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At least 109 records · Page 6Linked to original sources
PubMed1989

Sera-reactivity in inflammatory bowel disease: frequency of recognition of Crohn's disease tissue primed nude mouse lymphoid tissue in an interinstitutional blinded study.

We used a double-blinded interinstitutional study with an indirect immunofluorescence assay to evaluate the immunoreactivity of Crohn's disease (CD) sera against hyperplastic and malignant lymph nodes from nude mice primed with CD tissue filtrates. We assessed the reactivity for potential usefulness as a serodiagnostic test by using sera from different clinical subgroups of patients with inflammatory bowel disease. The immunoreactivity of 86 coded sera from ambulatory patients treated at the Mount Sinai Medical Center were examined-29 from patients with CD, 25 from patients with ulcerative colitis (UC), 21 from disease controls, and 11 from normal controls. Each serum was tested at the Albert Einstein College of Medicine against lymph nodes from at least two of six nude mice inoculated with CD tissue filtrates or CD filtrate-induced lymphoma. There was positive immunofluorescent staining in 11 of 29 (38%) CD patients, 4 of 25 (16%) UC patients, 1 of 21 (4.8%) disease controls, and 0 of 11 normal volunteers. Statistically significant differences in immunoreactivity were seen between CD patients compared to non-inflammatory-bowel-disease controls (p = 0.007) and to normals (p = 0.02).

Animals↗
PubMed2006

Detection of PrP(CWD) in postmortem rectal lymphoid tissues in Rocky Mountain elk (Cervus elaphus nelsoni) infected with chronic wasting disease.

Preclinical diagnostic tests for transmissible spongiform encephalopathies have been described for mule deer (Odocoileus hemionus), using biopsy tissues of palatine tonsil, and for sheep, using lymphoid tissues from palatine tonsil, third eyelid, and rectal mucosa. The utility of examining the rectal mucosal lymphoid tissues to detect chronic wasting disease (CWD) was investigated in Rocky Mountain elk (Cervus elaphus nelsoni), a species for which there is not a live-animal diagnostic test. Postmortem rectal mucosal sections were examined from 308 elk from two privately owned herds that were depopulated. The results of the postmortem rectal mucosal sections were compared to immunohistochemical staining of the brainstem, retropharyngeal lymph nodes, and palatine tonsil. Seven elk were found positive using the brainstem (dorsal motor nucleus of the vagus nerve), retropharyngeal lymph nodes, and palatine tonsil. Six of these elk were also found positive using postmortem rectal mucosal sections. The remaining 301 elk in which CWD-associated abnormal isoform of the prion protein (PrP(CWD)) was not detected in the brainstem and cranial lymphoid tissues were also found to be free of PrP(CWD) when postmortem rectal mucosal sections were examined. The use of rectal mucosal lymphoid tissues may be suitable for a live-animal diagnostic test as part of an integrated management strategy to limit CWD in elk.

Animals↗
PubMed2003

Th1-biased tertiary lymphoid tissue supported by CXC chemokine ligand 13-producing stromal network in chronic lesions of autoimmune gastritis.

Secondary lymphoid tissue is developmentally programmed and characterized by well-ordered compartmentalization of lymphocyte subsets and specialized stromal cells supporting the tissue architecture. By contrast, tertiary lymphoid tissue is defined as that induced in ectopic sites by inflammation, although its immunological role is largely unknown. In this study, we characterize the lymphoid tissue induced in the chronic lesion of murine autoimmune gastritis (AIG). Within the lymphoid cluster in the gastric mucosa, there is a clear segregation of T and B cells. Follicle-like B cell areas are always located on the luminal side of the mucosa, while T cells are located in the basal part. A typical lymphoid reticular network and follicular dendritic cells support the structure. Importantly, complement receptor 1(+) follicular dendritic cells within the follicle express a B cell homing chemokine, CXC chemokine ligand 13. The number and size of the clusters correlate with the age of the mice and the serum autoantibody titer, suggesting the functional importance of the clusters in local Ab production, although involvement of the autoantibody in the disease progression is still unclear. AIG gastric lesions are known to constitute a Th1-biased, memory T cell-dependent immunomicroenvironment. The expression pattern of cytokines, including lymphotoxin-beta, and chemokines in the AIG stomach is consistent with this observation. Taken together, these facts suggest that, during the chronic phase of autoimmunity, long-lasting lymphocyte infiltration probably induces a unique tertiary lymphoid tissue that has a function distinct from that of regional lymph nodes. These neolymphoid tissues may maintain the local self reactivity supporting the vicious cycle of Th1-type reaction as well as autoantibody production.

