Specific adsorption of HTLV-I to various target human and animal cells

Abstract

In this report, we describe a flow cytometric analysis of HTLV-I specific binding to fresh and cultured cells on a single cell basis. This assay uses rhodamine hydrocarbon tagged, purified HTLV-I virions according to the procedure originally described for avian retroviruses. Successful HTLV-I transmission was detected by analysis of integrated HTLV-I DNA, virion-associated reverse transcriptase, and/or intracellular HTLV-I core antigen p19 expression. Only a specific virus- cell interaction was detected because nonrhodamine-tagged homologous virus or related HTLV-II interfered with tagged HTLV-I binding. In contrast, an unrelated, nonlabeled animal retrovirus was unable to block tagged HTLV binding. Of the cell lines tested, 2 nonlymphoid mammalian and 3 human lymphoid bound significantly high to moderate levels of HTLV-I-tagged virions. The other three human lymphocyte cell lines were insensitive to HTLV-I adsorption. A direct correlation was observed between HTLV-I binding sites and infectivity of human lymphoid cells alone and not other nonlymphoid animal cells. Fresh normal human mononuclear cells bound low levels of HTLV-I virions. As expected, T lymphocytes demonstrated more binding than did the non-T cell population. Enhancement of HTLV-I cell binding in a subpopulation of mononuclear target cells was achieved with phytohemagglutinin (PHA) activation and interleukin 2 (IL2) stimulation, which correlates well with previously published infectivity studies.

Analysis of the molecules involved in human T-cell leukaemia virus type 1 entry by a vesicular stomatitis virus pseudotype bearing its envelope glycoproteins

“…HTLV-1 primarily infects CD4 + T-cells, but also infects many different types of cells, such as CD8 + T-cells, B-cells, monocyte/macrophages and endothelial cells. Experimentally, HTLV-1 infects various species, including monkeys, rabbits and rats (Poiesz et al , 1980 ; Krichbaum-Stenger et al , 1987 ; Fan et al , 1992 ). HTLV-1 envelope glycoproteins, which are synthesized as a precursor, gp61, consist of a cell surface (gp46) and a transmembrane (gp21) glycoprotein (Seiki et al , 1983 ; Pique et al , 1992 ).…”