Biology subjects

Celum, C.

Publications and source records attributed to Celum, C..

5 recordsLinked to original sources

bioRxiv2025

Pre-Human Immunodeficiency Virus (HIV) infection Th17 CD4+ T cells as predictors of early HIV disease progression

Interleukin-17-producing T helper (Th17) CD4+ T cells are highly susceptible to HIV infection and are depleted early in people living with HIV. Here, we investigated whether systemic Th17 cell levels prior to HIV infection are associated with subsequent HIV disease progression. We analyzed archived cryopreserved peripheral blood mononuclear cells (PBMCs) collected within one year prior to HIV acquisition from participants enrolled in a South African cohort (HIV Vaccine Trials Network [HVTN] 503; n = 35) and an East African cohort (Partners Pre-exposure Prophylaxis/Couples Observational Study [PP/COS]; n = 32). Th17 cell frequencies were quantified by flow cytometry. In HVTN 503, higher pre-HIV IL-17+ CD4+ T cell frequencies were inversely correlated with CD4/CD8 ratio measured both within 180 days (Spearman rank R = -0.42, p = 0.012) and beyond 180 days (R = -0.55, p = 0.001) after HIV infection, and were associated with faster CD4+ T cells decline (adjusted hazard ratio [aHR] = 3.5, 95% CI: 1.2-9.9, p = 0.020). In contrast, no significant association with CD4 decline was observed in the PP/COS cohort (HR = 1.2, 95% CI: 0.4-3.4, p = 0.795). Sex-stratified analyses in HVTN 503 indicated a more pronounced association between pre-HIV IL-17+ CD4+ T cells and faster CD4 decline in males than females. In analyses combining all cohorts, higher pre-HIV IL-17+ CD4+ T cell frequencies remained associated with faster CD4 decline, particularly among younger participants (HR = 3.5; 95% CI: 1.35-9.22, p = 0.010). Pre-HIV IL-17+ CD4+ T cell frequencies were not associated with peak or set-point viral load in either cohort. Together, these findings suggest that pre-HIV Th17 cells abundance may influence subsequent HIV disease progression independently of early viral replication. Author SummaryHIV infection leads to progressive damage of the immune system, but the rate at which this damage occurs varies widely between individuals. Understanding the factors that influence HIV disease progression is essential for improving prevention and treatment strategies. Previous studies have suggested that immune characteristics present before infection may shape disease outcomes after HIV acquisition. In this study, we examined whether the abundance of IL-17-producing CD4+ T cells, known as Th17 cells, measured prior to HIV acquisition, were associated with markers of disease progression after infection. We analyzed blood samples from individuals who were HIV-negative at the time of sampling and later acquired HIV during follow-up. We found that individuals with higher pre-infection levels of Th17 cells experienced faster immune decline after HIV infection, including more rapid loss of CD4+ T cells and lower CD4/CD8 ratios. These associations were observed independently of viral load and varied by cohort, age and sex. Our findings indicate that immune conditions present before HIV infection can influence subsequent disease progression and suggest that Th17 cells may serve as biomarkers to identify individuals at higher risk of rapid HIV-related immune damage.

immunology↗

bioRxiv2025

Identifying a Vaginal Microbiome-Derived Selective Antibiotic Metabolite via Microbiome Pharmacology Analysis

The vaginal microbiome plays a critical role in maintaining immune and epithelial homeostasis in the female reproductive tract. Bacterial Vaginosis (BV) is deleterious to female health, causing the loss of beneficial Lactobacillus species, overgrowth of anaerobic taxa, changes in vaginal pH, breakdown of protective mucins and epithelial barriers, and activation of the immune system. Treatment with gel-based antibiotics (Metronidazole or Clindamycin) resolves BV for 85% of patients, but 50% of those cases recur, indicating a need to identify strategies for overcoming antibiotic resistance and achieving a more durable response. Here, we developed a systems biology approach termed Microbiome Pharmacology Analysis to characterize the antibiotic potential of vaginal microbes, their metabolites and functions, via computational fusion of human cohort multi-omics and post-drug perturbation transcriptomic profiles. We focused on Clindamycin and Metronidazole as candidate drugs and screened 780 vaginal microbiome-drug mimicry candidates to identify candidate taxa and metabolites with antibiotic potential. We demonstrate experimentally that Lactobacillus crispatus-derived Hydroxyisocaproate (HICA) selectively kills Gardnerella vaginalis and that HICA enhances epithelial barrier integrity in a human vagina-on-a-chip system. Our work demonstrates the first use of Pharmacobiome Analysis, for discovering novel, selective antibiotic metabolites for BV with implications for charting the full pharmacologic potential of the vaginal microbiome.

