T-Lymphocyte Profile and Total and Virus-Specific Immunoglobulin Concentrations in the Cervix of HIV-1-Infected Women

ART influences HIV persistence in the female reproductive tract and cervicovaginal secretions

The recently completed HIV prevention trials network study 052 is a landmark collaboration demonstrating that HIV transmission in discordant couples can be dramatically reduced by treating the infected individual with antiretroviral therapy (ART). However, the cellular and virological events that occur in the female reproductive tract (FRT) during ART that result in such a drastic decrease in transmission were not studied and remain unknown. Here, we implemented an in vivo model of ART in BM/liver/thymus (BLT) humanized mice in order to better understand the ability of ART to prevent secondary HIV transmission. We demonstrated that the entire FRT of BLT mice is reconstituted with human CD4+ cells that are shed into cervicovaginal secretions (CVS). A high percentage of the CD4+ T cells in the FRT and CVS expressed CCR5 and therefore are potential HIV target cells. Infection with HIV increased the numbers of CD4+ and CD8+ T cells in CVS of BLT mice. Furthermore, HIV was present in CVS during infection. Finally, we evaluated the effect of ART on HIV levels in the FRT and CVS and demonstrated that ART can efficiently suppress cell-free HIV-RNA in CVS, despite residual levels of HIV-RNA+ cells in both the FRT and CVS.

Relationship Between Genital Drug Concentrations and Cervical Cellular Immune Activation and Reconstitution in HIV-1-Infected Women on a Raltegravir Versus a Boosted Atazanavir Regimen

Determinants of HIV-infected women's genital tract mucosal immune health are not well understood. Because raltegravir (RAL) achieves relatively higher genital tract concentrations than ritonavir-boosted atazanavir (ATV), we examined whether an RAL-based regimen is associated with improved cervical immune reconstitution and less activation in HIV(+) women compared to an ATV-based regimen. Peripheral blood, cervical brushings, cervical-vaginal lavage (CVL), and cervical biopsies were collected from HIV(+) women on tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) and either RAL (n=14) or ATV (n=19) with CD4(+) T cells>300 cells/mm(3) and HIV RNA<48 copies/ml. HLA-DR(+)CD38(+) T cells were measured in blood and cervical cells using flow cytometry, CD4(+) and CD8(+) T cells were quantified in cervical biopsies by immunofluorescent analysis, and HIV RNA (VL), ATV, and RAL concentrations were measured in CVL. In a linear regression model of log(CVL concentration) versus both log(plasma concentration) and treatment group, the RAL CVL level was 519% (95% CI: 133, 1,525%) higher than for ATV (p<0.001). Genital tract VL was undetectable in 90% of subjects and did not differ by regimen. There were no significant differences between groups in terms of cervical %HLA-DR(+)CD38(+)CD4(+) or CD8(+) T cells, CD4(+) or CD8(+) T cells/mm(2), or CD4:CD8 ratio. After adjusting for treatment time and group, the CVL:plasma drug ratio was not associated with the cervical CD4:CD8 ratio or immune activation (p>0.6). Despite significantly higher genital tract penetration of RAL compared to ATV, there were no significant differences in cervical immune activation or reconstitution between women on these regimens, suggesting both drug regimens achieve adequate genital tract levels to suppress virus replication.

Early HIV-1 infection is associated with reduced frequencies of cervical Th17 cells

BACKGROUND

The hallmark of HIV infection is progressive but variable rates of systemic and mucosal CD4 depletion, leading to immunodeficiency. The impact of early HIV infection on cervical CD4 T-cell populations in humans remains poorly described.

METHODS

We analyzed cytobrush-derived immune cells by flow cytometry and cytokines in cervicovaginal lavage from participants in early HIV (<6 months postinfection), chronic HIV, and HIV-uninfected controls.

RESULTS

CD4:CD8 ratios declined rapidly in both the cervix and the blood following HIV infection. In contrast, absolute cervical CD4 T-cell counts in early HIV were comparable to HIV-uninfected participants, declining only in chronic infection. Early HIV infection was associated with increases in RANTES and MIP3a in cervicovaginal fluids. Concurrently, slight increases in activated cells (CD38HLA-DR) and higher levels of CTLA4 expression on Tregs in the cervix were observed. Although study groups did not differ with respect to levels of CCR5, integrin B7, or CD69, the frequencies of Th17 cells (defined as CCR6CCR10) was reduced by >10-fold in early HIV infection and Th1 cells (defined as CCR6CXCR3) were reduced by >2-fold. Although CCR6CCR10 cells did not differ in HIV receptor expression, these cells produced higher levels of interferon gamma and interleukin 17.

