Paired single-cell and spatial transcriptional profiling reveals a central osteopontin macrophage response mediating tuberculous granuloma formation - Single Cell Portal
Granulomas are classic manifestations of tuberculosis pathogenesis. They result from an ensemble of immune responses to Mycobacterium tuberculosis infection, but the identities, arrangement, cellular interactions, and regulation of the cells that comprise them have thus far been incompletely understood. To better understand the composition of granulomas, we conducted spatial and single-cell RNA sequencing of granulomas in biopsy specimens from patients with tuberculosis. We found that granulomas consist of concentric transcriptional laminae surrounding areas of central necrosis. We identified distinct populations of granuloma-associated stromal cells, fibroblasts, lymphocytes, mast cells, dendritic cells, neutrophils, and macrophages. Furthermore, gene expression among these cell populations differed by location within granulomas. We used inferential analysis to predict dominant granuloma cell-cell interactions, the activity of major signaling pathways, and transcription factor activities. Using spatial deconvolution, we mapped a conserved pattern of cellular organization dominated by macrophages rich in SPP1/osteopontin expression. Trajectory analysis of macrophage subtypes mapped their differentiation and supported the importance of SPP1 to granuloma macrophage polarization. Using the Mycobacterium marinum-zebrafish model, we found that mycobacterial infection induces spp1 expression in macrophages and that spp1 ablation results in granuloma formation defects and reduced survival in adult animals. Cumulatively, we have identified a dominant macrophage granuloma population as well as its central regulatory gene in human samples and confirmed the importance of spp1 to granuloma biology in vivo.
You can now explore the mRNA expression of your favorite TB gene of interest in our recently published human pulmonary M.tb granuloma single-cell dataset at the Broad Single Cell PORTAL!
@broadinstitute.org
@wallacewly.bsky.social
singlecell.broadinstitute.org/single_cell/...
04.09.2025 13:38 β
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Iβm excited to announce that our paper, describing early and opposing roles for neutrophils and CD4 T cells in determining #TB lesion structure, is out at @jem.org ! Huge thanks to my lab, and the Urdahl, @michael-gerner.bsky.social, and Aitchison labs who made this possible
doi.org/10.1084/jem....
30.07.2025 13:54 β
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YouTube video by The Late Show with Stephen Colbert
A Scientific Brain Drain Has Followed Trumpβs Gutting Of The NIH - Dr. Francis Collins
youtu.be/lW9c6t4potU?...
17.07.2025 12:53 β
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I also had never seen this format until our preprint was reviewed. Seems to be mostly preprint-focused. Anyways, thanks for sharing the biorxiv link π
08.07.2025 22:25 β
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We are looking for post-docs interested in studying T cell responses to M. tuberculosis infectionβ¦especially basic T cell immunologists who are interested in learning to work with BSL3 pathogens. The NIH intramural program is an amazing place to train!
30.05.2025 20:47 β
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It's world TB day.
The last two months have been a series of attacks on global health, infectious disease science and vulnerable populations. The damage will take decades to undo, and we are heading onto a steep global health disaster.
We can't stay quiet.
#tuberculosis #TB #WTBD2025
24.03.2025 14:43 β
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Today is the 24th of March and it's World TB Day. We typically have many activities to educate and raise awareness about TB and how important it is for us all to commit to doing more to end TB! This year feels different though.
24.03.2025 14:34 β
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Register | Turmoil, TB Care, & Taking Action
Join experts on World TB Day to discuss the history, innovations, and social justice impact of TB, the worldβs deadliest infectious disease.
For World TB Day, PIH is hosting a webinar at 12pm EST to discuss the repercussions of recently slashed US foreign aid and the hope that remains. #worldTBday @partnersinhealth.bsky.social
Register here:
act.pih.org/worldtbday2025
24.03.2025 15:09 β
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I recommend hating tuberculosis. It has fueled me like no other hate that came before.
11.03.2025 15:30 β
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Thanks, Tom!
