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PubMed2002

Mucosa-associated lymphoid tissue lymphomas with t(11;18)(q21;q21) and mucosa-associated lymphoid tissue lymphomas with aneuploidy develop along different pathogenetic pathways.

t(11;18)(q21;q21) and aneuploidy are recurrent chromosomal aberrations in mucosa-associated lymphoid tissue (MALT) lymphomas. To investigate their relationship and clinical significance, we developed a two-color fluorescence in situ hybridization (FISH) technique to detect t(11;18) and aneuploidy in nuclei isolated from paraffin-embedded tissue. Thirty-seven MALT lymphomas (all previously evaluated for t(11;18) by reverse transcriptase-polymerase chain reaction), 1 large cell lymphoma (LCL) arising subsequent to MALT lymphoma, and 16 controls were tested by FISH using the t(11;18) probe set and multiple centromeric probes. t(11;18)(q21;q21) was present by FISH in 11 of 12 polymerase chain reaction-positive MALT lymphomas (92%). The LCL and its clonally identical antecedent MALT lymphoma both showed t(11;18). The LCL had trisomy 12, and a small subset of MALT lymphoma cells had trisomy 3 and/or 12. Only one other MALT lymphoma with t(11;18) showed aneuploidy (trisomy 3) in a small clone, whereas 15 of 25 t(11;18)-negative MALT lymphomas (60%) showed trisomy of chromosomes 18 (n = 12), 3 (n = 8), 7 (n = 2), and/or 11 (n = 1). t(11;18) and aneuploidy are primarily mutually exclusive events, suggesting different pathogenetic pathways in the development of MALT lymphomas. Both t(11;18) and aneuploidy were seen disproportionately in lung, and both were associated with recurrent disease.

Adult↗
PubMed2006

Histopathology of mucosa-associated lymphoid tissue.

Mucosa-associated lymphoid tissue (MALT) is a generalized term incorporating a disseminated collection of lymphoid tissues in multiple sites throughout the body. MALT sites that have been/are primarily studied include bronchus-associated lymphoid tissue (BALT), gut-associated lymphoid tissue (GALT), and nasopharynx-associated lymphoid tissue (NALT). Since MALT sites are often under-sampled in conventional toxicity studies, MALT lesions have not been extensively documented in these lymphoid effector sites. Lesions of the nasopharyngeal lymphoid tissue and Peyer's patches include degeneration, inflammation, and both primary and metastatic neoplasia.

Animals↗
PubMed2001

Clinicopathological features of gastric mucosa-associated lymphoid tissue lymphoma: a comparison with diffuse large B-cell lymphoma without a mucosa-associated lymphoid tissue lymphoma component.

BACKGROUND AND AIMS: The aim of this study was to clinicopathologically distinguish the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma and diffuse large B-cell lymphoma without a MALT lymphoma component (DLL). METHODS: We investigated clinicopathological features of these gastric lymphomas including age, sex ratio, tumor location and depth, macroscopic appearance, and infection with Helicobacter pylori of these gastric lymphomas and hepatitis viruses in 24 patients with gastric low-grade MALT lymphoma, 10 patients with high-grade MALT lymphoma, and 19 patients with DLL. The frequency of H. pylori infection in lymphoma patients was compared with that in age- and sex-matched control subjects. RESULTS: There was a predominance of females with MALT lymphoma (male to female ratio, 8/16 for low-grade MALT lymphomas and 1/9 for high-grade MALT lymphomas), and there was a predominance of males with DLL (male to female ratio, 13/6); the ratios differed significantly (P < 0.05). Ninety-two percent of low-grade MALT lymphomas and 80% of high-grade MALT lymphomas were confined to the mucosal and submucosal layers, but lymphoma cells invaded the muscular layer or more deeply in 74% of DLL. Helicobacter pylori infection occurred significantly more often in patients with low-grade MALT lymphoma than in age- and sex-matched controls (96 vs 67%, P < 0.01). Conversely, the frequency of H. pylori infection in DLL patients did not differ from that in controls. CONCLUSIONS: These data suggest that H. pylori infection may be associated with the development of gastric MALT lymphoma, but not DLL, and that MALT lymphoma and DLL may have a different pathogenesis.

Adult↗
PubMed1985

Endometrial lymphoid tissue: an immunohistological study.

Lymphoid tissue of the endometrium was analysed by histological, immunohistological, and electron microscopical methods in 10 healthy uteri. A panel of monoclonal antibodies recognising macrophages (OKMI), HLA-DR antigen, B lymphocytes, T lymphocytes and their subsets, and dendritic reticulum cells was used in a two stage indirect immunoperoxidase labelling technique. Endometrial lymphoid tissue showed a remarkably consistent pattern of labelling in all cases. Lymphoid tissue was present in three sites: namely, (i) intraepithelial lymphocytes (predominantly T lymphocytes with occasional macrophages) associated with periglandular and sub-epithelial HLA-DR+, OKMI+ macrophages; (ii) interstitial lymphocytes and macrophages; (iii) lymphoid aggregates in the stratum basalis. These were composed mainly of T lymphocytes with a few B lymphocytes. Dendritic reticulum cells were found in those occasional lymphoid aggregates in which germinal centres were present. These features suggest that endometrial lymphoid tissue has many of the hallmarks of mucosal associated lymphoid tissue as found elsewhere in the body--for example, the bronchus and intestine. Endometrial lymphoid tissue appears to be unique, however, in that most of the stratum functionalis in which it is situated shows cyclical shedding during the menstrual cycle.

