Inflammation and structural changes of splenic lymphoid tissue in visceral leishmaniasis: A study on naturally infected dogs

ABSTRACT The levels of protection found in vaccine studies of murine visceral leishmaniasis are significantly lower than for cutaneous leishmaniasis; whether this is due to the high-challenge murine model employed and/or is a consequence of differences required in tissue-specific local immune responses is not understood. Consequently, an intradermal murine model of visceral leishmaniasis has been explored. Intradermal inoculation established a chronic infection in susceptible mice which was associated with a pattern of parasite clearance with time postinfection in the liver and skin; in contrast, parasite persistence and expansion was observed in lymphoid tissue (spleen and draining lymph node). The course of disease found appears to be similar to those reported for subclinical canine and human visceral leishmaniasis. Clearance of parasites from the skin was correlated with an inflammatory response and the infiltration and activation of CD4+ and CD8+ T cells. In contrast, in lymphoid tissue (lymph node or spleen), the production of Th1/Th2 cytokines (interleukin-4 [IL-4], IL-10, and gamma interferon) appeared to correlate with parasite burden and pathogenesis. In vaccination experiments employing the Leishmania infantum D-13 (p80) antigen, significantly higher levels of protection were found with the intradermal murine model (29 to 7,500-fold more than naive controls) than were found with a low-dose intravenous infection model (9 to 173-fold). Thus, this model should prove useful for further investigation of disease pathogenesis as well as vaccine studies of visceral leishmaniasis.

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Disruption of Splenic Lymphoid Tissue and Plasmacytosis in Canine Visceral Leishmaniasis: Changes in Homing and Survival of Plasma Cells

PLoS ONE ◽

10.1371/journal.pone.0156733 ◽

2016 ◽

Vol 11 (5) ◽

pp. e0156733 ◽

Cited By ~ 14

Author(s):

Joselli Silva-O’Hare ◽

Isabela Silva de Oliveira ◽

Thaís Klevorn ◽

Valter A. Almeida ◽

Geraldo G. S. Oliveira ◽

...

Keyword(s):

Visceral Leishmaniasis ◽

Lymphoid Tissue ◽

Plasma Cells ◽

Canine Visceral Leishmaniasis

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Neurological status and structural changes in the tracheal lymphoid tissue in rats with different resistance to emotional stress of experimental hemorrhagic stroke

Zhurnal nevrologii i psikhiatrii im S S Korsakova ◽

10.17116/jnevro202012008245 ◽

2020 ◽

Vol 120 (8) ◽

pp. 45

Author(s):

L.A. Klyueva ◽

E.V. Koplik ◽

E.V. Shvetsov ◽

K.A. Vasyanina

Keyword(s):

Emotional Stress ◽

Lymphoid Tissue ◽

Structural Changes ◽

Hemorrhagic Stroke ◽

Neurological Status

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High-Resolution, 3D Imaging of the Zebrafish Gill-Associated Lymphoid Tissue (GIALT) Reveals a Novel Lymphoid Structure, the Amphibranchial Lymphoid Tissue

Frontiers in Immunology ◽

10.3389/fimmu.2021.769901 ◽

2021 ◽

Vol 12 ◽

Author(s):

Alf S. Dalum ◽

Aurora Kraus ◽

Shanawaz Khan ◽

Erna Davydova ◽

Dimitri Rigaudeau ◽

...

Keyword(s):

