Pregnancy in HIV-infected teenagers in London

OBJECTIVE

The aim of the study was to describe pregnancies in HIV-infected teenagers.

METHODS

A review of the case notes of HIV-infected pregnant teenagers aged 13-19 years from 12 London hospitals was carried out for the period 2000-2007.

RESULTS

There were 67 pregnancies in 58 young women, of whom one was known to have acquired HIV vertically. The overall mother-to-child transmission (MTCT) rate of HIV was 1.5% (one of 66). There were 66 live births. Median ages at HIV diagnosis and conception were 17 and 18 years, respectively. Sixty-three per cent of women were diagnosed with HIV infection through routine antenatal screening. Eighty-two per cent of pregnancies (41 of 50) were unplanned, with 65% of women (26 of 40) using no contraception. Forty-three per cent of the women (20 of 46) had a past history of a sexually transmitted infection (STI). In 63 pregnancies, antiretroviral therapy was started post-conception, with prevention of HIV MTCT the only indication in 81% of cases. Fifty-eight per cent of those on highly active antiretroviral therapy (HAART) had an undetectable HIV viral load by delivery. Eighty-seven per cent were uncomplicated pregnancies. Seventy-one per cent delivered by Caesarean section and 21% (14 of 64) had a preterm delivery (<37 weeks). In the 12 months after delivery, 45% of women received contraceptive advice and 25% of women became pregnant again.

CONCLUSION

Obstetric and virological outcomes were favourable in this group of HIV-infected young women. However, the majority of pregnancies were unplanned with poor documentation of contraception use and advice and low rates of STI screening. A quarter of women conceived again within 12 months of delivery. Effective measures to reduce STIs, unplanned pregnancies and onward HIV transmission in HIV-infected teenagers are needed.

Human T-cell leukemia virus type 1 Tax protein binds to assembled nuclear proteasomes and enhances their proteolytic activity

The human T-cell leukemia virus type 1 (HTLV-1) Tax protein activates the HTLV-1 long terminal repeat and key regulatory proteins involved in inflammation, activation, and proliferation and may induce cell transformation. Tax is also the immunodominant target antigen for cytotoxic T cells in HTLV-1 infection. We found that Tax bound to assembled nuclear proteasomes, but Tax could not be detected in the cytoplasm. Confocal microscopy revealed a partial colocalization of Tax with nuclear proteasomes. As Tax translocated into the nucleus very quickly after synthesis, this process probably takes place prior to and independent of proteasome association. Tax mutants revealed that both the Tax N and C termini play a role in proteasome binding. We also found that proteasomes from Tax-transfected cells had enhanced proteolytic activity on prototypic peptide substrates. This effect was not due to the induction of the LMP2 and LMP7 proteasome subunits. Furthermore, Tax appeared to be a long-lived protein, with a half-life of around 15 h. These data suggest that the association of Tax with the proteasome and the enhanced proteolytic activity do not target Tax for rapid degradation and may not determine its immunodominance.

The presence and characterization of a virF gene on Agrobacterium vitis Ti plasmids

Octopine and nopaline strains of Agrobacterium tumefaciens differ in their ability to induce tumors on Nicotiana glauca. The presence of a virF locus on the octopine Ti plasmid makes N. glauca a host plant for these strains, indicating that the VirF protein is a host-range determinant. Here we show the presence of a virF locus not only on the Agrobacterium vitis octopine/cucumopine plasmids pTiAg57 and pTiTm4, but also on the nopaline Ti plasmids pTiAT1, pTiAT66a, and pTiAT66b. On the octopine Ti plasmids from A. tumefaciens the virF gene is located between the virE locus and the left border of the T-region. In contrast, the virF gene on Ti plasmids of A. vitis is located at the very left end of the vir-region near the virA locus. The virF gene of pTiAg57 has been sequenced and codes for a protein of 202 amino acids with a molecular mass of 22,280 Da. Comparison showed that the virF gene from A. vitis strain Ag57 is almost identical to that from A. tumefaciens octopine strains. The transcription of the pTiAg57 virF is inducible by the plant phenolic compound acetosyringone through the presence of a vir-box consensus sequence in its promoter region. The VirF protein from pTiAg57 can complement octopine A. tumefaciens strains deleted for virF as shown by tumor formation on N. glauca.