Biology subjects

Hadda, V.

Publications and source records attributed to Hadda, V..

3 recordsLinked to original sources

bioRxiv2026

Sphingosine-1-Phosphate Restrains Foamy Macrophage Formation and Modulates Inflammation in Multidrug-Resistant Tuberculosis

The high abundance of lipid loaded foamy macrophages in the granulomatous lesions is a key hallmark of advanced pulmonary tuberculosis. These macrophages serve as lipid-rich intracellular hiding niches that provides Mycobacterium tuberculosis (M.tb) survival and persistence during prolonged anti-tubercular treatment. Persistent infection and dysregulated inflammatory responses further complicate disease control, particularly in multidrug-resistant tuberculosis (MDR-TB), highlighting the need for host-directed therapeutic strategies. Our previous preclinical study demonstrated the therapeutic potential of the host sphingolipid sphingosine-1-phosphate (S1P) in reducing the mycobacterial burden in M.tb-infected animals, accompanied by enhanced pulmonary macrophage activation. To explore its translational potential, we investigated whether S1P modulates foamy macrophage formation in CD14 monocyte-derived macrophages from healthy donors and patients with MDR-TB. Notably, macrophages derived from patients with MDR-TB exhibited greater intracellular lipid droplet accumulation than those derived from healthy donors. This phenotype was further characterized by increased nitric oxide production and quantitative RT-PCR analysis of genes associated with immune regulation and lipid metabolism, including APOE, LDLR1, CLEC4E, CLEC7A, GP96, IL4, and IL13, which suggested a Th2-associated immunological bias in foamy macrophages. Collectively, these findings highlight the potential role of host sphingolipids in modulating foamy macrophage phenotypes and associated immunometabolic dysregulation, supporting further investigation of S1P as a host-directed therapeutic strategy against MDR-TB.

immunology↗

bioRxiv2026

L-Serine potentiates the efficacy of Isoniazid, and Rifampicin as host-directed adjunctive treatment for Mycobacterium tuberculosis.

Host-directed therapies (HDTs) have acquired paramount importance for management of tuberculosis (TB). L-Serine is an important metabolite and immunomodulatory biomolecule with promising role in managing infections, and autoimmune diseases. However, the role of L-Serine as host directed therapeutic against Mycobacterium tuberculosis (M.tb) remains unexplored. Therefore, we adopted de novo-based approach and employed L-Serine and palmitoyl CoA precursors for enhancing sphingolipid in host and accessed their anti-tubercular potential. In this study, we investigated whether L-Serine could modulate the antibiotics efficacy against M.tb. L-Serine particularly in combination with palmitic acid, rifampicin and isoniazid showed enhanced intracellular bacterial clearance in a dose- and time-dependent manner in murine and human macrophages. This synergistic effect was accompanied by increased nitric oxide production and modulation of the host immune response. We identified elevated levels of pro-inflammatory cytokine TNF- and reduced anti-inflammatory IL-10 expression. Furthermore, L-Serine supplementation demonstrated antimicrobial activity in isolated primary CD14 monocytes from TB patients. Similarly, the metabolic supplementation of L-Serine in combination with isoniazid, rifampicin, and palmitic acid significantly reduced bacterial burden in the lungs and spleen, while improving tissue architecture in murine infection model. Our observations suggest that L-Serine and palmitic acid in combination with isoniazid and rifampicin contributes to the observed therapeutic effects. Collectively, this study concludes that L-Serine and palmitic acid acts as a promising host-directed therapeutic adjunct, which enhances antimicrobial immunity and potentiating antibiotic efficacy, providing a potential strategy for improving tuberculosis treatment outcomes.

microbiology↗

bioRxiv2025

ATLS2021-PA (A Sphingolipid mimetic): Upcoming Host Directed Therapy for Acute and MDR Tuberculosis

Several reports have shown that reduced Sphingolipids content in the lungs largely contributes to the outcome of Tuberculosis diseases. In this context, our pioneer study has advocated that Sphingosine -1 phosphate (a central Sphingolipid metabolite) can help host in limiting Mycobacterium tuberculosis burden in lungs by their virtue of tweaking M1 retuning of infected macrophages. This indicated that S1P may serve as anti-tubercular regimen, however allergic and autoimmune manifestation of S-1P refrain its further use as anti-tubercular Drugs. In view of this limitation, and high demand of developing newer host directed anti tubercular regimen, we explored whether enhancing / boosting Sphingolipids levels via de novo pathways by our patented drugs ATLS2021 and PA would also help host in controlling mycobacterial infection. Our results prudently demonstrated that ATLS2021 was effective in controlling survival of both wild type and MDR strain of TB in various models we tested. Our results further demonstrated the influence of ATLS2021 on NO mediated killing of mycobacteria which indicated one of most possible anti-mycobacterial mechanism of ATLS2021. Additionally, ATLS2021 lowered the IC50 value of Rifampicin for both wild-type and MDR TB by sensitizing the MDR clinical isolate of Mycobacterium tuberculosis to Rifampicin-mediated killing. ATLS2021 induced immunogenic responses in blood derived CD14+ macrophages from both healthy donors as well as MDR-TB patient demonstrating immune adjuvant potential of ATLS2021. Real time PCR data demonstrated that ATLS2021 enhanced the expression of almost all key enzymes involved in the Sphingolipid biosynthesis pathways in the CD14 positive monocytes from healthy donors and MDR TB patients. Taken together these results potentially advocated that ATLS2021 based approach is potentially immunogenic interventions against TB.

pharmacology and toxicology↗