High Resolution ◽

Lymphoid Tissue ◽

Structural Changes ◽

Nk Cell ◽

Active Role ◽

Gill Arch ◽

Lymphoid Cells ◽

Lymphoid Tissues ◽

A Site ◽

Conserved Epitope

The zebrafish is extensively used as an animal model for human and fish diseases. However, our understanding of the structural organization of its immune system remains incomplete, especially the mucosa-associated lymphoid tissues (MALTs). Teleost MALTs are commonly perceived as diffuse and scattered populations of immune cells throughout the mucosa. Yet, structured MALTs have been recently discovered in Atlantic salmon (Salmo salar L.), including the interbranchial lymphoid tissue (ILT) in the gills. The existence of the ILT was only recently identified in zebrafish and other fish species, highlighting the need for in-depth characterizations of the gill-associated lymphoid tissue (GIALT) in teleosts. Here, using 3-D high-resolution microscopy, we analyze the GIALT of adult zebrafish with an immuno-histology approach that reveals the organization of lymphoid tissues via the labeling of T/NK cells with an antibody directed to a highly conserved epitope on the kinase ZAP70. We show that the GIALT in zebrafish is distributed over at least five distinct sub-regions, an organization found in all pairs of gill arches. The GIALT is diffuse in the pharyngeal part of the gill arch, the interbranchial septum and the filaments/lamellae, and structured in two sub-regions: the ILT, and a newly discovered lymphoid structure located along each side of the gill arch, which we named the Amphibranchial Lymphoid Tissue (ALT). Based on RAG2 expression, neither the ILT nor the ALT constitute additional thymi. The ALT shares several features with the ILT such as presence of abundant lymphoid cells and myeloid cells embedded in a network of reticulated epithelial cells. Further, the ILT and the ALT are also a site for T/NK cell proliferation. Both ILT and ALT show structural changes after infection with Spring Viraemia of Carp Virus (SVCV). Together, these data suggest that ALT and ILT play an active role in immune responses. Comparative studies show that whereas the ILT seems absent in most neoteleosts (“Percomorphs”), the ALT is widely present in cyprinids, salmonids and neoteleosts, suggesting that it constitutes a conserved tissue involved in the protection of teleosts via the gills.

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Structural changes in the lacrimal sac epithelium and associated lymphoid tissue during experimental dacryocystitis

Clinical Ophthalmology ◽

10.2147/opth.s26048 ◽

2011 ◽

pp. 1567 ◽

Cited By ~ 5

Author(s):

Makoto Ishikawa ◽

Kubo ◽

Sawada ◽

Yoshitomi ◽

Maeda ◽

...

Keyword(s):

Lymphoid Tissue ◽

Structural Changes ◽

Lacrimal Sac

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ГІСТОЛОГІЧНИЙ АНАЛІЗ ЛІМФОЇДНИХ УТВОРЕНЬ ШЛУНКА І ТОНКОЇ КИШКИ У КЛІНІКО-ПАТОГЕНЕТИЧНОМУ ПРОФІЛІ БАБЕЗІОЗУ

The Medical and Ecological Problems ◽

10.31718/mep.2021.25.3-4.06 ◽

2021 ◽

Vol 25 (3-4) ◽

pp. 28-32

Author(s):

І.І. Торяник

Keyword(s):

Small Intestine ◽

Lymphoid Tissue ◽

Structural Changes ◽

Plasma Cells ◽

Single Cells ◽

Molecular Genetic ◽

Histological Changes ◽

Lymphoid Follicles ◽

Active Involvement ◽

Nodular Hyperplasia

Peripheral lymphoid organs respond immediately to a decrease in the body's defence responses, and their localisation and morphological specificity account for their active involvement in immunogenesis (especially in animals). This fact accentuates the morpho-functional estimation of the lymphoid tissue condition with the purpose of timely diagnostics of starting deviations and preventing the development of decompensated changes. Thus, the analysis of histological changes of the latter in natural and experimental prototypes of babesiosis is relevant. The aim of the research is to define the role of histological changes of lymphoid masses in the stomach and small intestine in the formation of the clinical and pathogenetic profile of babesiosis. We studied the structural changes of lymphoid masses of the stomach and small intestine in animals with babesiosis postmortem by histological methods. Fixation was traditionally carried out in 12% aqueous formalin solution, dehydration in alcohol (30º to absolute), and pouring (paraffin/ celloidin). Staining was conducted with eosin and haematoxylin, Van Gizon, Brasche. Analysis was performed using an Olympus BX-41 microscope, Japan (x 100; x 200; x 1350). Verification was carried out by cytological, ultramicroscopic, molecular genetic methods (polymerase chain reaction) and in a biological experiment on animals. Analysis of specimens of the lamina propria in the gastric mucosa of the animals in the experimental group and clinical observation group established that the latter contained diffuse accumulations of the lymphoid tissue. Their dispersal involved different parts of the organ, including quite large areas. Haematoxylin and eosin staining gave a clear histological pattern with a marked contrast of fragments, which contributed to diagnostic resources. Lymphoid follicles were observed occasionally, their marginal, mantle zones were blurred. The germinative centres were not detected and did not show any lucency. Neutrophilic granulocytes, monocytes and plasma cells predominated among the cellular leucocyte populations. Examination of the lymphoid apparatus of the small intestine showed predominantly diffuse nodular hyperplasia, which was widespread. A focal version of the nosological prototype was observed in individual specimens occasionally, presented as single cells (most often in the terminal parts of the organ). Histological changes of lymphoid masses of the stomach and small intestine in animals with babesiosis consisted in the development of expressive diffuse nodular hyperplasia with disorganization of the structure of lymphoid follicles, destruction of zonality of the latter, making it impossible to detect germinative centres.

