Differential Signature of the Microbiome and Neutrophils in the Oral Cavity of HIV-Infected Individuals

Abstract

HIV infection is associated with a wide range of changes in microbial communities and immune cell components of the oral cavity. The purpose of this study was to evaluate the oral microbiome in relationship to oral neutrophils in HIV-infected compared to healthy individuals. We evaluated oral washes and saliva samples from HIV-infected individuals (n=52) and healthy controls (n=43). Using 16S-rRNA gene sequencing, we found differential β-diversity using Principal Coordinate Analysis (PCoA) with Bray-Curtis distances. The α-diversity analysis by Faith’s, Shannon, and observed OTUs indexes indicated that the saliva samples from HIV-infected individuals harbored significantly richer bacterial communities compared to the saliva samples from healthy individuals. Notably, we observed that five species of Spirochaeta including Spirochaetaceae, Spirochaeta, Treponema, Treponema amylovorum, and Treponema azotonutricum were significantly abundant. In contrast, Helicobacter species were significantly reduced in the saliva of HIV-infected individuals. Moreover, we found a significant reduction in the frequency of oral neutrophils in the oral cavity of HIV-infected individuals, which was positively related to their CD4+ T cell count. In particular, we noted a significant decline in CD44 expressing neutrophils and the intensity of CD44 expression on oral neutrophils of HIV-infected individuals. This observation was supported by the elevation of soluble CD44 in the saliva of HIV-infected individuals. Overall, the core oral microbiome was distinguishable between HIV-infected individuals on antiretroviral therapy compared to the HIV-negative group. The observed reduction in oral neutrophils might likely be related to the low surface expression of CD44, resulting in a higher bacterial diversity and richness in HIV-infected individuals.

Elevated ATP via enhanced miRNA-30b, 30c, and 30e downregulates the expression of CD73 in CD8+ T cells of HIV-infected individuals

“…The next day, RPMI culture media containing 10% FBS was added in the bottom chamber as the chemoattractant. The cell migration was calculated by the quantification of the fluorescence using a fluorescence plate reader according to the manufacturer's instructions as we have reported elsewhere [80].…”

Advances in the oral microbiota and rapid detection of oral infectious diseases

“…Herpes simplex virus contributes to herpetic gingivostomatitis, herpes labialis, herpes genitalis, herpetic paterecleris, and mucocutaneous orofacial disease ( Dai and Zhou, 2018 ; Crimi et al, 2019 ; Atyeo et al, 2021 ). HIV-related lesions include oral hairy leukoplakia, oral candidiasis, linear gingival erythema, necrotizing ulcerative periodontitis, Kaposi sarcoma, and non-Hodgkin lymphoma ( Moyes et al, 2016 ; Ottria et al, 2018 ; Polvora et al, 2018 ; Santella et al, 2019 ; Sharma Mahendra et al, 2020 ; Perez Rosero et al, 2021 ).…”

HIV Infection and Oral Manifestations: An Update

“…In the oral cavity of PLWH, microbial diversity was lower in individuals of this group than in individuals free of HIV infection and patients using ART; that is, in this HIV-infected population, the presence of aggressive bacteria was greater, and moreover, the presence of more virulent fungal communities can be identified. Therefore, the literature suggests that oral dysbiosis in PLWH promote greater chances of OL appearances due to the presence of more aggressive bacterial and fungal communities, even with a lower diversity of strains in the region [91][92][93].…”