CONCLUSIONS

These data support the model of initial CD4 T-cell depletion followed by overall T-cell influx in response to infection and concomitant increases in immune activation, inflammation, and regulatory markers. These data are among the earliest characterization of the cellular milieu in the female genital tract following male-to-female HIV transmission.

Characteristics and quantities of HIV host cells in human genital tract secretions

Human immunodeficiency virus (HIV)-infected leukocytes have been detected in genital secretions from HIV-infected men and women and may play an important role in the sexual transmission of HIV. However, they have been largely overlooked in studies on mechanisms of HIV transmission and in the design and testing of HIV vaccine and microbicide candidates. This article describes the characteristics and quantities of leukocytes in male and female genital secretions under various conditions and also reviews evidence for the involvement of HIV-infected cells in both horizontal and vertical cell-associated HIV transmission. Additional research is needed in this area to better target HIV prevention strategies.

HIV Infection in Uncircumcised Men Is Associated With Altered CD8 T-cell Function But Normal CD4 T-cell Numbers in the Foreskin

BACKGROUND

Human immunodeficiency virus (HIV)-infected (HIV+) men are more susceptible to sexually transmitted infections, and may be superinfected by HIV. We hypothesized that HIV induces immune alterations in the foreskin that may impact the subsequent acquisition/clearance of genital coinfections.

METHODS

Foreskin tissue and blood were obtained from 70 HIV-uninfected and 20 HIV+ men undergoing circumcision. T cells were characterized by flow cytometry, immunohistochemistry, and polymerase chain reaction.

RESULTS

There was substantial influx of CD8 T-cells into the foreskins of HIV+ men (108.8 vs 23.1 cells/mm(2); P < .001); but foreskin CD4 T-cell density was unchanged (43.0 vs 33.7/mm(2); P = .67), despite substantial blood depletion (409.0 vs 877.8 cells/µL; P < .001). While frequencies of foreskin C-C chemokine receptor type 5(+) (CCR5(+)) T cells, T regulatory cells, and T-helper 17 cells were unaltered in HIV+ men, CD8 T-cell production of tumor necrosis factor α (TNFα) was decreased. HIV-specific CD8 T cells were present in the foreskins of HIV+ men, although their frequency and function was reduced compared to the blood.

CONCLUSIONS

Foreskin CD4 T-cell density and CCR5 expression were not reduced during HIV infection, perhaps explaining susceptibility to HIV superinfection. Foreskin CD8 T-cell density was increased, but decreased production of TNFα may enhance susceptibility to genital coinfections in HIV+ men.

CCR5 expression is elevated on endocervical CD4+ T cells in healthy postmenopausal women

BACKGROUND

New HIV-1 infections are increasing in older American women largely through heterosexual transmission. Activated CD4+ T cells and CCR5 expression are linked to HIV-1 susceptibility, but whether these parameters are altered in the cervix of older women is unknown.

METHODS

Whole blood and in some instances endocervical brush samples were collected from healthy premenopausal (n = 22) and postmenopausal women (n = 24). Percentages of HLA-DR(DR)+CD38(38)+CD4+ T cells and HIV-1 chemokine coreceptor expression were determined by flow cytometry.

RESULTS

Percentages of DR+38+CD4+ T cells were 6 times greater in cervix (median: 6.4%) than blood (median: 1.1%; P < 0.001) but did not differ within each compartment between premenopausal and postmenopausal women (P = 0.2). Postmenopausal women had greater percentages of CCR5+CD4+ and CCR5+DR+38+CD4+ T cells compared with premenopausal women in cervix (median: 70% vs. 42%, P = 0.005; and 80% vs. 57%; P = 0.05, respectively) and blood (medians: 22% vs. 13%, and 76% vs. 62%, respectively; P < 0.001). Postmenopausal women had more CCR5 molecules on cervical DR+38+CD4+ T cells (median: 3176) than premenopausal women (median: 1776; P = 0.02). Age and percent CCR5+CD4+ and CCR5+DR+38+CD4+ cells were linearly related in cervix (r(2) = 0.47, P < 0.001 and r(2) = 0.25, P = 0.01, respectively) and blood (r(2) = 0.20, P = 0.001 and r(2) = 0.31, P < 0.001; respectively), but confounding of age with menopause could not be excluded. Cervical CXCR4 expression did not differ substantially between premenopausal and postmenopausal women.

