Abstract: Provided are methods and compositions for treating an individual with cancer or infectious disease. Multivalent Dectin-2 stimulating agents are provided that include: (a) an agent that binds to Dectin-2 and stimulates Dectin-2 signaling; and (b) an antibody and/or an immunomodulatory agent, wherein (a) and (b) are conjugated to one another. In some cases, (a) is a mannobiose glycopolypeptide that binds to Dectin-2. In some cases (b) is a stimulatory ligand for a TLR (e.g., TLR7, TLR8, TLR7/8, TLR2, and the like). Methods of treating an individual with cancer and/or an infectious disease can include administering to the individual an effective amount of a Dectin-2 stimulating composition. In some cases, the Dectin-2 stimulating composition comprises a Dectin-2 stimulating glycopolymer. In some cases the Dectin-2 stimulating composition comprises a multivalent Dectin-2 stimulating agent.

Abstract: Methods for producing isotopically-labelled peptides are provided. Aspects of the method include: contacting a sample including a metabolically tagged protein with a cleavable probe to produce a probe-protein conjugate; separating the probe-protein conjugate from the sample; digesting the probe-protein conjugate to produce a probe-peptide conjugate; and cleaving a cleavable linker to release an isotopically labelled peptide. The method may further include: identifying a predetermined isotopic pattern in a mass spectrum; determining an amino acid sequence of the isotopically labelled peptide; and identifying the site of protein glycosylation based on the determined amino acid sequence. Also provided are cleavable probes for practicing the subject methods, described by the Formula: A-L-(M-Z) where A is an affinity tag, L is a cleavable linker, M is an isotopic label and Z is a chemoselective tag capable of cross-linking a metabolically tagged protein.

Abstract: Methods for producing isotopically-labelled peptides are provided. Aspects of the method include: contacting a sample including a metabolically tagged protein with a cleavable probe to produce a probe-protein conjugate; separating the probe-protein conjugate from the sample; digesting the probe-protein conjugate to produce a probe-peptide conjugate; and cleaving a cleavable linker to release an isotopically labelled peptide. The method may further include: identifying a predetermined isotopic pattern in a mass spectrum; determining an amino acid sequence of the isotopically labelled peptide; and identifying the site of protein glycosylation based on the determined amino acid sequence. Also provided are cleavable probes for practicing the subject methods, described by the Formula: A-L-(M-Z) where A is an affinity tag, L is a cleavable linker, M is an isotopic label and Z is a chemoselective tag capable of cross-linking a metabolically tagged protein.

Abstract: Provided are methods relating to the inhibition of inhibitory immune receptors. Aspects of the present disclosure include methods that include administering to an individual receiving an antibody therapy an inhibitory immune receptor inhibitor. Also provided are compositions and kits that find use, e.g., in practicing the methods of the present disclosure.

Abstract: The present disclosure features a condensation reaction and a luciferin-unmasking reaction that can be carried out under physiological conditions. In general, the condensation reaction involves reacting a bicyclic reactant with an aminothiol derivative, generating a luciferin or luciferin derivative. A luciferin can provide detectable luminescence. A luciferin derivative can be unmasked to provide detectable luminescence in a luciferin-unmasking reaction. The present disclosure provides bicyclic reactants and aminothiol derivatives suitable for use in the condensation reaction. The condensation and luciferin-unmasking reactions find use in a variety of applications, which are also provided.

Abstract: Provided are conjugates including a targeting moiety that binds to a cell surface molecule of a target cell and a target cell surface-editing enzyme. Also provided are compositions and kits that include the conjugates, as well as methods of using the conjugates. Methods of making conjugates are also provided.

