Abstract: The present invention relates to amino acid sequences that are directed G-protein coupled receptors (GPCRs), as well as to compounds or constructs, and in particular proteins and polypeptides, that comprise or essentially consist of one or more such amino acid sequences. The invention also relates to nucleic acids encoding such amino acid sequences and polypeptides to methods for preparing such amino acid sequences and polypeptides; to host cells expressing or capable of expressing such amino acid sequences or polypeptides; to compositions, and in particular to pharmaceutical compositions, that comprise such amino acid sequences, polypeptides, nucleic acids and/or host cells; and to uses of such amino acid sequences or polypeptides, nucleic acids, host cells and/or compositions, in particular for prophylactic, therapeutic or diagnostic purposes, such as the prophylactic, therapeutic or diagnostic purposes mentioned herein.

Abstract: The present invention relates to amino acid sequences that block the interaction between (a target on) an antigen presenting cell (APC) and (a target on) a T-cell. More particularly, the present invention relates to amino acid sequences that are directed against (as defined herein) a target on an APC (also referred to herein as “APC target”) or a target on a T-cell (also referred to herein as “T-cell target”).

Abstract: A method of inhibiting viral infection using a monovalent antigen binding protein comprising a single domain binding unit capable of binding to a virus is described. Preferably the protein is a heavy chain variable domain derived from an immunoglobulin naturally devoid of light chains. Food, pharmaceutical and cosmetic products comprising such proteins are also described together with a method for selecting inhibiting proteins from a large population of mainly containing non-inhibiting, but infectious agent binding fragments.

Abstract: A method of inhibiting viral infection using a monovalent antigen binding protein comprising a single domain binding unit capable of binding to a virus is described. Preferably the protein is a heavy chain variable domain derived from an immunoglobulin naturally devoid of light chains. Food, pharmaceutical and cosmetic products comprising such proteins are also described together with a method for selecting inhibiting proteins from a large population of mainly containing non-inhibiting, but infectious agent binding fragments.