The foamy viruses.

Identification of an ER retrieval signal in a retroviral glycoprotein

“…The foamy viruses are a genus of retroviruses that infect a wide variety of mammalian hosts; e.g., they are ubiquitous in nonhuman primates, bovines, and felines and occasionally infect humans and other mammals (Hooks and Gibbs, 1975). However, foamy viruses have yet to be associated definitively with any disease process (Weiss, 1988;Mergia and Luciw, 1991;Neumann-Haefelin et al, 1993).…”

“…However, foamy viruses have yet to be associated definitively with any disease process (Weiss, 1988;Mergia and Luciw, 1991;Neumann-Haefelin et al, 1993). Similar to certain classic oncoviruses, the foamy viruses utilize a B/D-type virus assembly strategy by which immature viral capsids assemble in the cytoplasm in advance of virion budding (Achong et al, 1971;Hooks and Gibbs, 1975). As demonstrated by electron microscopy, the characteristic foamy cytopathic effect is due to syncytium formation and a proliferation of swollen, intracytoplasmic membrane-bound structures.…”

“…As demonstrated by electron microscopy, the characteristic foamy cytopathic effect is due to syncytium formation and a proliferation of swollen, intracytoplasmic membrane-bound structures. Furthermore, foamy viruses bud intracellularly into these cytoplasmic structures and also from the plasma membrane (Hooks and Gibbs, 1975).…”

Characterization of the transcriptional trans activator of human foamy retrovirus

“…The third subfamily of the Retroviridae, the foamy viruses, or spumaviruses, includes members able to replicate in a wide variety of species including cats, hamsters, cows, monkeys, chimpanzees, and humans (13,35). These ubiquitous viruses are also able to grow in a range of cell types, including fibroblasts, and are relatively easy to isolate from their infected hosts (13). In fact, the human spumaretrovirus (HSRV) was the first human retrovirus to be cultured in vitro (1).…”

“…In fact, the human spumaretrovirus (HSRV) was the first human retrovirus to be cultured in vitro (1). In tissue culture cells, spumaviruses are highly cytopathic, giving rise to characteristic multinucleated syncytia that have a highly vacuolated, "foamy" appearance (13,36). However, spumaviruses have yet to be clearly associated with any specific disease state and do not cause significant * Corresponding author.…”