Ultrasensitive p24 Antigen Assay for Diagnosis of Perinatal Human Immunodeficiency Virus Type 1 Infection

We evaluated an ultrasensitive p24 antigen enzyme immunosorbent assay on 802 plasma specimens from 582 infants and children of 0 to 180 days of age. Overall sensitivity and specificity were 91.7% and 98.5%, respectively. After exclusion of infants of less than 7 days of age, the sensitivity and specificity were 93.7% and 98.3%, respectively

Evaluation of an Ultrasensitive p24 Antigen Assay as a Potential Alternative to Human Immunodeficiency Virus Type 1 RNA Viral Load Assay in Resource-Limited Settings

An inexpensive enzyme-linked immunosorbent assay method for human immunodeficiency virus type 1 quantitation, ultrasensitive p24 antigen assay (Up24), was compared with RNA viral load assay (VL). Up24 had 100% sensitivity of detection at a viral load of ≥30,000, with sensitivity of 46.4% at a viral load o

A chimeric Ty3/Moloney murine leukemia virus integrase protein is active in vivo.

This report describes the results of experiments to determine whether chimeras between a retrovirus and portions of Ty3 are active in vivo. A chimera between Ty3 and a Neo(r)-marked Moloney murine leukemia virus (M-MuLV) was constructed. The C-terminal domain of M-MuLV integrase (IN) was replaced with the C-terminal domain of Ty3 IN. The chimeric retroviruses were expressed from an amphotrophic envelope packaging cell line. The virus generated was used to infect the human fibrosarcoma cell line HT1080, and cells in which integration had occurred were selected by G418 resistance. Three independently integrated viruses were rescued. In each case, the C-terminal Ty3 IN sequences were maintained and short direct repeats of the genomic DNA flanked the integration site. Sequence analysis of the genomic DNA flanking the insertion did not identify a tRNA gene; therefore, these integration events did not have Ty3 position specificity. This study showed that IN sequences from the yeast retrovirus-like element Ty3 can substitute for M-MuLV IN sequences in the C-terminal domain and contribute to IN function in vivo. It is also one of the first in vivo demonstrations of activity of a retrovirus encoding an integrase chimera. Studies of chimeras between IN species with distinctive integration patterns should complement previous work by expanding our understanding of the roles of nonconserved domains

A chimeric Ty3/Moloney murine leukemia virus integrase protein is active in vivo.

This report describes the results of experiments to determine whether chimeras between a retrovirus and portions of Ty3 are active in vivo. A chimera between Ty3 and a Neo(r)-marked Moloney murine leukemia virus (M-MuLV) was constructed. The C-terminal domain of M-MuLV integrase (IN) was replaced with the C-terminal domain of Ty3 IN. The chimeric retroviruses were expressed from an amphotrophic envelope packaging cell line. The virus generated was used to infect the human fibrosarcoma cell line HT1080, and cells in which integration had occurred were selected by G418 resistance. Three independently integrated viruses were rescued. In each case, the C-terminal Ty3 IN sequences were maintained and short direct repeats of the genomic DNA flanked the integration site. Sequence analysis of the genomic DNA flanking the insertion did not identify a tRNA gene; therefore, these integration events did not have Ty3 position specificity. This study showed that IN sequences from the yeast retrovirus-like element Ty3 can substitute for M-MuLV IN sequences in the C-terminal domain and contribute to IN function in vivo. It is also one of the first in vivo demonstrations of activity of a retrovirus encoding an integrase chimera. Studies of chimeras between IN species with distinctive integration patterns should complement previous work by expanding our understanding of the roles of nonconserved domains

The organization of the human HPRT gene.

The organization of the X-linked gene for human hypoxanthine phosphoribosyltransferase (HPRT, EC 2.4.2.8.) has been determined by a combination of restriction endonuclease mapping, heteroduplex analysis and DNA sequence analysis of overlapping genomic clones. The entire gene is 42 kilobases in length and split into 9 exons. The sizes of the 7 internal exons and the exon-intron boundaries are identical to those of mouse HPRT gene. The 5' end of the gene lacks the prototypical 5' transcriptional regulatory sequence elements but contains extremely GC-rich sequences and five GC hexanucleotide motifs (5'-GGCGGG-3'). These structural features are very similar to those found in the mouse HPRT gene and to some of the regulatory signals common to a class of constitutively expressed "housekeeping" genes. Several transcriptional start sites have been identified by nuclease protection studies. Extensive sequence homology between the mouse and human genes is found in the 3' non-coding portion of the gene

Ultrasensitive p24 Antigen Assay for Diagnosis of Perinatal Human Immunodeficiency Virus Type 1 Infection▿

We evaluated an ultrasensitive p24 antigen enzyme immunosorbent assay on 802 plasma specimens from 582 infants and children of 0 to 180 days of age. Overall sensitivity and specificity were 91.7% and 98.5%, respectively. After exclusion of infants of less than 7 days of age, the sensitivity and specificity were 93.7% and 98.3%, respectively