Topic
White pulp
About: White pulp is a research topic. Over the lifetime, 1068 publications have been published within this topic receiving 29417 citations.
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Papers
Journal Article•
TL;DR: Sympathetic noradrenergic nerve fibers innervate both the vasculature and parenchymal fields of lymphocytes and associated cells in several lymphoid organs, including the thymus, spleen, lymph nodes, gut-associated lymphoid tissue (GALT), and bone marrow, in a variety of mammalian species.
Abstract: Sympathetic noradrenergic nerve fibers innervate both the vasculature and parenchymal fields of lymphocytes and associated cells in several lymphoid organs, including the thymus, spleen, lymph nodes, gut-associated lymphoid tissue (GALT), and bone marrow, in a variety of mammalian species. This innervation is both regional and specific, and generally is directed into zones of T lymphocytes and plasma cells rather than into nodular regions or B lymphocyte regions. In the thymus, noradrenergic fibers enter with nerve bundles and plexuses around blood vessels, travel into the cortex from subcapsular plexuses and with the vasculature, and branch into the parenchyma of the thymic cortex. The vasculature and parenchymal regions of both the outer and deep cortex are innervated by these fibers. In the spleen, noradrenergic fibers enter with the vasculature, travel along the trabeculae and along the branching vasculature, and are distributed mainly in the white pulp along the central artery and associated periarterial lymphatic sheath. Fibers branch from a dense plexus around the central artery and travel into the parenchyma, where they end among fields of lymphocytes and other cell types. In lymph nodes, noradrenergic fibers enter at the hilus, travel along the vasculature and in a subcapsular plexus, and branch into the parenchyma in paracortical and cortical regions, where they end among lymphocytes. In the GALT, represented in these studies by rabbit appendix, sacculus rotundus, and Peyer's patches, noradrenergic fibers enter at the serosal surface, travel longitudinally with the muscularis interna, turn radially into internodular plexuses, plunge directly through the thymus-dependent zones, and ramify profusely among lymphocytes, enterochromaffin cells, and plasma cells in the interdomal regions. In the bone marrow, noradrenergic fibers enter with blood vessels, distribute deeply into the marrow on those vessels, and branch sparsely into the substance of the marrow. Immunocytochemical observations revealed the presence of neuro-peptide-like immunoreactivity in the thymus and spleen. Vasoactive intestinal peptide (VIP)-like immunoreactivity is found in varicose profiles in the thymus within the cortex. In the spleen, immunoreactive profiles showing neuropeptide Y-like, Met-enkephalin-like, cholecystokinin-8 (CCK)-like, and neurotensin-like immunoreactivity are present along the central artery of the white pulp and its smaller branches, with only sparse fibers of most of these peptides entering the parenchyma. CCK-like profiles are present in abundance in the white pulp among parenchymal elements.(ABSTRACT TRUNCATED AT 400 WORDS)
1,040 citations
TL;DR: Mice rendered deficient in lymphotoxin by gene targeting in embryonic stem cells have no morphologically detectable lymph nodes or Peyer's patches, although development of the thymus appears normal, and data suggest an essential role for LT in the normal development of peripheral lymphoid organs.
Abstract: Mice rendered deficient in lymphotoxin (LT) by gene targeting in embryonic stem cells have no morphologically detectable lymph nodes or Peyer's patches, although development of the thymus appears normal. Within the white pulp of the spleen, there is failure of normal segregation of B and T cells. Spleen and peripheral blood contain CD4+CD8- and CD4-CD8+ T cells in a normal ratio, and both T cells subsets have an apparently normal lytic function. Lymphocytes positive for immunoglobulin M are present in increased numbers in both the spleen and peripheral blood. These data suggest an essential role for LT in the normal development of peripheral lymphoid organs.
1,035 citations
TL;DR: The spleen is the largest secondary immune organ in the body and is responsible for initiating immune reactions to blood-borne antigens and for filtering the blood of foreign material and old or damaged red blood cells.
