The present invention relates to oligonucleotide conjugates and preparation and applications thereof. In particular, the present invention relates to an oligonucleotide conjugated to a biomolecule (e.g. an antibody) and/or an agent of interest (e.g. a drug). In certain embodiments, the oligonucleotide of the present invention is a hybridized complex of a single strand oligonucleotide carrying a biomolecule and a complementary strand oligonucleotide bearing an agent of interest where the hybridized nucleotide segment acts as a linker to link the biomolecule and the agent of interest in one molecule.

Embodiments of the disclosure include methods and compositions related to treating an individual for HER2+ positive cancer with an appropriate treatment based on outcome of a multiparameter classifier. The methods allow for identification of HER2+ individuals that are suitable to avoid chemotherapy, in specific embodiments. Methods of the disclosure also allow for identification of HER2+ individuals that should not avoid chemotherapy. In specific embodiments, the multiparameter classifier identifies whether there is (1) a ratio of HER2 amplification, relative to a control probe, of greater than or equal to 4.5; (2) a HER2 expression level score of 3+, as determined by immunohistochemistry, in at least 90% of breast cancer cells; (3) whether there is a HER2-enriched molecular subtype; and (4) whether the individual has a wildtype PIKC3A gene.

Embodiments of the disclosure include methods and compositions related to treating an individual for HER2+ positive cancer with an appropriate treatment based on outcome of a multiparameter classifier. The methods allow for identification of HER2+ individuals that are suitable to avoid chemotherapy, in specific embodiments. Methods of the disclosure also allow for identification of HER2+ individuals that should not avoid chemotherapy. In specific embodiments, the multiparameter classifier identifies whether there is (1) a ratio of HER2 amplification, relative to a control probe, of greater than or equal to 4.5; (2) a HER2 expression level score of 3+, as determined by immunohistochemistry, in at least 90% of breast cancer cells; (3) whether there is a HER2-enriched molecular subtype; and (4) whether the individual has a wildtype PIKC3A gene.

This disclosure provides an E. coli strain, which lacks thioredoxin reductase activity encoded by trxB and thioredoxin 1 activity encoded by trxA, and glutathione reductase activity encoded by gor. Said E. coli strain expresses a mutated AhpC protein having glutathione reductase activity and a cytosolic prokaryotic disulfide isomerase. The E. coli strain has an oxidative cytosol and can be used to efficiently produce proteins having disulfide bonds.

This disclosure provides an E. coli strain, which lacks thioredoxin reductase activity encoded by trxB and thioredoxin 1 activity encoded by trxA, and glutathione reductase activity encoded by gor. Said E. coli strain expresses a mutated AhpC protein having glutathione reductase activity and a cytosolic prokaryotic disulfide isomerase. The E. coli strain has an oxidative cytosol and can be used to efficiently produce proteins having disulfide bonds.

The present disclosure provides a site-specific protein conjugate and the method for preparation of the same. The protein conjugate comprising a protein and an oligosaccharide, wherein said oligosaccharide comprises

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wherein: said GlcNAc is directly or indirectly linked to an amino acid of said protein; said Gal is a galactose; said (Fuc) is a fucose, b is 0 or 1; said Fuc* comprises a fucose or a fucose derivative linked to a molecule of interest (MOI), said protein comprises an antigen binding fragment and/or a Fc fragment.

The application provides a multi-specific antibody-like protein having a N-terminal and a C-terminal, comprising in tandem from the N-terminal to the C-terminal, a first binding domain (D1) at the N-terminal, a second binding domain (D2) comprising a light chain moiety, a Fc region, a third binding domain (D3), and a fourth binding domain (D4) at the C-terminal, wherein the light chain moiety comprises a fifth binding domain (D5) covalently attached to the C-terminal, a sixth binding domain (D6) covalently attached to the N-terminal, or both, and wherein the D1, D2, D3, D4, D5 and D6 each has a binding specificity against a tumor antigen, an immune signaling antigen, or a combination thereof.

The application provides a multi-specific antibody-like protein having a N-terminal and a C-terminal, comprising in tandem from the N-terminal to the C-terminal, a first binding domain (D1) at the N-terminal, a second binding domain (D2) comprising a light chain moiety, a Fc region, a third binding domain (D3), and a fourth binding domain (D4) at the C-terminal, wherein the light chain moiety comprises a fifth binding domain (D5) covalently attached to the C-terminal, a sixth binding domain (D6) covalently attached to the N-terminal, or both, and wherein the D1, D2, D3, D4, D5 and D6 each has a binding specificity against a tumor antigen, an immune signaling antigen, or a combination thereof.

Provided is application of chimeric antigen receptor (CAR)-modified T (CART) cells in preparing drugs for cancer treatment, the CART cells contain an artificially-introduced costimulatory signal transduction domain, and the CART cell does not contain an artificially-introduced first signal transduction domain.

This invention provides fully human monoclonal antibodies that recognize HER2. The invention further provides methods of using such monoclonal antibodies in a variety of therapeutic, diagnostic, and prophylactic indications.