Animals↗
PubMed2004

Cellular composition of pancreas-associated lymphoid tissue during human fetal pancreatic development.

AIM: To study human fetal pancreatic tissue between 15 weeks of gestation and term, analysing the development of pancreatic lymphoid tissue and focusing on the presence and maturational status of dendritic cells (DCs). During normal human fetal pancreatic development lymphoid tissue arises in and around the pancreas. DCs are antigen-presenting cells which are capable of initiating immunity, but are also essential in inducing and maintaining T-cell tolerance. METHODS AND RESULTS: First, the presence and general composition of intra- and peripancreatic lymphoid tissue was investigated by histology and immunohistochemistry with antibodies to CD3, CD4, CD8, CD14, CD20, CD68, and CD79. Intrapancreatic lymphoid tissue (IPLT) appeared to be present only from 29 weeks of gestation onwards, and had a similar composition to peripancreatic lymphoid tissue (PPLT), which was found in all 23 specimens examined. Both forms of lymphoid tissue had an architecture similar to lymph nodes, with separate B- and T-lymphocyte areas and scattered macrophages. DCs were investigated in detail by immunohistochemistry for CD1a, CD83, CD86, CD123, Langerin, and DC-LAMP. Both Langerin, a marker for immature DCs, as well as DC-LAMP, a marker for mature DCs, were expressed by cells in both the IPLT and PPLT at all ages examined. CONCLUSION: The presence of DCs at all developmental stages, expressing various maturation-related markers, in addition to the general composition of the human fetal PPLT and IPLT suggests that this is fully functional and has a function comparable to peripheral lymph nodes.

Antigens, CD↗
PubMedDate not supplied

Are follicular dendritic cells, macrophages and interdigitating cells of the lymphoid tissue productively infected by HIV?

Numerous data demonstrate that lymphoid tissues represent a major HIV reservoir and sites of virus replication. To gain more information about the phenotype of cells in which HIV replicates in the lymphoid tissue, we applied HIV RNA hybridization technique in combination with immunohistochemistry on 10 lymph nodes and 2 lymphoepithelial cysts (LEC) of the parotid gland. In addition, to determine whether or not follicular dendritic cells (FDC) are important targets for HIV, we also analysed isolated and sorted FDC from 4 lymph nodes. The tissues showed follicular hyperplasia and heavy RNA signals in the germinal centres (GC), where diffuse labelling in the light zone as well as single cells with > 50 silver grains were present. The extrafollicular parenchyma contained only a few productively infected cells. The diffuse labelling was intimately related to the FDC network. However, electron microscopic examination and in situ hybridization on isolated FDC did not provide convincing evidence for virus replication in these cells. Virus-producing cells in the GC were almost exclusively CD45RO+, CD57- T cells. Macrophages with HIV RNA were mainly found in LEC of the parotid gland. S-100+ interdigitating cells of the T-dependent zone were HIV RNA-. However, some large S-100+ cells in the squamous epithelium covering the LEC or lying subepithelial did express HIV RNA. These findings suggest that local factors (cytokines?) in the lymphoid tissue probably influence the expression of HIV.

Dendritic Cells↗
PubMed1999

Primary hepatic B-cell lymphoma of mucosa-associated lymphoid tissue.

Mucosa-associated lymphoid tissue (MALT) lymphomas are low-grade B-cell lymphomas that occur in a variety of extranodal sites but rarely as a primary hepatic lymphoma. We describe the histological findings, immunophenotype, and immunohistochemistry of one such lymphoma found incidentally in a 69-year-old woman. The lymphoid infiltrate invaded the liver in a serpiginous configuration with entrapment of nodules of normal liver. Reactive follicles were surrounded by intermediate-sized lymphoid cells with slightly irregular nuclei and pale cytoplasm. Only a few scattered lymphoepithelial lesions were identified since most of the bile ducts were destroyed. The immunophenotype determined by flow cytometry identified the lymphoid cells as being CD19, CD20 positive and exhibiting lambda light chain restriction. CD5, CD10, and CD23 were negative. Immunohistochemistry showed the neoplastic cells to be positive for CD20 (L-26) and bcl-2. The reactive follicles were negative for bcl-2. CD3 showed only a few scattered T cells. Cyclin D1 did not stain the neoplastic cells. Cytokeratin (AE1/AE3) highlighted the lymphoepithelial lesions and residual bile ducts. MALT lymphomas need to be recognized and distinguished from other B-cell lymphomas, particularly mantle cell lymphomas, because of the difference in behavior and treatment.

