Enriched LPS Staining within the Germinal Center of a Lymph Node from an HIV-Infected Long-Term Nonprogressor but Not from Progressors.

Lei Huang,Wei Jiang,Guoyang Liao,Ren Lang,Jianning Deng

doi:10.1155/2020/7471380

Abstract

An increased level of microbial translocation has been observed in HIV-infected individuals. The host response to microbial translocation is compromised in HIV-infected progressors but remains unknown in HIV-infected long-term nonprogressors (LTNPs). To evaluate microbial translocation in HIV, we assessed lipopolysaccharide (LPS) immunohistochemistry staining in lymph nodes. We found enriched bacterial LPS immunohistochemistry staining in the germinal center of a lymph node from an HIV-infected LTNP, evenly distributed from three progressors with impaired germinal center structures and rarely detected from two HIV-negative individuals. The impaired germinal center structures were consistent with collagen deposition in lymph nodes using immunohistochemistry staining. These results suggest greater immune responses against bacterial LPS translocation in LTNPs, which may reveal an important mechanism in controlling microbial translocation and disease progression in HIV LTNPs.

Highlights

Inflammation and chronic immune activation can be driven by microbial product translocation and residual viral effects in patients with antiretroviral therapy (ART) treatment [5]; bacterial product translocation may contribute to HIV disease progression
Node from a Long-term nonprogressor LN (LTNP); evenly distributed LPS was observed in lymph nodes from three progressors with impaired germinal center structures; and LPS staining was rarely observed in lymph nodes of two HIV-negative individuals
Consistent with HIV-associated “leaky” gut and microbial translocation [8], LPS staining was increased in three HIV+ progressors (Figures 1(c)–1(e)) and one HIV+ LTNP (Figure 1(f)) compared to the HIV-negative donors (Figures 1(a) and 1(b))

Summary

Introduction

HIV-infected long-term nonprogressors (LTNPs) comprise less than 1 percent of HIV-infected individuals who control HIV replication and do not progress to AIDS without medications [1]. Chronic immune activation and inflammation are wellknown hallmarks for CD4+ T cell depletion and HIV disease progression even in patients with antiretroviral therapy (ART) treatment [3]. Inflammation and chronic immune activation can be driven by microbial product translocation and residual viral effects in patients with ART treatment [5]; bacterial product translocation may contribute to HIV disease progression. It remains unclear whether there is an increased level of microbial translocation in LTNPs as shown in progressors compared to healthy individuals [6, 7]. Node from a LTNP; evenly distributed LPS was observed in lymph nodes from three progressors with impaired germinal center structures; and LPS staining was rarely observed in lymph nodes of two HIV-negative individuals

Results and Discussion

Experimental Procedures

Ethical Approval