Xin Gao, Hayley A McNamara, Jiwon Lee, Adrian F Lo, Deepyan Chatterjee, Dominik Spensberger, Daniel Fernandez-Ruiz, Kevin Walz, Ke Wang, Hannah G Kelly, Kai Pohl, Patricia E Carreira, Andrea Do, Le Xiong, Lynette Beattie, Alexandra J Spencer, Daniel HD Gray, Friedrich Frischknecht, Melanie Rug, Ian A. Cockburn
{"title":"B cells targeting parasites capture spatially linked antigens to secure T cell help","authors":"Xin Gao, Hayley A McNamara, Jiwon Lee, Adrian F Lo, Deepyan Chatterjee, Dominik Spensberger, Daniel Fernandez-Ruiz, Kevin Walz, Ke Wang, Hannah G Kelly, Kai Pohl, Patricia E Carreira, Andrea Do, Le Xiong, Lynette Beattie, Alexandra J Spencer, Daniel HD Gray, Friedrich Frischknecht, Melanie Rug, Ian A. Cockburn","doi":"10.1101/2024.08.10.607257","DOIUrl":"https://doi.org/10.1101/2024.08.10.607257","url":null,"abstract":"Our understanding of T-cell-dependent humoral responses has been largely shaped by studies involving model antigens such as recombinant proteins and small viruses 1,2. In these contexts, B cells internalize the entire antigen or pathogen, to present a range of antigen to helper CD4+ T cells to initiate the humoral response. However, this model does not account for large pathogens such as parasites that are too large to be taken up by individual B cells, and the mechanisms by which B cells acquire and present antigens from large complex pathogens to T cells remain poorly understood. Here we used Plasmodium, the causative parasite of malaria, as a model to investigate the requirements for T cell help for B cells targeting the Plasmodium surface circumsporozoite protein (CSP). Upon Plasmodium sporozoite (SPZ) immunization, CSP-specific B cells can form a synapse-like structure with SPZs and take up CSP and non-CSP surface antigens. As a result, CSP-specific B cells can receive help from CD4+ T cells specific to antigens that are located on the surface but not cytosol of the Plasmodium SPZ. Therefore, B cells can obtain help, not only from T cells with the same protein specificity, but also from T cells specific for spatially linked antigens. This flexibility in T cell help, may enhance the initiation and maintenance of immune responses to complex pathogens.","PeriodicalId":501182,"journal":{"name":"bioRxiv - Immunology","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Calvin Xu, Andreas Obers, Minyi Qin, Alice Brandli, Joelyn Wong, Xin Huang, Allison Clatch, Aly Fayed, Graham Starkey, Rohit DCosta, Claire L Gordon, Lynette Beattie, Laura K Mackay, Dale I Godfrey, Hui-Fern Koay
{"title":"Selective regulation of IFN-γ and IL-4 co-producing unconventional T cells by purinergic signalling","authors":"Calvin Xu, Andreas Obers, Minyi Qin, Alice Brandli, Joelyn Wong, Xin Huang, Allison Clatch, Aly Fayed, Graham Starkey, Rohit DCosta, Claire L Gordon, Lynette Beattie, Laura K Mackay, Dale I Godfrey, Hui-Fern Koay","doi":"10.1101/2024.08.11.607476","DOIUrl":"https://doi.org/10.1101/2024.08.11.607476","url":null,"abstract":"Unconventional T cells, including mucosal-associated invariant T (MAIT), natural killer T (NKT), and gamma-delta T (γδT) cells, comprise distinct T-bet+, IFN-γ+ and RORγt+, IL-17+ subsets which play differential roles in health and disease. NKT1 cells are susceptible to ARTC2-mediated P2X7 receptor (P2RX7) activation, but the effects on other unconventional T-cell types are unknown. Here, we show that MAIT, γδT, and NKT cells express P2RX7 and are sensitive to P2RX7-mediated cell death. Mouse peripheral T-bet+ MAIT1, γδT1, and NKT1 cells, especially in liver, co-express ARTC2 and P2RX7, which can be further upregulated by retinoic acid. Blocking ARTC2 or inhibiting P2RX7 protected MAIT1, γδT1, and NKT1 cells from cell death, enhanced their survival in vivo, and increased the number of IFN-γ-secreting cells without affecting IL-17 production. Importantly, this revealed the existence of IFN-γ and IL-4 co-producing unconventional T-cell populations normally lost upon isolation due to ARTC2/P2RX7-induced death. Administering extracellular NAD in vivo activated this pathway, depleting P2RX7-sensitive unconventional T cells. Our study reveals ARTC2/P2RX7 as a common regulatory axis modulating the unconventional T-cell compartment, affecting the viability of IFN-γ- and IL-4-producing T cells, offering important insights to facilitate future studies into how these cells can be regulated in health and disease.","PeriodicalId":501182,"journal":{"name":"bioRxiv - Immunology","volume":"92 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Deepak Kaushik, Aysika Das, Claudia Silva, Charlotte D'Mello, Luiz Gustavo N Almeida, Nazanin Ghasemi, Paola Neri, Antoine Dufour, Nizar Jacques Bahlis, Mengzhou Xue, Voon Wee Yong
