Marta E. Bull

Monotypic human immunodeficiency virus type 1 genotypes across the uterine cervix and in blood suggest proliferation of cells with provirus

ABSTRACT Understanding the dynamics and spread of human immunodeficiency virus type 1 (HIV-1) within the body, including within the female genital tract with its central role in heterosexual and peripartum transmission, has important implications for treatment and vaccine development. To study HIV-1 populations within tissues, we compared viruses from across the cervix to those in peripheral blood mononuclear cells (PBMC) during effective and failing antiretroviral therapy (ART) and in patients not receiving ART. Single-genome sequences of the C2-V5 region of HIV-1 env were derived from PBMC and three cervical biopsies per subject. Maximum-likelihood phylogenies were evaluated for differences in genetic diversity and compartmentalization within and between cervical biopsies and PBMC. All subjects had one or more clades with genetically identical HIV-1 env sequences derived from single-genome sequencing. These sequences were from noncontiguous cervical biopsies or from the cervix and circulating PBMC in seven of eight subjects. Compartmentalization of virus between genital tract and blood was observed by statistical methods and tree topologies in six of eight subjects, and potential genital lineages were observed in two of eight subjects. The detection of monotypic sequences across the cervix and blood, especially during effective ART, suggests that cells with provirus undergo clonal expansion. Compartmentalization of viruses within the cervix appears in part due to viruses homing to and/or expanding within the cervix and is rarely due to unique viruses evolving within the genital tract. Further studies are warranted to investigate mechanisms producing monotypic viruses across tissues and, importantly, to determine whether the proliferation of cells with provirus sustain HIV-1 persistence in spite of effective ART.

Genetic Analyses of HIV-1 env Sequences Demonstrate Limited Compartmentalization in Breast Milk and Suggest Viral Replication within the Breast That Increases with Mastitis

ABSTRACT The concentration of human immunodeficiency virus type 1 (HIV-1) is generally lower in breast milk than in blood. Mastitis, or inflammation of the breast, is associated with increased levels of milk HIV-1 and risk of mother-to-child transmission through breastfeeding. We hypothesized that mastitis facilitates the passage of HIV-1 from blood into milk or stimulates virus production within the breast. HIV-1 env sequences were generated from single amplicons obtained from breast milk and blood samples in a cross-sectional study. Viral compartmentalization was evaluated using several statistical methods, including the Slatkin and Maddison (SM) test. Mastitis was defined as an elevated milk sodium (Na+) concentration. The association between milk Na+ and the pairwise genetic distance between milk and blood viral sequences was modeled using linear regression. HIV-1 was compartmentalized within milk by SM testing in 6/17 (35%) specimens obtained from 9 women, but all phylogenetic clades included viral sequences from milk and blood samples. Monotypic sequences were more prevalent in milk samples than in blood samples (22% versus 13%; P = 0.012), which accounted for half of the compartmentalization observed. Mastitis was not associated with compartmentalization by SM testing (P = 0.621), but Na+ was correlated with greater genetic distance between milk and blood HIV-1 populations (P = 0.041). In conclusion, local production of HIV-1 within the breast is suggested by compartmentalization of virus and a higher prevalence of monotypic viruses in milk specimens. However, phylogenetic trees demonstrate extensive mixing of viruses between milk and blood specimens. HIV-1 replication in breast milk appears to increase with inflammation, contributing to higher milk viral loads during mastitis.

Human Immunodeficiency Viruses Appear Compartmentalized to the Female Genital Tract in Cross-Sectional Analyses but Genital Lineages Do Not Persist Over Time

BACKGROUND Whether unique human immunodeficiency type 1 (HIV) genotypes occur in the genital tract is important for vaccine development and management of drug resistant viruses. Multiple cross-sectional studies suggest HIV is compartmentalized within the female genital tract. We hypothesize that bursts of HIV replication and/or proliferation of infected cells captured in cross-sectional analyses drive compartmentalization but over time genital-specific viral lineages do not form; rather viruses mix between genital tract and blood. METHODS Eight women with ongoing HIV replication were studied during a period of 1.5 to 4.5 years. Multiple viral sequences were derived by single-genome amplification of the HIV C2-V5 region of env from genital secretions and blood plasma. Maximum likelihood phylogenies were evaluated for compartmentalization using 4 statistical tests. RESULTS In cross-sectional analyses compartmentalization of genital from blood viruses was detected in three of eight women by all tests; this was associated with tissue specific clades containing multiple monotypic sequences. In longitudinal analysis, the tissues-specific clades did not persist to form viral lineages. Rather, across women, HIV lineages were comprised of both genital tract and blood sequences. CONCLUSIONS The observation of genital-specific HIV clades only in cross-sectional analysis and an absence of genital-specific lineages in longitudinal analyses suggest a dynamic interchange of HIV variants between the female genital tract and blood.

Biomarkers of inflammation in HIV-infected Peruvian men and women before and during suppressive antiretroviral therapy.

