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Li C, Hendrikse NW, Mai M, Farooqui MA, Argall-Knapp Z, Kim JS, Wheat EA, Juang T. Microliter whole blood neutrophil assay preserving physiological lifespan and functional heterogeneity. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2023.08.28.23294744. [PMID: 37693613 PMCID: PMC10491351 DOI: 10.1101/2023.08.28.23294744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
For in vitro neutrophil functional assays, neutrophils are typically isolated from whole blood, having the target cells exposed to an artificial microenvironment with altered kinetics. Isolated neutrophils exhibit limited lifespans of only a few hours ex vivo, significantly shorter than the 3-5 day lifespan of neutrophils in vivo. In addition, due to neutrophil inherently high sensitivity, neutrophils removed from whole blood exhibit stochastic non-specific activation that contributes to assay variability. Here we present a method - named micro-Blood - that enables functional neutrophil assays using a microliter of unprocessed whole blood. micro-Blood allows multiple phenotypic readouts of neutrophil function (including cell/nucleus morphology, motility, recruitment, and pathogen control). In micro-Blood, neutrophils show sustained migration and limited non-specific activation kinetics (<0.1% non-specific activation) over 3-6 days. In contrast, neutrophils isolated using traditional methods show increased and divergent activation kinetics (10-70% non-specific activation) in only 3 h. Finally, micro-Blood allows the capture and quantitative comparison of distinct neutrophil functional heterogeneity between healthy donors and cancer patients in response to microbial stimuli with the preserved physiological lifespan over 6 days.
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Li C, Hendrikse NW, Argall-Knapp Z, Mai M, Kim JS. In Vitro Neutrophil-Bacteria Assay in Whole Blood Microenvironments with Single-Cell Confinement. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.22.576723. [PMID: 38328183 PMCID: PMC10849536 DOI: 10.1101/2024.01.22.576723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Blood is a common medium through which invasive bacterial infections disseminate in the human body. In vitro neutrophil-bacteria assays allow flexible mechanistic studies and screening of interventional strategies. In standard neutrophil-bacteria assays, both the immune cells and microorganisms are typically interrogated in an exogenous, homogeneous, bulk fluid environment (e.g., culture media or bacterial broth in microtiter plates), lacking the relevant physicochemical factors in the heterogenous blood-tissue microenvironment (e.g., capillary bed) with single-cell confinement. Here we present an in vitro neutrophil-bacteria assay by leveraging an open microfluidic model known as "μ-Blood" that supports sub-microliter liquid microchannels with single-cell confinement. In this study we compare the exogenous and endogenous fluids including neutrophils in RPMI (standard suspension cell culture media) and whole blood in response to Staphylococcus aureus ( S. aureus , a gram-positive, non-motile bacterium) in phosphate buffered saline (PBS), Mueller Hinton Broth (MHB), and human serum. Our results reveal a significant disparity between the exogenous and endogenous fluid microenvironments in the growth kinetics of bacteria, the spontaneous generation of capillary (i.e., Marangoni) flow, and the outcome of neutrophil intervention on the spreading bacteria.
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Tsioumpekou M, Krijgsman D, Leusen JHW, Olofsen PA. The Role of Cytokines in Neutrophil Development, Tissue Homing, Function and Plasticity in Health and Disease. Cells 2023; 12:1981. [PMID: 37566060 PMCID: PMC10417597 DOI: 10.3390/cells12151981] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 07/28/2023] [Accepted: 07/31/2023] [Indexed: 08/12/2023] Open
Abstract
Neutrophils are crucial innate immune cells and comprise 50-70% of the white blood cell population under homeostatic conditions. Upon infection and in cancer, blood neutrophil numbers significantly increase because of the secretion of various chemo- and cytokines by, e.g., leukocytes, pericytes, fibroblasts and endothelial cells present in the inflamed tissue or in the tumor microenvironment (TME). The function of neutrophils in cancer has recently gained considerable attention, as they can exert both pro- and anti-tumorigenic functions, dependent on the cytokine milieu present in the TME. Here, we review the effect of cytokines on neutrophil development, tissue homing, function and plasticity in cancer and autoimmune diseases as well as under physiological conditions in the bone marrow, bloodstream and various organs like the spleen, kidney, liver, lung and lymph nodes. In addition, we address several promising therapeutic options, such as cytokine therapy, immunocytokines and immunotherapy, which aim to exploit the anti-tumorigenic potential of neutrophils in cancer treatment or block excessive neutrophil-mediated inflammation in autoimmune diseases.
