In this group of high-risk African women, hormonal contraception and HSV-2 infection were both associated with increased risk for HIV-1 acquisition. HIV-1 risk associated with hormonal contraceptive use was not related to HSV-2 serostatus.

To characterize epitopes on human papillomavirus (HPV) virus-like particles (VLPs), a panel of mutated HPV-16 VLPs was created. Each mutated VLP had residues substituted from HPV-31 or HPV-52 L1 sequences to the HPV-16 L1 backbone. Mutations were created on the HPV-31 and ؊52 L1 proteins to determine if HPV-16 type-specific recognition could be transferred. Correct folding of the mutated proteins was verified by resistance to trypsin digestion and by binding to one or more conformation-dependent monoclonal antibodies. Several of the antibodies tested were found to bind to regions already identified as being important for HPV VLP recognition (loops DE, EF, FG, and HI). Sequences at both ends of the long FG loop (amino acids 260 to 290) were required for both H16.V5 and H16.E70 reactivity. A new antibody-binding site was discovered on the C-terminal arm of L1 between positions 427 and 445. Recognition of these residues by the H16.U4 antibody suggests that this region is surface exposed and supports a recently proposed molecular model of HPV VLPs.The human papillomavirus (HPV) virion is composed of major (L1) and minor (L2) capsid proteins. The L1 protein self-assembles into virus-like particles (VLPs) that appear identical to infectious virus both by electron microscopy and immunologically (8, 9, 11). The L2 protein is important for assembly of infectious virus (20) but does not contain the conformation-dependent and type-specific epitopes most frequently recognized by anti-HPV sera (2, 9).The VLP is a T ϭ 7 icosahedron composed of 72 pentamers of L1, termed capsomers. Sixty of the capsomers subunits are at hexavalent positions, interacting with six neighboring capsomers with the remaining 12 capsomers at pentavalent positions (1). The only HPV L1 crystal structure solved to date is of T1 particles (3), in which all capsomers are at pentavalent positions. In the T1 particle, capsomers interact through a portion of the C-terminal tail. This flexible arm extends away from the capsomer of origin, interacts with similar regions from neighboring capsomers and returns to the capsomer from which it came. The remainder of this C-terminal region extends around the circumference of the capsomer, participating in the core ␤-sheet structure, forming a short helix (h5) and finally reinserting into the core of the pentamer from which it came. Missing from this model is an intercapsomer disulfide bond, shown by others to help stabilize the VLP structure (12, 21).A revised model for HPV VLPs was proposed by Modis et al. (18). In this model, the C-terminal extension adopts a conformation similar to its conformation in the T1 structure, but instead of returning to the capsomer of origin, the arm is displaced onto, and ultimately invades, a neighboring capsomer. The C-terminal arm is anchored by the previously described disulfide bond between the cysteine from this region (amino acids 428) and cysteine 175 of a neighboring capsomer. The new model was termed the "invading arm" model because of its similarity to the simian virus 40 a...

Objectives Several studies have demonstrated an association between herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus type 1 (HIV-1), but limited data on risk factors for HSV-2 acquisition are available. The objective of this analysis was to determine the incidence and risk factors for HSV-2 acquisition among HIV-1-seronegative Kenyan female sex workers. Methods Between February 1993 and December 2006, HIV-1-seronegative women attending a municipal sexually transmitted infections (STI) clinic were invited to enroll in a prospective cohort study. Screening for HIV-1 and STIs were done at monthly follow-up visits. Archived blood samples were tested for HSV-2. Results Of 1527 HIV-1-seronegative women enrolled, 302 (20%) were HSV-2-seronegative at baseline, of whom, 297 had at least one follow-up visit. HSV-2 incidence was high (23 cases/100 person-years; 115 cases). In multivariate analysis, HSV-2 was significantly associated with more recent entry into sex work, workplace, and higher number of sex partners per week. Condom use was protective, although this was statistically significant only for the intermediate strata (25–75% condom use, HR 0.43, p=0.05). There were statistical trends for bacterial vaginosis to increase HSV-2 risk (HR 1.56, p=0.07) and for oral contraceptive use to decrease risk (HR 0.50, p=0.08). The 23% annual HSV-2 incidence in this study is among the highest reported anywhere in the world. Conclusions Women were at increased risk if they had recently entered sex work, had a higher number of sex partners, or worked in bars. HSV-2 risk reduction interventions are urgently needed among high-risk African women.

Human immunodeficiency type 1 (HIV-1) continues to spread at an alarming rate. The virus may be transmitted through blood, genital secretions, and breast milk, and higher levels of systemic virus in the index case, as measured by plasma RNA viral load, have been shown to correlate with increased risk of transmitting HIV-1 both vertically and sexually. Less is known about the correlation between transmission and HIV-1 levels in breast milk or genital secretions, in part because reliable quantitative assays to detect HIV-1 in these fluids are not available. Here we show that the Gen-Probe HIV-1 viral load assay can be used to accurately quantify viral load in expressed breast milk and in cervical and vaginal samples collected on swabs. Virus could be quantified from breast milk and swab samples spiked with known amounts of virus, including HIV-1 subtypes A, C, and D. As few as 10 copies of HIV-1 RNA could be detected above background threshold levels in >77% of assays performed with spiked breast milk supernatants and mock swabs. In genital swab samples from HIV-1-infected women, similar levels of HIV-1 RNA were consistently detected in duplicate swabs taken from the same woman on the same clinic visit, suggesting that the RNA values from a single swab sample can be used to measure genital viral load.

The association between hormone fluctuations during the menstrual cycle and human immunodeficiency virus type 1 (HIV-1) RNA shedding in cervical and vaginal secretions was examined daily for 17 HIV-1-seropositive women, for the duration of 1 cycle. Serum levels of RNA were evaluated 3 times/week. A marginally significant positive correlation between serum levels of progesterone and serum levels of HIV-1 RNA (P=.04) was observed. Cervical virus levels were significantly correlated with the number of days from the midcycle surge in luteinizing hormone (LH) (P=.008). The lowest levels of cervical HIV-1 RNA were present at the LH surge, and this nadir was followed by an increase in virus levels that reached a maximum before the start of menses. In contrast, there was no significant association between the number of days from the LH surge and the level of HIV-1 RNA in vaginal secretions (P=.4). These data support the hypothesis that the level of HIV-1 RNA in cervical secretions is influenced by the menstrual cycle, and they suggest that the risk of heterosexual transmission of HIV-1 may increase as menses is approached.