Localization and identification of granzymes A and B-expressing cells in normal human lymphoid tissue and peripheral blood.

Cytoplasmic granules from activated natural killer (NK) and cytotoxic T lymphocytes (CTL) contain a pore-forming protein, perforin, and several homologous serine proteinases called granzymes. Expression of these proteins correlates with the cytolytic potential of cytotoxic lymphocytes. Using a panel of MoAbs specific for human granzyme A and B, respectively, expression of these proteinases in non-pathological lymphoid tissue and peripheral blood lymphocyte (PBL) subpopulations was investigated. Using immunohistochemistry and double stainings, the phenotype of granzyme-expressing cells in lymphoid tissue was investigated. Granzyme-positive cells were detected in all lymphoid tissues tested. No large differences in the number and distribution between granzyme A- and granzyme B-positive cells were observed. The highest number of positive cells was located in the red pulp of the spleen. Significant numbers were detected in tonsil, lymph nodes, liver and thymus. Low numbers were present in the lamina propria of non-inflamed stomach, small intestine and colon. Phenotypic analysis and cell sorting showed that most of the granzyme-positive cells in lymphoid tissue and PBL consisted of CD3-CD16+CD56+ lymphocytes. Hardly any granzyme-positive CD3+CD8+ CTL were present in peripheral blood. The synthesis of granzyme A as well as B by both CD3+CD16+CD56+ and CD3+CD8+ cells in peripheral blood was increased upon IL-2 stimulation. These results indicate that in normal lymphoid tissue the predominant cytolytic cell population is formed by the NK cells, and activated CTL are rare.     

Transcriptional response of immune genes in gills and the interbranchial lymphoid tissue of Atlantic salmon challenged with infectious salmon anaemia virus

Previously, it has been assumed that fish lack organized mucosa-associated lymphoid structures. Recently, an interbranchial lymphoid tissue (ILT) was described in salmonid gills at a site with substantial exposure to antigen.     

Immunohistochemistry of the lymphoid tissues of the tammar wallaby,Macropus eugenii

The lymphoid tissues of the metatherian mammal, the adult tammar wallaby, Macropus eugenii, were investigated using immunohistochemical techniques. Five cross-reactive antibodies previously shown to recognize surface markers in marsupial tissues and five previously untested antibodies were used. The distribution of T-cells in the tissue beds of spleen, lymph node, thymus, gut-associated lymphoid tissue (GALT) and bronchus-associated lymphoid tissue (BALT) was documented using antibodies to CD3 and CD5. Similarly, B-cells were identified in the same tissues using anti-CD79b. Antibodies to CD8, CD31, CD79a and CD68 failed to recognize cells in these tissue beds. In general the pattern of cellular distribution identified using these antibodies was similar to that observed in other marsupial and eutherian lymphoid tissues. This study provides further information on the commonality of lymphoid tissue structure in the two major groups of extant mammals, metatherians and eutherians.     

Roles of embryonic and adult lymphoid tissue inducer cells in primary and secondary lymphoid tissues

The nomenclature "embryonic lymphoid tissue inducer (LTi) cell" reflects the fundamental role of the cell in secondary lymphoid tissue organization. In addition, it is equally important in primary lymphoid tissue development as it regulates central tolerance to self-antigens in the thymus. An adult LTi cell constitutively expresses two sets of tumor necrosis factor (TNF) family members, whereas its embryonic counterpart expresses only one. The first set is lymphotoxin (LT)alpha, LTbeta, and TNalpha, which are essential for the secondary lymphoid organogenesis during embryogenesis and for maintaining an organized secondary lymphoid structure during adulthood. The second set is OX40- and CD30-ligands, which are critical for memory T cell generation. Adult LTi cells regulate adaptive immune responses by providing LTbetaR signals to stromal cells to maintain secondary lymphoid tissue structure, and determine adaptive immune responses by providing OX40 and CD30 survival signals to activated T cells in memory T cell generation. Along with the consideration of the roles of embryonic LTi cells in primary and secondary lymphoid tissues, this review highlights the roles of adult LTi cells in secondary lymphoid tissue function.     

A Histological and Immunohistochemical Analysis of Lymphoid Tissues of the Tasmanian Devil

Tasmanian devil lymphoid tissues (thymus, spleen, and lymph node) from seven animals, including pouch young, juvenile, and adult devils, were investigated using histological and immunohistochemical techniques. Antibodies against the conserved intracytoplasmic portion of CD3 and CD79b (T‐ and B‐cell markers, respectively) and MHC II were used to label immune cells. The thymus from the juvenile devils and the pouch young had CD3+ cells that were primarily located in the medulla of the organ. The spleen consisted of red and white pulp areas with characteristic lymphoid follicles with CD79b+ and MHC II+ cells and nonfollicular T‐cell‐dominated periarteriolar lymphoid sheaths. Peripheral lymph nodes presented three distinct regions, outer cortex and medulla (both with primarily CD79b+ and MHC II+ cells) and paracortex (mainly CD3+ cells). Tissue architecture and distribution of the immune cells were similar to that seen in eutherian mammals and other marsupials, indicating that the Tasmanian devil has all the structural elements necessary for effective adaptive immunity. Anat Rec, 292:611–620, 2009. © 2009 Wiley‐Liss, Inc.     