Abstract: A method of labelling a cell is provided. Aspects of the method include the contacting the cell with a cholesteryl-cargo conjugate having the formula: C-L-Z (I) wherein C is a cholesterylamine anchor group, L is an optional linker and Z is a linked cargo moiety to non-covalently bind the cholesterylamine anchoring group to the cell membrane thereby displaying Z at the cell surface for an extended period of time. Aspects of the method further include administering the labelled cell to a subject. Also provided is a method of modulating an immune response in a subject and a method of targeting a cell in a subject. Cholesterylamine conjugates, labelled cells and kits including the same that fmd use in the subject methods are also provided.

Abstract: The present disclosure features a condensation reaction and a luciferin-unmasking reaction that can be carried out under physiological conditions. In general, the condensation reaction involves reacting a bicyclic reactant with an aminothiol derivative, generating a luciferin or luciferin derivative. A luciferin can provide detectable luminescence. A luciferin derivative can be unmasked to provide detectable luminescence in a luciferin-unmasking reaction. The present disclosure provides bicyclic reactants and aminothiol derivatives suitable for use in the condensation reaction. The condensation and luciferin-unmasking reactions find use in a variety of applications, which are also provided.

Abstract: A series of carbohydrate-dye conjugates, as well as a method for detection of pathogenic or other organisms (e.g., bacteria) using the same are provided. The carbohydrate-dye conjugate can be enzymatically incorporated into live and active (viable) bacteria of interest for facile detection of said bacteria. The conjugate incorporation is achieved by utilizing one or more of the enzymes that are endogenous to the bacteria of interest, which can incorporate the conjugate via the conjugate's carbohydrate. A detectable signal is produced by the conjugate's dye only upon incorporation into the bacteria of interest, due to the changes in the dye's local environment upon incorporation. The conjugate may be metabolically incorporated into the fatty outer membrane of a bacterial cell wall, which provides a distinctly hydrophobic environment for the conjugate's dye, causing it to produce a detectable signal.

Abstract: Methods for producing isotopically-labelled peptides are provided. Aspects of the method include: contacting a sample including a metabolically tagged protein with a cleavable probe to produce a probe-protein conjugate; separating the probe-protein conjugate from the sample; digesting the probe-protein conjugate to produce a probe-peptide conjugate; and cleaving a cleavable linker to release an isotopically labelled peptide. The method may further include: identifying a predetermined isotopic pattern in a mass spectrum; determining an amino acid sequence of the isotopically labelled peptide; and identifying the site of protein glycosylation based on the determined amino acid sequence. Also provided are cleavable probes for practicing the subject methods, described by the Formula: A-L-(M-Z) where A is an affinity tag, L is a cleavable linker, M is an isotopic label and Z is a chemoselective tag capable of cross-linking a metabolically tagged protein.

Abstract: Provided are methods and compositions for treating an individual with cancer by administering to the individual a composition that includes a Dectin-2 stimulating agent that stimulates Dectin-2 signaling in myeloid cells (e.g., induces Dectin-2 clustering on the cell surface), thereby stimulating an anti-cancer immune response in the individual. In some cases, the myeloid cells are tumor-associated myeloid (TAM) cells. Methods and compositions are also provided for: treating an individual with cancer via contacting a cancer cell from the individual with an alpha-mannosidase class 1 inhibitor (e.g.

Abstract: Methods for producing isotopically-labelled peptides are provided. Aspects of the method include: contacting a sample including a metabolically tagged protein with a cleavable probe to produce a probe-protein conjugate; separating the probe-protein conjugate from the sample; digesting the probe-protein conjugate to produce a probe-peptide conjugate; and cleaving a cleavable linker to release an isotopically labelled peptide. The method may further include: identifying a predetermined isotopic pattern in a mass spectrum; determining an amino acid sequence of the isotopically labelled peptide; and identifying the site of protein glycosylation based on the determined amino acid sequence. Also provided are cleavable probes for practicing the subject methods, described by the Formula: A-L-(M-Z) where A is an affinity tag, L is a cleavable linker, M is an isotopic label and Z is a chemoselective tag capable of cross-linking a metabolically tagged protein.

