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Annals of the New York Academy of... 2008In the last 5 years major advances have been made in the field of tissue engineering. However, while engineering of tissues from nearly every major system in the body... (Review)
Review
In the last 5 years major advances have been made in the field of tissue engineering. However, while engineering of tissues from nearly every major system in the body have been studied and improved, little has been done with the engineering of viable lymphatic tissues. Recent advances in understanding of lymphatic biology have allowed the easy isolation of pure lymphatic cell cultures, increasing, in turn, the ability to study lymphatic biology in greater detail. This has allowed the elucidation of lymphatic properties on the structural, cellular, and molecular levels, making possible the successful development of the first lymphatic engineered tissues. Among such advances are the engineering of lymphatic capillaries, the development of a functioning bioreactor designed to culture lymph nodes in vitro, and in vivo growth of lymphatic organoids. However, there has been no research on the engineering of functional lymphangions. While the advances made in the study of lymphatic biology are encouraging, the complexities of the system make the engineering of certain functional lymphatic tissues somewhat more difficult.
Topics: Animals; Bioreactors; Cells, Cultured; Endothelium, Vascular; Humans; Lymphatic Vessels; Lymphoid Tissue; Mice; Mice, SCID; Tissue Engineering
PubMed: 18519958
DOI: 10.1196/annals.1413.004 -
Circulation Research Apr 2023Secondary lymphoid organs, such as lymph nodes, harbor highly specialized and compartmentalized niches. These niches are optimized to facilitate the encounter of naive... (Review)
Review
Secondary lymphoid organs, such as lymph nodes, harbor highly specialized and compartmentalized niches. These niches are optimized to facilitate the encounter of naive lymphocytes with antigens and antigen-presenting cells, enabling optimal generation of adaptive immune responses. Lymphatic vessels of lymphoid organs are uniquely specialized to perform a staggering variety of tasks. These include antigen presentation, directing the trafficking of immune cells but also modulating immune cell activation and providing factors for their survival. Recent studies have provided insights into the molecular basis of such specialization, opening avenues for better understanding the mechanisms of immune-vascular interactions and their applications. Such knowledge is essential for designing better treatments for human diseases given the central role of the immune system in infection, aging, tissue regeneration and repair. In addition, principles established in studies of lymphoid organ lymphatic vessel functions and organization may be applied to guide our understanding of specialization of vascular beds in other organs.
Topics: Humans; Endothelial Cells; Peyer's Patches; Lymph Nodes; Lymphocytes; Lymphatic Vessels; Lymphoid Tissue
PubMed: 37104555
DOI: 10.1161/CIRCRESAHA.123.322136 -
European Journal of Immunology Jun 2022Long-term T-cell memory is dependent on the maintenance of memory T cells in the lymphoid tissues, and at the surface interfaces that provide entry routes for pathogens....
Long-term T-cell memory is dependent on the maintenance of memory T cells in the lymphoid tissues, and at the surface interfaces that provide entry routes for pathogens. However, much of the current information on human T-cell memory is based on analyzing circulating T cells. Here, we have studied the distribution and age-related changes of memory T-cell subsets in samples from blood, mesenteric LNs, spleen, and ileum, obtained from donors ranging in age from 5 days to 67 years of age. Our data show that the main reservoir of polyclonal naive cells is found in the LNs, and the resting memory subsets capable of self-renewal are also prominent there. In contrast, nondividing but functionally active memory subsets dominate the spleen, and especially the ileum. In general, the replacement of naive cells with memory subsets continues throughout our period of observation, with no apparent plateau. In conclusion, the analysis of lymphoid and nonlymphoid tissues reveals a dynamic pattern of changes distinct to each tissue, and with substantial differences between CD4 and CD8 compartments.
Topics: CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cell Differentiation; Humans; Immunologic Memory; Lymphocyte Count; Lymphoid Tissue; Spleen; T-Lymphocyte Subsets
PubMed: 35307831
DOI: 10.1002/eji.202149465 -
Immunity Jun 2023During development, lymph node (LN) initiation is coordinated by lymphoid tissue organizer (LTo) cells that attract lymphoid tissue inducer (LTi) cells at strategic...
