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PLoS Pathogens Jan 2024Alveolar macrophages (AMs) play a critical role during Mycobacterium tuberculosis (Mtb) infection as the first cells in the lung to encounter bacteria. We previously...
Alveolar macrophages (AMs) play a critical role during Mycobacterium tuberculosis (Mtb) infection as the first cells in the lung to encounter bacteria. We previously showed that AMs initially respond to Mtb in vivo by mounting a cell-protective, rather than pro-inflammatory response. However, the plasticity of the initial AM response was unknown. Here, we characterize how previous exposure to Mycobacterium, either through subcutaneous vaccination with Mycobacterium bovis (scBCG) or through a contained Mtb infection (coMtb) that mimics aspects of concomitant immunity, impacts the initial response by AMs. We find that both scBCG and coMtb accelerate early innate cell activation and recruitment and generate a stronger pro-inflammatory response to Mtb in vivo by AMs. Within the lung environment, AMs from scBCG vaccinated mice mount a robust interferon-associated response, while AMs from coMtb mice produce a broader inflammatory response that is not dominated by Interferon Stimulated Genes. Using scRNAseq, we identify changes to the frequency and phenotype of airway-resident macrophages following Mycobacterium exposure, with enrichment for both interferon-associated and pro-inflammatory populations of AMs. In contrast, minimal changes were found for airway-resident T cells and dendritic cells after exposures. Ex vivo stimulation of AMs with Pam3Cys, LPS and Mtb reveal that scBCG and coMtb exposures generate stronger interferon-associated responses to LPS and Mtb that are cell-intrinsic changes. However, AM profiles that were unique to each exposure modality following Mtb infection in vivo are dependent on the lung environment and do not emerge following ex vivo stimulation. Overall, our studies reveal significant and durable remodeling of AMs following exposure to Mycobacterium, with evidence for both AM-intrinsic changes and contributions from the altered lung microenvironments. Comparisons between the scBCG and coMtb models highlight the plasticity of AMs in the airway and opportunities to target their function through vaccination or host-directed therapies.
Topics: Mice; Animals; Macrophages, Alveolar; Lipopolysaccharides; Tuberculosis; Mycobacterium tuberculosis; Interferons
PubMed: 38236787
DOI: 10.1371/journal.ppat.1011871 -
Frontiers in Cellular and Infection... 2023The COVID-19 pandemic, caused by SARS-CoV-2 virus, has been one of the top public health threats across the world over the past three years. BCG is currently the only...
The COVID-19 pandemic, caused by SARS-CoV-2 virus, has been one of the top public health threats across the world over the past three years. BCG is currently the only licensed vaccine for tuberculosis, one of the deadliest infectious diseases in the world, that is caused by . In the past decades, recombinant BCG has been studied as a novel vaccine vector for other infectious diseases in humans besides tuberculosis, such as viral infections. In the current study, we generated a recombinant BCG strain AspikeRBD that expresses a fusion protein consisting of Ag85A protein and the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein using synthetic biology technique. Our results show that the recombinant BCG strain successfully expressed this fusion protein. Interestingly, the recombinant BCG strain AspikeRBD significantly induced SARS-CoV-2 spike-specific T cell activation and IgG production in mice when compared to the parental BCG strain, and was more potent than the recombinant BCG strain expressing SARS-CoV-2 spike RBD alone. As expected, the recombinant BCG strain AspikeRBD activated an increased number of Ag85A-specific IFNγ-releasing T cells and enhanced IgG production in mice when compared to the parental BCG strain or the BCG strain expressing SARS-CoV-2 spike RBD alone. Taken together, our results indicate a potential application of the recombinant BCG strain AspikeRBD as a novel dual vaccine against SARS-CoV-2 and in humans.
Topics: Humans; Animals; Mice; COVID-19 Vaccines; BCG Vaccine; Pandemics; Antigens, Bacterial; COVID-19; Vaccines, Synthetic; SARS-CoV-2; Tuberculosis; Recombinant Proteins; Communicable Diseases; Immunoglobulin G
PubMed: 37965265
DOI: 10.3389/fcimb.2023.1273019 -
PloS One 2023Serological assays for bovine tuberculosis diagnosis require the use of multiple Mycobacterium bovis specific antigens to ensure the detection of infected animals. In...
