Increased expression of CD4 molecules on Jurkat cells mediated by human immunodeficiency virus tat protein.
The tat gene of the human immunodeficiency virus, tat-III, when introduced into T-lymphoblastoid Jurkat cells by a Moloney retroviral recombinant DNA vector expressed high levels of the functional tat protein as measured by the chloramphenicol acetyltransferase assay. Immunofluorescence analysis with CD4-specific monoclonal antibodies demonstrated that the cell surface levels of the CD4 antigen were increased by 5- to 10-fold in the tat-III-infected Jurkat cells. Cellular cytoplasmic RNA analysis indicated that the enhanced CD4 expression was mediated at the mRNA level. Our findings suggest that the single expression of the human immunodeficiency virus tat protein in the absence of the other viral proteins causes an upregulation of CD4 gene expression on helper T cells, although infection of these cells by the virus, thus expressing all the viral gene products including tat, is known to downregulate CD4 antigen expression.
Koka
P
P
Division of Pediatric Oncology, Dana-Farber Cancer Institute, Massachusetts 02115.
Yunis
J
J
Passarelli
A L
AL
Dubey
D P
DP
Faller
D V
DV
Ynis
E J
EJ
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis*; D002478:Cells, Cultured; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis; D003001:Cloning, Molecular; D004351:Drug Resistance / Q000235:genetics; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D015696:Gene Products, tat; D005814:Genes, Viral; D005822:Genetic Vectors; D005839:Gentamicins; D006678:HIV / Q000235:genetics*; D006801:Humans; D008979:Moloney murine leukemia virus / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D012367:RNA, Viral / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000382:microbiology; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D054322:tat Gene Products, Human Immunodeficiency Virus
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D015696:Gene Products, tat; D005839:Gentamicins; D012333:RNA, Messenger; D012367:RNA, Viral; D014157:Transcription Factors; D054322:tat Gene Products, Human Immunodeficiency Virus; C010680:antibiotic G 418; D015500:Chloramphenicol O-Acetyltransferase