# Description of T-Cell and Monocyte Populations in the Circulation of People with HIV Prior to AIDS-NHL Diagnosis

## TL;DR

This study explores immune cell changes in HIV-positive individuals before they develop a type of lymphoma, identifying potential early warning signs.

## Contribution

The study identifies novel immune signatures in HIV-positive individuals prior to AIDS-NHL diagnosis using advanced single-cell analysis.

## Key findings

- Elevated levels of specific T-cells and M2-like monocytes were observed in HIV-positive pre-NHL individuals.
- Positive correlations were found between certain B-cell subsets and T-cell or monocyte metaclusters.
- Unsupervised analysis revealed increased frequencies of CD8+CD20+ T-cells in HIV-positive individuals.

## Abstract

People with HIV (PWH) are at an increased risk for AIDS-associated non-Hodgkin lymphoma (AIDS-NHL); however, the immune signatures underlying this risk are not well understood. In this study, we utilized mass cytometry by time-of-flight (CyTOF) to analyze T-cells and monocytes in the PBMCs of treatment-naïve PWH, including those 3 to 36 months before an AIDS-NHL diagnosis (HIV-positive pre-NHL), as well as people without HIV (PWoH). Mass cytometry is an advanced single-cell analysis platform that combines flow cytometry principles with mass spectrometry. Unlike conventional flow cytometry, this technology employs antibodies conjugated to unique metal isotopes instead of fluorescent markers, enabling simultaneous measurement of over 40 distinct cellular markers per individual cell without spectral overlap limitations. Participants were enrolled at the Los Angeles site of the MACS/WIHS Combined Cohort Study (MWCCS). Unsupervised clustering and Uniform Manifold Approximation and Projection (UMAP) analysis identified CD3+ T-cell and CD14+ monocyte metaclusters, and Spearman’s rank correlation assessed their relationships with B-cell subsets exhibiting aberrant phenotypes. We observed elevated levels of CD8+CD20+ T-cells, CD8+CD14+ T-cells, and M2-like CD14+CD163+ monocytes in HIV-positive pre-NHL individuals compared to HIV-negative controls. Positive correlations were found between CD19+ AICDA+ cMYC+ B-cells and M1-like CD14+cMYC+ monocytes (metacluster, MC02), and between metaclusters of CD8+PD-1+CD27+CXCR4− T-cells (MC05) and CD4+FoxP3+PD-1+CD27+CD28+CXCR4− ICOS+ T-cells (MC08). In addition, a different CD19+ B-cell metacluster (FoxP3+AICDA+cMYC+) was positively associated with a metacluster of CD8+PD-1+CD27+CD28+CXCR4+ T-cells (MC03). Moreover, the metacluster of CD8+PD-1+CD27+CXCR4− T-cells (MC05) negatively correlated with M2-like CD14+CD163+ monocytes (MC06), while CD8+CD14+ T-cells positively correlated with AICDA+ Bregs and IL-10+ B-regs in HIV-positive pre-NHL individuals. Unsupervised analysis revealed increased frequencies of CD8+CD20+ T-cells in HIV-positive individuals compared to HIV-negative controls. These immune alterations provide valuable insights into potential biomarkers for early detection, monitoring, and therapeutic strategies for AIDS-NHL.