Live attenuated simian immunodeficiency virus prevents super-infection by cloned SIVmac251 in cynomolgus monkeys.

The ability of a live attenuated simian immunodeficiency virus (SIV) to protect against challenge with cloned SIVmac251/BK28 was evaluated in four cynomolgus macaques. The intravenous infection of the C8 variant of the SIVmac251/32H virus, carrying an in-frame 12 bp deletion in the nef gene, did not affect the CD4+ and CD8+ cell counts, and a persistent infection associated with an extremely low virus burden in peripheral blood mononuclear cells (PBMCs) was established. After 40 weeks, these monkeys were challenged intravenously with a 50 MID50 dose of SIVmac251/BK28 virus grown on macaque cells. Four naive monkeys were infected as controls. Monkeys were monitored for 62 weeks following challenge. Attempts to rescue virus from either PBMCs or bone marrow from the C8-vaccinated monkeys were unsuccessful, but in two cases virus was re-isolated from lymph node cells. The presence of the SIV provirus with the C8 variant genotype maintaining its original nef deletion was shown by differential PCR in PBMCs, lymph nodes and bone marrow. Furthermore, in contrast to the control monkeys, the vaccinated monkeys showed normal levels for CD4+ and CD8+ cells, minimal lymphoid hyperplasia and no clinical signs of infection. Our results confirm that vaccination with live attenuated virus can confer protection. This appears to be dependent on the ability of the C8 variant to establish a persistent but attenuated infection which is necessary for inducing an immune response, as suggested by the persistence of a strong immune B cell memory and by the over-expression of interleukin (IL)-2, interferon-gamma and IL-15 mRNAs in PBMCs of C8-vaccinated monkeys but not in those of control monkeys

Control of SHIV-89.6p infection of cynomolgus monkeys by the HIV-1 tat protein vaccine

Vaccine strategies aimed at blocking virus entry have so far failed to induce protection against heterologous viruses. Thus, the control of viral infection and the block of disease onset may represent a more achievable goal of human immunodeficiency virus (HIV) vaccine strategies. Here we show that vaccination of cynomolgus monkeys with a biologically active HIV-1 Tat protein is safe, elicits a broad (humoral and cellular) specific immune response and reduces infection with the highly pathogenic simian-human immunodeficiency virus (SHIV)-89.6P to undetectable levels, preventing the CD4+ T-cell decrease. These results may provide new opportunities for the development of a vaccine against AIDS

Incidence of cervical disease associated to HPV in human immunodeficiency infected women under highly active antiretroviral therapy

<p>Abstract</p> <p>Background</p> <p>Women infected with human immunodeficiency virus (HIV) may be at higher risk of developing cervical cancer than non infected women. In a pilot study, we assessed the relationships among cervical cytology abnormalities associated to Human Papillomavirus (HPV), HIV infection and Highly Active Antiretroviral Therapy (HAART) on the development of Squamous Intraepithelial lesions (SILs). Out of the 70 HIV infected women from Douala -Cameroon (Central Africa) that we included in the study, half (35) were under HAART. After obtaining information related to their lifestyle and sexual behaviour, cervicovaginal samples for Pap smears and venous blood for CD4 count were collected and further divided into two groups based upon the presence or absence of cervical cytology abnormalities i.e. those with normal cervical cytology and those with low and high Squamous Intraepithelial lesions (LSIL, HSIL).</p> <p>Results</p> <p>Assessment was done according to current antiretroviral regimens available nationwide and CD4 count. It was revealed that 44.3% of HIV-infected women had normal cytology. The overall prevalence of LSIL and HSIL associated to HPV in the studied groups was 24.3% (17/70) and 31.4% (22/70) respectively. Among the 22 HSIL-positive women, 63.6% (14/22) were not on antiretroviral therapy, while 36.4% (8/22) were under HAART. HIV infected women under HAART with positive HSIL, showed a median CD4+ T cell count of 253.7 +/- 31.7 higher than those without therapy (164.7 +/- 26.1). The incidence of HSIL related to HPV infection within the study group independently of HAART initiation was high.</p> <p>Conclusion</p> <p>These results suggest the need for extension and expansion of the current study in order to evaluate the incidence of HPV infection and cervical cancer among HIV-infected and non HIV- infected women in Cameroon.</p

Control of SHIV-89.6P-infection of cynomolgus monkeys by HIV-1 Tat protein vaccine

Vaccine strategies aimed at blocking virus entry have so far failed to induce protection against heterologous viruses. Thus, the control of viral infection and the block of disease onset may represent a more achievable goal of human immunodeficiency virus (HIV) vaccine strategies. Here we show that vaccination of cynomolgus monkeys with a biologically active HIV-1 Tat protein is safe, elicits a broad (humoral and cellular) specific immune response and reduces infection with the highly pathogenic simian-human immunodeficiency virus (SHIV)-89.6P to undetectable levels, preventing the CD4+ T-cell decrease. These results may provide new opportunities for the development of a vaccine against AIDS