bioRxiv Science⌕ Search

Biology subjects

Vahlas, Z.

Publications and source records attributed to Vahlas, Z..

3 recordsLinked to original sources

Inhibition of glycolysis in tuberculosis-mediated metabolic rewiring reduces HIV-1 spread across macrophages

Tuberculosis (TB) is a significant aggravating factor in individuals living with human immunodeficiency virus type 1 (HIV-1), the causative agent for acquired immunodeficiency syndrome (AIDS). Both Mycobacterium tuberculosis (Mtb), the bacterium responsible for TB, and HIV-1 target macrophages. Understanding how Mtb subverts these cells may facilitate the identification of new druggable targets. Here, we explored how TB can induce macrophages to form tunneling nanotubes (TNT), promoting HIV-1 spread. We found that TB triggers metabolic rewiring of macrophages, increasing their glycolytic ATP production. Using pharmacological inhibitors and glucose deprivation, we discovered that disrupting aerobic glycolysis significantly reduces HIV-1 exacerbation in these macrophages. Glycolysis is essential for tunneling nanotubes (TNT) formation, which facilitates viral transfer and cell-to-cell fusion and induces the expression of the sialoadhesin Siglec-1, enhancing both HIV-1 binding and TNT stabilization. Glycolysis did not exacerbate HIV-1 infection when TNT formation was pharmacologically prevented, indicating that higher metabolic activity is not sufficient per se to make macrophages more susceptible to HIV-1. Overall, these data might facilitate the development of targeted therapies aimed at inhibiting glycolytic activity in TB-induced immunomodulatory macrophages to ultimately halt HIV-1 dissemination in co-infected patients.

immunology↗

The immunosuppressive Tuberculosis-associated microenvironment inhibits viral replication and promotes HIV-1 latency in CD4+ T cells

Author SummaryMycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is the most common coinfection among people living with HIV-1. This coinfection alters the efficacy of the immune response against both HIV-1 and Mtb, and is associated with accelerated HIV-1 disease progression and reduced survival. Enhanced HIV-1 replication in macrophages induced by Mtb coinfection may contribute to the worsened clinical outcomes observed in HIV-1/TB coinfected individuals. However, the impact of the HIV-1/TB coinfection on HIV-1 replication and latency in CD4+ T cells remains poorly studied. In this study, we used the acellular fraction of tuberculous pleural effusion (TB-PE) as a proxy for the microenvironment generated by Mtb infection. Using this physiologically relevant fluid, we investigated whether viral replication and HIV-1 latency in CD4+ T cells are affected by a TB-associated microenvironment. Interestingly, our results revealed that TB-PE shaped the transcriptional profile of CD4+ T cells impairing T cell receptor-dependent cell activation and decreased HIV-1 replication. Moreover, this immunosuppressive TB microenvironment promoted viral latency and inhibited HIV-1 reactivation in CD4+ T cells from people living with HIV-1. This study indicates that the immune response induced by TB may contribute to the persistence of the viral reservoir by silencing HIV-1 expression in individuals coinfected with both pathogens, allowing the virus to persist undetected by the immune system and increasing the size of the HIV-1 latent reservoir in cells at the site of the coinfection.

pathology↗

Glycolytic imprinting of monocytes impairs HIF1α-driven migration of dendritic cells in tuberculosis

During tuberculosis, migration of dendritic cells (DCs) from the site of infection to the draining lymph nodes is known to be impaired, hindering the rapid development of protective T-cell mediated immunity. However, the mechanisms involved in the delayed migration of DCs during tuberculosis (TB) are still poorly defined. Here, we found that infection of DCs with Mycobacterium tuberculosis (Mtb) triggers HIF-1-mediated aerobic glycolysis in a TLR2-dependent manner, and that this metabolic profile is essential for DC migration. In particular, the lactate dehydrogenase (LDH) inhibitor oxamate and the HIF-1 inhibitor PX-478 abrogated Mtb-induced DC migration in vitro to the lymphoid tissue-specific chemokine CCL21, and in vivo to lymph nodes in mice. Strikingly, we found that although monocytes from TB patients are inherently biased toward glycolysis metabolism, they differentiate into poorly glycolytic and poorly migratory DCs, compared with healthy subjects. Taken together, these data suggest that because of their preexisting glycolytic state, circulating monocytes from TB patients are refractory to differentiation into migratory DCs, which may explain the delayed migration of these cells during the disease and opens avenues for host-directed therapies for TB. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/535400v6_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@9c6849org.highwire.dtl.DTLVardef@82981dorg.highwire.dtl.DTLVardef@1d0b7faorg.highwire.dtl.DTLVardef@1deb76f_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