41 research outputs found

    Secure Data Transmission Using DNA ENCRYPTION

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    DNA Encryption is preferable biological technique for securing text/image because of its parallelism, vast storage and fast computing quality. The process involve biological molecule present in human body called DNA abbreviated as Deoxyribose  Nucleic Acid .The DNA molecule is synthesized and protein component part is extracted and then converted to nitrogen base . This nitrogen base is used in Encryption/Decryption and formulated as A (Adenine), C (Cytosine), T (Thymine) and G (Guanine) characters. DNA Cryptography components are ACTG characters only and how the message gets merged and located is known as DNA Cryptography. This ACTG characters create DNA Sequence S and merged with message M to produce new sequence S’ and send to receiver where Sequence S’ back converted to S. The paper will introduce traditional methods of DNA cryptography in which there is need of key and proposed methods ,in which introduction to key is not required ,hence removing the tension of securing the key.  The proposed method involves Complementary pair method

    SARS-CoV-2 neutralizing antibodies : longevity, breadth, and evasion by emerging viral variants

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    The Severe Acute Respiratory Syndrome Coronavirus 2 (SAU ARS-CoV-2) antibody neutralization response and its evasion by emerging viral variants and variant of concern (VOC) are unknown, but critical to understand reinfection risk and breakthrough infection following vaccination. Antibody immunoreactivity against SARS-CoV-2 antigens and Spike variants, inhibition of Spike-driven virus–cell fusion, and infectious SARS-CoV-2 neutralization were characterized in 807 serial samples from 233 reverse transcription polymerase chain reaction (RT-PCR)–confirmed Coronavirus Disease 2019 (COVID-19) individuals with detailed demographics and followed up to 7 months. A broad and sustained polyantigenic immunoreactivity against SARS-CoV-2 Spike, Membrane, and Nucleocapsid proteins, along with high viral neutralization, was associated with COVID-19 severity. A subgroup of “high responders” maintained high neutralizing responses over time, representing ideal convalescent plasma donors. Antibodies generated against SARS-CoV-2 during the first COVID-19 wave had reduced immunoreactivity and neutralization potency to emerging Spike variants and VOC. Accurate monitoring of SARS-CoV-2 antibody responses would be essential for selection of optimal responders and vaccine monitoring and design

    A persistent neutrophil-associated immune signature characterizes post-COVID-19 pulmonary sequelae

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    Interstitial lung disease and associated fibrosis occur in a proportion of individuals who have recovered from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection through unknown mechanisms. We studied individuals with severe coronavirus disease 2019 (COVID-19) after recovery from acute illness. Individuals with evidence of interstitial lung changes at 3 to 6 months after recovery had an up-regulated neutrophil-associated immune signature including increased chemokines, proteases, and markers of neutrophil extracellular traps that were detectable in the blood. Similar pathways were enriched in the upper airway with a concomitant increase in antiviral type I interferon signaling. Interaction analysis of the peripheral phosphoproteome identified enriched kinases critical for neutrophil inflammatory pathways. Evaluation of these individuals at 12 months after recovery indicated that a subset of the individuals had not yet achieved full normalization of radiological and functional changes. These data provide insight into mechanisms driving development of pulmonary sequelae during and after COVID-19 and provide a rational basis for development of targeted approaches to prevent long-term complications

    Mobilization of HIV Spread by Diaphanous 2 Dependent Filopodia in Infected Dendritic Cells

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    Paramount to the success of persistent viral infection is the ability of viruses to navigate hostile environments en route to future targets. In response to such obstacles, many viruses have developed the ability of establishing actin rich-membrane bridges to aid in future infections. Herein through dynamic imaging of HIV infected dendritic cells, we have observed how viral high-jacking of the actin/membrane network facilitates one of the most efficient forms of HIV spread. Within infected DC, viral egress is coupled to viral filopodia formation, with more than 90% of filopodia bearing immature HIV on their tips at extensions of 10 to 20 µm. Live imaging showed HIV filopodia routinely pivoting at their base, and projecting HIV virions at µm.sec−1 along repetitive arc trajectories. HIV filopodial dynamics lead to up to 800 DC to CD4 T cell contacts per hour, with selection of T cells culminating in multiple filopodia tethering and converging to envelope the CD4 T-cell membrane with budding HIV particles. Long viral filopodial formation was dependent on the formin diaphanous 2 (Diaph2), and not a dominant Arp2/3 filopodial pathway often associated with pathogenic actin polymerization. Manipulation of HIV Nef reduced HIV transfer 25-fold by reducing viral filopodia frequency, supporting the potency of DC HIV transfer was dependent on viral filopodia abundance. Thus our observations show HIV corrupts DC to CD4 T cell interactions by physically embedding at the leading edge contacts of long DC filopodial networks