{"title":"EMMPRIN confers metabolic advantage for monocytes and macrophages to promote disease in a model of multiple sclerosis","authors":"Deepak Kaushik, Aysika Das, Claudia Silva, Charlotte D'Mello, Luiz Gustavo N Almeida, Nazanin Ghasemi, Paola Neri, Antoine Dufour, Nizar Jacques Bahlis, Mengzhou Xue, Voon Wee Yong","doi":"10.1101/2024.08.11.607460","DOIUrl":"https://doi.org/10.1101/2024.08.11.607460","url":null,"abstract":"Monocytes and monocyte-derived macrophages have important roles in the initiation and progression of multiple sclerosis (MS). These cells undergo metabolic reprogramming to generate immunophenotypes that promote leukocyte infiltration, axonal degeneration and demyelination, worsening MS pathology. The mechanisms that dictate metabolic programs in monocytes and macrophages in MS remain unclear. We previously reported that extracellular matrix metalloproteinase inducer (EMMPRIN, CD147), a glycoprotein that acts as a chaperone of monocarboxylate transporter 4 (MCT4), assisted with glycolysis-driven pro-inflammatory phenotype in macrophages in experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Using newly-generated CCR2CreERT2:EMMPRINfl/fl (CCR2:EMMP) mice, we report that presymptomatic deletion of EMMPRIN in CCR2+ monocytes prevented or reduced clinical disability of EAE. This was correspondent with decreased infiltration of leukocytes into the CNS. Single cell RNA-seq of blood monocytes from EAE and proteomics analysis of macrophages from CCR2:EMMP-/- mice revealed significant alterations in metabolic programs, particularly reduced glycolysis and elevated mitochondrial electron transport and fatty acid oxidation, which were linked to their reduced pro-inflammatory traits. Our findings implicate EMMPRIN as a key regulator of metabolic pathways that exacerbate pro-inflammatory functions of monocytes in MS.","PeriodicalId":501182,"journal":{"name":"bioRxiv - Immunology","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Noor Momin, Steffen Pabel, Arnab Rudra, Nina Kumowski, I-Hsiu Lee, Kyle Mentkowski, Masahiro Yamazoe, Laura Stengel, Charlotte G. Muse, Hana Seung, Alexandre Paccalet, Cristina Gonzalez-Correa, Emily B. Jacobs, Jana Grune, Maximilian J. Schloss, Samuel Sossalla, Gregory Wojtkiewicz, Yoshiko Iwamoto, Patrick McMullen, Richard N. Mitchell, Patrick T. Ellinor, Daniel G. Anderson, Kamila Naxerova, Matthias Nahrendorf, Maarten Hulsmans
{"title":"Therapeutic Spp1 silencing in TREM2+ cardiac macrophages suppresses atrial fibrillation","authors":"Noor Momin, Steffen Pabel, Arnab Rudra, Nina Kumowski, I-Hsiu Lee, Kyle Mentkowski, Masahiro Yamazoe, Laura Stengel, Charlotte G. Muse, Hana Seung, Alexandre Paccalet, Cristina Gonzalez-Correa, Emily B. Jacobs, Jana Grune, Maximilian J. Schloss, Samuel Sossalla, Gregory Wojtkiewicz, Yoshiko Iwamoto, Patrick McMullen, Richard N. Mitchell, Patrick T. Ellinor, Daniel G. Anderson, Kamila Naxerova, Matthias Nahrendorf, Maarten Hulsmans","doi":"10.1101/2024.08.10.607461","DOIUrl":"https://doi.org/10.1101/2024.08.10.607461","url":null,"abstract":"Atrial fibrillation (AFib) and the risk of its lethal complications are propelled by fibrosis, which induces electrical heterogeneity and gives rise to reentry circuits. Atrial TREM2+ macrophages secrete osteopontin (encoded by Spp1), a matricellular signaling protein that engenders fibrosis and AFib. Here we show that silencing Spp1 in TREM2+ cardiac macrophages with an antibody-siRNA conjugate reduces atrial fibrosis and suppresses AFib in mice, thus offering a new immunotherapy for the most common arrhythmia.","PeriodicalId":501182,"journal":{"name":"bioRxiv - Immunology","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kathryn M Moore, Stephanie L Foster, Elizabeth J Elrod, Katharine A Floyd, M. Elliott Williams, Meenakshi Kar, Jacob Vander Velden, Madison Ellis, Ansa Malik, Bushra Wali, Stacey Lapp, Amanda Metz, Steven E Bosinger, Robert A Seder, Rama Rao Amara, Vineet D Menachery, Jacob E Kohlmeier, Arash Grakoui, Mehul S Suthar