25.02.2025 05:04 β
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Thank you Alissa! Moving, starting up the lab, and getting this submitted felt like an extreme sport π
Very grateful to have a supportive community at NIH and the always inspiring early career TB research crew to look up to (like you π)
P.S. SO bummed I couldn't be at KS to catch up!
25.02.2025 00:35 β
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But microbial factors could be at play. Especially since we know Mtb resides in the caseum and prompts macrophage necrosis. We are hoping some of our organoid work will help us decouple the chicken-and-egg relationship between hypoxia and bacterial burden.
25.02.2025 00:32 β
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This is a great question. To try to get at it, we are currently evaluating granulomas from an earlier timepoint of infection. These grans have much higher CFU but less hypoxia. The main thrust of hypoxia appears to be caseation and it may be exacerbated by the degree of neutrophil influx...
25.02.2025 00:32 β
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Thank you! We are excited to finally be able to share it with everyone.
24.02.2025 22:16 β
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Thanks for tuning in! Please feel free to reach out with any feedback or questions on our preprint. (20/20)
24.02.2025 22:15 β
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The senior authors on this paper (especially my PhD advisor, Mike Angelo) have been the most incredible mentors to me and the wind behind my sails as I transitioned from Stanford to the NIH to start my own group. Despite...everything π...I am excited for the cool science we are cooking up! (19/20)
24.02.2025 22:15 β
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In Nov 2023 I started my lab at the NIH (the Spatial Immunology Unit) as an Independent Research Scholar. We are combining spatial mapping of tissues with functional assays in organoid models to define the principles of immune programming during infection and inflammation with a focus on TB. (18/20)
24.02.2025 22:15 β
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A HUGE thank you my co-author, Alea Delmastro, who began as my undergrad mentee in 2018, adapted MIBI for NHP tissues (no small feat), and then became my co-lead on this study. Here we are celebrating after we stained the study cohort during the pandemic (a culmination of 3 years of work). (17/20)
24.02.2025 22:15 β
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I would like to thank the extremely creative, talented, and hard-working individuals who worked on this study. This team spans 8 institutions and much of this work was done in the depths of the pandemic. I am so grateful for their brilliance, collaboration, and friendship. (16/20)
24.02.2025 22:15 β
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Moral of the story? Granuloma hypoxia is associated with pathologic immune cell states, dysfunctional cellular organization of the granuloma, and a near-complete blockade of lymphocyte infiltration that would be required for a successful host response. (14/20)
24.02.2025 22:15 β
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Lastly, we confirmed that the same phenomenon of immunometabolic zonation is present in human pulmonary TB, underscoring the translational relevance of our findings. (13/20)
24.02.2025 22:15 β
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We also applied QUICHE (from the talented Jolene Ranek in the Angelo lab) to map the spatial networks of low- versus high-bacterial burden granulomas. With this analysis we found that hypoxia-associated spatial niches were over-represented in high-bacterial burden granulomas. (12/20)
24.02.2025 22:15 β
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One of the most notable findings from this analysis is that T cell infiltration in the myeloid core VERY sharply drops off with the onset of hypoxia, something that is very evident in poor-controlling granulomas. (11/20)
24.02.2025 22:15 β
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With this approach we generated a consensus map of what we termed granuloma radial immunotopography. With this mapping we can model how cell phenotypes, metabolic niches, and functional programs coordinate with each other over 2D space. (10/20)
24.02.2025 22:15 β
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We next asked how hypoxia influences global granuloma structure and function? To do this, we teamed up with Russ Butlerβs group at AdventHealth to adapt a radial topography algorithm from the geographical information system (GIS) field. (9/20)
P.S. Stay tuned for more to come re: microGIS
24.02.2025 22:15 β
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This gave us the chance to dig even deeper into the cellular phenotypes we identified in our imaging data. We confirmed the tight coupling of macrophage metabolism and functional state with increasing evidence that hypoxia is associated with suppressive and pathologic immune responses. (8/20)
24.02.2025 22:15 β
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AND my newly formed lab at the NIH (more on this laterβ¦) had also just done our first spatial transcriptomic pilot study on some of the same granulomas we evaluated with multiplexed imaging. (7/20)
24.02.2025 22:15 β
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