Activation of the signal transducer and activator of transcription 1 signaling pathway in thymocytes from HIV-1-infected human thymus.
OBJECTIVE
To identify HIV-induced host factors in the severe combined immunodeficient (SCID)-hu Thy/Liv mouse that may contribute to HIV pathogenesis in the thymus.


METHODS
To identify genes specifically altered by HIV-1 infection using the cDNA microarray assay, SCID-hu Thy/Liv organs derived from the same donors were used. Therefore, no genetic variations existed between HIV and mock-infected samples. In addition, the 12-14 day post-infection timepoint was chosen because no significant thymocyte depletion was detected in HIV-infected Thy/Liv organs, so mRNA from the same cell types could be compared.


METHODS
Using SCID-hu Thy/Liv mice constructed from the same donor tissues, we analysed the expression of 9183 host genes in response to HIV infection with cDNA microarrays. Expression of selected genes with more than threefold induction was confirmed by measuring RNA (reverse transcriptase-polymerase chain reaction; RT-PCR) and proteins.


RESULTS
HIV-1 (JD or NL4-3) infection of the SCID-hu Thy/Liv mouse led to more than threefold induction of 19 genes, 12 of which were IFN-inducible and six were unknown EST clones. We confirmed induction by RT-PCR and protein blots. Both signal transducer and activator of transcription (STAT)1 and STAT2 proteins were induced, and STAT1 was also activated by phosphorylation at the Tyr701 and Ser727 sites in human thymus infected with HIV-JD or NL4-3. Treatment of human fetal thymus organ culture or human thymocytes with recombinant HIV-1 gp120 proteins also led to induction or activation of STAT1.


CONCLUSIONS
HIV-1 infection of the thymus led to activation of the STAT1 signaling pathway in thymocytes, which may contribute to HIV-1 pathogenesis in the thymus.
Miller
Eric D
ED
Lineberger Comprehensive Cancer Center, Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, 27599, USA.
Smith
Jonathan A
JA
Lichtinger
Monika
M
Wang
Liping
L
Su
Lishan
L
D000818:Animals; D004268:DNA-Binding Proteins / Q000032:analysis / Q000235:genetics*; D015870:Gene Expression; D020869:Gene Expression Profiling; D015699:HIV Envelope Protein gp120 / Q000494:pharmacology; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D023421:Models, Animal; D020411:Oligonucleotide Array Sequence Analysis; D009924:Organ Culture Techniques; D011994:Recombinant Proteins / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050794:STAT1 Transcription Factor; D050795:STAT2 Transcription Factor; D015398:Signal Transduction / Q000235:genetics*; D013601:T-Lymphocytes / Q000378:metabolism / Q000821:virology*; D013950:Thymus Gland / Q000196:embryology / Q000378:metabolism / Q000821:virology; D015534:Trans-Activators / Q000032:analysis / Q000235:genetics*
D004268:DNA-Binding Proteins; D015699:HIV Envelope Protein gp120; D011994:Recombinant Proteins; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D050795:STAT2 Transcription Factor; C494084:STAT2 protein, human; C494080:Stat1 protein, mouse; C494085:Stat2 protein, mouse; D015534:Trans-Activators