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Affiliation(s)
- Maria Tsioumpekou
- Center for Translational Immunology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands; (M.T.); (D.K.); (J.H.W.L.)
| | - Daniëlle Krijgsman
- Center for Translational Immunology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands; (M.T.); (D.K.); (J.H.W.L.)
- Center for Molecular Medicine, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Jeanette H. W. Leusen
- Center for Translational Immunology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands; (M.T.); (D.K.); (J.H.W.L.)
| | - Patricia A. Olofsen
- Center for Translational Immunology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands; (M.T.); (D.K.); (J.H.W.L.)
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da Silva JGL, Gonçalves AAM, Oliveira LT, Garcia GM, Batista MA, de Mendonça LZ, Viana KF, Sant’Ana RDCO, Melo Júnior OADO, Silveira-Lemos D, Dutra WO, Martins-Filho OA, Galdino AS, de Moura SAL, Mosqueira VCF, Giunchetti RC. Polymeric Delivery Systems as a Potential Vaccine against Visceral Leishmaniasis: Formulation Development and Immunogenicity. Vaccines (Basel) 2023; 11:1309. [PMID: 37631877 PMCID: PMC10459565 DOI: 10.3390/vaccines11081309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 07/13/2023] [Accepted: 07/18/2023] [Indexed: 08/27/2023] Open
Abstract
Recent studies suggest that the association of antigens in microparticles increases the anti-Leishmania vaccine immunogenicity. This study aims to investigate the in situ effect of the adjuvant performance consisting of chitosan-coated poly(D,L-lactic) acid submicrometric particles (SMP) and analyze the inflammatory profile and toxicity. Two formulations were selected, SMP1, containing poly(D,L-lactide) (PLA) 1% wt/v and chitosan 1% wt/v; and SMP2, containing PLA 5% wt/v and chitosan 5% wt/v. After a single dose of the unloaded SMP1 or SMP2 in mice, the SMPs promoted cell recruitment without tissue damage. In addition, besides the myeloperoxidase (MPO) activity having demonstrated similar results among the analyzed groups, a progressive reduction in the levels of N-acetyl-β-D-glucosaminidase (NAG) until 72 h was observed for SMPs. While IL-6 levels were similar among all the analyzed groups along the kinetics, only the SMPs groups had detectable levels of TNF-α. Additionally, the Leishmania braziliensis antigen was encapsulated in SMPs (SMP1Ag and SMP2Ag), and mice were vaccinated with three doses. The immunogenicity analysis by flow cytometry demonstrated a reduction in NK (CD3-CD49+) cells in all the SMPs groups, in addition to impairment in the T cells subsets (CD3+CD4+) and CD3+CD8+) and B cells (CD19+) of the SMP2 group. The resulting data demonstrate that the chitosan-coated SMP formulations stimulate the early events of an innate immune response, suggesting their ability to increase the immunogenicity of co-administered Leishmania antigens.
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Affiliation(s)
- João Guilherme Lino da Silva
- Laboratory of Biology of Cell Interactions, Department of Morphology, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (J.G.L.d.S.); (A.A.M.G.); (M.A.B.); (L.Z.d.M.); (K.F.V.); (R.d.C.O.S.); (O.A.d.O.M.J.); (W.O.D.)
- Nucleus for Research in Biological Sciences (NUPEB), Federal University of Ouro Preto, Ouro Preto 35400-000, Brazil
| | - Ana Alice Maia Gonçalves
- Laboratory of Biology of Cell Interactions, Department of Morphology, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (J.G.L.d.S.); (A.A.M.G.); (M.A.B.); (L.Z.d.M.); (K.F.V.); (R.d.C.O.S.); (O.A.d.O.M.J.); (W.O.D.)
| | - Liliam Teixeira Oliveira
- Laboratory of Pharmaceutics and Nanotechnology (LDGNano), School of Pharmacy, Federal University of Ouro Preto, Ouro Preto 35400-000, Brazil; (L.T.O.); (G.M.G.); (V.C.F.M.)
| | - Giani Martins Garcia
- Laboratory of Pharmaceutics and Nanotechnology (LDGNano), School of Pharmacy, Federal University of Ouro Preto, Ouro Preto 35400-000, Brazil; (L.T.O.); (G.M.G.); (V.C.F.M.)
| | - Maurício Azevedo Batista
- Laboratory of Biology of Cell Interactions, Department of Morphology, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (J.G.L.d.S.); (A.A.M.G.); (M.A.B.); (L.Z.d.M.); (K.F.V.); (R.d.C.O.S.); (O.A.d.O.M.J.); (W.O.D.)
