amphotropic

Amphotropic is an adjective used in virology and molecular biology to describe viruses, viral envelopes, or vectors that can infect cells from multiple host species. The term contrasts with ecotropic tropism, which is restricted to cells of a single species, and xenotropic tropism, which targets cells of species other than the producer species but not its own cells.

In retrovirology, amphotropic murine leukemia virus (A-MuLV) is the canonical example. The amphotropic envelope enables entry into cells from many mammalian species, including humans, by using receptors such as Pit1 and Pit2 (phosphate transporters) present on diverse cell types. This broad host range makes amphotropic vectors useful for laboratory gene transfer experiments, as they can transduce a wide variety of cell lines.

In practice, amphotropic MLV-based vectors were widely used for gene delivery before safety and biosafety concerns led researchers to favor other systems. Enveloped pseudotypes with amphotropic tropism remain a reference tool for certain in vitro applications; however, their use in clinical gene therapy has diminished due to risks like insertional mutagenesis and the availability of alternative vectors such as lentiviruses and adeno-associated viruses.

Etymology: ampho- from Greek ambi, "both" or "around," and -tropic from tropus, "turning toward" or "charging toward."