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).

Abstract: The present invention provides for a genetically modified host cell capable of reducing one or more isoprenoid, or precursor thereof, said genetically modified host cell comprising one or more geranylgeranyl reductases (GGRs), or polypeptides comprising an amino acid sequence having at least 70% identity to an amino acid sequence of a geranylgeranyl reductase (GGR), wherein the polypeptide comprises the enzymatic activity for catalyzing one or more GGR catalyzed reactions, and/or reducing one or more C15 or C20 prenyl alcohols or prenyl pyrophosphates.