| | - Ludmila Zanandreis de Mendonça
- Laboratory of Biology of Cell Interactions, Department of Morphology, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (J.G.L.d.S.); (A.A.M.G.); (M.A.B.); (L.Z.d.M.); (K.F.V.); (R.d.C.O.S.); (O.A.d.O.M.J.); (W.O.D.)
| | - Kelvinson Fernandes Viana
- Laboratory of Biology of Cell Interactions, Department of Morphology, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (J.G.L.d.S.); (A.A.M.G.); (M.A.B.); (L.Z.d.M.); (K.F.V.); (R.d.C.O.S.); (O.A.d.O.M.J.); (W.O.D.)
| | - Rita de Cássia Oliveira Sant’Ana
- Laboratory of Biology of Cell Interactions, Department of Morphology, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (J.G.L.d.S.); (A.A.M.G.); (M.A.B.); (L.Z.d.M.); (K.F.V.); (R.d.C.O.S.); (O.A.d.O.M.J.); (W.O.D.)
| | - Otoni Alves de Oliveira Melo Júnior
- Laboratory of Biology of Cell Interactions, Department of Morphology, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (J.G.L.d.S.); (A.A.M.G.); (M.A.B.); (L.Z.d.M.); (K.F.V.); (R.d.C.O.S.); (O.A.d.O.M.J.); (W.O.D.)
| | - Denise Silveira-Lemos
- Integrated Research Group on Biomarkers, René Rachou Research Center, Oswaldo Cruz Foundation, Belo Horizonte 30190-009, Brazil;
| | - Walderez Ornelas Dutra
- Laboratory of Biology of Cell Interactions, Department of Morphology, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (J.G.L.d.S.); (A.A.M.G.); (M.A.B.); (L.Z.d.M.); (K.F.V.); (R.d.C.O.S.); (O.A.d.O.M.J.); (W.O.D.)
- National Institute of Science and Technology in Tropical Diseases, INCT-DT, Salvador 40110-060, Brazil
| | - Olindo Assis Martins-Filho
- Laboratory of Diagnosis and Monitoring Biomarkers, René Rachou Research Center, Oswaldo Cruz Foundation, Belo Horizonte 30190-009, Brazil;
| | - Alexsandro Sobreira Galdino
- Laboratory of Microorganism Biotechnology, Federal University of São João Del-Rei (UFSJ), Midwest Campus, Divinópolis 35501-296, Brazil;
| | - Sandra Aparecida Lima de Moura
- Laboratory of Biomaterials and Experimental Pathology, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto 35402-136, Brazil;
| | - Vanessa Carla Furtado Mosqueira
- Laboratory of Pharmaceutics and Nanotechnology (LDGNano), School of Pharmacy, Federal University of Ouro Preto, Ouro Preto 35400-000, Brazil; (L.T.O.); (G.M.G.); (V.C.F.M.)
| | - Rodolfo Cordeiro Giunchetti
- Laboratory of Biology of Cell Interactions, Department of Morphology, Federal University of Minas Gerais (UFMG), Belo Horizonte 31270-901, Brazil; (J.G.L.d.S.); (A.A.M.G.); (M.A.B.); (L.Z.d.M.); (K.F.V.); (R.d.C.O.S.); (O.A.d.O.M.J.); (W.O.D.)