CONCLUSIONS

Elevated cervical CCR5 expression in postmenopausal women may increase their risk for HIV-1 acquisition. Studies are needed to confirm whether elevated CCR5 expression confers increased HIV-1 susceptibility in postmenopausal women, and if it is related to hormonal or nonhormonal effects of aging.

Development of a pigtail macaque model of sexually transmitted infection/HIV coinfection using Chlamydia trachomatis, Trichomonas vaginalis, and SHIV(SF162P3)

BACKGROUND

Sexually transmitted infections (STIs) are associated with an increased risk of HIV infection. To model the interaction between STIs and HIV infection, we evaluated the capacity of the pigtail macaque model to sustain triple infection with Trichomonas vaginalis, Chlamydia trachomatis, and SHIV(SF162P3).

METHODS

Seven SHIV(SF162P3) -infected pigtail macaques were inoculated with T. vaginalis only (n = 2), C. trachomatis only (n = 1), both T. vaginalis and C. trachomatis (n = 2), or control media (no STI; n = 2). Infections were confirmed by culture and/or nucleic acid testing. Genital mucosa was visualized by colposcopy.

RESULTS

Characteristic gynecologic signs were observed for both STIs, but not in control animals. Manifestations were most prominent at days 7-10 post-infection. STIs persisted between 4 and 6 weeks and were cleared with antibiotics.

CONCLUSIONS

These pilot studies demonstrate the first successful STI-SHIV triple infection of pigtail macaques, with clinical presentation of genital STI symptoms similar to those observed in humans.

In situ distribution of HIV-binding CCR5 and C-type lectin receptors in the human endocervical mucosa

The endocervical mucosa is believed to be a primary site of HIV transmission. However, to date there is little known about the distribution of the HIV co-receptor CCR5 and the HIV-binding C-type lectin receptors, including Langerin, dendritic cell (DC)-specific intercellular adhesion molecule-grabbing non-integrin (DC-SIGN) and mannose receptor (MR) at this site. We therefore characterized the expression of these molecules in the endocervix of HIV seronegative women by computerized image analysis. Endocervical tissue biopsies were collected from women (n = 6) undergoing hysterectomy. All study individuals were diagnosed with benign and non-inflammatory diseases. CCR5+ CD4+ CD3+ T cells were found within or adjacent to the endocervical epithelium. The C-type lectin Langerin was expressed by intraepithelial CD1a+ CD4+ and CD11c+ CD4+ Langerhans cells, whereas DC-SIGN+ MR+ CD11c myeloid dendritic cells and MR+ CD68+ macrophages were localized in the submucosa of the endocervix. The previously defined immune effector cells including CD8+, CD56+, CD19+ and IgD+ cells were also found in the submucosa as well as occasional CD123+ BDCA-2+ plasmacytoid dendritic cells. Understanding the spatial distribution of potential HIV target cells and immune effector cells in relation to the endocervical canal forms a basis for deciphering the routes of HIV transmission events in humans as well as designing HIV-inhibiting compounds.

Increases in human papillomavirus detection during early HIV infection among women in Zimbabwe

BACKGROUND

Individuals who acquire human immunodeficiency virus (HIV) may experience an immediate disruption of genital tract immunity, altering the ability to mount a local and effective immune response. This study examined the impact of early HIV infection on new detection of human papillomavirus (HPV).

METHODS

One hundred fifty-five Zimbabwean women with observation periods before and after HIV acquisition and 486 HIV-uninfected women were selected from a cohort study evaluating hormonal contraceptive use and risk of HIV acquisition. Study visits occurred at 3-month intervals. Cervical swab samples available from up to 6 months before, at, and up to 6 months after the visit when HIV was first detected were typed for 37 HPV genotypes or subtypes.

RESULTS

We observed ∼5-fold higher odds of multiple (≥2) new HPV detections only after HIV acquisition, relative to HIV-negative women after adjusting for sexual behavior and concurrent genital tract infections. We also observed ∼2.5-fold higher odds of single new HPV detections at visits before and after HIV acquisition, relative to HIV-uninfected women in multivariable models.

CONCLUSIONS

These findings suggest that HIV infection has an immediate impact on genital tract immunity, as evidenced by the high risk of multiple new HPV detections immediately after HIV acquisition.