Abstract: The spleen is the largest secondary immune organ in the body and is responsible for initiating immune reactions to blood-borne antigens and for filtering the blood of foreign material and old or damaged red blood cells. These functions are carried out by the 2 main compartments of the spleen, the white pulp (including the marginal zone) and the red pulp, which are vastly different in their architecture, vascular organization, and cellular composition. The morphology of these compartments is described and, to a lesser extent, their functions are discussed. The variation between species and effects of aging and genetics on splenic morphology are also discussed.
880 citations
TL;DR: The bursa of Fabricius and the thymus are "central lymphoid organs" in the chicken, essential to the ontogenetic development of adaptive immunity in that species, and surgical removal of one or both of these organs has permitted recognition of two morphologically distinct cell systems in the "peripheral lymphoid tissues" of the spleen, gut, and other organs.
Abstract: The bursa of Fabricius and the thymus are "central lymphoid organs" in the chicken, essential to the ontogenetic development of adaptive immunity in that species. Surgical removal of one or both of these organs in the newly hatched chicken, followed by sublethal X-irradiation the next day, has permitted recognition of two morphologically distinct cell systems in the "peripheral lymphoid tissues" of the spleen, gut, and other organs, and clear definition of the separate functions of each cell system.
The thymus-dependent development is represented morphologically by the small lymphocytes of the circulation and the white pulp type of development in the tissues. As in mammals, the thymus-dependent tissues of the chicken are basic to the ontogenesis of cellular immunity: graft versus host reactions, responses of delayed hypersensitivity and homograft rejection; and play a less clearly defined role in the antibody response to at least some antigens. Thymectomized-irradiated chickens are deficient in all these responses, and grow more slowly than any of the other experimental groups. In these animals germinal centers, plasma cells, and capacity for immunoglobulin synthesis remain intact.
The bursa-dependent development is represented morphologically by the larger lymphocytes of the germinal centers and the plasma cells, and functionally by the immunoglobulins. Bursectomized-irradiated chickens are agammaglobulinemic and unable to produce detectable antibody despite intense, repeated stimulation with bovine serum albumin and Brucella abortus organisms. The thymus-dependent development in these animals seems to be normal; they have adequate numbers of lymphocytes in the circulation and tissues, are able to reject skin homografts, though more slowly than usual, and to exercise graft versus host reactions. The short life span of these chickens has precluded adequate study of responses of delayed hypersensitivity.
There was no evidence of significant impairment of reticuloendothelial function in either the bursectomized-irradiated or the thymectomized-irradiated group, as judged by the clearance of colloidal gold and I131-tagged keyhole limpet hemocyanin.
806 citations
TL;DR: The marginal zone of the spleen functions not only as an area of initial filtration and phagocytosis of antigens from the blood, but also as a site of lymphocyte emigration.
Abstract: Publisher Summary This chapter provides an overview of the various nonlymphoid and lymphoid cell types localized in the marginal zone and the way they are arranged in the basic structure of this compartment. It also discusses the role of the marginal zone, with emphasis to the intriguing ways these cell types interact with each other in the defense against invading pathogens. The spleen can be divided into a red pulp compartment, distinguishable by the abundance of erythrocytes, and a white pulp compartment, consisting of large nodules of organized lymphoid tissue. It is in the red pulp that blood filtration takes place, whereas the white pulp is involved in the specific immunological defense against bloodborne antigens. The marginal zone is described as a layer surrounding the periarteriolar lymphocyte sheath (PALS) and B cell follicles, predominantly composed of intermediate-sized lymphocytes. The basic structure of the marginal zone consists of a meshwork of reticular cells, which are concentrically layered around the PALS and the follicular areas, with a more dispersed three-dimensional appearance toward the red pulp. The opening of a part of the arterial blood supply into the wider spaces of the marginal sinus, right at the border of the marginal zone and the white pulp, results in a blood flow with a lower resistance.
442 citations
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Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 2 |
| 2024 | 22 |
| 2023 | 40 |
| 2022 | 42 |
| 2021 | 27 |
| 2020 | 40 |