{"title":"Eosinophils protect against SARS-CoV-2 following a vaccine breakthrough infection","authors":"Kathryn M Moore, Stephanie L Foster, Elizabeth J Elrod, Katharine A Floyd, M. Elliott Williams, Meenakshi Kar, Jacob Vander Velden, Madison Ellis, Ansa Malik, Bushra Wali, Stacey Lapp, Amanda Metz, Steven E Bosinger, Robert A Seder, Rama Rao Amara, Vineet D Menachery, Jacob E Kohlmeier, Arash Grakoui, Mehul S Suthar","doi":"10.1101/2024.08.08.607190","DOIUrl":"https://doi.org/10.1101/2024.08.08.607190","url":null,"abstract":"Waning immunity and the emergence of immune evasive SARS-CoV-2 variants jeopardize vaccine efficacy leading to breakthrough infections. We have previously shown that innate immune cells play a critical role in controlling SARS-CoV-2. To investigate the innate immune response during breakthrough infections, we modeled breakthrough infections by challenging low-dose vaccinated mice with a vaccine-mismatched SARS-CoV-2 Beta variant. We found that low-dose vaccinated infected mice had a 2-log reduction in lung viral burden, but increased immune cell infiltration in the lung parenchyma, characterized by monocytes, monocyte-derived macrophages, and eosinophils. Single cell RNA-seq revealed viral RNA was highly associated with eosinophils that corresponded to a unique IFN-γ biased signature. Antibody-mediated depletion of eosinophils in vaccinated mice resulted in increased virus replication and dissemination in the lungs, demonstrating that eosinophils in the lungs are protective during SARS-CoV-2 breakthrough infections. These results highlight the critical role for the innate immune response in vaccine mediated protection against SARS-CoV-2.","PeriodicalId":501182,"journal":{"name":"bioRxiv - Immunology","volume":"141 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Antonia O. Cuff, Ee Von Woon, Thomas Bainton, Brendan Browne, Phoebe M. Kirkwood, Frances Collins, Douglas A Gibson, Philippa Saunders, Andrew W. Horne, Mark R. Johnson, David A. MacIntyre, Victoria Male
{"title":"Dynamic roles of ILC3 in endometrial repair and regeneration","authors":"Antonia O. Cuff, Ee Von Woon, Thomas Bainton, Brendan Browne, Phoebe M. Kirkwood, Frances Collins, Douglas A Gibson, Philippa Saunders, Andrew W. Horne, Mark R. Johnson, David A. MacIntyre, Victoria Male","doi":"10.1101/2024.08.10.606309","DOIUrl":"https://doi.org/10.1101/2024.08.10.606309","url":null,"abstract":"Innate lymphoid cells (ILC) are prominent in the human uterine mucosa and play physiological roles in pregnancy. ILC3 are the second-most common ILC subset in the uterine mucosa, but their role remains unclear. Here we define two subsets of lineage-negative CD56+ CD117+ CRTH2- uterine ILC3, distinguished by their expression of CD127. The CD127- subset is most numerous and active during menstruation and immediately after parturition, suggesting a role in repair of the uterine mucosa (called endometrium outside of pregnancy); the CD127+ subset is most numerous and active immediately after menstruation, as the endometrium regenerates. In healthy endometrium, ILC3 are spatially associated with glandular epithelial and endothelial cells, which both express receptors for the ILC3-derived cytokines, IL-22 and IL-8. In the eutopic endometrium of people with endometriosis, ILC3 are located further from glandular epithelial and endothelial cells suggesting that these cells may be less exposed to ILC3 products, potentially with negative consequences for endometrial regeneration. Our findings highlight the dynamic nature of ILC3 in the uterine mucosa and suggest their primary role is in repair and regeneration. An improved understanding of uterine ILC3 will inform future research on endometrial health and disease.","PeriodicalId":501182,"journal":{"name":"bioRxiv - Immunology","volume":"78 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Natalie B Hagan, Charles Inaku, Nikesh Kunder, Tayleur White, Thierry Iraguha, Anna Meyer, Kristen Pauken, Jason Matthew Schenkel
