A Rho GDP Dissociation Inhibitor Produced by Apoptotic T-Cells Inhibits Growth of Mycobacterium tuberculosis

Abstract

In this study, we found that a subpopulation of CD4+CD25+ (85% Foxp3+) cells from persons with latent tuberculosis infection (LTBI) inhibits growth of M. tuberculosis (M. tb) in human monocyte-derived macrophages (MDMs). A soluble factor, Rho GDP dissociation inhibitor (D4GDI), produced by apoptotic CD4+CD25+ (85% Foxp3+) cells is responsible for this inhibition of M. tb growth in human macrophages and in mice. M. tb-expanded CD4+CD25+Foxp3+D4GDI+ cells do not produce IL-10, TGF-β and IFN-γ. D4GDI inhibited growth of M. tb in MDMs by enhancing production of IL-1β, TNF-α and ROS, and by increasing apoptosis of M. tb-infected MDMs. D4GDI was concentrated at the site of disease in tuberculosis patients, with higher levels detected in pleural fluid than in serum. However, in response to M. tb, PBMC from tuberculosis patients produced less D4GDI than PBMC from persons with LTBI. M. tb-expanded CD4+CD25+ (85% Foxp3+) cells and D4GDI induced intracellular M. tb to express the dormancy survival regulator DosR and DosR-dependent genes, suggesting that D4GDI induces a non-replicating state in the pathogen. Our study provides the first evidence that a subpopulation of CD4+CD25+ (85% Foxp3+) cells enhances immunity to M. tb, and that production of D4GDI by this subpopulation inhibits M. tb growth.

A TLR9 agonist promotes IL-22-dependent pancreatic islet allograft survival in type 1 diabetic mice

“…complementary DNA (cDNA) was generated from 0.5 mg RNA and random hexamer primers using the Maxima First Strand cDNA Synthesis Kit for RT-qPCR (BIO-RAD), according to manufacturer's instructions, and real time PCR was performed as previously reported65. Gene expression of the immune system-related genes IL-1β, TNF, IFN-γ, IL-10, IL-6, FoxP3, TGF-β, IL-18, IL-23 and IL-22 was quantified in the lymphoid organs, and the cell regeneration genes Reg1a, Reg2, Reg3a and Reg3g and insulin secretion-regulating genes pdx1, Foxa2, IRE1 and TXNIP were measured in cytokine-treated islets using the Syber green master mix (Qiagen) and gene-specific primers (Sigma-Aldrich) (Supplementary Table 1) on an ABI Prism 7600.…”

“…Cells were then incubated at 4 °C for 30 min, washed twice and fixed in 1% paraformaldehyde before acquisition on a FACSCalibur (BD Biosciences). In some experiments, intracellular staining was performed according to the manufacturer's instructions65.…”

BCG vaccination reduces the mortality of Mycobacterium tuberculosis–infected type 2 diabetes mellitus mice

“…Three months of after vaccination, some of the mice were induced with T2DM. For infection studies, some of the BCG-vaccinated T2DM mice were infected with Mtb H37Rv using an aerosol exposure chamber as described previously (81,82). Briefly, Mtb H37Rv was grown to the mid-log phase in liquid culture medium and then frozen in aliquots at -70°C.…”

Alcohol enhances type 1 interferon-α production and mortality in young mice infected with Mycobacterium tuberculosis

“…Mice were fed the alcohol and control diets, and after three months, they were infected with Mtb H37Rv using an aerosol exposure chamber as described previously [ 58 ]. Briefly, Mtb H37Rv was grown to the mid-log phase in liquid medium and then frozen in aliquots at -70°C.…”