PRODUCTIVE PERSISTENT INFECTION OF HEMATOPOIETIC-CELLS BY HUMAN FOAMYVIRUS

Human foamy virus can establish persistent infections in human hematop oietic cell lines, such as H92.1.7 (erythroblastoid cells), Jurkat (CD 4(+) T cells), and U937 (myeloid-monocytic cells), The infection is ch aracterized by constant production of infectious viruses (for >2 1/2 y ears) with no cytopathic effects on the host cells, Electron microscop y of the infected cells showed a viral morphology similar to that obse rved for particles produced after acute infection, We have detected, i n addition to the full-length form of bell, a previously described del etion in the bell gene of the proviral DNA in these cells, RNA contain ing this 301-bp deletion, which mapped to the splice donor and accepto r sites of the intron of the bet gene, was also found in encapsidated virion RNA, However, the presence of this defective provirus harboring the deletion in bell does not prevent productive persistence in these chronically infected cells, since the virus titer does not decrease d uring cultivation.