MAC-TB/HIV

FRAMEWORK

• Context: International Research Project (IRP).

• Duration: Dec 2020 – Dec 2025.

• Status: Completed.

• Role: Principal Investigator.

• Co-Principal Investigator: Dr. Christel Vérollet, DR2/Inserm.

• Funding:

2023 — 2026 ANRS I MIE ECT278855, Role as Work Package Manager.

“Understanding cell-to-cell transfer of HIV-1 towards activated macrophages: a perspective for HIV/Tuberculosis co-infection.”

2023 — 2025  Sidaction AAP33-2_13457, Role as Co-PI. 

“How does Mycobacterium tuberculosis exacerbate HIV-1 infection? Role of macrophage metabolism.”

2021 — 2025 MAC-TB/HIV, Role as Co-PI.

PROJET DE RECHERCHE INTERNATIONAL (IRP)/CNRS

“Understanding how tuberculosis-associated microenvironment increases susceptibility to HIV-1 infection: a perspective on Metabolism and Activated Macrophages.”

2020 — 2023 ANRS2014-049, Role as Co-PI.

“Cellular and molecular mechanisms involved in Tuberculosis-mediated exacerbation of HIV-1 infection in macrophages: Focus on Siglec-1 and Tunneling nanotubes.” 

• Personnel participating in this project:

  • Dr. Geanncarlo Lugo-Villarino, DR2/CNRS

  • Dr. Olivier Neyrolles, DRCE/CNRS 

  • Zoi Vahlas, Postdoctoral Fellow (2021-2023)

  • Natacha Faivre, PhD candidate (2022-2025)

  • Marine Joly, Master candidate (2022)

• Collaboration: IPBS/CNRS, Toulouse

  • Partner Team: Dr. Christel Vérollet and Renaud Poincloux

  • Key Personnel: 

    • Dr. Christel Vérollet, DR2/Inserm

    • Dr. Arnaud Metais, Research Engineer (CNRS)

• Collaboration: IPBS/CNRS, Toulouse

  • Partner Team: Dr. Jérôme Nigou

  • Key Personnel: 

    • Dr. Emilie Layre, CRCN/CNRS

• Collaboration: INBIRS

  • • Country: Argentina

    • Partner Unit: INBIRS/University of Buenos Aires

    • Partner Team: Dr. Luciana Balboa

    • Key Personnel: 

      • Dr. Luciana Balboa, Principal Investigator 

      • Mariano Maio, PhD graduate (2021-2025)

      • Joaquina Barros, PhD candidate (2022-2026)

      • Leandro Ferrini, Postdoctoral fellow (2025-2028)

AIM 1: Identification of Host Factors Controlling the Metabolic and Activation State of Macrophages Exposed to TB-Associated Microenvironments. 

This aim sought to elucidate how the TB-associated microenvironment alters macrophage metabolism and activation, ultimately compromising their ability to control Mycobacterium tuberculosis (Mtb) infection. Our research has focused on two complementary studies (among others) that together reveal the central role of lipids and lipid-mediated signaling pathways in this process.

A. Role of Lipids (Eicosanoids) in Macrophage Activation in Tuberculosis.

• Student: José Luis Marin Franco (PhD defended in March 2021, Argentina) 

• Supervisors: Luciana Balboa (Argentina) and Geanncarlo Lugo-Villarino (France)

SUMMARY: Mtb manipulates macrophage metabolism to create a permissive environment for its proliferation. The activation of macrophages toward a microbicidal (M1-like) phenotype is dependent on metabolic reprogramming, specifically a shift from oxidative phosphorylation (OXPHOS) to glycolysis, mediated by HIF-1α. We hypothesized that the TB-associated microenvironment disrupts this metabolic reprogramming, thereby impairing macrophage function. Our findings demonstrated that exposure of M1 macrophages to the acellular fraction of TB pleural effusions (PE-TB) reduced glycolytic activity, increased OXPHOS levels, and elevated bacterial burden compared to untreated M1 macrophages. We identified the lipid fraction, particularly eicosanoids, in PE-TB as responsible for these metabolic alterations. Stabilizing HIF-1α (using DMOG) reversed the effects of PE-TB, restoring glycolytic metabolism in M1 macrophages. In vivo, mice infected with Mtb and treated with DMOG exhibited lower bacterial loads and a pronounced M1-like metabolic profile in alveolar macrophages.

SIGNIFICANCE: These results demonstrate that lipids from a TB-associated microenvironment disrupt macrophage metabolic reprogramming by inhibiting HIF-1α activation, thereby compromising control of Mtb infection. These results were published in Cell Reports in December 2020, with Jose as the first author, and Dr. Balboa and me as the last authors (Marin-Franco JL et al., Cell Reports, 2020). 

B. Role of Lipids and GPR32 in Macrophage Metabolic Reprogramming and Response to Mtb

• Student: Joaquina Barros (PhD candidate, Argentina) 

• Supervisors: Luciana Balboa (Argentina) and Geanncarlo Lugo-Villarino (France)

SUMMARY: Building on the findings from Study A, we further investigated the specific lipid mediators involved in macrophage metabolic reprogramming. Our analysis identified resolvin D5 (RvD5), a lipid mediator enriched in PE-TB, as a key player. RvD5 activates the GPR32 receptor in macrophages, reducing their microbicidal activity. PE-TB is sufficient to induce RvD5 secretion by monocytes, consistent with the high expression of enzymes involved in RvD5 biosynthesis in pleural monocytes from TB patients. Mechanistically, RvD5 binds to GPR32, reducing glycolysis without increasing oxidative phosphorylation. This metabolic reprogramming impairs macrophage ability to control bacterial growth by inhibiting HIF-1α. Our results suggest that the RvD5-GPR32 pathway is a critical mediator of the metabolic alterations observed in macrophages exposed to TB-associated microenvironments.

