The disclosure provides non-naturally occurring mutant neuraminidase (NA) polypeptides that improve expression and or modifies the open/closed tetrameric conformational state of the NA polypeptide, and uses thereof.

Engineered Influenza polynucleotides, viruses, vaccines, and methods of making and using the same are provided. More specifically, the present inventors have developed replication competent engineered influenza viruses having, for example, a modified segment 4 and/or segment 6 that include at least one additional polynucleotide encoding a heterologous polypeptide.

Methods are provided for the prognosis, diagnosis and treatment of various pathological states, including cancer, chemotherapy resistance and dementia associated with Alzheimer's disease. The methods provided herein are based on the discovery that various proteins with a high level of sialylation are shown herein to be associated with disease states, such as, cancer, chemotherapy resistance and dementia associated with Alzheimer's disease. Such methods provide a lysosomal exocytosis activity profile comprising one or more values representing lysosomal exocytosis activity. Also provided herein, is the discovery that low lysosomal sialidase activity is associated with various pathological states. Thus, the methods also provide a lysosomal sialidase activity profile, comprising one or more values representing lysosomal sialidase activity. A lysosomal sialidase activity profile is one example of a lysosomal exocytosis activity profile.

Isolated monoclonal antibodies and antigen binding fragments thereof that specifically bind neuraminidase (NA) of an N1 subtype influenza virus are disclosed herein. These antibodies and antigen binding fragments can be used for the detection of an N1 subtype influenza virus and for determining the immunogenicity of vaccines. The antibodies and antigen binding fragments also can be used for the treatment of a subject to prevent or ameliorate an influenza infection.

The present disclosure provides compositions and methods for treating an infection by EV-D68. In particular, the present disclosure provides methods that entail administering agents having an anchoring domain that anchors the compound to the surface of a target cell, and a sialidase domain that can act extracellularly to inhibit infection of a target cell by EV-D68.

Methods and compositions for treating Middle East respiratory syndrome coronavirus (MERS-CoV) infection using polypeptides having sialidase activity are provided herein.

The invention provides compositions and methods for treating inflammatory diseases, such as cardiac or hepatic inflammatory diseases, involving the use of parasite-derived neurotrophic factor (PDNF), or fragment of PDNF. The invention also provides compositions featuring PDNF, or a fragment thereof, and methods for using such compositions for the proliferation and/or mobilization of a stem cell (e.g., cardiac stem cell) or progenitor cell (e.g., hepatic progenitor cell). In one aspect, the invention provides a method of decreasing inflammation in a nonneuronal tissue of a subject. In another aspect, the invention provides a method of decreasing inflammation in a cardiac, liver, pancreas, or gastrointestinal tissue of a subject. In still another aspect, the invention provides a method of increasing expression of an anti-inflammatory factor in a non-neuronal cell or tissue.

A method for detection of active form of analytes in a sample and/or for determination of ability of tested substances to bind to the active site of these analytes has the following steps: a) analyte or group of analytes from the sample is immobilized on the surface of a solid carrier; b) analyte or group of analytes is incubated with a detection probe; c) then the solid carrier is washed to remove unbound detection probe; and subsequently, the amount of bound detection probe is determined.

The present invention provides new compositions and methods for preventing and treating pathogen infection. In particular, the present invention provides compounds having an anchoring domain that anchors the compound to the surface of a target cell, and a therapeutic domain that can act extracellularly to prevent infection of a target cell by a pathogen, such as a virus. The present invention also comprises therapeutic compositions having sialidase activity, including protein-based compounds having sialidase catalytic domains. Compounds of the invention can be used for treating or preventing pathogen infection, and for treating and reducing allergic and inflammatory responses. The invention also provides compositions and methods for enhancing transduction of target cells by recombinant viruses. Such compositions and methods can be used in gene therapy.

The present invention relates to a new method for rescuing an influenza virus and a composition therefor. The method comprises providing a host cell stably integrated with and expressing influenza virus PA, PB1, PB2 and NP genes, and introducing an influenza virus rescue system in which a stop codon is introduced into the PA, PB1, PB2 and NP genes respectively into the host cell to achieve virus rescue. The produced virus particles can be used as a live attenuated influenza vaccine, which is characterized in that, since the genes encoding the related proteins are mutated, it has no replication and proliferation ability in human and normal animal cells, and replication and proliferation can be achieved only in the host cells constructed above and it can fully stimulate the body immunity and effectively protect the body while ensuring the safety.