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Fine Structural Changes in the Microvasculature of the Mouse Pinna: Aging and Radiation Injury

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050287 ◽

1974 ◽

Vol 32 ◽

pp. 54-55

Author(s):

S. Phyllis Steamer ◽

Rosemarie L. Devine

Keyword(s):

Structural Changes ◽

Radiation Treatment ◽

Arterial Stenosis ◽

Ultrastructural Changes ◽

Vascular Effects ◽

Microvascular Changes ◽

Surrounding Connective Tissue ◽

Fission Neutrons ◽

Total Body

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.

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Evaluation of single-electron movies of glutamine synthetase molecules

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100075191 ◽

1983 ◽

Vol 41 ◽

pp. 280-281

Author(s):

W. Kunath ◽

E. Zeitler ◽

M. Kessel

Keyword(s):

Electron Microscope ◽

Glutamine Synthetase ◽

Electron Irradiation ◽

Structural Damage ◽

Structural Changes ◽

Single Electron ◽

Continuous Series ◽

Digital Recording ◽

Recording Device ◽

Low Exposure

The features of digital recording of a continuous series (movie) of singleelectron TV frames are reported. The technique is used to investigate structural changes in negatively stained glutamine synthetase molecules (GS) during electron irradiation and, as an ultimate goal, to look for the molecules' “undamaged” structure, say, after a 1 e/Å2 dose.The TV frame of fig. la shows an image of 5 glutamine synthetase molecules exposed to 1/150 e/Å2. Every single electron is recorded as a unit signal in a 256 ×256 field. The extremely low exposure of a single TV frame as dictated by the single-electron recording device including the electron microscope requires accumulation of 150 TV frames into one frame (fig. lb) thus achieving a reasonable compromise between the conflicting aspects of exposure time per frame of 3 sec. vs. object drift of less than 1 Å, and exposure per frame of 1 e/Å2 vs. rate of structural damage.

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Fine Structural Changes in the Adenohypophyses of Rats Following Destruction of the Pituitary Stalk

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079917 ◽

1977 ◽

Vol 35 ◽

pp. 496-497

Author(s):

K. Kovacs ◽

E. Horvath ◽

J. M. Bilbao ◽

F. A. Laszlo ◽

I. Domokos

Keyword(s):

Structural Changes ◽

Tissue Injury ◽

Anterior Lobe ◽

Uranyl Acetate ◽

Male Rats ◽

Pituitary Stalk ◽

Sequence Of Events ◽

Pituitary Glands ◽

Electrolytic Lesions ◽

Ultrathin Sections

Electrolytic lesions of the pituitary stalk in rats interrupt adenohypophysial blood flow and result in massive infarction of the anterior lobe. In order to obtain a deeper insight into the morphogenesis of tissue injury and to reveal the sequence of events, a fine structural investigation was undertaken on adenohypophyses of rats at various intervals following destruction of the pituitary stalk.The pituitary stalk was destroyed electrolytically, with a Horsley-Clarke apparatus on 27 male rats of the R-Amsterdam strain, weighing 180-200 g. Thirty minutes, 1,2,4,6 and 24 hours after surgery the animals were perfused with a glutaraldehyde-formalin solution. The skulls were then opened and the pituitary glands removed. The anterior lobes were fixed in glutaraldehyde-formalin solution, postfixed in osmium tetroxide and embedded in Durcupan. Ultrathin sections were stained with uranyl acetate and lead citrate and investigated with a Philips 300 electron microscope.

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