Induction of apoptosis by HIV-1-infected monocytic cells.
We have previously described a soluble 6000-Da peptide produced by an HIV-1-infected human macrophage cell line, clone 43(HIV), which induces apoptosis in T and B cells. We have identified this factor as the novel cDNA clone FL14676485 that encodes for the human hypothetical protein, FLJ21908. The FL14676485 cDNA clone was isolated from a 43(HIV) lambda ZAP Escherichia coli expression library and screened with a panel of rabbit and mouse anti-apoptotic Abs. We transfected the FL14676485 clone into Bosc cells and non-HIV-1-infected 43 cells. Western blot analysis of lysates from the FL14676485-transfected 43 cells and Bosc cells using anti-proapoptotic factor Abs revealed a protein with a molecular mass of 66 kDa corresponding to the size of the full-length gene product of the FL14676485 clone, while Western blot of the supernatant demonstrated a doublet of 46-kDa and 6000-Da peptide that corresponds to our previously described proapoptotic factor. Primary HIV-1(BaL)-infected monocytes also produce the FLJ21908 protein. Supernatants from these transfected cells induced apoptosis in PBMC, CD4(+), and CD8(+) T and B cells similar to the activity of our previously described proapoptotic factor. PCR analysis of 43 cells and 43(HIV) cells revealed a base pair fragment of 420 bp corresponding to the FL14676485 gene product in 43(HIV) cells, but not in 43 cells. The FLJ21908 protein induces apoptosis through activation of caspase-9 and caspase-3. We have further demonstrated that the FLJ21908 protein has apoptotic activity in the SH-SY5Y neuronal cell line and can be detected in brain and lymph tissue from HIV-1-infected patients who have AIDS dementia. The FLJ21908 protein may contribute to the apoptosis and dementia observed in AIDS patients.
Sperber
Kirk
K
Division of Clinical Immunology, Mount Sinai School of Medicine, New York, NY 10029, USA. Kirk.Sperber@mssm.edu
Beuria
Prarthana
P
Singha
Netai
N
Gelman
Irwin
I
Cortes
Patricia
P
Chen
Houchu
H
Kraus
Thomas
T
D015526:AIDS Dementia Complex / Q000378:metabolism / Q000473:pathology; D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000276:immunology*; D051017:Apoptosis Regulatory Proteins; D002458:Cell Fractionation; D002460:Cell Line; D002474:Cell-Free System / Q000737:chemistry / Q000502:physiology; D002478:Cells, Cultured; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D008264:Macrophages / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009000:Monocytes / Q000166:cytology* / Q000276:immunology / Q000821:virology*; D009474:Neurons / Q000166:cytology / Q000276:immunology / Q000473:pathology; D011506:Proteins / Q000302:isolation & purification / Q000502:physiology*; D014162:Transfection; D014407:Tumor Cells, Cultured; D020298:U937 Cells
D051017:Apoptosis Regulatory Proteins; D011506:Proteins; C472351:RPAP3 protein, human