Deletion of TgF-beta 1 increases Bacterial clearance by cytotoxic T cells in a Tuberculosis granuloma Model

Authored by Denise E Kirschner, Jennifer J Linderman, Elsje Pienaar, Joshua T Mattila, Hayley C Warsinske

Date Published: 2017

DOI: 10.3389/fimmu.2017.01843

Sponsors: United States National Institutes of Health (NIH) United States Department of Energy (DOE)

Platforms: No platforms listed

Model Documentation: Other Narrative Flow charts Mathematical description

Model Code URLs: Model code not found

Abstract

Mycobacterium tuberculosis is the pathogenic bacterium that causes tuberculosis (TB), one of the most lethal infectious diseases in the world. The only vaccine against TB is minimally protective, and multi-drug resistant TB necessitates new therapeutics to treat infection. Developing new therapies requires a better understanding of the complex host immune response to infection, including dissecting the processes leading to formation of granulomas, the dense cellular lesions associated with TB. In this work, we pair experimental and computational modeling studies to explore cytokine regulation in the context of TB. We use our next-generation hybrid multi-scale model of granuloma formation (GranSim) to capture molecular, cellular, and tissue scale dynamics of granuloma formation. We identify TGF-beta 1 as a major inhibitor of cytotoxic T-cell effector function in granulomas. Deletion of TGF-beta 1 from the system results in improved bacterial clearance and lesion sterilization. We also identify a novel dichotomous regulation of cytotoxic T cells and macrophages by TGF-beta 1 and IL-10, respectively. These findings suggest that increasing cytotoxic T-cell effector functions may increase bacterial clearance in granulomas and highlight potential new therapeutic targets for treating TB.
Tags
Agent-based modeling tuberculosis Immune-response Necrosis-factor-alpha Mycobacterium-tuberculosis Interferon-gamma Growth-factor-beta Tgf-beta Transforming growth-factor-beta-1 Ifn-gamma Cells-t cells Cytotoxic Infections-bacterial Transforming growth factor beta Pulmonary Macrophage activation Identifying mechanisms