During development, lymph node (LN) initiation is coordinated by lymphoid tissue organizer (LTo) cells that attract lymphoid tissue inducer (LTi) cells at strategic positions within the embryo. The identity and function of LTo cells during the initial attraction of LTi cells remain poorly understood. Using lineage tracing, we demonstrated that a subset of Osr1-expressing cells was mesenchymal LTo progenitors. By investigating the heterogeneity of Osr1 cells, we uncovered distinct mesenchymal LTo signatures at diverse anatomical locations, identifying a common progenitor of mesenchymal LTos and LN-associated adipose tissue. Osr1 was essential for LN initiation, driving the commitment of mesenchymal LTo cells independent of neural retinoic acid, and for LN-associated lymphatic vasculature assembly. The combined action of chemokines CXCL13 and CCL21 was required for LN initiation. Our results redefine the role and identity of mesenchymal organizer cells and unify current views by proposing a model of cooperative cell function in LN initiation.
Topics: Transcription Factors; Cell Differentiation; Organogenesis; Lymph Nodes; Lymphoid Tissue
PubMed: 37160119
DOI: 10.1016/j.immuni.2023.04.014 -
Immunogenetics Feb 2021The function of a tissue is determined by its construction and cellular composition. The action of different genes can thus only be understood properly when seen in the... (Review)
Review
The function of a tissue is determined by its construction and cellular composition. The action of different genes can thus only be understood properly when seen in the context of the environment in which they are expressed and function. We now experience a renaissance in morphological research in fish, not only because, surprisingly enough, large structures have remained un-described until recently, but also because improved methods for studying morphological characteristics in combination with expression analysis are at hand. In this review, we address anatomical features of teleost immune tissues. There are approximately 30,000 known teleost fish species and only a minor portion of them have been studied. We aim our review at the Atlantic salmon (Salmo salar) and other salmonids, but when applicable, we also present information from other species. Our focus is the anatomy of the kidney, thymus, spleen, the interbranchial lymphoid tissue (ILT), the newly discovered salmonid cloacal bursa and the naso-pharynx associated lymphoid tissue (NALT).
Topics: Animals; Fishes; Gills; Kidney; Lymphoid Tissue; Nasopharynx; Salmo salar; Spleen; Thymus Gland
PubMed: 33426583
DOI: 10.1007/s00251-020-01196-0 -
Immunology Sep 2013Secondary lymphoid organs function to increase the efficiency of interactions between rare, antigen-specific lymphocytes and antigen presenting cells, concentrating... (Review)
Review
Secondary lymphoid organs function to increase the efficiency of interactions between rare, antigen-specific lymphocytes and antigen presenting cells, concentrating antigen and lymphocytes in a supportive environment that facilitates the initiation of an adaptive immune response. Homeostatic lymphoid tissue organogenesis proceeds via exquisitely controlled spatiotemporal interactions between haematopoietic lymphoid tissue inducer populations and multiple subsets of non-haematopoietic stromal cells. However, it is becoming clear that in a range of inflammatory contexts, ectopic or tertiary lymphoid tissues can develop inappropriately under pathological stress. Here we summarize the role of stromal cells in the development of homeostatic lymphoid tissue, and assess emerging evidence that suggests a critical role for stromal involvement in the tertiary lymphoid tissue development associated with chronic infections and inflammation.
Topics: Adaptive Immunity; Animals; Antigen-Presenting Cells; Homeostasis; Humans; Inflammation; Lymphoid Tissue; Models, Immunological; Organogenesis; Stromal Cells
PubMed: 23621403
DOI: 10.1111/imm.12119 -
Theranostics 2017The immune system protects the body against a wide range of infectious diseases and cancer by leveraging the efficiency of immune cells and lymphoid organs. Over the... (Review)
Review
The immune system protects the body against a wide range of infectious diseases and cancer by leveraging the efficiency of immune cells and lymphoid organs. Over the past decade, immune cell/organ therapies based on the manipulation, infusion, and implantation of autologous or allogeneic immune cells/organs into patients have been widely tested and have made great progress in clinical applications. Despite these advances, therapy with natural immune cells or lymphoid organs is relatively expensive and time-consuming. Alternatively, biomimetic materials and strategies have been applied to develop artificial immune cells and lymphoid organs, which have attracted considerable attentions. In this review, we survey the latest studies on engineering biomimetic materials for immunotherapy, focusing on the perspectives of bioengineering artificial antigen presenting cells and lymphoid organs. The opportunities and challenges of this field are also discussed.
