Infection of CD4+ T lymphocytes by the human T cell leukemia virus type 1 is mediated by the glucose transporter GLUT-1: evidence using antibodies specific to the receptor's large extracellular domain.
To analyze HTLV-1 cytotropism, we developed a highly sensitive vaccinia virus-based assay measuring activation of a reporter gene upon fusion of two distinct cell populations. We used this system in a functional cDNA screening to isolate and confirm that the glucose transporter protein 1 (GLUT-1) is a receptor for HTLV-1. GLUT-1 is a ubiquitously expressed plasma membrane glycoprotein with 12 transmembrane domains and 6 extracellular loops (ECL). We demonstrate for the first time that peptide antibodies (GLUT-IgY) raised in chicken to the large extracellular loop (ECL1) detect GLUT-1 at the cell surface and inhibit envelope (Env)-mediated fusion and infection. Efficient GLUT-IgY staining was detected with peripheral blood CD4(+) lymphocytes purified by positive selection. Further, GLUT-IgY caused efficient inhibition of Env-mediated fusion and infection of CD4(+) T and significantly lower inhibition of CD8(+) T lymphocytes. The specificity of GLUT-IgY antibodies to GLUT-1 was demonstrated by ECL1 peptide competition studies. Grafting ECL1 of GLUT-1 onto the receptor-negative GLUT-3 conferred significant receptor activity. In contrast, grafting ECL1 of GLUT-3 onto GLUT-1 resulted in a significant loss of the receptor activity. The ECL1-mediated receptor activity was efficiently blocked with four different human monoclonal antibody (HMab) to HTLV-1 Env. The ECL1-derived peptide blocked HTLV-1 Env-mediated fusion with several nonhuman mammalian cell lines. The results demonstrate the utilization of cell surface GLUT-1 in HTLV-1 infection of CD4(+) T lymphocytes and implicate a critical role for the ECL1 region in viral tropism.
Jin
Qingwen
Q
Department of Microbiology and Immunology, Walther Cancer Institute, Indiana University School of Medicine, Indianapolis, IN 46202-5114, USA.
Agrawal
Lokesh
L
VanHorn-Ali
Zainab
Z
Alkhatib
Ghalib
G
D000818:Animals; D000906:Antibodies / Q000378:metabolism; D000911:Antibodies, Monoclonal / Q000276:immunology; D000914:Antibodies, Viral / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000821:virology*; D002460:Cell Line; D005434:Flow Cytometry; D017930:Genes, Reporter; D051272:Glucose Transporter Type 1 / Q000032:analysis / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D051274:Glucose Transporter Type 3 / Q000235:genetics; D015368:Human T-lymphotropic virus 1 / Q000502:physiology*; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D011991:Receptors, Virus / Q000032:analysis / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000502:physiology; D013194:Staining and Labeling; D001616:beta-Galactosidase / Q000032:analysis / Q000235:genetics
D000906:Antibodies; D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D051272:Glucose Transporter Type 1; D051274:Glucose Transporter Type 3; C016512:IgY; D007136:Immunoglobulins; D010455:Peptides; D011991:Receptors, Virus; D011993:Recombinant Fusion Proteins; D001616:beta-Galactosidase