Serological assays for bovine tuberculosis diagnosis require the use of multiple Mycobacterium bovis specific antigens to ensure the detection of infected animals. In the present study, identification and selection process of antigens, based on data from published proteomic studies and involving the use of bioinformatics tools and an immuno-screening step, was firstly performed for identifying novel antigens that elicit an antibody response in M. bovis infection. Based on this approach, a panel of 10 M. bovis antigens [with known relevance (MPB70, MPB83, MPB70/83, and ESAT6/CFP10) and novel (Mb1961c, Mb1301c, Mb3871, Mb1403, Mb0592, and PE25/PPE41)] were constructed and thenused to develop a new multiplexed serological assay based on Luminex technology. The performance of the Luminex-bTB immunoassay was evaluated using sera from cattle with known tuberculosis status. Among the proteins whose ability to detect bovine tuberculosis was evaluated for the first time, PE25/PPE41 and Mb1403, but not Mb3871, showed good detection capacity. Following multiple antigen combination, the final Luminex-bTB immunoassay included seven antigens (MPB70, MPB83, MPB70/83, ESAT6/CFP10, PE25/PPE41, Mb1403, and Mb0592) and showed better global performance than the immunoassay using the four usual antigens (MPB70, MPB70/83, MPB83 and ESAT6/CFP10). The specificity and sensitivity values were, respectively, of 97.6% and 42.8% when the cut-off of two-positive antigens was used to classify samples as positive. With the use of the more-restrictive criterion of three-positive antigens, the specificity increased to 99.2% but the sensitivity decreased to 23.9%. The analysis of antigen profiles generated with the Luminex-bTB immunoassay showed that mainly serodominant proteins were recognized in samples from infected cattle. The detection of Mb1961c and Mb1301c appeared to be associated with presumed false-positive results. Moreover, sera from cattle originating from bTB-outbreaks but having inconclusive or negative skin test results were identified as positive by the Luminex-bTB immunoassay and showed an antigen pattern associated with M. bovis infection. The Luminex-bTB immunoassay including seven antigens may be useful as adjunct test for the detection of M. bovis-infected herds, and different cut-offs could be applied according to the bovine tuberculosis epidemiological context.
Topics: Animals; Cattle; Tuberculosis, Bovine; Mycobacterium bovis; Proteomics; Antigens, Bacterial; Immunoassay; Enzyme-Linked Immunosorbent Assay
PubMed: 37812634
DOI: 10.1371/journal.pone.0292590 -
Frontiers in Cellular and Infection... 2023(Mtb) is an intracellular bacterium that causes a highly contagious and potentially lethal tuberculosis (TB) in humans. It can maintain a dormant TB infection within...
(Mtb) is an intracellular bacterium that causes a highly contagious and potentially lethal tuberculosis (TB) in humans. It can maintain a dormant TB infection within the host. DosR (dormancy survival regulator) (Rv3133c) has been recognized as one of the key transcriptional proteins regulating bacterial dormancy and participating in various metabolic processes. In this study, we extensively investigate the still not well-comprehended role and mechanism of DosR in () Bacillus Calmette-Guérin (BCG) through a combined omics analysis. Our study finds that deleting DosR significantly affects the transcriptional levels of 104 genes and 179 proteins. Targeted metabolomics data for amino acids indicate that DosR knockout significantly upregulates L-Aspartic acid and serine synthesis, while downregulating seven other amino acids, including L-histidine and lysine. This suggests that DosR regulates amino acid synthesis and metabolism. Taken together, these findings provide molecular and metabolic bases for DosR effects, suggesting that DosR may be a novel regulatory target.
Topics: Humans; Mycobacterium bovis; Bacterial Proteins; Multiomics; Tuberculosis; Mycobacterium tuberculosis; Lysine; BCG Vaccine
PubMed: 38076461
DOI: 10.3389/fcimb.2023.1292864 -
Current Issues in Molecular Biology Jul 2023Bovine tuberculosis is endemic in Nigeria with control measures as provided by the laws of the country being minimally enforced mostly at the abattoirs only. This study...
