an iron storage protein, is known for its microbicidal activity and its ability to modulate the immune system, mediated through specific interactions with receptors on cell surfaces for internalization. These activities confer a significant versatility to lactoferrin, presenting it as a targeting ligand to disease-bearing cells. Early efforts in developing targeted delivery systems have focused on nano- and microcomposites comprised of metal and polymeric materials. These can be targeted through conjugation or adsorption of lactoferrin to achieve recognition to receptor-expressing cells. More recently, efforts are underway to utilize lactoferrin itself as a medium in loading the therapeutic agent. The functional efficiency of drug-loaded lactoferrin nanoparticles has been evaluated in different disease conditions such as cancer, HIV, Parkinson’s disease, etc. This review will present the details of composition and performance of various delivery systems designed and developed using lactoferrin as targeting agent for the treatment of cancer.

BACKGROUND:Alzheimer's disease (AD) is a widespread dementia-related disease affecting mankind worldwide. A cholinergic hypothesis is considered the most effective target for treating mild to moderate AD. Present study aims to identify new scaffolds for inhibiting acetylcholinesterase activity.METHODS:To find Acetylcholinesterase (AChE) inhibitors, we computationally designed and chemically synthesized a series of cation-π inhibitors based on novel scaffolds that potentially block AChE. The cytotoxic effect of inhibitors were determined by MTT. AChE inhibition experiment was performed by Ellman and the Amplex red method in the SH-SY5Y cell line. Further, the experimental data on designed compounds corroborate with various computational studies that further elucidate the binding mode of interactions and binding affinity.RESULTS:The inhibitors were designed to promote dual binding and were incorporated with groups that may facilitate any of the cation- π, hydrophobic and hydrogen-bonding interactions with the conserved and hot-spot residues in the binding site. The inhibitors possessing pyridine-N-methylated pyridinium group and thereby involved in cation- π interactions are highly active relative to the marketed drug Donepezil as well as the designed analogs that lack the group. In vitro enzymatic Ellman assay and Amplex red assay on SH-SY5Y cell line estimated IC50 of the designed compounds in nM range with one having binding affinity higher than Donepezil. Compounds exhibit no significant toxicity up to µM range.CONCLUSIONS:Compounds possessing methylidenecyclohexanone scaffolds, with characteristic dual-binding and involving strong cation-π interactions, serves as new leads for AChE and opens a new direction for drug discovery efforts.

Tau protein aggregation is identified as one of the key phenomena associated with the onset and progression of Alzheimer’s disease. In the present study, we performed on-chip confocal imaging of tau protein aggregation and tau–drug interactions using a spiral-shaped passive micromixing platform. Numerical simulations and experiments were performed in order to validate the performance of the micromixer design. We performed molecular modeling of adenosine triphosphate (ATP)-induced tau aggregation in order to successfully validate the concept of helical tau filament formation. Tau aggregation and native tau restoration were realized using an immunofluorescence antibody assay. The dose–response behavior of an Alzheimer’s drug, methylthioninium chloride (MTC), was monitored on-chip for defining the optimum concentration of the drug. The proposed device was tested for reliability and repeatability of on-chip tau imaging. The amount of the tau protein sample used in our experiments was significantly less than the usage for conventional techniques, and the whole protein–drug assay was realized in less than two hours. We identified that intensity-based tau imaging could be used to study Alzheimer’s drug response. In addition, it was demonstrated that cell-free, microfluidic tau protein assays could be used as potential on-chip drug evaluation tools for Alzheimer’s disease.

A series of anthracenyl pyrazoline derivatives (3a–o) were synthesized with an aim to evaluate their in vitro anticancer activities. Anthracenyl pyrazoline compounds were prepared by the reaction between various anthracenyl chalcones (1a–o) and hydrazine hydrate (2). The reactions were carried out under reflux in the presence of triethylamine and ethanol for 24 h, and the obtained yields were from good to excellent (90–97%). The structure of each compound is well characterized by IR, 1H‐NMR, 13C‐NMR, elemental analyses, and mass spectroscopic technics, and the molecular structures of compounds 3d and 3e were solved by single‐crystal X‐ray crystallographic methods. The newly synthesized compounds (3a–o) were evaluated for their in vitro cytotoxic studies against four human cancer cell lines MCF‐7 (breast cancer cell lines), SK‐N‐SH (neuroblastoma cancer cell lines), HeLa (cervical cancer cell lines), and HepG2 (liver cancer cell lines), and the screening results show strong cytotoxic effects for most of the synthesized compounds against the three cell lines except SK‐N‐SH cells. Notably, compounds 3a, 3j, 3l, 3m, 3n, and 3o showed a highly potential activity against HeLa cells (IC50: 0.22, 0.3, 0.3, 0.10, 0.25, and 0.25 μM), while compounds 3i, 3k, 3l, and 3m showed a significant cytotoxic activity in HepG2 cells (IC50: 0.22, 0.44, 0.40, and 0.22 μM), whereas compounds 3a, 3b, 3d, and 3e exhibit a promising cytotoxicity against MCF‐7 cells (IC50: 0.73, 0.495, 0.493, and 0.66 μM).