IVD Publications

Search and Filter
Last Modified, December 05, 2021
Results per Page: 10
  • 5
  • 10
  • 20
  • 50
  • 100

HIV reservoir quantification by five-target multiplex droplet digital PCR

STAR Protoc

2021 Florian Hladik; Dara Lehman; Chelsea Amstuz; Keith Jerome

Most latent human immunodeficiency virus (HIV) proviruses are defective and cannot produce infectious virions. Thus, the number of HIV proviruses with intact genomes is a relevant clinical parameter to assess therapies for HIV cure. We describe high-molecular-weight DNA isolation, followed by restriction enzyme fragmentation that limits cutting within the HIV genome. Multiplexed droplet digital PCR quantifies five targets spanning the HIV genome to estimate potentially intact proviral copies. A reference assay counts the number of T lymphocytes and assesses the level of DNA shearing. For complete details on the use and execution of this protocol, please refer to Levy et al. (2021).

Integration features of intact latent HIV-1 in CD4(+) T cell clones contribute to viral persistence

J Exp Med

2021 Lillian Cohn

Latent intact HIV-1 proviruses persist in a small subset of long-lived CD4+ T cells that can undergo clonal expansion in vivo. Expanded clones of CD4+ T cells dominate latent reservoirs in individuals on long-term antiretroviral therapy (ART) and represent a major barrier to HIV-1 cure. To determine how integration landscape might contribute to latency, we analyzed integration sites of near full length HIV-1 genomes from individuals on long-term ART, focusing on individuals whose reservoirs are highly clonal. We find that intact proviruses in expanded CD4+ T cell clones are preferentially integrated within Krüppel-associated box (KRAB) domain-containing zinc finger (ZNF) genes. ZNF genes are associated with heterochromatin in memory CD4+ T cells; nevertheless, they are expressed in these cells under steady-state conditions. In contrast to genes carrying unique integrations, ZNF genes carrying clonal intact integrations are down-regulated upon cellular activation. Together, the data suggest selected genomic sites, including ZNF genes, can be especially permissive for maintaining HIV-1 latency during memory CD4+ T cell expansion.

A review of ex vivo placental perfusion models: an underutilized but promising method to study maternal-fetal interactions

J Matern Fetal Neonatal Med

2021 Florian Hladik

Studying the placenta can provide information about the mechanistic pathways of pregnancy disease. However, analyzing placental tissues and manipulating placental function in real-time during pregnancy is not feasible. The ex vivo placental perfusion model allows observing important aspects of the physiology and pathology of the placenta, while maintaining its viability and functional integrity, and without causing harm to mother or fetus. In this review, we describe and compare setups for this technically complex model and summarize outcomes from various published studies. We hope that our review will encourage wider use of ex vivo placental perfusion, which in turn would generate more knowledge to improve pregnancy outcomes.

A regulatory T cell signature distinguishes the immune landscape of COVID-19 patients from those with other respiratory infections

Sci Adv

2021 Andrew Konecny; Jennifer Lund; Sarah Vick; Marie Frutoso; Raphael Gottardo; Florian Mair; Martin Prlic; Jim Boonyaratanakornkit; Evan Greene; Joshua Schiffer

[Figure: see text].

Individual and poly-substance use and condomless sex among HIV-uninfected adults reporting heterosexual sex in a multi-site cohort

BMC Public Health

2021 Ann Duerr

BACKGROUND: We analyzed the association between substance use (SU) and condomless sex (CS) among HIV-negative adults reporting heterosexual sex in the Seek, Test, Treat, and Retain (STTR) consortium. We describe the impact of SU as well as person/partner and context-related factors on CS, identifying combinations of factors that indicate the highest likelihood of CS. METHODS: We analyzed data from four US-based STTR studies to examine the effect of SU on CS using two SU exposures: 1) recent SU (within 3months) and 2) SU before/during sex. Behavioral data were collected via 1:1 or self-administered computerized interviews. Adjusted individual-study, multivariable relative risk regression was used to examine the relationship between CS and SU. We also examined interactions with type of sex and partner HIV status. Pooled effect estimates were calculated using traditional fixed-effects meta-analysis. We analyzed data for recent SU (n=6781; 82% men, median age=33years) and SU before/during sex (n=2915; 69% men, median age=40years). RESULTS: For both exposure classifications, any SU other than cannabis increased the likelihood of CS relative to non-SU (8-16%, p-values<0.001). In the recent SU group, however, polysubstance use did not increase the likelihood of CS compared to single-substance use. Cannabis use did not increase the likelihood of CS, regardless of frequency of use. Type of sex was associated with CS; those reporting vaginal and anal sex had a higher likelihood of CS compared to vaginal sex only for both exposure classifications (18-21%, p<0.001). Recent SU increased likelihood of CS among those reporting vaginal sex only (9-10%, p<0.001); results were similar for those reporting vaginal and anal sex (5-8%, p<0.01). SU before/during sex increased the likelihood of CS among those reporting vaginal sex only (20%; p<0.001) and among those reporting vaginal and anal sex (7%; p=0.002). Single- and poly-SU before/during sex increased the likelihood of CS for those with exclusively HIV-negative partners (7-8%, p0.02), and for those reporting HIV-negative and HIV-status unknown partners (9-13%, p0.03). CONCLUSION: Except for cannabis, any SU increased the likelihood of CS. CS was associated with having perceived HIV-negative partners and with having had both anal/vaginal sex.