- National Institute of Science and Technology in Tropical Diseases, INCT-DT, Salvador 40110-060, Brazil
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Hamadani CM, Dasanayake GS, Chism CM, Gorniak ME, Monroe WG, Merrell A, Pride MC, Heintz R, Wong K, Hossain M, Taylor G, Edgecomb SX, Jones D, Dhar J, Banka A, Singh G, Vashisth P, Randall J, Darlington DS, Everett J, Jarrett E, Werfel TA, Eniola-Adefeso O, Tanner EEL. Selective Blood Cell Hitchhiking in Whole Blood with Ionic Liquid-Coated PLGA Nanoparticles to Redirect Biodistribution After Intravenous Injection. RESEARCH SQUARE 2023:rs.3.rs-3146716. [PMID: 37502854 PMCID: PMC10371090 DOI: 10.21203/rs.3.rs-3146716/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Less than 5% of intravenously-injected nanoparticles (NPs) reach destined sites in the body due to opsonization and immune-based clearance in vascular circulation. By hitchhiking in situ onto specific blood components post-injection, NPs can selectively target tissue sites for unprecedentedly high drug delivery rates. Choline carboxylate ionic liquids (ILs) are biocompatible liquid salts <100X composed of bulky asymmetric cations and anions. This class of ILs has been previously shown to significantly extend circulation time and redirect biodistribution in BALB/c mice post-IV injection via hitchhiking on red blood cell (RBC) membranes. Herein, we synthesized & screened 60 choline carboxylic acid-based ILs to coat PLGA NPs and present the impact of structurally engineering the coordinated anion identity to selectively interface and hitchhike lymphocytes, monocytes, granulocytes, platelets, and RBCs in whole mouse blood for in situ targeted drug delivery. Furthermore, we find this nanoparticle platform to be biocompatible (non-cytotoxic), translate to human whole blood by resisting serum uptake and maintaining modest hitchhiking, and also significantly extend circulation retention over 24 hours in BALB/c healthy adult mice after IV injection. Because of their altered circulation profiles, we additionally observe dramatically different organ accumulation profiles compared to bare PLGA NPs. This study establishes an initial breakthrough platform for a modular and transformative targeting technology to hitchhike onto blood components with high efficacy and safety in the bloodstream post-IV administration.
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Jakovija A, Chtanova T. Skin immunity in wound healing and cancer. Front Immunol 2023; 14:1060258. [PMID: 37398649 PMCID: PMC10312005 DOI: 10.3389/fimmu.2023.1060258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 05/24/2023] [Indexed: 07/04/2023] Open
Abstract
The skin is the body's largest organ. It serves as a barrier to pathogen entry and the first site of immune defense. In the event of a skin injury, a cascade of events including inflammation, new tissue formation and tissue remodeling contributes to wound repair. Skin-resident and recruited immune cells work together with non-immune cells to clear invading pathogens and debris, and guide the regeneration of damaged host tissues. Disruption to the wound repair process can lead to chronic inflammation and non-healing wounds. This, in turn, can promote skin tumorigenesis. Tumors appropriate the wound healing response as a way of enhancing their survival and growth. Here we review the role of resident and skin-infiltrating immune cells in wound repair and discuss their functions in regulating both inflammation and development of skin cancers.
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Affiliation(s)
- Arnolda Jakovija
- Immunity Theme, Garvan Institute of Medical Research, Sydney, Australia
- St. Vincent’s School of Medicine, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Tatyana Chtanova
- Immunity Theme, Garvan Institute of Medical Research, Sydney, Australia
- School of Biotechnology and Biomolecular Sciences, Faculty of Science, University of New South Wales, Sydney, Australia
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Koenderman L, Tesselaar K, Vrisekoop N. Human neutrophil kinetics: a call to revisit old evidence. Trends Immunol 2022; 43:868-876. [PMID: 36243621 DOI: 10.1016/j.it.2022.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 09/13/2022] [Accepted: 09/14/2022] [Indexed: 01/12/2023]
Abstract
The half-life of human neutrophils is still controversial, with estimates ranging from 7-9 h to 3.75 days. This debate should be settled to understand neutrophil production in the bone marrow (BM) and the potential and limitations of emergency neutropoiesis following infection or trauma. Furthermore, cellular lifespan greatly influences the potential effect(s) neutrophils have on the adaptive immune response. We posit that blood neutrophils are in exchange with different tissues, but particularly the BM, as it contains the largest pool of mature neutrophils. Furthermore, we propose that the oldest neutrophils are the first to die following a so-called conveyor belt model. These guiding principles shed new light on our interpretation of existing neutrophil lifespan data and offer recommendations for future research.
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Affiliation(s)
- Leo Koenderman
- Department of Respiratory Medicine, University Medical Center Utrecht, The Netherlands; Center for Translational Immunology, University Medical Center Utrecht, The Netherlands.
