The role of the Tat gene in the pathogenesis of HIV infection.
The human immunodeficiency virus Tat regulatory protein is essential for virus replication and for the efficient transcription of HIV-1 provirus, and in the pathogenesis of AIDS. The role of the tat gene was investigated in 300 samples. It was found that 71.7% were subtype CRF_01AE, 9.3% were subtype B, while 11.7 and 7.3% of them were cross-reactive and non-typeable, respectively. Moreover the results from peptide ELISA also showed that a low CD4 cell count was related to a low anti-Tat antibody (p < 0.05), which may be due to the progression of HIV-1, which can be found predominantly in AIDS patients. The results of nested PCR showed that the second Tat exon might also play a role in T-cell activation. Reverse transcription polymerase chain reaction (RT-PCR) was used to measure HIV-1 mRNA expression in PBMC. RT-PCR negative results were found mostly in the asymptomatic HIV-seropositive group (88%). HIV-1 mRNA expression was found to correlate with current immunologic status. The differences in Tat protein sequences from DNA sequencing between the patients who had anti-Tat antibody positive and anti-Tat antibody negative, were not significant (p > 0.05). These results suggested that the Tat amino acid sequences were conserved among each group of samples and did not change significantly compared with the consensus sequence in previous studies. Several factors make Tat an attractive target for vaccine design.
Amarapal
Pornsawan
P
Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. g4537221@ego.co.th
Tantivanich
Surang
S
Balachandra
Kruavon
K
Matsuo
Kazuhiro
K
Pitisutithum
Punnee
P
Chongsa-nguan
Manus
M
D000328:Adult; D000368:Aged; D001483:Base Sequence; D018791:CD4 Lymphocyte Count; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D015756:Genes, tat / Q000235:genetics*; D015483:HIV Antibodies / Q000032:analysis; D015658:HIV Infections / Q000235:genetics*; D015497:HIV-1 / Q000235:genetics* / Q000472:pathogenicity*; D006801:Humans; D007223:Infant; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger; D017422:Sequence Analysis, DNA; D013785:Thailand; D014779:Virus Replication / Q000235:genetics*
D015483:HIV Antibodies; D012333:RNA, Messenger