Stability and transport of cervical cytobrushes for isolation of mononuclear cells from the female genital tract

Cervical cytobrushing, biopsy, or lavages have previously been used to collect mononuclear cells from the female genital tract. Compared with blood, obtaining cells from the female genital tract is more invasive and generally yields few cells for subsequent immune studies. Because of the value of including mucosal sampling in HIV vaccine trials, standardisation of methods for collection, processing, and analysis of immunity from cells derived from the female genital tract is important. The aim of this study was to assess the effect of transport conditions on the viability, recovery and antigenic responsiveness of cervical T cells. This was investigated in cervical cytobrush specimens collected from 215 chronically HIV-infected women. Cytobrushes were either processed immediately, after cryopreservation, or after 24h at 37°C, 4°C or room temperature. CD3(+) T cell numbers were quantified using Guava automated cell counting. Viability was assessed using Trypan and Annexin/PI staining. Intracellular cytokine staining was used to evaluate IFN-γ responses to PMA, PHA and CEF peptides in cytobrush-derived T cells ex vivo and after delayed processing. In vitro polyclonal expansion of thawed cervical lymphocytes was conducted for 14days in the presence of anti-CD3 and IL-2. We found that CD3(+) T cell recovery and viability was similar in cytobrushes processed immediately or after 24h irrespective of the conditions at which they were maintained. Fifty percent of the CD3(+) T cells could be recovered after cryopreservation of cytobrushes and these could be polyclonally expanded in half of the cryopreserved samples. IFN-γ production following mitogenic stimulation was similar in ex vivo and delayed processing cytobrushes. Maintaining cytobrushes at 37°C prior to processing significantly improved the detection of CEF-specific T cell responses compared to ex vivo. We conclude that cervical cytobrush-derived T cells are robust and can preserve their viability, phenotype and function over 24h of mock transport.

The potential impact of CD4+ T cell activation and enhanced Th1/Th2 cytokine ratio on HIV-1 secretion in the lungs of individuals with advanced AIDS and active pulmonary infection

Bronchoalveolar lavage fluid (BALF) provides a source of mucosal CD4(+) T cells. We investigated the physiological properties of T lymphocytes from BALF and blood and their role on the dynamic of HIV-1 replication among AIDS patients with active lung infections. Pulmonary CD4(+) T cells consist mainly of effector memory cells (CD45RO(+) and CCR7(-)) with increased expression of activation markers (HLA-DR(+) and CD69(+)) when compared to the blood counterpart. We observed a high frequency of BALF cells capable of secreting HIV-1-Ags suggesting that the local lung environment may support favorable conditions for CD4(+) T lymphocytes harboring HIV-1 DNA to initiate the viral cycle. Nevertheless, the high number of IFN-γ-producing cells and the predominance of Th1 immune response in the lung could limit the secretion of HIV-1 RNA. In conclusion, the capacity of activated CD4(+) T cells to produce HIV-1 is driven by both the level and quality of cellular activation in the lung.

Foreskin inflammation is associated with HIV and herpes simplex virus type-2 infections in Rakai, Uganda

DESIGN

We assessed foreskin inflammation associated with HIV and herpes simplex virus type 2 (HSV-2) in circumcised men.

METHODS

Foreskin tissues were assessed in 97 HIV-infected and 135 HIV-uninfected men enrolled in randomized trials of circumcision in Rakai, Uganda. Inflammation was quantified using an ordinal score evaluating extent, intensity, and cellular composition of infiltrates in the epithelium and stroma. Prevalence rate ratios of inflammation were estimated by multivariate Poisson regression.

RESULTS

Foreskin inflammation was primarily focal. Epithelial inflammation was present in 4.2% of men with neither HIV nor HSV-2 infection; 7.8% of men with only HSV-2; 19.0% with HIV alone (P = 0.04); and 31.6% in HIV/HSV-2 coinfected men [prevalence rate ratio (PRR) 7.5, 95% confidence interval (CI) 2.3-23.8, P < 0.001]. Stromal inflammation was present in 14.1% of HIV/HSV-2 uninfected men, compared with 29.7% in men with HSV-2 alone (P = 0.03), 33.3% in men with HIV alone (P = 0.04), and 61.0% in men with HIV/HSV-2 coinfection (PRR 4.3, 95% CI 2.3-7.9, P < 0.001). In HIV-infected men, epithelial inflammation was associated with higher HIV viral load. Epithelial inflammation was more frequent among men reporting recent genital ulceration. Both epithelial and stromal inflammation were more common among men with smegma on physical examination.