Aged↗
PubMed1975

Subpopulations of thymus dependent and thymus independent lymphocytes in human gut associated lymphoid tissues.

Human gut associated lymphoid tissues were studied in terms of the presence of subpopulations of thymus dependent and thymus independent lymphocytes. Both thymus dependent and thymus independent lymphocytes were present in substantial numbers, as judged from their ability to form spontaneous and complement mediated rosettes with sheep red blood cells and the presence of surface bound immunoglobulins. The relationship between this finding and the question of what is the lymphoid organ which may be the human equivalent of the avian bursa is discussed.

Animals↗
PubMed2002

Morphological evidence of M cells in healthy canine conjunctiva-associated lymphoid tissue.

PURPOSE: To characterize the follicle-associated epithelium (FAE) and organized lymphoid nodules from dog nictitating membranes to determine if canine conjunctiva-associated lymphoid tissue (CALT) contains M cells analogous to those described in other regions of mucosa-associated lymphoid tissue (MALT). METHODS: Nictitan lymphoid follicles from 15 healthy dogs (30 eyes) were harvested immediately post-mortem. Twelve follicles from each nictitating membrane were isolated. Four follicles from each eye of 10 dogs were examined by light microscopy, transmission electron microscopy and scanning electron microscopy. Five of the 10 dogs were treated with a heat-killed staphylococcal topical suspension immediately prior to euthanasia. Nictitan follicles from five other dogs were processed for immunohistochemistry to characterize follicle lymphocyte populations. RESULTS: The FAE overlying CALT demonstrated morphology characteristic of M cells, including attenuated apical cell surface with blunted microvilli and microfolds, invaginated basolateral membrane forming a cytoplasmic pocket containing lymphocytes and macrophages, and diminished distance between the apical and pocket membrane. Heat-killed bacteria were bound to the surface and transcytosed to the cytoplasmic pocket of CALT M cells. Immunohistochemistry of organized lymphoid tissue subtending the FAE demonstrated B-cell germinal centers with T-cell predominant apical caps. CONCLUSIONS: In canine CALT, the FAE overlying lymphoid follicles, as well as the distribution of T and B lymphocytes subtending this region, contain morphologic and functional features analogous to MALT described in other regions. Documentation of canine conjunctival M cells is of clinical relevance in the study of primary ocular diseases, as well as a potential means of vaccination or drug delivery.

Animals↗
PubMed2002

High-grade B-cell lymphoma arising in mucosa-associated lymphoid tissue of the duodenum.

Duodenal mucosa-associated lymphoid tissue lymphoma is a rare neoplasm. We report a case of a 70-year-old man with non-Hodgkin's lymphoma located in the descending duodenum that was not associated with Helicobacter pylori infection of the stomach. A surgical resection due to obstruction of the bowel lumen above the ligament of Treitz was performed. No invasion into the adjacent structure was confirmed at surgery. The pathological examination showed an infiltration of the duodenal mucosa and submucosa with B lymphocytes. Monoclonal proliferation of the lymphoid tissue was demonstrated by polymerase chain reaction. The histological appearance and the demonstration of monoclonality fulfilled the criteria for malignant high-grade B-cell lymphoma arising from mucosa-associated lymphoid tissue.

Aged↗
PubMed1982

Evaluation of a tissue transport medium for immunological characterization of benign and malignant lymphoid tissues.

A tissue transport medium was evaluated for its usefulness in immunologic characterization of lymphocytes in tissue sections. A variety of lymphoid tissues were studied, including normal tissue, hyperplastic tissue and malignant lymphoma. Approximately equal parts of biopsy samples were taken and one part was immediately snap-frozen while the other was held in transport medium for up to one week before processing for frozen section. Sections were stained with fluorescein-conjugated anti-immunoglobulin antisera and with a variety of murine monoclonal antibodies to T-cell antigens or Ia antigen followed by staining with fluorescein-conjugated goat-antimouse gamma globulin. In all cases studied, there was complete agreement in the staining patterns of tissues which were either immediately snap-frozen or held in transport medium.

Antibodies, Monoclonal↗
PubMed2006

Lymphoid tissue inducer cells in intestinal immunity.

