Glycoproteomic Study Reveals Altered Plasma Proteins Associated with HIV Elite Suppressors

Abstract

HIV elite suppressors (ES) or controllers are individuals achieving control of viremia by their natural immunological mechanisms without highly active antiretroviral therapy (HAART). Study of the mechanisms responsible for the immunological suppression of viremia in ES may lead to the detection of individuals with ES and the effective control of HIV infection. We hypothesize that plasma glycoproteins play essential roles in the immune system of ES since plasma proteins are critical and highly relevant in anti-viral immunity and most plasma proteins are glycoproteins. To examine glycoproteins associated with ES, plasma samples from ES individuals (n=20), and from individuals on HAART (n=20), with AIDS (n=20), and no HIV infection (n=10) were analyzed by quantitative glycoproteomics. We found that a number of glycoproteins changed between ES versus HAART, AIDS and HIV- individuals. In sharp contrast, the level of plasma glycoproteins in the HAART cohort showed fewer changes compared with AIDS and HIV- individuals. These results showed that although both ES and HAART effectively suppress viremia, ES appeared to profoundly affect immunologically relevant glycoproteins in plasma as consequence of or support for anti-viral immunity. Bioinformatic analysis revealed that altered proteins in ES plasma were mainly associated with inflammation. This analysis suggests that overlapping, while distinguishable, glycoprotein profiles for inflammation and immune activation appeared to be present between ES and non-ES (HAART+AIDS) cohorts, indicating different triggers for inflammation and immune activation between natural and treatment-related viral suppression.

Identification of glycoproteins associated with HIV latently infected cells using quantitative glycoproteomics

“…Our SPEG method substantially reduces the complexity of sample that allows identification of low abundant but biologically relevant glycosite‐containing peptides . To quantify the samples, we apply label free LC‐MS/MS analysis that avoids the use of expensive labeling reagents and enables an unlimited number of experiments for comparison . Reproducibility of the LC‐MS platform is crucial in the label free quantification .…”

“…To quantify the samples, we apply label free LC‐MS/MS analysis that avoids the use of expensive labeling reagents and enables an unlimited number of experiments for comparison . Reproducibility of the LC‐MS platform is crucial in the label free quantification . To ensure the reproducibility, we inspected the Pep3D image and used the alignment‐scoring algorithm in the SIEVE software.…”

“…In HIV neuropathogenesis, cell surface glycoproteins JAM‐A and ALCAM are important for CD14+ CD16+ monocytes to cross the blood brain barrier that is an important step in the development of HIV associated neurocognitive disorders . We have previously shown that HIV infection caused changed secretion of glycoproteins from latently infected cells that might interplay with the immune system and contributed to significant change in the glycoprotein profile in sera from HIV+ people with acquired immune deficiency syndrome (AIDS), HAART‐treatment or elite suppression . The changed secretion of glycoproteins from latently infected cells indicates that cellular glycoproteome may also change.…”

“…In this study, N‐linked glycosite‐containing peptides were isolated by hydrazide chemistry and released using PNGase F . The glycosite‐containing peptides were subjected to label‐free quantitative nano‐LC‐MS/MS analysis . Bioinformatic analysis was used to reveal roles of glycoproteins with changed glycosite‐containing peptides.…”

Simultaneous Enrichment of Plasma Soluble and Extracellular Vesicular Glycoproteins Using Prolonged Ultracentrifugation-Electrostatic Repulsion-hydrophilic Interaction Chromatography (PUC-ERLIC) Approach*

“…Using a similar LC-MS/MS platform to that employed in the current report, Yang et al (56) used solid phase extraction of N-linked glycoproteins (SPEG) to enable the identification of 462 glycopeptides from 185 N-glycoproteins in nondepleted human plasma. In contrast, Drake et al (57) used affinity capture workflows to facilitate the detection of 227 N-glycosylation sites covering 119 N-glycoproteins recovered from MARS-depleted plasma.…”