| | - Kiki Tesselaar
- Center for Translational Immunology, University Medical Center Utrecht, The Netherlands; Department of Immunology, University Medical Center Utrecht, The Netherlands
| | - Nienke Vrisekoop
- Department of Respiratory Medicine, University Medical Center Utrecht, The Netherlands; Center for Translational Immunology, University Medical Center Utrecht, The Netherlands
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8
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Liu J, Yu C. Lymphangiogenesis and Lymphatic Barrier Dysfunction in Renal Fibrosis. Int J Mol Sci 2022; 23:ijms23136970. [PMID: 35805972 PMCID: PMC9267103 DOI: 10.3390/ijms23136970] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/20/2022] [Accepted: 06/20/2022] [Indexed: 11/16/2022] Open
Abstract
As an integral part of the vascular system, the lymphatic vasculature is essential for tissue fluid homeostasis, nutritional lipid assimilation and immune regulation. The composition of the lymphatic vasculature includes fluid-absorbing initial lymphatic vessels (LVs), transporting collecting vessels and anti-regurgitation valves. Although, in recent decades, research has drastically enlightened our view of LVs, investigations of initial LVs, also known as lymphatic capillaries, have been stagnant due to technical limitations. In the kidney, the lymphatic vasculature mainly presents in the cortex, keeping the local balance of fluid, solutes and immune cells. The contribution of renal LVs to various forms of pathology, especially chronic kidney diseases, has been addressed in previous studies, however with diverging and inconclusive results. In this review, we discuss the most recent advances in the proliferation and permeability of lymphatic capillaries as well as their influencing factors. Novel technologies to visualize and measure LVs function are described. Then, we highlight the role of the lymphatic network in renal fibrosis and the crosstalk between kidney and other organs, such as gut and heart.
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Műzes G, Bohusné Barta B, Sipos F. Colitis and Colorectal Carcinogenesis: The Focus on Isolated Lymphoid Follicles. Biomedicines 2022; 10:biomedicines10020226. [PMID: 35203436 PMCID: PMC8869724 DOI: 10.3390/biomedicines10020226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/09/2022] [Accepted: 01/20/2022] [Indexed: 02/05/2023] Open
Abstract
Gut-associated lymphoid tissue is one of the most diverse and complex immune compartments in the human body. The subepithelial compartment of the gut consists of immune cells of innate and adaptive immunity, non-hematopoietic mesenchymal cells, and stem cells of different origins, and is organized into secondary (and even tertiary) lymphoid organs, such as Peyer's patches, cryptopatches, and isolated lymphoid follicles. The function of isolated lymphoid follicles is multifaceted; they play a role in the development and regeneration of the large intestine and the maintenance of (immune) homeostasis. Isolated lymphoid follicles are also extensively associated with the epithelium and its conventional and non-conventional immune cells; hence, they can also function as a starting point or maintainer of pathological processes such as inflammatory bowel diseases or colorectal carcinogenesis. These relationships can significantly affect both physiological and pathological processes of the intestines. We aim to provide an overview of the latest knowledge of isolated lymphoid follicles in colonic inflammation and colorectal carcinogenesis. Further studies of these lymphoid organs will likely lead to an extended understanding of how immune responses are initiated and controlled within the large intestine, along with the possibility of creating novel mucosal vaccinations and ways to treat inflammatory bowel disease or colorectal cancer.
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Affiliation(s)
| | | | - Ferenc Sipos
- Correspondence: ; Tel.: +36-20-478-0752; Fax: +36-1-266-0816
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Collado-Diaz V, Medina-Sanchez JD, Gkountidi AO, Halin C. Imaging leukocyte migration through afferent lymphatics. Immunol Rev 2021; 306:43-57. [PMID: 34708414 PMCID: PMC9298274 DOI: 10.1111/imr.13030] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/11/2021] [Accepted: 10/13/2021] [Indexed: 12/11/2022]
Abstract
Afferent lymphatics mediate the transport of antigen and leukocytes, especially of dendritic cells (DCs) and T cells, from peripheral tissues to draining lymph nodes (dLNs). As such they play important roles in the induction and regulation of adaptive immunity. Over the past 15 years, great advances in our understanding of leukocyte trafficking through afferent lymphatics have been made through time‐lapse imaging studies performed in tissue explants and in vivo, allowing to visualize this process with cellular resolution. Intravital imaging has revealed that intralymphatic leukocytes continue to actively migrate once they have entered into lymphatic capillaries, as a consequence of the low flow conditions present in this compartment. In fact, leukocytes spend considerable time migrating, patrolling and interacting with the lymphatic endothelium or with other intralymphatic leukocytes within lymphatic capillaries. Cells typically only start to detach once they arrive in downstream‐located collecting vessels, where vessel contractions contribute to enhanced lymph flow. In this review, we will introduce the biology of afferent lymphatic vessels and report on the presumed significance of DC and T cell migration via this route. We will specifically highlight how time‐lapse imaging has contributed to the current model of lymphatic trafficking and the emerging notion that ‐ besides transport – lymphatic capillaries exert additional roles in immune modulation.
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Affiliation(s)
| | | | | | - Cornelia Halin
- Institute of Pharmaceutical Sciences, ETH Zurich, Zurich, Switzerland
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