During fetal development, lymphoid tissue inducer cells (LTis) seed the developing lymph node and Peyer's patch anlagen and initiate the formation of both types of lymphoid organs. In the adult, a similar population of cells, termed lymphoid tissue inducer-like cells (LTi-like cells), supports the formation of organized gut-associated lymphoid tissue (GALT) in the intestine, including both isolated lymphoid follicles (ILFs) and cryptopatches (CPs). Both LTi and LTi-like cells require expression of the transcription factor RORgammat for their differentiation and function, and mice lacking RORgammat lack lymph nodes, Peyer's patches, and other organized GALT. In ILFs and cryptopatches, LTi-like cells are in close contact with different populations of intestinal dendritic cells (DCs), including a subpopulation recently shown to extend dendrites and sample luminal microflora. This interaction may allow for communication between the intestinal lumen and the immune cells in the lamina propria, which is necessary for maintaining homeostasis between the commensal microflora and the intestinal immune system. The potential functional implications of the organization of LTi-like cells, DCs, and lymphocytes in the lamina propria are discussed in the context of maintenance of homeostasis and of infectious diseases, particularly HIV infection.

Animals↗
PubMed1993

Bronchus-associated lymphoid tissue (BALT) in human fetal and infant lung.

Bronchus-associated lymphoid tissue (BALT) has been defined as the organized lymphoid tissue of the lung. Although well described in a variety of animal species, documentation of its presence and development in human lung is limited. Because the tissue to volume ratio in adult lungs is so low, a systematic search for BALT would involve so many sections as to be impractical. In this study, therefore, we have studied post-mortem specimens of fetal (n = 102) and infant (n = 17) lungs, which have a much higher tissue to volume ratio. Fetal death was due to various causes but all but two infants died from sudden infant death syndrome. In the fetal lungs, the presence of BALT was almost invariably associated with chorioamnionitis or intrauterine pneumonia, being present in 24 of 51 of these cases (47 per cent). The earliest ill-defined lymphoid aggregate was seen at 16 weeks' gestation, while lymphoepithelium, a hallmark of mucosa-associated lymphoid tissue, could be identified at 20 weeks. In 51 fetuses without infection, BALT was found in only five cases (10 per cent). BALT was identified in 13/17 (77 per cent) of infant lungs and well-developed lymphoepithelium was evident in four cases. This study shows that BALT may be present in the human fetal and infant lung, but that its appearance is probably dependent on antigenic stimulation.

Bronchi↗
PubMed1999

[MALT lymphoma of the lacrimal apparatus (mucosa-associated lymphoid tissue)].

Mucosa-associated lymphoid tissue lymphoma can occur in various localizations. We describe the case of a patient presenting bilateral MALT lymphoma involving a lacrimal gland and a lacrimal duct. Biopsy specimens are required for histologic diagnosis. Such low-grade lymphomas are generally treated medically with radiotherapy or chemotherapy. Prognosis is generally favorable. A complete work-up is required to determine extension. These patients should be followed regularly.

Biopsy↗
PubMedDate not supplied

Intestinal lymphoid tissue changes in the cortisone-treated Wistar rat.

This paper continues the previous investigation of the Department on the lymphoid tissue of central and peripheral lymphoid organs under different experimental conditions. The morphological reactional modalities of the intestinal lymphoid tissue in the male Wistar rat were followed up under endocrine imbalance conditions following cortisone administration. Seven days after administration cortisone induced a hyperplasia of the intestinal lymphoid tissue in parallel with a depletion of the lymph node parenchyma and a hypercellularity of bone marrow. After a 6-week postcortisone interval, the lymphoid tissue showed changes corresponding to a cellular depletion in parallel with the restoration of the lymph node parenchyma and a normocellular bone marrow.

Animals↗
PubMed1992

Immunohistological characterization of proximal colonic lymphoid tissue in the rat.

Proximal colonic lymphoid tissue (PCLT) is a lymphoid structure located in the proximal colon of the mouse and the rat. In the present investigation we studied the immunomorphology and cytology of PCLT in the rat. We also studied sites of lymphocyte proliferation using the BrdU-anti BrdU technique. Results demonstrated no evident phenotypical differences between the lymphocyte populations of PCLT and either jejunal or ileal Peyer's patches (PP). The majority of the lymphocytes within PCLT were B cells localized in follicles, which were separated from each other by interfollicular T cell areas. Germinal centers (GC), containing ED5+ follicular dendritic cells, are found within PCLT follicles. The T cell areas contained both MHC Class II+ interdigitating cells and high endothelial venules. Studies using BrdU-anti BrdU indicated that lymphocyte proliferation within PCLT takes place mainly in germinal centers. Together the data show that the organization, lymphoid constituents, and sites of lymphocyte production are very similar in PCLT and PP. We therefore conclude that PCLT in the rat is not a Bursa equivalent, but more likely a PP with some special characteristics.

Animals↗
PubMed2006

Expression of 5-lipoxygenase in specialized epithelial cells of nasopharyngeal-associated lymphoid tissue.

