Abstract: The invention relates to the use of a single heavy chain variable domain antibody against human cytomegalovirus protein US28, which antibody binds to the extracellular region including, for example, the N-terminal extracellular region and/or the extracellular loops of US28, for isolation of cells that are infected with cytomegalovirus and/or for ex vivo reactivation of cytomegalovirus in latently infected cells. The invention further relates to the anti-US28 antibody for use in a method of reactivating cytomegalovirus in infected cells, or in a method of eliminating infected cells. The invention further relates to a tissue, organ, or cells such as bone marrow stem cells, from which cells that were infected with CMV have been removed with the use of the anti-US28 antibody.

Abstract: The invention relates to a novel class of antagonistic and inverse agonistic anti-US28 antibodies, more specifically to single heavy chain variable domain antibodies (VHH) and variants and modifications thereof. The invention further relates to methods for producing these antibodies and to the use of the antibodies in methods for diagnostic and therapeutic purposes, especially for treatment of an individual suffering from a CMV-positive tumor such as glioblastoma.