Biology subjects

Roessler, J.

Publications and source records attributed to Roessler, J..

5 recordsLinked to original sources

bioRxiv2026

L1CAM-CAR T cells with enhanced potency overcome low-density antigen expression in rhabdomyosarcoma

Rhabdomyosarcoma (RMS), the most common pediatric soft tissue sarcoma, shows dismal survival in relapsed or metastatic alveolar disease. Chimeric antigen receptor (CAR) T cells are promising but limited by scarce tumor-selective antigens and suboptimal efficacy at low antigen density. We investigated L1 cell adhesion molecule (L1CAM) as a therapeutic target by profiling its expression by flow cytometry, immunoblotting, and immunohistochemistry in cell lines, patient-derived xenografts, and healthy tissues. Using the scFv derived from the CE7 antibody, we engineered L1CAM-CARs with distinct hinge and costimulatory domains and tested them in vitro and in orthotopic RMS mouse models against clinically tested CE7- and B7-H3-CARs. L1CAM was consistently expressed at moderate levels in RMS, especially alveolar subtypes, but very weakly expressed in healthy tissues. Flow cytometry revealed a moderate density typically limiting CAR activity. Among constructs, L1CAM.III (CE7-CAR with long hinge and CD28 domain) showed the strongest cytotoxicity and IFN-{gamma} release. In vivo, L1CAM.III-CAR T cells regressed tumors, prolonged survival, and persisted in orthotopic RMS models, showing greater efficacy in alveolar RMS and no off-tumor activity. These findings establish L1CAM as a rational RMS therapeutic target. Optimized L1CAM.III-CAR T cells overcome moderate antigen density, achieving potent and persistent antitumor activity comparable to B7-H3-CARs but with improved safety. This work supports CAR optimization for clinical translation to broaden pediatric sarcoma immunotherapy.

cancer biology↗

bioRxiv2024

Pneumonia induced rise in glucagon promotes endothelial damage and vascular thrombogenicity

BackgroundRecent studies have demonstrated a link between respiratory infections and increased short-term risk of cardiovascular disease (CVD). However, the molecular mechanisms underlying the increased cardiovascular risk after respiratory infections are only poorly understood. Here, we aimed to decipher pathophysiological circuits of pneumonia associated CVD in experimental models of bacterial pneumonia and vascular injury. MethodsC57BL/6J mice were exposed to intranasal inoculation with either Streptococcus pneumoniae (S. pneumoniae) serotype 4 (pneumonia group) or phosphate buffered saline (PBS) (control group). 24 hours post infectionem (p.i.) mice were treated with antibiotics until the end of the study. On day 7 p.i. carotid artery injury (CI) was induced by electric stimulation and vascular repair was analyzed 3 days after injury. Plasma proteomic analyses were performed by Olink Bioscience. Primary human aortic endothelial cells (HAECs) were used to study alterations of the endothelial functional properties, bioenergetic state and thrombogenic potential in vitro. Intravital fluorescence microscopy equipped with video recording was applied to measure thrombus formation in real-time. ResultsBacterial pneumonia impaired repair capacity of the endothelium after vascular injury. Proteomic analyses revealed significantly higher plasma levels of glucagon in mice after recovery from pneumonia relative to controls, which was further confirmed by ELISA detecting glucagon. Mechanistically, we found that glucagon impaired mitochondrial bioenergetics and migratory potential in HAECs and induced an inflammatory response. Moreover, glucagon fostered vascular thrombogenicity as demonstrated by increased thrombocyte adhesion to HAECs and accelerated carotid artery thrombus formation in vivo. Acute application of the glucagon-like peptide-1 receptor (GLP1-R) agonist liraglutide to lower blood glucagon levels, restored vascular repair potential and attenuated vascular thrombogenicity in mice with pneumonia. ConclusionsOur findings reveal a novel mechanism that associates elevated circulatory glucagon levels to dysfunctional endothelium and increased vascular thrombogenicity, suggesting glucagon signaling as a potential therapeutic target to prevent pneumonia-induced cardiovascular events. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=138 SRC="FIGDIR/small/592488v1_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@1dab59eorg.highwire.dtl.DTLVardef@1c9a033org.highwire.dtl.DTLVardef@34a566org.highwire.dtl.DTLVardef@56e33d_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗

bioRxiv2024

A torpor-like state (TLS) in mice slows blood epigenetic aging and prolongs healthspan

