Biology subjects

Hoelscher, C.

Publications and source records attributed to Hoelscher, C..

5 recordsLinked to original sources

bioRxiv2026

Crosstalk between Stromal cells and Macrophages Shapes Host Immunity to Mycobacteria

Granulomas are disease-defining heterocellular tissue structures in mycobacterial infections. They play a multifaceted role ranging from containing the pathogen to causing tissue destruction. Here, we established a mature peritoneal granuloma model in C57BL/6 mice to investigate the dynamic cell-cell interactions during mycobacterial infection, including long-term immune alterations in serous cavities as important sites of disease manifestation. We found that mycobacteria reside in stromal cells, which actively modulate the local tissue environment and shape macrophage responses, particularly through formation of chemokines and colony-stimulating factor 1. Chronic infection induces sustained reprogramming and diversification of stromal cells toward specialized, immune-like states, including active transfer of mycobacteria to macrophages and a pronounced interferon response. Consequently, stromal cells acquire immunoregulatory properties and support pathogen handling, monocyte recruitment and macrophage maturation, thereby playing a decisive role in granuloma formation and thus in the immune response to mycobacteria. HIGHLIGHTSO_LIA novel peritoneal mycobacterial infection model reveals heterocellular crosstalk in mature granulomas. C_LIO_LIMycobacterial infections persistently reshape immune architecture of serous cavities as important disease sites. C_LIO_LIStromal cells act as mycobacterial host cells and acquire immune effector functions. C_LIO_LIStromal cells co-organize the tissue host-pathogen interface by recruiting and directly communicating with bone marrow-derived monocytes. C_LI

immunology↗

bioRxiv2024

C1q in non-immune human serum has a non-redundant complement function towards clinical Mycobacterium tuberculosis complex strains

The Mycobacterium tuberculosis complex (MTBC) includes three human-adapted species: Mycobacterium tuberculosis, Mycobacterium africanum, and Mycobacterium canettii. With their genetic diversity and inherent virulence, these bacteria interact with host factors to influence tuberculosis (TB) transmission and pathogenesis. A critical yet poorly understood aspect of the immune response in TB involves the role of the complement system. Our study aimed to assess the general interaction between the complement system and key clinical MTBC strains representing the principal lineages known to vary in virulence. We found that not only mannose binding lectin (MBL) from the lectin pathway, but also C1q from the classical pathway directly recognize mycobacteria. While MBL generally showed a higher level of binding than C1q, the binding interactions varied across different MTBC strains. We further observed that complement activation products C4b, C3b and the terminal complement complex (TCC) were deposited on the surface of MTBC strains. Inhibition of MBL alone did not substantially alter complement activation, whereas C1q inhibition ceased activation for most strains investigated. Exposure to human serum did not impact the viability or growth of the MTBC strains. In conclusion, both the classical and lectin pathways of complement via C1q and MBL are activated by a broad range of lineages of the MTBC. The classical pathway is the main complement activator in non-immune serum across diverse MTBC lineages, with C1q playing a potentially novel role in the immune response in TB.

immunology↗

bioRxiv2023

Handedness and its association with education and spatial navigation assessed in over 400,000 participants across 41 countries

There is an active debate concerning the association of handedness and spatial ability. Past studies used small sample sizes within a single country. Determining the effect of handedness on spatial ability requires a large, cross-cultural sample of participants, and a navigation task with real-world validity. Here, we overcome these challenges via the mobile app Sea Hero Quest. We analysed the navigation performance from 422,772 participants from 41 countries and found no reliable evidence for any difference in spatial ability between left- and right-handers across all countries. Using 749,037 participants from the larger sample, we replicate previous findings that age, gender, and country of residence have an impact on the prevalence of left-handedness, and found an effect of education on left-handedness prevalence in China, Indonesia, India, Taiwan, and Hong Kong. Our study clarifies the factors associated with spatial ability and outlines new ways in which cultural patterns influence handedness. Statement of RelevanceWhat is the relation between handedness and navigation ability? Evidence so far has been mixed, and findings from small-scale and large-scale tasks seem to point in opposite directions. Part of the reason is that cultural and sociodemographic differences have a significant impact on both spatial ability and handedness. Tackling the question requires a large, cross-cultural sample of participants performing an ecologically valid navigation task. Here, we employ a mobile app, Sea Hero Quest, to test the navigation ability of a large number of participants across many different countries. What we find is that there is no reliable connection between handedness and navigation ability. Then, we use our data to explore the prevalence of left-handedness across countries, and find that age, gender, and country of residency all have an effect on the ratio of left-handedness. Moreover, we find an effect of education on left-handedness in China, Indonesia, India, Taiwan, and Hong Kong.