Topics: Animals; Antigen-Presenting Cells; Artificial Cells; Biomimetic Materials; Humans; Lymphoid Tissue
PubMed: 28912891
DOI: 10.7150/thno.19017 -
Tissue & Cell Feb 2024Tertiary lymphoid structures (TLSs) are accumulations of lymphoid cells within non-lymphoid organs that share the cellular compartments, spatial organization,... (Review)
Review
Tertiary lymphoid structures (TLSs) are accumulations of lymphoid cells within non-lymphoid organs that share the cellular compartments, spatial organization, vasculature, chemokines, and function with secondary lymphoid organs, especially lymph nodes. TLSs are organized into a separate T cell and B cell compartments which contain germinal centers with follicular dendritic cells. In most cases, TLSs contain Peripheral Node addressin (PNAD) expressing high endothelial venules (HEVs). TLSs have been described in various mouse models of inflammation and are associated with a wide range of autoimmune diseases. Other than these, TLSs have been described in chronic allograft rejection and cancer.
Topics: Mice; Animals; Tertiary Lymphoid Structures; Lymphoid Tissue; B-Lymphocytes; T-Lymphocytes; Lymphocytes
PubMed: 38101028
DOI: 10.1016/j.tice.2023.102288 -
Cold Spring Harbor Perspectives in... Jan 2015Group 2 innate lymphoid cells (ILC2s) play critical roles in anti-helminth immunity, airway epithelial repair, and metabolic homeostasis. Recently, these cells have also... (Review)
Review
Group 2 innate lymphoid cells (ILC2s) play critical roles in anti-helminth immunity, airway epithelial repair, and metabolic homeostasis. Recently, these cells have also emerged as key players in the development of allergic inflammation at multiple barrier surfaces. ILC2s arise from common lymphoid progenitors in the bone marrow, are dependent on the transcription factors RORα, GATA3, and TCF-1, and produce the type 2 cytokines interleukin (IL)-4, IL-5, IL-9, and/or IL-13. The epithelial cell-derived cytokines IL-25, IL-33, and TSLP regulate the activation and effector functions of ILC2s, and recent studies suggest that their responsiveness to these cytokines and other factors may depend on their tissue environment. In this review, we focus on recent advances in our understanding of the various factors that regulate ILC2 function in the context of immunity, inflammation, and tissue repair across multiple organ systems.
Topics: Humans; Immunity, Innate; Lymphoid Tissue; Skin; Transcription Factors
PubMed: 25573713
DOI: 10.1101/cshperspect.a016337 -
Anatomical Record (Hoboken, N.J. : 2007) Nov 2020The presence of bronchus-associated lymphoid tissue (BALT) and its size in humans largely depends upon age. It is detected in 35% of children less than 2 years of age,... (Review)
Review
The presence of bronchus-associated lymphoid tissue (BALT) and its size in humans largely depends upon age. It is detected in 35% of children less than 2 years of age, but absent in the healthy adult lung. Environmental gases or allergens may have an effect on the number of BALT. Lungs of rhesus macaque monkeys were screened by histology for the presence, size, and location of BALT after exposure to filtered air for 2, 6, 12, or 36 months or 12 and 36 months to ozone or 2, 12, or 36 months of house dust mite or a combination of ozone and house dust mite for 12 months. In the lungs of monkeys housed in filtered air for 2 months, no BALT was identified. After 6, 12, or 36 months, the number of BALT showed a significantly increased correlation with age in monkeys housed in filtered air. After 2 months of episodic house dust mite (HDM) exposure, no BALT was found. Monkeys exposed to HDM or HDM + ozone did not show a significant increase in BALT compared to monkeys housed in filtered air. However, monkeys exposed to ozone alone did show significant increases in BALT compared to all other groups. In particular, there were frequent accumulations of lymphocytes in the periarterial space of ozone exposed animals. In conclusion, BALT in rhesus monkeys housed under filtered air conditions is age-dependent. BALT significantly increased in monkeys exposed to ozone in comparison with monkeys exposed to HDM.
Topics: Air Pollutants; Allergens; Animals; Lung; Lymphoid Tissue; Macaca mulatta; Ozone; Pyroglyphidae
PubMed: 32445535
DOI: 10.1002/ar.24456