Adolescent↗
PubMed1989

[Effect of glucocorticoid on lung tissue and bronchus-associated lymphoid tissue of experimental granulomatous lung].

The effect of glucocorticoid on the immunological response in the delayed type hypersensitivity reaction of granulomatous disorders was investigated in order to elucidate the mechanism of glucocorticoid on the suppressive course of the reaction. Experimental pulmonary granuloma model in rats was induced by an intravenous injection of heat killed BCG, and the effects of methylprednisolone (MPSL) on the granulomatous lung tissue, bronchus associated lymphoid tissue (BALT) and the population of cells from bronchoalveolar lavage fluid (BALF) and peripheral blood were examined by the cytological and immunohistochemical methods. The pulmonary granulomatous reaction was reduced effectively by the administration of MPSL. A remarkable reduction of the number of Ia antigen positive alveolar macrophages (Ia+ A.M phi) and T lymphocytes in the granulomatous lung tissue and BALF was observed. T helper cells to non-helper cells (TH/TNH) ratio in BALF decreased remarkably. Furthermore, a reduction of Ia antigen positive macrophages (Ia+ M phi) and T cells was noted in the parafollicular area of BALT. These findings suggest that glucocorticoid may suppress the immunological activity of M phi and T cell through its inhibitory effect on the differentiation of Ia+ M phi and activated T cells, which result in the diminishment of pulmonary granulomatous reaction through the disorder of M phi - T cell interaction. On the other hand, lymphocytopenia with decreased TH/TNH ratios in peripheral blood was observed simultaneously with the reduction of the pulmonary granulomatous reaction. Thus, the mechanism of reduced pulmonary granulomatous reaction after MPSL administration may be not only due to local immunosuppression, but also to impaired systemic immune response. In addition, the disappearance of the germinal center and the reduction of surface IgM-positive cells in the follicular area of BALT occurred with the reduction of pulmonary granulomatous reaction. These results suggest that glucocorticoid also suppress the humoral immune responses in BALT during the course of delayed type hypersensitivity reaction.

Animals↗
PubMed1981

Localization of IgGFc and complement receptors in chicken lymphoid tissue.

Chicken lymphoid organs were examined for IgGFc and complement receptors (FcR/CR) by immune adherence on frozen tissue sections. Indicator systems were sheep erythrocytes (E) coated with chicken anti-E IgG (EAch), E coated with rabbit anti-E IgG (EArab) and normal chicken serum (EAC), and FITC-labelled zymosan particles coated with chicken serum (ZyC). In the spleen, FcR and CR activity was confined to B-dependent areas, i.e. the periellipsoidal sheaths and germinal centres and the red pulp. No FcR were found in the thymic or bursal lymphoid tissue, but CR activity was observed in the medulla of bursal follicles. Chicken and turkey IgG, chicken IgGFc, and bovine serum albumin (BSA)--chicken anti-BSA complexes inhibited binding of Each. No inhibition was obtained with chicken IgGF(ab')2, IgM or albumin, or with BSA--rabbit anti-BSA complexes and human or rabbit IgG. E did not adhere to the sections, nor did EArab, EArab incubated with heat-inactivated chicken serum, or EAC complexes prepared with EArab and guinea-pig complement. The data suggest that chicken B lymphocytes and macrophages have receptors for avian IgGFc and C which can be demonstrated in tissue sections.

Animals↗
PubMed2004

Suitability of stratagene reference RNA for analysis of lymphoid tissues.

We evaluated a lymphoid RNA standard prepared in our laboratory for spotted microarrays against the Universal Human Reference standard from Stratagene. Our goal was to determine if the Stratagene standard, which contains only two lymphoid cell lines out of a pool of 10 human cancer cell lines, had acceptable gene coverage to serve as a comprehensive standard for gene expression profiling of lymphoid tissues. Our lymphoid standard was prepared from thymus, spleen, tonsil, and cell lines representing immature B cells, plasma cells, and natural killer (NK) cells, thus covering the entire spectrum of lymphoid cells and most stromal elements present in specialized lymphoid tissues. The two standards were co-hybridized on oligonucleotide microarrays containing 17,260 genes, and both had fluorescence intensities above background for approximately 85% of the genes. Despite the limited representation of lymphoid cells in the Stratagene standard, only 4.2% genes exhibited expression differences greater than 2-fold including only 0.35% with differences greater than 4-fold. Although the lymphoid standard reflected a more comprehensive representation of immune system-associated genes, the Stratagene standard has the advantage of being commercially available, enabling easier comparison across laboratories and allowing comparative studies across a long period of time.