animal behavior and cognition↗

bioRxiv2020

Glycosyltransferase POMGNT1 deficiency affects N-cadherin-mediated cell-cell adhesion

Defects in protein O-mannosylation lead to severe congenital muscular dystrophies known as -dystroglycanopathy. A hallmark of these diseases is the loss of the O-mannose-bound matriglycan on -dystroglycan, which leads to a reduction in cell adhesion to the extracellular matrix. Mutations in protein O-mannose {beta}1,2-N-acetylglucosaminyltransferase 1 (POMGNT1), which is crucial for the elongation of O-mannosyl glycans, are mainly associated with muscle-eye-brain (MEB) disease. In addition to defects in cell-extracellular matrix adhesion, aberrant cell-cell adhesion has occasionally been observed in response to defects in POMGNT1. However, direct molecular mechanisms are largely unknown. We used POMGNT1 knock-out HEK293T cells and fibroblasts from a MEB patient to gain a deeper insight into the molecular changes in POMGNT1 deficiency. A combination of biochemical and molecular biological techniques with proteomics, glycoproteomics and glycomics revealed that a lack of POMGNT1 activity strengthens cell-cell adhesion. We demonstrate that the altered intrinsic adhesion properties are due to an increased abundance of N-cadherin (N-Cdh). In addition, site-specific changes in the N-glycan structures in the extracellular domain of N-Cdh were detected, which positively impact on homotypic interactions. We found that in POMGNT1 deficient cells ERK1/2 and p38 signaling pathways are activated and transcriptional changes that are comparable to the epithelial-mesenchymal transition (EMT) are triggered, defining a possible molecular mechanism underlying the observed phenotype. Our study indicates that changes in cadherin-mediated cell-cell adhesion and other EMT-related processes may contribute to the complex clinical symptoms of MEB or -dystroglycanopathy in general, and suggests a previously underestimated impact of changes in O-mannosylation on N-glycosylation.

biochemistry↗

bioRxiv2020

WNT6-ACC2-induced accumulation of triacylglycerol rich lipid droplets is exploited by Mycobacterium tuberculosis

In view of emerging drug-resistant tuberculosis, host directed therapies are urgently needed to improve treatment outcomes with currently available anti-tuberculosis therapies. One option is to interfere with the formation of lipid-laden “foamy” macrophages in the infected host. Here, we provide evidence that WNT6, a member of the evolutionary conserved WNT signaling pathway, promotes foam cell formation by regulating key lipid metabolic genes including acetyl-CoA carboxylase-2 (ACC2) during pulmonary TB. In addition, we demonstrate that Mycobacterium tuberculosis (Mtb) facilitates its intracellular growth and dissemination in the host by exploiting the WNT6-ACC2 pathway. Using genetic and pharmacological approaches, we show that lack of functional WNT6 or ACC2 significantly reduces intracellular TAG levels, Mtb growth and necrotic cell death of macrophages. In combination with the anti-TB drug isoniazid, pharmacological inhibition of ACC2 improved anti-mycobacterial treatment in vitro and in vivo. Therefore, we propose the WNT6-ACC2 signaling pathway as a promising target for a host-directed therapy to reduce intracellular replication of Mtb by modulating neutral lipid metabolism.Competing Interest StatementDrs. N. Reiling and J. Brandenburg (Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany) have filed a patent application entitled ACC inhibitors as means and methods for treating mycobacterial diseases(WO2018007430A1, patent pending).View Full Text

immunology↗