Tat protein of HIV-1 stimulates growth of cells derived from Kaposi's sarcoma lesions of AIDS patients.
Kaposi's sarcoma (KS) is frequently associated with human immunodeficiency virus-1 (HIV-1) infection. Supernatants from HIV-1-infected T cells carrying the CD4 antigen promote the growth of cells derived from KS lesions of AIDS patients (AIDS-KS cells), and the HIV-1 tat gene, introduced into the germ line of mice, induces skin lesions closely resembling KS. Here we report that the tat gene product (Tat) is released from both HIV-1-acutely infected H9 cells and tat-transfected COS-1 cells. These Tat-containing supernatants specifically promote growth of AIDS-KS cells which are inhibited by anti-Tat antibodies; recombinant Tat has the same growth-promoting properties. Therefore a viral regulatory gene product can be released as a biologically active protein and directly act as a growth stimulator. These and previous data indicate that extracellular Tat could be involved in the development or progression, or both, of KS in HIV-1-infected individuals.
Ensoli
B
B
Laboratory of Tumor Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
Barillari
G
G
Salahuddin
S Z
SZ
Gallo
R C
RC
Wong-Staal
F
F
D000163:Acquired Immunodeficiency Syndrome / Q000150:complications*; D002455:Cell Division; D002460:Cell Line; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D015696:Gene Products, tat / Q000235:genetics / Q000502:physiology*; D015497:HIV-1 / Q000378:metabolism*; D006801:Humans; D007163:Immunosorbent Techniques; D011994:Recombinant Proteins / Q000494:pharmacology; D012514:Sarcoma, Kaposi / Q000209:etiology / Q000473:pathology*; D015534:Trans-Activators / Q000502:physiology*; D014162:Transfection; D054322:tat Gene Products, Human Immunodeficiency Virus
D015696:Gene Products, tat; D011994:Recombinant Proteins; D015534:Trans-Activators; D054322:tat Gene Products, Human Immunodeficiency Virus