Abstract: Methods for chemoselective modification of a target molecule comprising an amine N-oxide in a biological sample are provided. Aspects of the methods include selectively reacting the amine N-oxide group of the target molecule with a boron agent, where the reacting reduces the amine N-oxide to an amine to produce a modified target molecule. Modification of the target molecule using the subject methods may produce an activated target molecule, e.g., a detectable or bioactive. In some cases, chemoselective modification leads to cleavage of the modified target molecule to produce a first target fragment and a second target fragment. Also provided are compositions useful in practicing various embodiments of the subject methods.

Abstract: Methods are provided for detecting a glycosylated target protein in a sample. Aspects of the methods include: (a) contacting a sample comprising a probe-labeled glycosylated target protein with: (i) a first conjugate comprising a first nucleic acid tag linked to a first capture agent that specifically binds the target protein; (ii) a second conjugate comprising a second nucleic acid tag linked to a second capture agent that specifically binds the probe; and (iii) a bridging nucleic acid that hybridizes to the first and second nucleic acid tags; under conditions sufficient to specifically bind the first and second capture agents to the probe-labeled target protein and to hybridize the bridging nucleic acid to the first and second nucleic acid tags to produce a nucleic acid complex; and (b) detecting the nucleic acid complex. Also provided are compositions and kits useful in practicing various embodiments of the subject methods.

Abstract: The present disclosure provides modified bacteria and modified peptidoglycan comprising modified D-amino acids; compositions comprising the modified bacteria or peptidoglycan; and methods of using the modified bacteria or peptidoglycan. The modified D-amino acids include a bioorthogonal functional group such as an azide, an alkyne or a norbornene group. Also provided are modified peptidoglycans conjugated to a molecule of interest via a linker.

Abstract: Pharmaceutical compositions are provided for extending the serum half-life of a therapeutic agent. The composition may include a strained alkyne-labeled therapeutic agent. Also provided is a strained alkyne-carrier protein adduct including a vinyl thioether-linkage to a cysteine residue of the carrier protein. Methods of chemoselectively modifying a carrier protein are provided, that include conjugating a cysteine residue of a carrier protein with a cyclooctyne-labeled cargo agent to produce a vinyl thioether-linked conjugate. Also provided is a method of increasing the in vivo half-life of a bioactive agent including administering a strained alkyne-labeled bioactive agent to a subject.

Abstract: The present disclosure provides modified bacteria and modified peptidoglycan comprising modified D-amino acids; compositions comprising the modified bacteria or peptidoglycan; and methods of using the modified bacteria or peptidoglycan. The modified D-amino acids include a bioorthogonal functional group such as an azide, an alkyne or a norbornene group. Also provided are modified peptidoglycans conjugated to a molecule of interest via a linker.

Abstract: The present disclosure provides modified bacteria and modified peptidoglycan comprising modified D-amino acids; compositions comprising the modified bacteria or peptidoglycan; and methods of using the modified bacteria or peptidoglycan. The modified D-amino acids include a bioorthogonal functional group such as an azide, an alkyne or a norbornene group. Also provided are modified peptidoglycans conjugated to a molecule of interest via a linker.

Abstract: The present disclosure provides modified bacteria and modified peptidoglycan comprising modified D-amino acids; compositions comprising the modified bacteria or peptidoglycan; and methods of using the modified bacteria or peptidoglycan. The modified D-amino acids include a bioorthogonal functional group such as an azide, an alkyne or a norbornene group. Also provided are modified peptidoglycans conjugated to a molecule of interest via a linker.

Abstract: The present disclosure provides fluorogenic azide compounds. Also provided are methods of using the subject compounds for labelling a target biomolecule that includes an alkyne. In some embodiments, the method includes contacting the biomolecule with a fluorogenic azide compound, wherein the contacting results in covalent linkage of the compound with the alkyne moiety of the target biomolecule.