Transcriptional Profiles Analysis of COVID-19 and Malaria Patients Reveals Potential Biomarkers in Children.

The clinical presentation overlap between malaria and COVID-19 poses special challenges for rapid diagnosis in febrile children. In this study, we collected RNA-seq data of children with malaria and COVID-19 infection from the public databases as raw data in fastq format paired end files. A group of six, five and two biological replicates of malaria, COVID-19 and healthy donors respectively were used for the study. We conducted differential gene expression analysis to visualize differences in the expression profiles. Using edgeR, we explored particularly gene expression levels in different phenotype groups and found that 1084 genes and 2495 genes were differentially expressed in the malaria samples and COVID-19 samples respectively when compared to healthy controls. The highly expressed gene in the COVID-19 group we found CD151 gene which is facilitates in T cell proliferation, while in the malaria group, among the highly expressed gene we identified GBP5 gene which involved in inflammatory response and response to bacterium. By comparing both malaria and COVID-19 infections, the overlap of 62 differentially expressed genes patterns were identified. Among them, three genes (ENSG00000234998, H2AC19 and TXNDC5) were highly upregulated in both infections. Strikingly, we observed 13 genes such as HBQ1, HBM, SLC7A5, SERINC2, ATP6V0C, ST6GALNAC4, RAD23A, PNPLA2, GAS2L1, TMEM86B, SLC6A8, UBALD1, RNF187 were downregulated in children with malaria and uniquely upregulated in children with COVID-19, thus may be further validated as potential biomarkers to delineate COVID-19 from malaria-related febrile infection. The hemoglobin complexes and lipid metabolism biological pathways are highly expressed in both infections. Our study provided new insights for further investigation of the biological pattern in hosts with malaria and COVID-19 coinfection.

Mycobacterium tuberculosis PE17 (Rv1646) promotes host cell apoptosis via host chromatin remodeling mediated by reduced H3K9me3 occupancy.

Tuberculosis caused by Mycobacterium tuberculosis remains a serious global public health threat. M. tuberculosis PE and PPE proteins are closely involved in pathogen-host interaction. To explore the predicted function of the M. tuberculosis PE17 (Rv1646), we heterologously expressed PE17 in a non-pathogenic Mycobacterium smegmatis strain (Ms_PE17). PE17 can reduce the survival of M. smegmatis within macrophages associated with altering the transcription levels of inflammatory cytokines IL1ß, IL6, TNFα, and IL10 in Ms_PE17 infected macrophages through JNK signaling. Furthermore, macrophages apoptosis was increased upon Ms_PE17 infection in a caspases-dependent manner, accompanied by the activation of the Endoplasmic Reticulum stress IRE1α/ASK1/JNK signaling pathway. This can be largely interpreted by the epigenetic changes through reduced H3K9me3 chromatin occupancy post Ms_PE17 infection. To our knowledge, this is the first report that PE17 altered the macrophages apoptosis via H3K9me3 mediated chromatin remodeling.

Mycobacterium tuberculosis PPE10 (Rv0442c) alters host cell apoptosis and cytokine profile via linear ubiquitin chain assembly complex HOIP-NF-κB signaling axis.

Tuberculosis caused by Mycobacterium tuberculosis infection remains one of the top ten causes of deaths worldwide. M. tuberculosis genome devoted 10% capacity for highly repeated PE/PPE genes family. To explore the role of PPE10 in host-pathogen interaction, PPE10 encoding gene Rv0442c was heterologously expressed in the nonpathogenic M. smegmatis strain. PPE10 altered the bacterial cell surface properties, colony morphology, and biofilm formation. Ms_PPE10 showed more resistance to stress conditions such as diamide, and low pH, as well as higher survival within the macrophage. Moreover, the host's cell apoptosis was regulated via decreased expression of caspases, IL-1, IL-6, and TNF-α through the Linear Ubiquitin Chain Assembly Complex (LUBAC) HOIP-NF-κB signaling axis. The study revealed novel insights into the mechanism of action of the PPE family.

Mycobacterium tuberculosis Raf kinase inhibitor protein (RKIP) Rv2140c is involved in cell wall arabinogalactan biosynthesis via phosphorylation.

Mycobacterium tuberculosis Rv2140c is a function unknown conserved phosphatidylethanolamine-binding protein (PEBP), homologous to Raf kinase inhibitor protein (RKIP) in human beings. To delineate its function, we heterologously expressed Rv2140c in a non-pathogenic M. smegmatis. Quantitative phosphoproteomic analysis between two recombinant strains Ms_Rv2140c and Ms_vec revealed that Rv2140c differentially regulate 425 phosphorylated sites representing 282 proteins. Gene ontology GO, and a cluster of orthologous groups COG analyses showed that regulated phosphoproteins by Rv2140c were mainly associated with metabolism and cellular processes. Rv2140c significantly repressed phosphoproteins involved in signaling, including serine/threonine-protein kinases and two-component system, and the arabinogalactan biosynthesis pathway phosphoproteins were markedly up-regulated, suggesting a role of Rv2140c in modulating cell wall. Consistent with phosphoproteomic data, Rv2140c altered some phenotypic properties of M. smegmatis such as colony morphology, cell wall permeability, survival in acidic conditions, and active lactose transport. In summary, we firstly demonstrated the role of PEBP protein Rv2140c, especially in phosphorylation of mycobacterial arabinogalactan biosynthesis proteins.