CONCLUSION

Foreskin inflammation is increased with HIV and HSV-2 infections, higher HIV viral load and presence of smegma. Foreskin inflammation may have implications for HIV transmission and acquisition in uncircumcised men.

Depletion of CD4+ T cells in semen during HIV infection and their restoration following antiretroviral therapy

BACKGROUND

Information concerning the effects of HIV-1 infection, disease progression, and antiretroviral therapy (ART) on male genital white blood cell (WBC) profiles could provide important insight into genital immune defense in HIV-infected men and seminal HIV transmission mechanisms.

OBJECTIVE

To compare concentrations of WBC populations in semen from HIV-1-seronegative (HIV) and HIV-1-seropositive (HIV) men and determine whether HIV disease stage and ART are associated with alterations in seminal WBC profiles.

SUBJECTS AND METHODS

Subjects were 102 HIV men, 98 ART-naive (ART) HIV men, and 22 HIV men on dual nucleoside ART, before and 6 months after addition of indinavir. Seminal WBCs, macrophages (MØ), and T-lymphocyte subpopulations were enumerated by immunohistology technique.

RESULTS

Seminal CD4 and CD8 T-cell populations were severely depleted in most ART HIV men regardless of peripheral blood CD4 cell count. Seminal MØ counts were reduced by 50%. HIV men on dual nucleoside ART had significantly higher seminal MØ, CD4, and CD8 T-cell counts than ART HIV men; addition of indinavir led to a dramatic (>25-fold, P < 0.001) increase in seminal CD4 T-cell counts which paralleled an increase in blood CD4 cell counts. Two outlier ART HIV men with notably elevated seminal WBC profiles (>20 x 10 WBCs/mL) and infectious cell-associated HIV in semen are described.

CONCLUSIONS

HIV infection severely depletes CD4 T cells in the male genital tract as it does at other mucosal sites. This provides evidence that ART HIV men have depressed T cell-dependent genital immune defense functions and are vulnerable to other genital infections that could promote HIV transmission. Seminal CD4 T-cell counts rebounded after treatment with a viral-suppressing ART regimen, indicating that ART may reverse HIV-associated genital immunosuppression. The relative abundance of seminal MØ in HIV men suggests that these cells may be predominant HIV host cells in the male genital tract and vectors of HIV transmission. A subgroup of HIV men with exceptionally elevated seminal MØ and CD4 T-cell counts and HIV titers may be highly infectious and contribute disproportionately to HIV transmission.

Impact of human immunodeficiency virus 1 infection and inflammation on the composition and yield of cervical mononuclear cells in the female genital tract

Cervical cytobrush sampling is a relatively non-invasive method for obtaining mucosal cells from the female genital tract. To define mucosal immune cells sampled by cervical cytobrushing and to validate this approach for local immunity studies, we investigated the impact of human immunodeficiency virus (HIV) status and inflammation on the yield and composition of cervical cytobrush specimens. Cervical cytobrush samples were obtained from 89 chronically HIV-infected and 46 HIV-negative women. The HIV-infected women had significantly higher yields of CD3(+), CD45(+), CD19(+), CD14(+), Langerin(+) and CD24(+) cells than the uninfected women. While cytobrush-derived T cells from uninfected women were predominantly CD4(+) (4.2 CD4 : 1 CD8), CD8(+) T cells were predominant in HIV-infected women (0.6 CD4 : 1 CD8). The majority of CD4(+) and CD8(+) T cells from HIV-infected and uninfected women were of the effector memory (CD45RA(-) CCR7(-) CD27(-)) phenotype. HIV-infected women had significantly elevated levels of interleukin (IL)-1beta, IL-6 and IL-8 in cervical supernatants compared with uninfected women. We observed a significant positive correlation between T-cell counts and IL-1beta, tumour necrosis factor (TNF)-alpha and IL-12 concentrations. Neutrophil counts correlated significantly with cervical concentrations of IL-1beta, TNF-alpha, IL-8, IL-6 and IL-10. Antigen-presenting cell numbers correlated significantly with TNF-alpha and IL-12 concentrations. HIV-infected women on antiretroviral therapy had similar levels of cervical lymphocyte infiltration and inflammation to women naïve to therapy. In conclusion, we suggest that inflammation at the cervix and HIV infection are likely to be key determinants in the absolute number of mucosal immune cells recovered by cervical cytobrushing.