Carbocyanines↗
PubMed2003

An essential function for the nuclear receptor RORgamma(t) in the generation of fetal lymphoid tissue inducer cells.

Lymphoid tissue inducer (LTi) cells are associated with early development of lymph nodes and Peyer's patches. We show here that during fetal life the nuclear hormone receptor RORgamma(t) is expressed exclusively in and is required for the generation of LTi cells. RORgamma(t+) LTi cells provide essential factors, among which lymphotoxin-alpha1beta2 is necessary but not sufficient for activation of the mesenchyma in lymph node and Peyer's patch anlagen. This early LTi cell-mediated activation of lymph node and Peyer's patch mesenchyma forms the necessary platform for the subsequent development of mature lymphoid tissues.

Animals↗
PubMed1979

Comparison of the cytotoxic activities of different human lymphoid tissues.

Normal human lymphoid cells from peripheral blood, spleen, tonsils and thymus were examined for their ability to mediate three different cytotoxic effector cell functions: antibody-dependent cellular cytotoxicity (ADCC); lectin-induced cellular cytotoxicity (LICC) and natural killer activity (NK), against 51Cr labelled erythroid and tumor target cells. We found a hierarchy of cytotoxic activities in the different lymphoid tissues. Peripheral blood and spleen cells were able to mediate LICC, ADCC and NK activities. Tonsil cells showed a natural segregation of the different cytotoxic functions: NK and ADCC activity against tumor target cells were absent, whereas LICC activity was fully present. With respect to ADCC activity against erythroid targets, tonsil cells showed low, but significant, cytotoxicity. Thymus cells had no detectable ADCC, NK and LICC activities. Correlation in the different lymphoid tissues between cytotoxic activities and cell surface marker studies revealed: (a) that the presence of E-SRBC rosette forming cells was not always associated with the detection of LICC activity, as is the case with the thymus; (b) that, in the absence of detectable Eox-7S rosette forming cells (thymus and tonsils), NK and ADCC activities against tumor cells were always absent, but LICC was observed (tonsils), indicating that the presence of this Fc(7S) receptor bearing cells is strongly associated with the expression of NK and ADCC but not with LICC.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1987

Precocious development of lectin (Ulex europaeus agglutinin I) receptors in dome epithelium of gut-associated lymphoid tissues.

Dome epithelium (DE), the tissue covering lymphoid domes of gut-associated lymphoid tissues, was examined in both adult and neonatal rabbit appendix or sacculus rotundus to determine if dome epithelial cells matured earlier than epithelial cells covering adjacent villi. The localization of well-differentiated epithelial cells in rabbit gut-associated lymphoid tissues (GALT) was accomplished histochemically by use of molecular probes: fluorescein isothiocyanate or horseradish peroxidase conjugates of Ulex europaeus agglutinin I (UEA), a lectin specific for terminal L-fucose molecules on certain glycoconjugates. The villus epithelial cells of newborn and 2-, 5-, or 10-day-old rabbits did not bind UEA, but between the twelfth and fifteenth days of postnatal life, UEA receptors were expressed by well-differentiated villus epithelial cells. In contrast to villus epithelium, DE in appendix and sacculus rotundus of neonatal rabbits expressed UEA receptors two days after birth, a feature that distinguished the DE of neonatal GALT for the next two weeks. In adult rabbits, UEA receptors were associated with dome epithelial cells extending from the mouths of glandular crypts to the upper domes; in contrast to the domes, UEA receptors were only present on well-differentiated epithelial cells at the villus tips. Results suggested that in neonatal rabbits most dome epithelial cells developed UEA receptors shortly after birth, reflecting precocious development of DE as compared to villus epithelium. In adult rabbit dome epithelium UEA receptors appeared on dome epithelial cells as they left the glandular crypts, representing accelerated epithelial maturation.

Animals↗
PubMed2003

Organogenesis of lymphoid tissues.

The development of lymphoid organs depends on the correct expression of several molecules within a defined timeframe during ontogeny. Although this is an extremely complex process, with each secondary lymphoid tissue requiring subtly different signals, a common framework for lymphoid development is beginning to emerge. Drawing on studies of lymph nodes, Peyer's patches and nasal-associated lymphoid tissue, an integrative model of lymphoid-tissue development, involving adhesion molecules, cytokines and chemokines, which emphasizes the role of interactions between CD3-CD4+CD45+ 'inducer' cells and VCAM1+ICAM1+ stromal 'organizer' cells is presented.

Animals↗
PubMedDate not supplied

The role of lymphotoxin in development and maintenance of secondary lymphoid tissues.

Secondary lymphoid organs provide the necessary microenvironment for the cooperation of antigen-specific T- and B-lymphocytes and antigen-presenting cells in order to initiate an efficient immune response. Remarkable progress in understanding of the mechanisms of lymphoid organogenesis was achieved due to the analysis of various gene-targeted mice. This review primarily focuses on the role of lymphotoxin (LT) in development, maturation and maintenance of secondary lymphoid organs.

Animals↗