Objective:Inflammatory biomarkers associated with cardiovascular disease are elevated in HIV-infected persons. These biomarkers improve with antiretroviral therapy (ART) but do not normalize to values observed in HIV-uninfected adults. Little is known regarding biomarkers of inflammation in HIV-infected Peruvians, in whom an increased burden of infectious diseases may exacerbate inflammation, and women, in whom sex difference may alter inflammation compared with men. Methods:Peruvians initiating first-line ART were enrolled in a prospective observational study. Individuals with suppression of HIV RNA plasma loads to less than 30 copies/ml when determined quarterly over 24 months of ART, had biomarkers of inflammation and cellular activation measured pre-ART and at 24-months of ART, and evaluated for associations with sex and clinical parameters. Results:Pre-ART high-sensitivity C-reactive protein (hsCRP) values of men were in the high-risk cardiovascular disease category (>3.0 mg/l) more frequently compared with women (P = 0.02); most womens values were in the low/average-risk categories. At 24 months of suppressive ART, hsCRP concentrations decreased in men (P = 0.03), but tended to increase in women, such that the proportion with high-risk hsCRP did not differ by sex. Pre-ART, soluble CD163 concentrations were higher in women compared with men (P = 0.02), and remained higher after 24 months of suppressive ART (P = 0.02). All other inflammatory biomarkers (P < 0.03) decreased across sexes. Biomarker concentrations were not associated with BMI or coinfections. Conclusion:Elevated inflammatory biomarkers persisted despite 24 months of suppressive ART in a subset of Peruvians, and to a greater extent in women compared with men. These findings suggest that lifestyle or pharmacologic interventions may be required to optimize the health of HIV-infected Peruvians, particularly women.

HIV-1 shedding from the female genital tract is associated with increased Th1 cytokines/chemokines that maintain tissue homeostasis and proportions of CD8+FOXP3+ T cells.

Background:HIV-1 shedding from the female genital tract is associated with increased sexual and perinatal transmission and has been broadly evaluated in cross-sectional studies. However, few longitudinal studies have evaluated how the immune microenvironment effects shedding. Methods:Thirty-nine HIV-1–infected women had blood, cervicovaginal lavage, and biopsies of the uterine cervix taken quarterly for up to 5 years. Cytokines/chemokines were quantified by Luminex assay in cervicovaginal lavage, and cellular phenotypes were characterized using immunohistochemistry in cervical biopsies. Comparisons of cytokine/chemokine concentrations and the percent of tissue staining positive for T cells were compared using generalized estimating equations between non-shedding and shedding visits across all women and within a subgroup of women who intermittently shed HIV-1. Results:Genital HIV-1 shedding was more common when plasma HIV-1 was detected. Cytokines associated with cell growth (interleukin-7), Th1 cells/inflammation (interleukin-12p70), and fractalkine were significantly increased at shedding visits compared with non-shedding visits within intermittent shedders and across all subjects. Within intermittent shedders and across all subjects, FOXP3+ T cells were significantly decreased at shedding visits. However, there were significant increases in CD8+ cells and proportions of CD8+FOXP3+ T cells associated with HIV-1 shedding. Conclusions:Within intermittent HIV-1 shedders, decreases in FOXP3+ T cells at the shedding visit suggests that local HIV-1 replication leads to CD4 T-cell depletion, with increases in the proportion of CD8+FOXP3+ cells. HIV-1–infected cell loss may promote a cytokine milieu that maintains cellular homeostasis and increases immune suppressor cells in response to HIV-1 replication in the cervical tissues.

Genetic analyses of HIV env associated with uveitis in antiretroviral-naive individuals

Objective: To analyze and compare HIV-1 env sequences from the eye to those from the blood of individuals with uveitis attributed to HIV with the goal of gaining insight into the pathogenesis of HIV-associated eye disease. Design: A prospective case series of five HIV-infected antiretroviral-naive individuals with uveitis negative for other pathogens. Methods: RNA from blood plasma and ocular aqueous humor was reverse transcribed using random hexamers. HIV env C2-V5 (HXB2: 6990–7668) sequences were generated by single-genome amplification using nested polymerase chain reaction followed by bidirectional Sanger sequencing. Sequence analyses by Geneious, Geno2Pheno, N-GLYCOSITE, DIVEIN, and HyPhy evaluated relationships between HIV in plasma and aqueous humor. Results: A median of 20 (range: 13–22) plasma and 15 (range: 9–18) aqueous humor sequences were generated from each individual. The frequencies of sequences with predicted-N-linked-glycosylation sites and C-X-C chemokine receptor type 4 were comparable in aqueous humor and plasma of all five patients. Aqueous humor sequences had lower median genetic diversity compared with plasma across all patients, but similar divergence, in four of five patients. Aqueous humor HIV sequences were compartmentalized from plasma across subjects by Critchlow correlation coefficient, Slatkin and Maddison, nearest-neighbor statistic, and Fixation index. Conclusion: Among antiretroviral-naive individuals with uveitis attributed to HIV, the universal compartmentalization and decreased diversity of eye compared with blood sequences suggests time-limited passage of a small subset of variants from each patients viral population into the eye tissues, followed by limited immune selection despite the inflammatory uveitis.