Cells of the myeloid lineage, particularly monocytes and macrophages, play a key role in HIV infection by contributing to viral replication, immune response, and maintaining immune balance during suppressive therapy. We hypothesized that metabolic reprogramming and altered chemokine signaling in people living with HIV (PWH) on long-term antiretroviral therapy (ART) affect monocyte transport and polarization due to ongoing inflammation. Therefore, the present study aimed to identify the mechanism of impaired monocyte/macrophage function in PWH on well-treated ART that can lead to clinical intervention strategies to improve health. Single-cell RNA sequencing, immune-phenotyping, and metabolic modeling identified altered expression of chemokine and metabolite receptors and altered metabolic flux in PWH monocytes that decreased monocyte migration. The plasma secretome revealed a nonclassical inflammatory microenvironment in PWH. Integrative multi-omics and single-cell proteomics of differentiated monocyte-derived macrophages (MDMs) detected metabolic reprogramming orchestrated by α-ketoglutarate (AKG) that affected macrophage function and HIV infection. Increased levels of AKG in plasma were shown to occur in PWH under ART. Therefore, when differentiating MDM with serum from PWH or AKG, macrophage function was found polarized towards an M2-like state. AKG alone was shown to increase CCR5 levels and increase HIV-1 infection in MDM. Here, we utilize systems biology-driven identification and ex vivo assays to show impaired macrophage polarization, due to metabolic training, can leads to a low-grade nonclassical inflammatory environment in well-treated PWH.

Metastasis is the principal cause of cancer treatment failure and an area of dire diagnostic needs. Colorectal cancer metastases to the liver (CRCLMs) are predominantly classified into desmoplastic and replacement based on their histological growth patterns (HGPs). Desmoplastic responds well to current treatments, while replacement HGP has a poor prognosis with low overall survival rates.
We hypothesised that complex cellular response underlying HGPs may be reflected in the proteome of circulating extracellular vesicles (EVs). EV proteomics data was generated through LC-MS/MS and analysed with Maxquant and Perseus. To validate the S100A9 signature, ELISA was performed, and IHC and IF were conducted on tissue for marker detection and colocalization study.
Plasma EV proteome signature distinguished desmoplastic from the replacement in patients with 22 differentially expressed proteins, including immune related markers. Unsupervised PCA analysis revealed clear separation of the two lesions. The marker with the highest confidence level to stratify the two HGPs was S100A9, which was traced in CRCLM lesions and found to colocalize with macrophages and neutrophils. EV-associated S100A9 in plasma may reflect the innate immunity status of metastatic lesions and their differential therapeutic responses.
Plasma EV-derived S100A9 could be useful in personalising therapy in patients with CRCLM.
© 2023. The Author(s).

The cellular composition of the tumor microenvironment, including tumor, immune, stromal, and endothelial cells, significantly influences responses to cancer therapies. In this study, we analyzed the impact of oxidative stress, induced by cold atmospheric plasma (CAP), on tumor cells, T cells, and macrophages, which comprise part of the melanoma microenvironment. To accomplish this, cells were grown in different in vitro cell culture models and were treated with varying amounts of CAP. Subsequent alterations in viability, proliferation, and phenotype were analyzed via flow cytometry and metabolic alterations by Seahorse Cell Mito Stress Tests. It was found that cells generally exhibited reduced viability and proliferation, stemming from CAP induced G2/M cell cycle arrest and subsequent apoptosis, as well as increased mitochondrial stress following CAP treatment. Overall, sensitivity to CAP treatment was found to be cell type dependent with T cells being the most affected. Interestingly, CAP influenced the polarization of M0 macrophages to a "M0/M2-like" phenotype, and M1 macrophages were found to display a heightened sensitivity to CAP induced mitochondrial stress. CAP also inhibited the growth and killed melanoma cells in 2D and 3D in vitro cell culture models in a dose-dependent manner. Improving our understanding of oxidative stress, mechanisms to manipulate it, and its implications for the tumor microenvironment may help in the discovery of new therapeutic targets.

The tumor immune microenvironment plays a critical role in cancer progression and response to immunotherapy in clear cell renal cell carcinoma (ccRCC), yet the composition and phenotypic states of immune cells in this tumor are incompletely characterized. We performed single-cell RNA and T cell receptor sequencing on 164,722 individual cells from tumor and adjacent non-tumor tissue in patients with ccRCC across disease stages: early, locally advanced, and advanced/metastatic. Terminally exhausted CD8+ T cells were enriched in metastatic disease and were restricted in T cell receptor diversity. Within the myeloid compartment, pro-inflammatory macrophages were decreased, and suppressive M2-like macrophages were increased in advanced disease. Terminally exhausted CD8+ T cells and M2-like macrophages co-occurred in advanced disease and expressed ligands and receptors that support T cell dysfunction and M2-like polarization. This immune dysfunction circuit is associated with a worse prognosis in external cohorts and identifies potentially targetable immune inhibitory pathways in ccRCC.
Copyright © 2021 Elsevier Inc. All rights reserved.

The presence and interaction of immune cells in the tumor microenvironment is of significant importance and has a great impact on disease progression and response to therapy. Hence, their identification is of high interest for prognosis and treatment decisions. Besides detailed phenotypic analyses of immune, as well as tumor cells, spatial analyses is an important parameter in the complex interplay of neoplastic and immune cells-especially when moving into focus efforts to develop and validate new therapeutic strategies. Ex vivo analysis of tumor samples by immunohistochemistry staining methods conserves spatial information is restricted to single markers, while flow cytometry (disrupting tissue into single cell suspensions) provides access to markers in larger numbers. Nevertheless, this comes at the cost of scarifying morphological information regarding tissue localization and cell-cell contacts. Further detrimental effects incurred by, for example, tissue digestion include staining artifacts. Consequently, ongoing efforts are directed towards methods that preserve, completely or in part, spatial information, while increasing the number of markers that can potentially be interrogated to the level of conventional flow cytometric methods. Progression in multiplex immunohistochemistry in the last ten years overcame the limitation to 1-2 markers in classical staining methods using DAB with counter stains or even pure chemical staining methods. In this study, we compared the multiplex method Chipcytometry to flow cytometry and classical IHCP using DAB and hematoxylin. Chipcytometry uses frozen or paraffin-embedded tissue sections stained with readily available commercial fluorophore-labeled antibodies in repetitive cycles of staining and bleaching. The iterative staining approach enables sequential analysis of a virtually unlimited number of markers on the same sample, thereby identifying immune cell subpopulations in the tumor microenvironment in the present study in a humanized mouse melanoma model.