Mce-associated protein Rv0177 alters the cell wall structure of Mycobacterium smegmatis and promotes macrophage apoptosis via regulating the cytokines.

The success of Mycobacterium tuberculosis as a pathogen largely contributes to its ability to infect, modify and persist within the host cells. M. tuberculosis Rv0177 is a gene of the mce1 operon (Mammalian cell entry), encoding a conserved hypothetical protein, essential for M. tuberculosis survival and up-regulated within murine macrophages. To explore its function, Rv0177 was heterologously expressed in M. smegmatis. The recombinant protein was located in the cell wall. M. smegmatis recombinant strain expressing Rv0177 altered sliding motility, its cell wall architecture and the permeability. Moreover, M. smegmatis expressing Rv0177 could up-regulate MCP-1 and downregulate the IL-6 expression in RAW264.7 macrophages in comparison to the control. MS_Rv0177 increased the expression of MCP-1 inducible protein (MCPIP) and a C/EBP homologous protein (CHOP) owing to MCP-1. In addition, the JNK signaling pathway was engaged in the interplay between MS_Rv0177 and macrophages. The macrophage caspase-3 activation and cell apoptosis were induced by the recombinant. This provided novel functional cues for the MCE-associated Rv0177.

The Synergistic Effect of Exogenous Glutamine and Rifampicin Against Mycobacterium Persisters.

Persisters, stochastic dormant variants of normal bacteria cell, represent a significant portion of the survivors upon exposure to antibiotics and other environmental stresses, which contributes substantially to high level antibiotics tolerance. Glutamine is a crucial component of the Mycobacteria nitrogen pool that is indispensable for survival upon stresses. To study whether a synergistic effect exists between glutamine and antibiotics against Mycobacterial persisters, the efficacy of rifampicin alone or together with exogenous glutamine upon Mycobacterium smegmatis mc2 155 persisters was monitored. The result showed that glutamine decreases M. smegmatis tolerance to rifampicin upon starvation. The reactive oxygen species level of the strains treated with rifampicin and glutamine increased. The synergism of glutamine and rifampicin to kill persisters might derive from altering the oxidative phosphorylation and TCA cycle, as both evidenced by both ATP level increase and transcriptome change. Glutamine might represent a synergistic agent of rifampicin to kill Mycobacteria persisters.

Mycobacterium tuberculosis toxin Rv2872 is an RNase involved in vancomycin stress response and biofilm development.

Bacterial toxin-antitoxin (TA) systems are emerging important regulators of multiple cellular physiological events and candidates for novel antibiotic targets. To explore the role of Mycobacterium tuberculosis function, unknown toxin gene Rv2872 was heterologously expressed in Mycobacterium smegmatis (MS_Rv2872). Upon induction, MS_Rv2872 phenotype differed significantly from the control, such as increased vancomycin resistance, retarded growth, cell wall, and biofilm structure. This phenotype change might result from the RNase activity of Rv2872 as purified Rv2872 toxin protein can cleave the products of several key genes involved in abovementioned phenotypes. In summary, toxin Rv2872 was firstly reported to be a endonuclease involved in antibiotic stress responses, cell wall structure, and biofilm development.

Emerging drugs and drug targets against tuberculosis.

Mycobacterium tuberculosis (M. tuberculosis), the causative agent of tuberculosis, uses various tactics to resist on antibiotics and evade host immunity. To control tuberculosis, antibiotics with novel mechanisms of action are urgently needed. Emerging new antibiotics and underlying novel drug targets are summarized in this paper.

Interleukin-10 Family and Tuberculosis: An Old Story Renewed.

The interleukin-10 (IL-10) family of cytokines consists of six immune mediators, namely IL-10, IL-19, IL-20, IL-22, IL-24 and IL-26. IL-10, IL-22, IL-24 and IL-26 are critical for the regulation of host defense against Mycobacterium tuberculosis infections. Specifically, IL-10 and IL-26 can suppress the antimycobacterial immunity and promote the survival of pathogen, while IL-22 and IL-24 can generate protective responses and inhibit the intracellular growth of pathogen. Knowledge about the new players in tuberculosis immunology, namely IL-10 family, can inform novel immunity-based countermeasures and host directed therapies against tuberculosis.