microbiology↗

bioRxiv2024

Computational Microbiome Pharmacology Analysis Elucidates the Anti-Cancer Potential of Vaginal Microbes and Metabolites

The vaginal microbiomes role in risk, progression, and treatment of female cancers has been widely explored. Yet, there remains a need to develop methods to understand the interaction of microbiome factors with host cells and to characterize their potential therapeutic functions. To address this challenge, we developed a systems biology framework we term the Pharmacobiome for microbiome pharmacology analysis. The Pharmacobiome framework evaluates similarities between microbes and microbial byproducts and known drugs based on their impact on host transcriptomic cellular signatures. Here, we apply our framework to characterization of the Anti-Gynecologic Cancer Vaginal Pharmacobiome. Using published vaginal microbiome multi-omics data from the Partners PrEP clinical trial, we constructed vaginal epithelial gene signatures associated with each profiled vaginal microbe and metabolite. We compared these microbiome-associated host gene signatures to post-drug perturbation host gene signatures associated with 35 FDA-approved anti-cancer drugs from the Library of Integrated Network-based Cellular Signatures database to identify vaginal microbes and metabolites with high statistical and functional similarity to these drugs. We found that Lactobacilli and their metabolites can regulate host gene expression in ways similar to many anti-cancer drugs. Additionally, we experimentally tested our model prediction that taurine, a metabolite produced by L. crispatus, kills cancerous breast and endometrial cancer cells. Our study shows that the Pharmacobiome is a powerful framework for characterizing the anti-cancer therapeutic potential of vaginal microbiome factors with generalizability to other cancers, microbiomes, and diseases.

systems biology↗

bioRxiv2024

Long-term in vitro exposure of Treponema pallidum to sub-bactericidal doxycycline did not induce resistance: Implications for doxy-PEP and syphilis

Doxycycline post-exposure prophylaxis (doxy-PEP) could significantly reduce syphilis incidence. However, the increase in intermittent doxycycline usage might select resistant Treponema pallidum (T. pallidum) strains. To assess whether resistance to doxycycline could be induced in this pathogen, we exposed the SS14 strain in vitro both intermittently and continuously to a sub-bactericidal doxycycline concentration that still exerts antibiotic pressure. During and after each exposure experiment, we assessed the doxycycline minimal inhibitory concentration in test and control treponemes and performed whole genome sequencing, concluding that no resistance developed. This work suggests that doxycycline-resistant T. pallidum is not an immediate threat for doxy-PEP implementation.

microbiology↗

bioRxiv2020

Neutralizing activity of broadly neutralizing anti-HIV-1 antibodies against primary African isolates

Novel therapeutic and preventive strategies are needed to contain the HIV-1 epidemic. Broadly neutralizing human antibodies (bNAbs) with exceptional activity against HIV-1 are currently being tested in HIV-1 prevention trials. The selection of anti-HIV-1 bNAbs for clinical development was primarily guided by their in vitro neutralizing activity against HIV-1 Env pseudotyped viruses. Here we report on the neutralizing activity of 9 anti-HIV-1 bNAbs now in clinical development against 126 Clade A, C, D PBMC-derived primary African isolates. The neutralizing potency and breadth of the bNAbs tested was significantly reduced compared to pseudotyped viruses panels. The difference in sensitivity between pseudotyped viruses and primary isolates varied from 3-to nearly 100-fold depending on the bNAb and the HIV-1 clade. Thus, the neutralizing activity of bNAbs against primary African isolates differs and cannot be predicted from their activity against pseudovirus panels. The data have significant implications for interpreting the results of ongoing HIV-1 prevention trials.

immunology↗