{"title":"In vivo antibody labeling route and fluorophore dictate labeling efficiency, sensitivity, and longevity","authors":"Natalie B Hagan, Charles Inaku, Nikesh Kunder, Tayleur White, Thierry Iraguha, Anna Meyer, Kristen Pauken, Jason Matthew Schenkel","doi":"10.1101/2024.08.10.607414","DOIUrl":"https://doi.org/10.1101/2024.08.10.607414","url":null,"abstract":"Leukocytes migrate through the blood and extravasate into organs to surveil the host for infection or cancer. Recently, we demonstrated that intravenous (IV) anti-CD45.2 antibody labeling allowed for precise tracking of leukocyte migration. However, the narrow labeling window can make this approach challenging for tracking rare migration events. Here, we show that altering antibody administration route and fluorophore can significantly extend the antibody active labeling time. We found that while both IV and intraperitoneal (IP) anti-CD45.2 antibody labeled circulating leukocytes after injection, they had different kinetic properties that impacted labeling time and intensity. Quantification of circulating antibody revealed that while unbound IV anti-CD45.2 antibody rapidly decreased, unbound IP anti-CD45.2 antibody increased over one hour. Using in vitro and in vivo serial dilution assays, we found that Alexa Fluor 647 (AF647) and Brilliant Blue 700 (BB700) dyes had the greatest labeling sensitivity compared to other fluorophores. However, IP antibody injection with anti-CD45.2 BB700, but not AF647, resulted in continuous blood leukocyte labeling for over 6 hours. Finally, we leveraged IP anti-CD45.2 BB700 antibody to track slower migrating leukocytes into tumors. We found that IP anti-CD45.2 antibody injection allowed for the identification of ~seven times as many tumor-specific CD8+ T cells that had recently migrated from blood into tumors. Our results demonstrate how different injection routes and fluorophores affect anti-CD45.2 antibody leukocyte labeling and highlight the utility of this approach for defining leukocyte migration in the context of homeostasis and cancer.","PeriodicalId":501182,"journal":{"name":"bioRxiv - Immunology","volume":"66 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Patrick Ross, Hijab Fatima, Daniel P Leaman, Jessica Matthias, Kathryn Spencer, Michael B Zwick, Scott C Henderson, Emily M. Mace, Charles Daniel Murin
{"title":"Spatial localization of CD16a at the human NK cell ADCC lytic synapse","authors":"Patrick Ross, Hijab Fatima, Daniel P Leaman, Jessica Matthias, Kathryn Spencer, Michael B Zwick, Scott C Henderson, Emily M. Mace, Charles Daniel Murin","doi":"10.1101/2024.08.09.605851","DOIUrl":"https://doi.org/10.1101/2024.08.09.605851","url":null,"abstract":"Natural Killer (NK) cells utilize effector functions, including antibody-dependent cellular cytotoxicity (ADCC), for the clearance of viral infection and cellular malignancies. NK cell ADCC is mediated by Fc𝛾RIIIa (CD16a) binding to the fragment crystallizable (Fc) region of immunoglobulin G (IgG) within immune complexes on a target cell surface. While antibody-induced clustering of CD16a is thought to drive ADCC, the molecular basis for this activity has not been fully described. Here we use MINFLUX nanoscopy to map the spatial distribution of stoichiometrically labeled CD16a across the NK cell membrane, revealing the presence of pairs of CD16a molecules with intra-doublet distance of approximately 17 nm. NK cells activated on supported lipid bilayers by Trastuzumab results in an increase of synaptic regions with greater CD16a density. Our results provide the highest spatial resolution yet described for CD16a imaging, offering new insight into how CD16a organization could influence ADCC activity, for example through self-association or with binding partners influencing the degree of ADCC signaling. MINFLUX holds great promise to further unravel the molecular details driving CD16a-based activation of NK cells.","PeriodicalId":501182,"journal":{"name":"bioRxiv - Immunology","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexandria C Wells, Djalma Souza Lima-Junior, Verena M Link, Margery Smelkinson, Siddharth R Krishnamurthy, Liang Chi, Elisha Segrist, Claudia A Rivera, Ana Teijeiro, Nicolas Bouladoux, Yasmine Belkaid
