HIV nucleoside reverse transcriptase inhibitors efavirenz and tenofovir change the growth and differentiation of primary gingival epithelium

Beyond the effects of HIV infection and integrase inhibitors-based therapies on oral bacteriome

Oral microbiome is the second largest microbial community in humans after gut. Human immunodeficiency virus (HIV) infection triggers an impairment of the immune system which could favour the growth and the colonization of pathogens in the oral cavity, and this dysbiosis has been associated with oral manifestations that worsen the quality of life of these patients. Antiretroviral therapy (ART) could also drive changes in specific oral bacterial taxa associated with such periodontal diseases. Integrase strand transfer inhibitors (INSTIs), therapy of choice in the treatment of naive HIV-patients, are able to reverse the impact of HIV infection on systemic inflammation, gut permeability, and gut bacterial diversity/richness. The objective of this study was to analyse the effects of HIV infection per se and INSTIs on salivary bacteriome composition, taking into consideration other factors such as smoking, that could also have a significant impact on oral microbiome. To accomplish this objective, 26 non-HIV-infected volunteers and 30 HIV-infected patients (15 naive and 15 under INSTIs-regimen) were recruited. Salivary samples were collected to measure lysozyme levels. Oral bacteriome composition was analysed using 16S rRNA gene sequencing. Naive HIV-infected patients showed statistically higher levels of lysozyme compared to controls (p < 0.001) and INSTIs-treated patients (p < 0.05). Our study was unable to detect differences in α nor β-diversity among the three groups analysed, although significant differences in the abundance of some bacterial taxonomical orders were detected (higher abundance in the phylum Pseudomonadota, in the order Acholeplasmatales, and in the genera Ezakiella and Acholeplasma in the naive group compared to controls; and higher abundance in the phylum Mycoplasmatota, in the order Acholeplasmatales, and in the genera Acholeplasma and uncultured Eubacteriaceae bacterium in the INTIs-treated HIV-infected patients compared to controls). These differences seem to be partially independent of smoking habit. HIV infection and INSTIs effects on oral microbiota seem not to be very potent, probably due to the modulation of other factors such as smoking and the greatest outward exposure of the oral cavity.

Findings from a pilot study of buprenorphine population pharmacokinetics: A potential effect of HIV on buprenorphine bioavailability

BACKGROUND

Buprenorphine is widely used in the treatment of opioid use disorder (OUD). There are few pharmacokinetic models of buprenorphine across diverse populations. Population pharmacokinetics (POPPK) allows for covariates to be included in pharmacokinetic studies, thereby opening the potential to evaluate the effect of comorbidities, medications, and other factors on buprenorphine pharmacokinetics. This pilot study used POPPK to explore buprenorphine pharmacokinetics in patients with and without HIV receiving buprenorphine for OUD.

METHODS

Plasma buprenorphine levels were measured in 54 patients receiving buprenorphine for OUD just prior to and 2-5 h following regular buprenorphine dosing. A linear one-compartment POPPK model with first-order estimation was used to evaluate buprenorphine clearance (CL/F) and volume of distribution (V/F). Covariates included weight and HIV status.

RESULTS

All HIV+ patients reported complete past-month adherence to taking antiretroviral therapy that included either efavirenz or nevirapine. Buprenorphine CL/F was 76% higher in HIV+ patients (n = 17) than HIV- patients (n = 37). Buprenorphine V/F was 41% higher in the HIV+ patients.

CONCLUSIONS

POPPK can be used to model buprenorphine pharmacokinetics in a real-world clinical population. While interactions between ART and buprenorphine alter buprenorphine CL/F, we also found alteration in V/F. Proportionate changes in CL/F and V/F might indicate a primary effect on bioavailability (F) rather than two separate effects. These findings indicate reduced buprenorphine bioavailability in patients with HIV.

Inflammatory cytologic alterations in the oral epithelium associated with HIV pre-exposure prophylaxis: a preliminary study

OBJECTIVE

The objective of this study was to assess inflammatory cytologic alterations in the oral epithelium of patients on human immunodeficiency virus pre-exposure prophylaxis (PrEP).

MATERIAL AND METHODS

Epithelial cells from the buccal mucosa of 30 patients were collected by exfoliative cytology and were evaluated according to inflammatory cellular alterations: karyomegaly, bi- or multinucleation, karyopyknosis, karyorrhexis, perinuclear halo formation, metachromasia, cytoplasmic vacuolization, indistinct cytoplasmic border, keratinization, and atrophy. Epithelial cells were collected initially before PrEP onset (T1) and then after 30 days of PrEP use (T2). Two experienced cytopathologists independently analyzed the slides.

RESULTS

The nonparametric Wilcoxon test showed that there was a statistically significant increase in the number of cells with karyomegaly at T2 compared to T1 (P = .033). The other cellular alterations did not present with statistically significant differences between the 2 moments of evaluation (P > .05).

CONCLUSION

The increased number of oral epithelial cells with karyomegaly after 30 days of using PrEP suggests the presence of inflammatory alterations at this site.