Torpor and hibernation are extreme physiological adaptations of homeotherms associated with pro-longevity effects. Yet the underlying mechanisms of how torpor affects aging, and whether hypothermic and hypometabolic states can be induced to slow aging and increase health span, remain unknown. We demonstrate that the activity of a spatially defined neuronal population in the avMLPA, which has previously been identified as a torpor-regulating brain region, is sufficient to induce a torpor like state (TLS) in mice. Prolonged induction of TLS slows epigenetic aging across multiple tissues and improves health span. We isolate the effects of decreased metabolic rate, long-term caloric restriction, and decreased core body temperature (Tb) on blood epigenetic aging and find that the pro-longevity effect of torpor-like states is mediated by decreased Tb. Taken together, our findings provide novel mechanistic insight into the pro-longevity effects of torpor and hibernation and support the growing body of evidence that Tb is an important mediator of aging processes.

physiology↗

bioRxiv2023

CAR T cells recognizing CD276 and Dual-CAR T cells against CD276/FGFR4 promote rhabdomyosarcoma clearance in an orthotopic mouse model

BackgroundRhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in childhood, whose prognosis is still poor especially for metastatic, high-grade, and relapsed RMS. New treatments are urgently needed, especially systemic therapies. Chimeric Antigen Receptor T cells (CAR Ts) are very effective against hematological malignancies, but their efficacy against solid tumors needs to be improved. CD276 is a target upregulated in RMS and detected at low levels in normal tissues. FGFR4 is a very specific target for RMS. Here, we optimized CAR Ts for these two targets, alone or in combination, and tested their anti-tumor activity in vitro and in vivo. MethodsFour different single-domain antibodies were used to select the most specific FGFR4-CAR construct. RMS cell killing and cytokine production by CD276- and FGFR4-CAR Ts expressing CD8 or CD28 HD/TM domains in combination with 4-1BB and/or CD28 co-stimulatory domains were tested in vitro. The most effective CD276- and FGFR4-CAR Ts were used to generate Dual-CAR Ts. Tumor killing was evaluated in vivo in three orthotopic RMS mouse models. ResultsCD276.V-CAR Ts (276.MG.CD28HD/TM.CD28CSD.3z) showed the strongest killing of RMS cells, and the highest release of IFN-{gamma} and Granzyme B in vitro. FGFR4.V-CAR Ts (F8-FR4.CD28HD/TM.CD28CSD.3z) showed the most specific killing. CD276-CAR Ts successfully eradicated RD- and Rh4-derived RMS tumors in vivo, achieving complete remission in 3/5 and 5/5 mice, respectively. In CD276low JR-tumors, however, they achieved complete remission in only 1/5 mice. FGFR4 CAR Ts instead delayed of Rh4 tumor growth. Dual-CAR Ts promoted Rh4-tumors clearance in 5/5 mice. ConclusionsCD276- and CD276/FGFR4-directed CAR Ts showed effective RMS cell killing in vitro and eradication of CD276high RMS tumors in vivo. CD276low tumors escaped the therapy showing a correlation of antigen density and effectiveness. FGFR4-CAR Ts showed specific killing in vitro but could only delay RMS growth in vivo. Our results show that combined expression of CD276-CAR with other CAR does not reduce its benefit. Introducing immunotherapy with CD276-CAR Ts in RMS seems to be feasible and promising, although CAR constructs design and target combinations have to be further improved to eradicate tumors with low target expression.

cancer biology↗

bioRxiv2022

Long lifespan is maintained by a unique Heat Shock Factor in reproductive ants

Among eusocial insects, reproductive females show longer lifespan than non-reproductive female workers despite high genetic similarity. Using an ant species (Harpegnathos saltator, Hsal) featuring inducible worker reproduction and correlated extended lifespan, we find that long-lived reproductive individuals (called "gamergates") show elevated expression of heat shock response (HSR) genes specifically in the absence of heat stress. This HSR gene elevation is driven in part by gamergate-specific constitutive upregulation of a heat shock transcription factor gene most similar to mammalian HSF2 (called hsalHSF2). In sterile workers hsalHSF2 is bound to DNA only upon heat stress, but in gamergates hsalHSF2 binds to DNA in the absence of heat stress, and correlates with caste-biased gene expression of a subset of heat-inducible genes, thus showing natural bias to gamergates. Remarkably, ectopic expression in D. melanogaster of hsalHSF2 leads to enhanced survival compared to hsalHSF1 following heat stress, as well as extended lifespan. Molecular characterization of these longer-lived flies illustrates multiple parallels between long-lived flies and gamergates, underscoring the centrality of hsalHSF2 to extended lifespan in gamergates. Hence, ant caste-specific heat stress resilience and excessive longevity is, remarkably, transferrable to flies via a specialized ant heat shock factor, HSF2. These findings reinforce the critical role of proteostasis to health and to aging, and reveal novel mechanisms underlying facultative lifespan extension.

genomics↗