TY - JOUR
T1 - Infection by human herpesvirus 6 (HHV-6) of human lymphoid T cells occurs through an endocytic pathway
AU - Cirone, M.
AU - Zompetta, C.
AU - Angeloni, A.
AU - Ablashi, D. V.
AU - Salahuddin, S. Z.
AU - Pavan, A.
AU - Torrisi, M. R.
AU - Frati, L.
AU - Faggioni, A.
PY - 1992
Y1 - 1992
N2 - We have analyzed by immunoelectron microscopy the early events of binding and internalization of human herpesvirus 6 (HHV-6, strain GS) on a susceptible T-lymphoblastoid cell line, HSB-2. The virions bound to the cell surface at 4°C were tightly associated with the plasma membrane. Gold immunolabeling of the viral envelope proteins was strong and specific. Warming at 37°C for different times showed viral internalization through smooth surfaced pits and vesicles. Fusion events of the virions with the cell plasma membrane were never observed. Gold immunolabeling performed in parallel experiments before or after viral internalization showed: (1) absence of viral envelope proteins on the cell plasma membranes at all times of internalization, again excluding fusion events; (2) entry of the virions with their envelopes. Treatment of the cells with chloroquine, a drug known to affect the endocytic pathway, led to an almost complete inhibition of viral infectivity, suggesting that the endocytosed virions are responsible for a successful infection. Comparable results were obtained using a second strain of HHV-6 (BA92), with biologic and molecular characteristics similar to the prototype strain Z29. The chloroquine inhibition was effective on two different T cell lines (HSB-2 and J-Jhan), as well as on phytohemagglutinin-stimulated peripheral blood mononuclear cells.
AB - We have analyzed by immunoelectron microscopy the early events of binding and internalization of human herpesvirus 6 (HHV-6, strain GS) on a susceptible T-lymphoblastoid cell line, HSB-2. The virions bound to the cell surface at 4°C were tightly associated with the plasma membrane. Gold immunolabeling of the viral envelope proteins was strong and specific. Warming at 37°C for different times showed viral internalization through smooth surfaced pits and vesicles. Fusion events of the virions with the cell plasma membrane were never observed. Gold immunolabeling performed in parallel experiments before or after viral internalization showed: (1) absence of viral envelope proteins on the cell plasma membranes at all times of internalization, again excluding fusion events; (2) entry of the virions with their envelopes. Treatment of the cells with chloroquine, a drug known to affect the endocytic pathway, led to an almost complete inhibition of viral infectivity, suggesting that the endocytosed virions are responsible for a successful infection. Comparable results were obtained using a second strain of HHV-6 (BA92), with biologic and molecular characteristics similar to the prototype strain Z29. The chloroquine inhibition was effective on two different T cell lines (HSB-2 and J-Jhan), as well as on phytohemagglutinin-stimulated peripheral blood mononuclear cells.
UR - http://www.scopus.com/inward/record.url?scp=0027081354&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027081354&partnerID=8YFLogxK
M3 - Article
C2 - 1337259
AN - SCOPUS:0027081354
VL - 8
SP - 2031
EP - 2037
JO - AIDS Research and Human Retroviruses
JF - AIDS Research and Human Retroviruses
SN - 0889-2229
IS - 12
ER -