Abstract: In one aspect, the invention relates to a method suitable for administering protein therapeutic molecules orally, sublingually, topically, intravenously, subcutaneously, nasally, vaginally, rectally or by inhalation so as to avoid inactivation, by using VHH polypeptides derived from Camelidae antibodies. The invention further relates to the said therapeutic molecules. The invention further a method for delivering therapeutic molecules to the interior of cells. The invention further relates to anti-IgE therapeutic molecules. In one aspect, the present invention relates to a method wherein an immunoglobulin single variable domain (such as a Nanobody) and/or construct thereof are absorbed in pulmonary tissue. More particularly, the invention provides systemic delivery of an immunoglobulin single variable domain and/or construct thereof via the pulmonary route.

Abstract: The present invention relates to amino acid sequences that are directed against 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; 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.