Spontaneous production of C-C chemokines by individuals infected with human T lymphotropic virus type II (HTLV-II) alone and HTLV-II/HIV-1 coinfected individuals.
To investigate the immunological features of human T lymphotropic virus type II (HTLV-II) infection and specific mechanisms whereby HTLV-II might influence the progression of HIV-1 disease in coinfected individuals, we have analyzed the production of the C-C chemokines RANTES and macrophage inflammatory proteins 1alpha and 1alpha (MIP-1alpha and MIP-1beta) by PBMCs from HTLV-II-infected and HTLV-II/HIV-1-coinfected individuals. We observed spontaneous production of significant levels of MIP-1alpha and -1beta and, to a lesser extent, RANTES, from individuals infected with HTLV-II alone or with concomitant HIV-1 infection. Spontaneous C-C chemokine production was not observed in PBMCs from uninfected or HIV-1-infected individuals. Although HTLV-II is known to preferentially infect CD8+ lymphocytes in vivo, we observed that whereas RANTES was produced exclusively by the CD8+-enriched fraction, MIP-1alpha and -1beta were produced by both the CD8+-enriched and CD8+-depleted fractions of HTLV-II-infected PBMCs. RT-PCR demonstrated active expression of the HTLV-II regulatory protein Tax in the infected CD8+ T lymphocyte population, and it was further shown that Tax transactivates the promoters of MIP-1beta and RANTES. Therefore, it appears that HTLV-II stimulates the production of C-C chemokines both directly at a transcriptional level via the viral transactivator Tax and also indirectly. Although the HTLV-II-infected individuals in this study are all virtually asymptomatic, they certainly display an abnormal immune phenotype. Moreover, our findings suggest that HTLV-II, via chemokine production, would be expected to alter the progression of HIV-1 infection in coinfected individuals.
Lewis
M J
MJ
Department of Medical Microbiology, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Ireland.
Gautier
V W
VW
Wang
X P
XP
Kaplan
M H
MH
Hall
W W
WW
D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000821:virology; D002460:Cell Line; D002478:Cells, Cultured; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D018946:Chemokine CCL5 / Q000096:biosynthesis / Q000235:genetics; D019742:Chemokines, CC / Q000096:biosynthesis*; D005260:Female; D016356:Gene Products, tax / Q000502:physiology; D015658:HIV Infections / Q000235:genetics / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D015491:HTLV-II Infections / Q000235:genetics / Q000276:immunology*; D015367:Human T-lymphotropic virus 2 / Q000276:immunology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism / Q000821:virology; D019402:Macrophage Inflammatory Proteins / Q000096:biosynthesis / Q000235:genetics; D008297:Male; D015533:Transcriptional Activation / Q000276:immunology; D014162:Transfection
D054405:Chemokine CCL3; D054407:Chemokine CCL4; D018946:Chemokine CCL5; D019742:Chemokines, CC; D016356:Gene Products, tax; D019402:Macrophage Inflammatory Proteins