{"title":"Adaptive immunity to retroelements promotes barrier integrity","authors":"Alexandria C Wells, Djalma Souza Lima-Junior, Verena M Link, Margery Smelkinson, Siddharth R Krishnamurthy, Liang Chi, Elisha Segrist, Claudia A Rivera, Ana Teijeiro, Nicolas Bouladoux, Yasmine Belkaid","doi":"10.1101/2024.08.09.606346","DOIUrl":"https://doi.org/10.1101/2024.08.09.606346","url":null,"abstract":"Maintenance of tissue integrity is a requirement of host survival. This mandate is of prime importance at barrier sites that are constitutively exposed to the environment. Here, we show that exposure of the skin to non-inflammatory xenobiotics promotes tissue repair; more specifically, mild detergent exposure promotes the reactivation of defined retroelements leading to the induction of retroelement-specific CD8+ T cells. These T cell responses are Langerhans cell dependent and establish tissue residency within the skin. Upon injury, retroelement-specific CD8+ T cells significantly accelerate wound repair via IL-17A. Collectively, this work demonstrates that tonic environmental exposures and associated adaptive responses to retroelements can be coopted to preemptively set the tissue for maximal resilience to injury.","PeriodicalId":501182,"journal":{"name":"bioRxiv - Immunology","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Desiree I. Frecot, Simone Blaess, Teresa R. Wagner, Philipp D. Kaiser, Bjoern Traenkle, Madeleine Fandrich, Meike Jakobi, Armin M. Scholz, Stefan Nueske, Nicole Schneiderhan-Marra, Cécile Gouttefangeas, Manfred Kneilling, Bernd J. Pichler, Dominik Sonanini, Ulrich Rothbauer
{"title":"Making the effect visible – OX40 targeting nanobodies for in vivo imaging of activated T cells","authors":"Desiree I. Frecot, Simone Blaess, Teresa R. Wagner, Philipp D. Kaiser, Bjoern Traenkle, Madeleine Fandrich, Meike Jakobi, Armin M. Scholz, Stefan Nueske, Nicole Schneiderhan-Marra, Cécile Gouttefangeas, Manfred Kneilling, Bernd J. Pichler, Dominik Sonanini, Ulrich Rothbauer","doi":"10.1101/2024.08.09.607337","DOIUrl":"https://doi.org/10.1101/2024.08.09.607337","url":null,"abstract":"Purpose: Human OX40 (hOX40/CD134), a member of the TNF receptor superfamily, is mainly expressed on activated T lymphocytes. Triggered by its ligand OX40L (CD252), it provides costimulatory signals that support the differentiation, proliferation and long-term survival of T cells. Besides being a relevant therapeutic target, hOX40 is also an important biomarker for monitoring the presence or infiltration of activated T cells within the tumor microenvironment (TME), the inflammatory microenvironment (IME) in immune-mediated diseases (IMIDs) and the lymphatic organs. Here, we developed novel single domain antibodies (nanobodies, Nbs) targeting hOX40 to monitor the activation status of T cells by in vivo molecular imaging. Methods: Nbs against hOX40 (hOX40-Nbs) were selected from an immunized Nb-library by phage display. The identified hOX40-Nbs were characterized in vitro, including determination of their specificity, affinity, stability, epitope recognition and their impact on OX40 signaling and T cell function. A lead candidate was site-specifically conjugated with a fluorophore via sortagging and applied for noninvasive in vivo optical imaging (OI) of hOX40-expressing cells in a xenograft mouse model.\u0000Results: Our selection campaign revealed four unique Nbs that exhibit strong binding affinities and high stabilities under physiological conditions. Epitope binning and domain mapping indicated the targeting of at least two different epitopes on hOX40. When analyzing their impact on OX40 signaling, an agonistic effect was excluded for all validated Nbs. Incubation of activated T cells with hOX40-Nbs did not affect cell viability or proliferation patterns, whereas differences in cytokine release were observed. In vivo OI with a fluorophore-conjugated lead candidate in experimental mice with hOX40-expressing xenografts demonstrated its specificity and functionality as an imaging probe. Conclusion: Considering the need for advanced probes for noninvasive in vivo monitoring of T cell activation dynamics, we propose, that our hOX40-Nbs have a great potential as imaging probes for noninvasive and longitudinal in vivo diagnostics. Quantification of OX40+ T cells in TME or IME will provide crucial insights into the activation state of infiltrating T cells, offering a valuable biomarker for assessing immune responses, predicting treatment efficacy, and guiding personalized immunotherapy strategies in patients with cancer or IMIDs.","PeriodicalId":501182,"journal":{"name":"bioRxiv - Immunology","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}