    A broad-spectrum macrocyclic peptide inhibitor of the SARS-CoV-2 spike protein

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    The ongoing COVID-19 pandemic has had great societal and health consequences. Despite the availability of vaccines, infection rates remain high due to immune evasive Omicron sublineages. Broad-spectrum antivirals are needed to safeguard against emerging variants and future pandemics. We used mRNA display under a reprogrammed genetic code to find a spike-targeting macrocyclic peptide that inhibits SARS-CoV-2 Wuhan strain infection and pseudoviruses containing spike proteins of SARS-CoV-2 variants or related sarbecoviruses. Structural and bioinformatic analyses reveal a conserved binding pocket between the receptor binding domain, N-terminal domain and S2 region, distal to the ACE2 receptor-interaction site. Our data reveal a hitherto unexplored site of vulnerability in sarbecoviruses that peptides and potentially other drug-like molecules can target

    A broad-spectrum macrocyclic peptide inhibitor of the SARS-CoV-2 spike protein

    Get PDF
    The ongoing COVID-19 pandemic has had great societal and health consequences. Despite the availability of vaccines, infection rates remain high due to immune evasive Omicron sublineages. Broad-spectrum antivirals are needed to safeguard against emerging variants and future pandemics. We used messenger RNA (mRNA) display under a reprogrammed genetic code to find a spike-targeting macrocyclic peptide that inhibits SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) Wuhan strain infection and pseudoviruses containing spike proteins of SARS-CoV-2 variants or related sarbecoviruses. Structural and bioinformatic analyses reveal a conserved binding pocket between the receptor-binding domain, N-terminal domain, and S2 region, distal to the angiotensin-converting enzyme 2 receptor-interaction site. Our data reveal a hitherto unexplored site of vulnerability in sarbecoviruses that peptides and potentially other drug-like molecules can target

    Embedding of HIV Egress within Cortical F-Actin

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    F-Actin remodeling is important for the spread of HIV via cell–cell contacts; however, the mechanisms by which HIV corrupts the actin cytoskeleton are poorly understood. Through live cell imaging and focused ion beam scanning electron microscopy (FIB-SEM), we observed F-Actin structures that exhibit strong positive curvature to be enriched for HIV buds. Virion proteomics, gene silencing, and viral mutagenesis supported a Cdc42-IQGAP1-Arp2/3 pathway as the primary intersection of HIV budding, membrane curvature and F-Actin regulation. Whilst HIV egress activated the Cdc42-Arp2/3 filopodial pathway, this came at the expense of cell-free viral release. Importantly, release could be rescued by cell–cell contact, provided Cdc42 and IQGAP1 were present. From these observations, we conclude that a proportion out-going HIV has corrupted a central F-Actin node that enables initial coupling of HIV buds to cortical F-Actin to place HIV at the leading cell edge. Whilst this initially prevents particle release, the maturation of cell–cell contacts signals back to this F-Actin node to enable viral release & subsequent infection of the contacting cell

    Herpes Simplex Virus Utilizes the Large Secretory Vesicle Pathway for Anterograde Transport of Tegument and Envelope Proteins and for Viral Exocytosis from Growth Cones of Human Fetal Axons▿

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    Axonal transport of herpes simplex virus (HSV-1) is essential for viral infection and spread in the peripheral nervous system of the host. Therefore, the virus probably utilizes existing active transport and targeting mechanisms in neurons for virus assembly and spread from neurons to skin. In the present study, we used transmission immnunoelectron microscopy to investigate the nature and origin of vesicles involved in the anterograde axonal transport of HSV-1 tegument and envelope proteins and of vesicles surrounding partially and fully enveloped capsids in growth cones. This study aimed to elucidate the mechanism of virus assembly and exit from axons of human fetal dorsal root ganglia neurons. We demonstrated that viral tegument and envelope proteins can travel in axons independently of viral capsids and were transported to the axon terminus in two types of transport vesicles, tubulovesicular membrane structures and large dense-cored vesicles. These vesicles and membrane carriers were derived from the trans-Golgi network (TGN) and contained key proteins, such as Rab3A, SNAP-25, GAP-43, and kinesin-1, involved in the secretory and exocytic pathways in axons. These proteins were also observed on fully and partially enveloped capsids in growth cones and on extracellular virions. Our findings provide further evidence to the subassembly model of separate transport in axons of unenveloped capsids from envelope and tegument proteins with final virus assembly occurring at the axon terminus. We postulate that HSV-1 capsids invaginate tegument- and envelope-bearing TGN-derived vesicles and utilize the large secretory vesicle pathway of exocytosis for exit from axons
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