Differential Efficacy of Novel Antiviral Substances in 3D and Monolayer Cell Culture

Repurposing of approved drugs that target host functions also important for virus replication promises to overcome the shortage of antiviral therapeutics. Mostly, virus biology including initial screening of antivirals is studied in conventional monolayer cells. The biology of these cells differs considerably from infected tissues. 3D culture models with characteristics of human tissues may reflect more realistically the in vivo events during infection. We screened first, second, and third generation epidermal growth factor receptor (EGFR)-inhibitors with different modes of action and the EGFR-blocking monoclonal antibody cetuximab in a 3D cell culture infection model with primary human keratinocytes and cowpox virus (CPXV) for antiviral activity. Antiviral activity of erlotinib and osimertinib was nearly unaffected by the cultivation method similar to the virus-directed antivirals tecovirimat and cidofovir. In contrast, the host-directed inhibitors afatinib and cetuximab were approx. 100-fold more efficient against CPXV in the 3D infection model, similar to previous results with gefitinib. In summary, inhibition of EGFR-signaling downregulates virus replication comparable to established virus-directed antivirals. However, in contrast to virus-directed inhibitors, in vitro efficacy of host-directed antivirals might be seriously affected by cell cultivation. Results obtained for afatinib and cetuximab suggest that screening of such drugs in standard monolayer culture might underestimate their potential as antivirals.

Oral and Gut Microbial Diversity and Immune Regulation in Patients with HIV on Antiretroviral Therapy

A feedback loop between dysbiotic gut microbiota, increased translocation of microbial products such as lipopolysaccharide, and inflammation has been hypothesized to cause immune system dysfunction in early HIV infection. However, despite evidence of a chronic inflammatory phenotype in patients on antiretroviral therapy (ART), the role of oral microbiota in systemic immune activation and the relationship between oral and gut bacterial and fungal diversity have not been explored. Our study suggests a crucial role for oral bacterial and fungal communities in long-term systemic immune activation in patients on ART, expanding the current paradigm focused on gut bacteria. Our results indicate that interventions targeting both inflammation and microbial diversity are needed to mitigate oral inflammation-related comorbidities, particularly in HIV-positive patients. More broadly, these findings can bolster general models of microbiome-mediated chronic systemic immune activation and aid the development of precise microbiota-targeted interventions to reverse chronic inflammation.

Despite evidence of a chronic inflammatory phenotype in people living with HIV (PLWH) on antiretroviral therapy (ART), the role of oral microbiota in chronic immune activation has not been fully explored. We aimed to determine the relationship between oral and gut microbiome diversity and chronic systemic inflammation in ART-treated PLWH with prevalent severe periodontitis, an inflammatory condition commonly associated with HIV infection. We assessed bacterial and fungal communities at oral and gastrointestinal sites in a cohort (n = 52) of primarily postmenopausal women on ART using 16S rRNA and internal transcribed spacer (ITS) sequencing and measured cellular and soluble markers of inflammation and immune dysfunction. Linear mixed-effect regression and differential abundance analyses were used to associate clinical characteristics and immunological markers with bacterial and fungal diversity and community composition. Bacterial α-diversity in plaque, saliva, and gut was associated with different immunological markers, while mycobial diversity was not associated with soluble or cellular biomarkers of immune stimulation or T cell dysfunction. Furthermore, lipopolysaccharide-positive (LPS⁺) bacteria previously linked to inflammatory outcomes were enriched at oral sites in patients with severe periodontitis. Fungal α-diversity was reduced in plaque from teeth with higher clinical attachment loss, a marker of periodontitis, and in saliva and plaque from patients with a history of AIDS. Our results show that both bacterial and fungal oral microbiome communities likely play a role in chronic systemic immune activation in PLWH. Thus, interventions targeting both inflammation and the microbiome, particularly in the oral cavity, may be necessary to reduce chronic immune dysregulation in patients with HIV.

IMPORTANCE A feedback loop between dysbiotic gut microbiota, increased translocation of microbial products such as lipopolysaccharide, and inflammation has been hypothesized to cause immune system dysfunction in early HIV infection. However, despite evidence of a chronic inflammatory phenotype in patients on antiretroviral therapy (ART), the role of oral microbiota in systemic immune activation and the relationship between oral and gut bacterial and fungal diversity have not been explored. Our study suggests a crucial role for oral bacterial and fungal communities in long-term systemic immune activation in patients on ART, expanding the current paradigm focused on gut bacteria. Our results indicate that interventions targeting both inflammation and microbial diversity are needed to mitigate oral inflammation-related comorbidities, particularly in HIV-positive patients. More broadly, these findings can bolster general models of microbiome-mediated chronic systemic immune activation and aid the development of precise microbiota-targeted interventions to reverse chronic inflammation.

Three-dimensional cell culture models for investigating human viruses

Three-dimensional (3D) culture models are physiologically relevant, as they provide reproducible results, experimental flexibility and can be adapted for high-throughput experiments. Moreover, these models bridge the gap between traditional two-dimensional (2D) monolayer cultures and animal models. 3D culture systems have significantly advanced basic cell science and tissue engineering, especially in the fields of cell biology and physiology, stem cell research, regenerative medicine, cancer research, drug discovery, and gene and protein expression studies. In addition, 3D models can provide unique insight into bacteriology, virology, parasitology and host-pathogen interactions. This review summarizes and analyzes recent progress in human virological research with 3D cell culture models. We discuss viral growth, replication, proliferation, infection, virus-host interactions and antiviral drugs in 3D culture models.