bioRxiv Science⌕ Search

bioRxiv · 10.64898/2026.10.18.760006

Brain microvascular endothelial cell dysfunction during Plasmodium infection does not result from astrocyte-derived wingless-related integration site (Wnt)7a deficiency

Abstract

Breakdown of the blood brain barrier is a key event leading to vasogenic edema that underpins pediatric cerebral malaria. Brain microvascular endothelial cells (BMECs) downregulate junction proteins in response to Plasmodium-infected red blood cells (iRBCs). Very little is known about how glial cell activation in Plasmodium infection dysregulates astrocyte-derived steady state signals that control BMEC junction expression. Astrocytes from mice infected with Plasmodium berghei ANKA (PbA) exhibit transcriptional changes dominated by interferon signaling pathways. Downregulation of wingless-related integration site (Wnt)7a transcription in astrocytes correlated with transcriptional changes in BMECs indicative of reduced {beta}-catenin activity. Incubation of the human astrocyte-like glioma cell-line CCF-STTG1 with interferon-{gamma} (IFN-{gamma}) decreased the general production of Wnt7a in response to P. falciparum iRBCs. However astrocyte conditioned medium incubated with IFN-{gamma} strengthened the barrier function in vitro when added onto monolayers the human cerebral microvascular endothelial cell line D3 (hCMEC/D3). This data suggests that the response of astrocytes during Plasmodium infection may be protective but unable to overcome dysfunctional responses of BMECs to Plasmodium iRBCs. To test this hypothesis we overexpressed Wnt7a in the brain tissue of mice using an AAV construct but this did not impart increased survival to the neurological effects of PbA infection. Therefore astrocyte responses during Plasmodium infection may not underlie the downregulation of junction proteins on BMECs leading to edema in cerebral malaria.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Roedel, M., Brooks, N., Andersen, J. N., Cornwall, D. H., Doddavaram, R., Chastang, K., Rubner, L., Liu, T., Lamb, T.. 2026-10-23. Brain microvascular endothelial cell dysfunction during Plasmodium infection does not result from astrocyte-derived wingless-related integration site (Wnt)7a deficiency. https://doi.org/10.64898/2026.10.18.760006

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Impact of RNA modification and IL-12 boosts on mRNA-LNP vaccine-elicited CD8+ T cell responses

Development of effective HIV-1 vaccines requires strategies for inducing both CD8+ T cell and neutralizing antibody responses. Nucleoside-modified mRNA-lipid-nanoparticles (LNP) induce more potent antibody responses than unmodified mRNA-LNP vaccines, while unmodified mRNA is typically employed for CD8+ T cell-inducing vaccines. Here, we compared the abilities of differing ratios of unmodified versus modified mRNA expressing a SIV conserved-region CD8+ T cell immunogen co-administered with IL-12-encoding mRNA-LNP during boosting to induce CD8+ T cell and humoral responses in non-human primates, assessing responses in ChAdOx1-primed controls in parallel. Serial priming and boosting with fully-unmodified mRNA elicited higher-magnitude, more CD8-biased T cell responses than fully-modified mRNA, that were durably maintained after the IL-12-encoding mRNA boosts. Inclusion of 30% nucleoside-modified mRNA enhanced antibody titers, suggesting potential benefits to a mixed-composition vaccine.

immunology↗

Evasion of Hepatic ILC1 Immunosurveillance Drives Breast Cancer Liver Metastasis

Metastasis, the dissemination of cancer cells to distant organs, is an inefficient process1, yet remains the leading cause of cancer-related mortality2. The cellular barriers and evasion mechanisms governing organ-specific susceptibility remain incompletely understood3-5, hindering the development of effective anti-metastatic therapies6. Here, we show that liver-resident type 1 innate lymphoid cells (ILC1s) constitute an essential immunosurveillance barrier against breast cancer liver metastasis that can be bypassed through either cancer cell intrinsic or host-dependent mechanisms. In a multi-organ metastatic breast cancer patient cohort, liver metastasis occurred later and was associated with poorer survival than lung metastasis, with elevated body mass index emerging as a clinical risk factor. This metabolic vulnerability was recapitulated in mice, where a high-fat diet induced hepatosteatosis and selectively enhanced breast cancer colonization of the liver. Mechanistically, liver and lung colonization were restrained by ILC1s and circulating natural killer (NK) cells, respectively. Following cancer cell challenge, NK cells expanded and activated, employing lytic granule pathways and the death receptor DR5 for clearance, whereas activated ILC1s selectively required high DR5 expression on cancer cells, supported by AP-2a (TFAP2A) mediated transcriptional activation, for effective immunosurveillance. Heterozygous copy number deletion at TNFRSF10B (encoding DR5) in human tumours reduced DR5 expression and predisposed to liver metastasis. Hepatosteatosis further compromised this barrier by reducing IL-15 expression in macrophages, thereby depleting hepatic ILC1s effects reversible with glucagon-like peptide-1 (GLP-1) receptor agonists. Thus, hepatic ILC1s form a critical organ-specific barrier to breast cancer metastasis, vulnerable to both cancer cell-intrinsic DR5 downregulation and host metabolic dysfunction.

immunology↗

Development of a multi-organ single-cell atlas of systemic sclerosis reveals shared and tissue-specific pathogenic pathways.

Objectives: Systemic sclerosis (SSc) is a multi-organ autoimmune disease for which no broadly effective disease-modifying treatment exists. We developed an integrated multi-organ single-cell atlas of SSc to identify shared and organ specific disease-associated transcriptional programmes and potential therapeutic targets. Methods: We integrated single-cell RNA-sequencing data from skin, lung, synovium, and peripheral blood mononuclear cells (six studies, 401,902 cells, 90 individuals) using Harmony. Pseudobulk differential expression and gene set enrichment analysis were performed at the tissue cell-compartment, cell-type, and subpopulation levels, including independent reclustering of lymphoid, myeloid and fibroblast populations. Results: Disease-associated transcriptional programmes showed marked tissue dependence, even within the same cell lineage, highlighting the importance of organ-specific mechanisms in SSc. Nevertheless, recurrent extracellular matrix (ECM) remodelling programmes were identified in lung, skin and synovium, and interferon signalling programmes in skin, synovium and peripheral blood mononuclear cells, across immune and fibroblast cell populations. Although no subpopulation was exclusive to SSc, a shared myofibroblast subpopulation expressing SFRP2, COL1A1, POSTN, ACTA2, and COMP was identified across lung, skin, and synovium. In addition, perivascular and mitotic fibroblast subpopulations exhibited both profibrotic and inflammatory signatures, including interferon- and IL-2-related signalling programmes. Conclusions: SSc is characterised by two complementary axes: a tissue-dependent cellular programme and a recurrent fibrotic and interferon-associated signature extending across multiple organs and cell populations. These findings are consistent with current organ-based therapeutic approaches while highlighting interferon signalling as a potential multi-organ therapeutic target. The resulting interactive single-cell atlas provides a resource for investigating shared and organ-specific disease mechanisms and guiding future therapeutic research.

immunology↗