Abstract: The present disclosure relates to a diagnostic assay to detect classic inborn galactosemia. The assay comprises detecting defective galactose metabolism using a substrate-specific recombinant phosphatase derived from Salmonella.

Abstract: The present invention provides methods for enhancing T cell activation and expansion, and methods for stimulating a T cell immune response in a subject. The methods of the invention involve the use of a targeting agent-enzyme conjugate that contains (a) a targeting moiety that specifically binds a cell surface molecule on T cells, and (b) a sialidase or enzymatically active fragment thereof. Also provided in the invention are targeting agent-enzyme conjugates that can be used in the therapeutic methods, including antibody conjugates that are formed of a sialidase and a T cell targeting antibody (e.g., an anti-PD1 antibody).