Bovine tuberculosis is endemic in Nigeria with control measures as provided by the laws of the country being minimally enforced mostly at the abattoirs only. This study focused on bovine tuberculosis in Adamawa and Gombe States. Tuberculosis lesions were observed in 183 of 13,688 slaughtered cattle in the regions between June and December 2020. Analysis of tissue samples resulted in 17 isolates, predominantly from Gombe State. Spoligotyping identified four spoligotypes, including SB0944, SB1025, SB1104, and one novel pattern. MIRU-VNTR analysis further differentiated these spoligotypes into eight profiles. All isolates belonged to the Af1 clonal complex. The study emphasises the need for broader coverage and more isolates to comprehensively understand the molecular epidemiology of bovine tuberculosis in Nigeria. To enhance research and surveillance, a cost-effective approach is proposed, utilising a discriminatory VNTR panel comprising five or nine loci. The five-locus panel consists of ETR-C, QUB26, QUB11b, MIRU04, and QUB323. Alternatively, the nine-locus panel includes ETR-A, ETR-B, QUB11a, and MIRU26. Implementing this approach would provide valuable insights into the genetic diversity of strains in Nigeria. These findings are crucial for developing effective control measures and minimising the impact of bovine tuberculosis on both animal and human health.
PubMed: 37504298
DOI: 10.3390/cimb45070382 -
Frontiers in Microbiology 2023Animal tuberculosis is a significant infectious disease affecting both livestock and wildlife populations worldwide. Effective disease surveillance and characterization...
Animal tuberculosis is a significant infectious disease affecting both livestock and wildlife populations worldwide. Effective disease surveillance and characterization of strains are essential for understanding transmission dynamics and implementing control measures. Currently, sequencing of genomic information has relied on culture-based methods, which are time-consuming, resource-demanding, and concerning in terms of biosafety. This study explores the use of culture-independent long-read whole-genome sequencing (WGS) for a better understanding of epidemiology in African buffaloes (). By comparing two sequencing approaches, we evaluated the efficacy of Illumina WGS performed on culture extracts and culture-independent Oxford Nanopore adaptive sampling (NAS). Our objective was to assess the potential of NAS to detect genomic variants without sample culture. In addition, culture-independent amplicon sequencing, targeting mycobacterial-specific housekeeping and full-length 16S rRNA genes, was applied to investigate the presence of microorganisms, including nontuberculous mycobacteria. The sequencing quality obtained from DNA extracted directly from tissues using NAS is comparable to the sequencing quality of reads generated from culture-derived DNA using both NAS and Illumina technologies. We present a new approach that provides complete and accurate genome sequence reconstruction, culture independently, and using an economically affordable technique.
PubMed: 38075895
DOI: 10.3389/fmicb.2023.1307440 -
International Journal of Molecular... Aug 2023Pyroptosis is a host immune strategy to defend against (Mtb) infection. , a calcium-binding protein that plays an important role in promoting cancer progression as well...
Pyroptosis is a host immune strategy to defend against (Mtb) infection. , a calcium-binding protein that plays an important role in promoting cancer progression as well as the pathophysiological development of various non-tumor diseases, has not been explored in Mtb-infected hosts. In this study, transcriptome analysis of the peripheral blood of patients with pulmonary tuberculosis (PTB) revealed that and were significantly up-regulated in PTB patients' peripheral blood. Furthermore, there was a positive correlation between the expression of and . KEGG pathway enrichment analysis showed that differentially expressed genes between PTB patients and healthy controls were significantly related to inflammation, such as the NOD-like receptor signaling pathway and NF-κB signaling pathway. To investigate the regulatory effects of on macrophage pyroptosis, THP-1 macrophages infected with (BCG) were pre-treated with exogenous , inhibitor or si-. This research study has shown that promotes the pyroptosis of THP-1 macrophages caused by BCG infection and activates NLRP3 inflammasome and NF-κB signaling pathways, which can be inhibited by knockdown or inhibition of . In addition, inhibition of NF-κB or NLRP3 blocks the promotion effect of on BCG-induced pyroptosis of THP-1 macrophages. In conclusion, activates the NF-κB/NLRP3 inflammasome signaling pathway to promote macrophage pyroptosis induced by Mtb infection. These data provide new insights into how affects Mtb-induced macrophage pyroptosis.
Topics: Humans; NF-kappa B; BCG Vaccine; Inflammasomes; NLR Family, Pyrin Domain-Containing 3 Protein; Pyroptosis; Signal Transduction; Macrophages; Mycobacterium bovis; Tuberculosis, Pulmonary; S100 Calcium-Binding Protein A4
PubMed: 37628889
DOI: 10.3390/ijms241612709 -
Frontiers in Immunology 2023() is the causative agent of animal tuberculosis (TB) which poses a threat to many of South Africa's most iconic wildlife species, including leopards (). Due to limited...
BACKGROUND
() is the causative agent of animal tuberculosis (TB) which poses a threat to many of South Africa's most iconic wildlife species, including leopards (). Due to limited tests for wildlife, the development of accurate ante-mortem tests for TB diagnosis in African big cat populations is urgently required. The aim of this study was to evaluate currently available immunological assays for their ability to detect infection in leopards.