Leukotrienes are lipid mediators that are produced primarily by certain types of leukocytes. The synthesis of the leukotriene LTB(4) is initiated by the enzyme 5-lipoxygenase and completed by LTA(4) hydrolase. Epithelial cells constitutively express LTA(4) hydrolase but normally lack 5-lipoxygenase. In this study, we report that the stratified squamous epithelial cells from inflamed or hyperplastic tissues of palatine and pharyngeal tonsils (nasopharyngeal-associated lymphoid tissue) express 5-lipoxygenase protein. The localization of 5-lipoxygenase was indicated by immunohistochemical staining and presence confirmed by immunoblot. Positive staining for 5-lipoxygenase in infiltrating leukocytes in inflamed tissues served as internal positive controls for immunohistochemical staining. Staining for 5-lipoxygenase in appendix tissue was negative for epithelial cells while positive for polymorphonuclear leukocytes, indicating that 5-lipoxygenase expression is not a general feature of epithelial cells in mucosa-associated lymphoid tissue. In tonsils, 5-lipoxygenase staining was pronounced in broad regions but reduced or absent in others, suggesting regional regulation of expression. Epithelial cells of tonsils were also positive for 5-lipoxygenase activating protein and leukotriene A(4) hydrolase, indicating a capacity to produce LTB(4). Taken together, these results suggest that the specialized epithelial cells of the mucosa-associated lymphoid tissue of human tonsils can synthesize LTB(4). This lipid mediator may serve to modulate the function of cells within the lymphoid tissue as well as promote an inflammatory response.

Appendix↗
PubMed1997

Comparison of the immunohistology of mucosa-associated lymphoid tissue in the larynx and lungs in cases of sudden infant death and controls.

The respiratory tract of children in the first two years of life, unlike that of adults, contains bronchus-associated lymphoid tissue (BALT) and larynx-associated lymphoid tissue (LALT) with no differences in frequency between SID and control children. Using immunohistochemical methods we examined the distribution of B, T, CD4+ and CD8+ lymphocytes, HLA-D+ cells, CD68+ macrophages and proliferating cells, comparing bronchus-associated and larynx-associated lymphoid tissue of sudden infant death cases and controls. In all groups the lymphoid tissue was organized in lymphoid follicles and parafollicular areas. With no differences in the cellular composition of BALT and LALT the lymphoid follicles contained mainly B lymphocytes with some CD4+ lymphocytes in the germinal centers. Remarkably T lymphocytes of both subset types and B lymphocytes were observed in equal numbers in the parafollicular areas in contrast to gut-associated lymphoid tissue. However, the respiratory tract of young children with no differences between SID and controls might play a similar role in mucosal immunity and might function as an inductive site.

Bronchi↗
PubMed2002

The relationship between simian immunodeficiency virus RNA levels and the mRNA levels of alpha/beta interferons (IFN-alpha/beta) and IFN-alpha/beta-inducible Mx in lymphoid tissues of rhesus macaques during acute and chronic infection.

To define the role of alpha/beta interferons (IFN-alpha/beta) in simian immunodeficiency virus (SIV) infection, IFN-alpha and IFN-beta mRNA levels and mRNA levels of Mx, an antiviral effector molecule, were determined in lymphoid tissues of rhesus macaques infected with pathogenic SIV. IFN-alpha/beta responses were induced during the acute phase and persisted in various lymphoid tissues throughout the chronic phase of infection. IFN-alpha/beta responses were most consistent in tissues with high viral RNA levels; thus, IFN-alpha/beta responses were not generally associated with effective control of SIV replication. IFN-alpha/beta responses were differentially regulated in different lymphoid tissues and at different stages of infection. The most consistent IFN-alpha/beta responses in acute and chronic SIV infection were observed in peripheral lymph nodes. In the spleen, only a transient increase in IFN-alpha/beta mRNA levels during acute SIV infection was observed. Further, IFN-alpha and IFN-beta mRNA levels showed a tissue-specific expression pattern during the chronic, but not the acute, phase of infection. In the acute phase of infection, SIV RNA levels in lymphoid tissues of rhesus macaques correlated with mRNA levels of both IFN-alpha and IFN-beta, whereas during chronic SIV infection only increased IFN-alpha mRNA levels correlated with the level of virus replication in the same tissues. In lymphoid tissues of all SIV-infected monkeys, higher viral RNA levels were associated with increased Mx mRNA levels. We found no evidence that monkeys with increased Mx mRNA levels in lymphoid tissues had enhanced control of virus replication. In fact, Mx mRNA levels were associated with high viral RNA levels in lymphoid tissues of chronically infected animals.

Animals↗