SIGNIFICANCE: These findings suggest that preserving macrophage metabolic function by inhibiting the RvD5-GPR32 pathway could be a promising therapeutic strategy to restore macrophage activation and improve control of Mtb infection. These results are available as a preprint on BioRxiv (2025) and are under revision at Cellular and Molecular Life Sciences, with Joaquina as the first author and Dr. Balboa and me as the last authors (Barros et al., BioRxiv, 2025).

Connection Between Studies A and B. 

Together, these studies provide a comprehensive understanding of how lipids and lipid-mediated signaling pathways within the TB-associated microenvironment disrupt macrophage metabolism and activation. Study A established the broad impact of lipids, particularly eicosanoids, on macrophage metabolic reprogramming, while Study B identified a specific lipid mediator (RvD5) and its receptor (GPR32) as key regulators of this process. By targeting these pathways, we aim to develop therapeutic strategies that restore macrophage function and enhance control of Mtb infection.

AIM 2: Mechanisms by Which TB Exacerbates HIV-1 Infection in Macrophages with a Focus on Intracellular Communication and Metabolism

This complementary aim focuses on understanding how TB-associated microenvironments exacerbate HIV-1 infection in macrophages, with a particular emphasis on intracellular communication and metabolic regulation. Our research has explored two key mechanisms: the role of type I interferons (IFN-I) and glycolysis in HIV-1 transfer between macrophages. Together, these studies provide a comprehensive understanding of how TB compromises macrophage function and promotes HIV-1 dissemination.

A. Role of Type I Interferons in HIV-1/TB Co-Infection 

• Student: Maeva Dupont (PhD defended in October 2019, France)

• Supervisors: Christel Vérollet (France) and Geanncarlo Lugo-Villarino (France)

SUMMARY: TB is a well-known risk factor for exacerbating HIV-1 infection, but the mechanisms underlying this interaction remain poorly understood. Our previous work demonstrated that HIV-1 infection and spread are significantly exacerbated in macrophages exposed to TB-associated microenvironments. To investigate this further, we conducted a transcriptomic analysis of macrophages conditioned with media from Mtb-infected human macrophages (cmMTB). This analysis revealed a striking upregulation of the IFN-I pathway, characterized by the overexpression of IFN-I-inducible genes. While IFN-I is typically recognized for its antiviral functions, our findings in the context of HIV-1/TB co-infection were unexpected. We discovered that the IFN-I signature in cmMTB-treated macrophages mirrored that observed in the blood of patients with active TB, with the timing of macrophage exposure to IFN-I playing a critical role in their ability to control HIV-1 infection. Notably, cmMTB-treated macrophages became hyporesponsive to exogenous IFN-I stimulation, which we used to simulate HIV-1 infection. However, inhibiting STAT1 expression via siRNA, thereby blocking IFN-I signaling, reduced the cmMTB-induced exacerbation of HIV-1 infection.

SIGNIFICANCE: This study elucidates why pre-exposure of macrophages to TB-derived IFN-I fails to induce antiviral immunity against HIV-1. Instead, these cells become hyporesponsive to exogenous IFN-I, impairing macrophage activation and control of HIV-1 infection. These results were published in the Journal of Leukocyte Biology in 2022, with Maeva Dupont as the first author and Dr. Vérollet and me as the last authors (Dupont et al., J Leukoc Biol, 2022).

B. Role of Glycolysis in HIV-1 Transfer Between Macrophages in the Context of Co-Infection

• Postdoctoral Researcher: Zoi Vahlas (2021-2023)

• Supervisors: Christel Vérollet (France) and Geanncarlo Lugo-Villarino (France)

SUMMARY: Both Mtb and HIV-1 target and subvert macrophages, making it crucial to understand their metabolic interactions. While recent advances have shed light on host-pathogen metabolic interactions, the metabolic state of macrophages in the context of HIV/Mtb co-infection has remained unclear. Using an in vitro approach, we investigated whether TB-associated microenvironments regulate macrophage metabolism and how this affects their susceptibility to HIV-1. Our findings revealed that macrophages exposed to TB-associated microenvironments (i.e., cmMTB, PE-TB) produce high levels of ATP, primarily through aerobic glycolysis. Transcriptomic analysis confirmed an enrichment of glycolytic genes in these macrophages. Using pharmacological inhibitors to target different metabolic pathways or glucose deprivation experiments, we demonstrated that altering aerobic glycolysis specifically affects HIV-1 infection. Importantly, glycolysis is essential for the formation of tunneling nanotubes (TNTs) decorated with the SIGLEC-1 receptor, which facilitate HIV-1 transfer between macrophages and thereby promote viral dissemination.

SIGNIFICANCE: This study highlights the critical role of glycolysis in HIV-1 transfer between macrophages, particularly in the context of TB-associated metabolic reprogramming. These results were published in Life Science Alliance in 2026, with Zoi Vahlas as the first author and Dr. Vérollet and me as the last authors (Vahlas et al., Life Sci Alliance, 2026).

Connection Between Studies A and B. 

These studies provide a detailed mechanistic understanding of how TB exacerbates HIV-1 infection in macrophages. Study A reveals how IFN-I contributes to macrophage hyporesponsiveness, impairing their ability to control HIV-1 infection. Study B demonstrates that glycolysis is essential for the formation of tunneling nanotubes, which facilitate HIV-1 transfer between macrophages. By targeting these pathways, IFN-I signaling and glycolytic metabolism, we aim to develop therapeutic strategies to restore macrophage function and limit HIV-1 dissemination in the context of TB co-infection.