Correlates of condomless anal intercourse with different types of sexual partners among men who have sex with men and transgender women in Lima, Peru


2021 Ann Duerr; Angela Ulrich

The Sabes study was registered in March 2013 with the National Institutes of Health at ClinicalTrials.gov (identifier: NCT01815580).

Methods to Measure Antibody Neutralization of Live Human Coronavirus OC43


2021 Emily Bossard; Justin Taylor; Emily Ford; Jim Boonyaratanakornkit; Larry Corey; Matthew Gray; Anton Sholukh

The human Betacoronavirus OC43 is a common cause of respiratory viral infections in adults and children. Lung infections with OC43 are associated with mortality, especially in hematopoietic stem cell transplant recipients. Neutralizing antibodies play a major role in protection against many respiratory viral infections, but to date a live viral neutralization assay for OC43 has not been described. We isolated a human monoclonal antibody (OC2) that binds to the spike protein of OC43 and neutralizes the live virus derived from the original isolate of OC43. We used this monoclonal antibody to develop and test the performance of two readily accessible in vitro assays for measuring antibody neutralization, one utilizing cytopathic effect and another utilizing an ELISA of infected cells. We used both methods to measure the neutralizing activity of the OC2 monoclonal antibody and of human plasma. These assays could prove useful for studying humoral responses to OC43 and cross-neutralization with other medically important betacoronaviruses.

Metabolic regulation by PD-1 signaling promotes long-lived quiescent CD8 T cell memory in mice

Sci Transl Med

2021 Vandana Kalia; Paul Nghiem; Surojit Sarkar; Martin Prlic; Stanley Riddell

[Figure: see text].

HIV disease dynamics, markers of inflammation and CNS injury during primary HIV infection and their relationship to cognitive performance

J Acquir Immune Defic Syndr

2021 Sayan Dasgupta; Ann Duerr; Yixin Wang; Siavash Pasalar; Rachel Bender Ignacio

INTRODUCTION: Early systemic and central nervous system viral replication and inflammation may impact brain integrity in people with HIV (PWH), leading to chronic cognitive symptoms not fully reversed by antiretroviral therapy (ART). This study examined associations between cognitive performance and markers of CNS injury associated with acute HIV infection and ART. METHODS: HIV-infected MSM and transgender women (average age: 27 and education: 13 years) enrolled within 100 days from estimated date of detectable infection [EDDI]. A cognitive performance (NP) protocol was administered at enrollment (before ART initiation) and every 24 weeks until week 192. An overall index of cognitive performance (NPZ) was created using local normative data. Blood (n=87) and cerebrospinal fluid (CSF; n=29) biomarkers of inflammation and neuronal injury were examined before ART initiation. Regression analyses assessed relationships between time since EDDI, pre-ART biomarkers, and NPZ. RESULTS: Adjusting for multiple comparisons, shorter time since EDDI was associated with higher pre-ART VL and multiple biomarkers in plasma and CSF. NPZ scores were within the normative range at baseline (NPZ=.52) and at each follow-up visit, with a modest increase through week 192. Plasma or CSF biomarkers were not correlated with NP scores at baseline or after ART. CONCLUSIONS: Biomarkers of CNS inflammation, immune activation and neuronal injury peak early and then decline during acute HIV infection, confirming and extending results of other studies. Neither plasma nor CSF biomarkers during acute infection corresponded to NP scores before or after sustained ART in this cohort with few psychosocial risk factors for cognitive impairment.

Self-Identity, Beliefs, and Behavior Among Men Who Have Sex with Transgender Women: Implications for HIV Research and Interventions

Arch Sex Behav

2021 Ann Duerr; Michele Andrasik

While transgender women have been identified as a global priority population for HIV prevention and treatment, little is known about the cisgender male partners of transgender women, including their sexual behavior and HIV prevalence. Previous research has suggested that these male partners have varied identities and sexual behavior, which make identifying and engaging them in research difficult. This paper describes interviews conducted with fifteen cisgender men who reported recent sexual activity with transgender women in Lima, Peru. The purpose of this research was to explore how these men reported their identities and sexual behavior, to better understand how they would interact with HIV outreach, research, and care. The major themes were sexual orientation and identity; view of transgender partners; social ties to transgender women and other men with transgender women partners; disclosure of relationships; HIV knowledge and risk perception; and attitudes toward interventions. We found that language used to assess sexual orientation was problematic in this population, due to lack of consistency between orientation and reported behavior, and unfamiliarity with terms used to describe sexual orientation. In addition, stigma, lack of knowledge of HIV prevention methods, and fear of disclosure of sexual behavior were identified as barriers that could impact engagement in HIV research, prevention, and care. However, participants reported social relationships with both transgender women and other men who have transgender partners, presenting possible avenues for recruitment into HIV research and healthcare services.