METHODS
Leopard whole blood (n=19) was stimulated using the QuantiFERON Gold Plus In-Tube System (QFT) to evaluate cytokine gene expression and protein production, along with serological assays. The GeneXpert MTB/RIF Ultra (GXU) qPCR assay, mycobacterial culture, and speciation by genomic regions of difference PCR, was used to confirm infection in leopards.
RESULTS
infection was confirmed in six leopards and individuals that were tuberculin skin test (TST) negative were used for comparison. The GXU assay was positive using all available tissue homogenates (n=5) from culture positive animals. culture-confirmed leopards had greater antigen-specific responses, in the QFT interferon gamma release assay, and gene expression assays, compared to TST-negative individuals. One culture-confirmed leopard had detectable antibodies using the DPP Vet TB assay.
CONCLUSION
Preliminary results demonstrated that immunoassays and TST may be potential tools to identify -infected leopards. The GXU assay provided rapid direct detection of infected leopards. Further studies should aim to improve TB diagnosis in wild felids, which will facilitate disease surveillance and screening.
Topics: Animals; Cats; Mycobacterium bovis; Panthera; Mycobacterium Infections; Animals, Wild; Antibodies
PubMed: 37727792
DOI: 10.3389/fimmu.2023.1216262 -
IScience Sep 2023Recent publications have explored intranasal (i.n.) adenovirus-based (Ad) vaccines as an effective strategy for SARS-CoV-2 in pre-clinical models. However, the effects...
Recent publications have explored intranasal (i.n.) adenovirus-based (Ad) vaccines as an effective strategy for SARS-CoV-2 in pre-clinical models. However, the effects of prior immunizations and infections have yet to be considered. Here, we investigate the immunomodulatory effects of BCG pre-immunization followed by vaccination with an S-protein-expressing i.n. Ad, termed Ad(Spike). While i.n. Ad(Spike) retains some protective effect after 6 months, a single administration of BCG-Danish prior to Ad(Spike) potentiates its ability to control viral replication of the B.1.351 SARS-CoV-2 variant within the respiratory tract. Though BCG-Danish did not affect Ad(Spike)-generated humoral immunity, it promoted the generation of cytotoxic/Th1 responses over suppressive FoxP3 T cells in the lungs of infected mice. Thus, this vaccination strategy may prove useful in limiting future pandemics by potentiating the long-term efficacy of mucosal vaccines within the context of the widely distributed BCG vaccine.
PubMed: 37670783
DOI: 10.1016/j.isci.2023.107612 -
Frontiers in Cellular and Infection... 2023Lung epithelial cells represent the first line of host defence against foreign inhaled components, including respiratory pathogens. Their responses to these exposures...
Lung epithelial cells represent the first line of host defence against foreign inhaled components, including respiratory pathogens. Their responses to these exposures may direct subsequent immune activation to these pathogens. The epithelial response to mycobacterial infections is not well characterized and may provide clues to why some mycobacterial infections are cleared, while others are persistent and pathogenic. We have utilized an air-liquid interface model of human primary bronchial epithelial cells (ALI-PBEC) to investigate the epithelial response to infection with a variety of mycobacteria: (Mtb), (BCG), . Airway epithelial cells were found to be infected by all four species, albeit at low frequencies. The proportion of infected epithelial cells was lowest for Mtb and highest for . Differential gene expression analysis revealed a common epithelial host response to mycobacteria, including upregulation of and , and downregulation of at 48 h post infection. Apical secretions contained predominantly pro-inflammatory cytokines, while basal secretions contained tissue growth factors and chemokines. Finally, we show that neutrophils were attracted to both apical and basal secretions of infected ALI-PBEC. Neutrophils were attracted in high numbers to apical secretions from PBEC infected with all mycobacteria, with the exception of secretions from -infected ALI-PBEC. Taken together, our results show that airway epithelial cells are differentially infected by mycobacteria, and react rapidly by upregulation of antimicrobials, and increased secretion of inflammatory cytokines and chemokines which directly attract neutrophils. Thus, the airway epithelium may be an important immunological component in controlling and regulating mycobacterial infections.
Topics: Humans; Mycobacterium Infections; Mycobacterium tuberculosis; Cytokines; Epithelial Cells; Chemokines
PubMed: 37822359
DOI: 10.3389/fcimb.2023.1253037