Morphological and Functional Peculiarities of Lymphoid Cells in Mice of Different Strains

We revealed differences in quantitative composition and functional activity of lymphoid cells in intact mice of different strains. Cellularity and counts of lymphoid elements in hemopoietic and lymphoid organs, proliferative activity of T and B lymphocytes, and counts of CD4+ and CD8+ lymphocytes in the spleen were minimum in CC57W and Balb/c mice and maximum in CBA/CaLac and DBA/2 mice. The highest absolute content of lymphoid elements in the spleen was detected in Balb/c mice, while CC57W mice had the highest content of these elements in the thymus.     

The appearance and distribution of mature T and B cells in the developing immune tissues of the stripe-faced dunnart (Sminthopsis macroura)

This paper describes the initial appearance and distribution of mature T and B cells in the developing immune tissues of the stripe-faced dunnart (Sminthopsis macroura) based on the use of species cross-reactive antibodies to the lymphocyte cell surface markers CD3, CD5 and CD79b. At birth no mature T or B cells were detected in the liver or bone marrow using anti-CD3, anti-CD5 or anti-CD79b antibodies. T cells were detected in the thymus with anti-CD3 by day 12 and anti-CD5 by day 50 postpartum, and T cells in the spleen were detected by day 43 and day 80 postpartum using anti-CD3 and anti-CD5, respectively. B cells were observed in the dunnart spleen by 43 days after birth. CD3- and CD79b-positive cells were detected in the lymph nodes by 50 days and CD5 by day 15 after birth, and in the gut-associated lymphoid tissues by day 50 and anti-CD5 by day 57 postpartum. The development and distribution of T and B cells in the immune tissues of dunnart pouch young is similar to that described in other marsupial species. Low numbers or absence of mature lymphocytes in immune tissues of early pouch young dunnarts further support the proposition that young marsupials are reliant on non-specific defence strategies and/or maternal strategies for a significant period of their time of development in the pouch.     

Histology and immunohistochemistry of the gut-associated lymphoid tissue of the eastern grey kangaroo, Macropus giganteus

Mesenteric lymph nodes and gut-associated lymphoid tissue (GALT) from juvenile eastern grey kangaroos were investigated. The mesenteric nodes had a similar structure to that described for eutherian mammals. They contained distinct regions of medulla and cortex, with prominent follicles and germinal centres. Gut associated lymphoid tissue consisted of areas of submucosal follicles. These varied from areas of densely packed lymphocytes with darkly staining, prominent coronas to areas with no defined follicles. The distribution of T cells in these tissues was documented by use of species-crossreactive antibodies to the surface markers CD3 and CD5; B cells were identified by antibodies to CD79b. Within the lymph nodes T cells were located mainly in the paracortex and cortex, with limited numbers observed in the follicles; B cells were located on the marginal zone of the follicles. In GALT, T cells were located in the peripheral regions of the germinal centres of secondary follicles, while B cells were abundant in primary follicles. These observations are consistent with those made in a range of other marsupials (metatherian) and eutherian mammals and are indicative of the capacity to respond to antigens entering via the mouth.     

Histological and immunohistological investigation of lymphoid tissue in the platypus (Ornithorhynchus anatinus)

The gross and histological appearance and the distribution of T and B lymphocytes and plasma cells are described for lymphoid tissues obtained from 15 platypuses. The spleen was bilobed and surrounded by a thick capsule of collagen, elastic fibres and little smooth muscle. White pulp was prominent and included germinal centres and periarterial lymphoid sheaths. Red pulp contained haematopoietic tissue. A thin lobulated thymus was located within the mediastinum overlying the heart. The cortex of lobules consisted of dense aggregates of small and medium lymphocytes, scattered macrophages and few reticular epithelial cells. In the medulla, Hassall's corpuscles were numerous, lymphocytes were small and less abundant, and reticular cells were more abundant than in the cortex. Lymphoid nodules scattered throughout loose connective tissue in cervical, pharyngeal, thoracic, mesenteric and pelvic sites measured 790±370 μm (mean±S.D. , n = 39) in diameter, the larger of which could be observed macroscopically. These consisted of single primary or secondary follicles supported by a framework of reticular fibres. Macrophages were common in the germinal centres. The platypus had a full range of gut-associated lymphoid tissue. No tonsils were observed macroscopically but histologically they consisted of submucosal follicles and intraepithelial lymphocytes. Peyer's patches were not observed macroscopically but histologically they consisted of several prominent submucosal secondary follicles in the antimesenteric wall of the intestine. Caecal lymphoid tissue consisted of numerous secondary follicles in the submucosa and densely packed lymphocytes in the lamina propria. Bronchus-associated lymphoid tissue was not observed macroscopically but was identified in 7 of 11 platypus lungs assessed histologically. Lymphoid cells were present as primary follicles associated with bronchi, as aggregates adjacent to blood vessels and as intraepithelial lymphocytes. The distribution of T lymphocytes, identified with antihuman CD3 and CD5, and B lymphocytes and plasma cells, identified with antihuman CD79a and CD79b and antiplatypus immunoglobulin, within lymphoid tissues in the platypus was similar to that described in therian mammals except for an apparent relative paucity of B lymphocytes. This study establishes that the platypus has a well-developed lymphoid system which is comparable in histological structure to that in therian mammals. It also confirms the distinctiveness of its peripheral lymphoid tissue, namely lymphoid nodules. Platypus lymphoid tissue has all the essential cell types, namely T and B lymphocytes and plasma cells, to mount an effective immune response against foreign antigens.     

突触体素、S一100蛋白和神经特异性烯醇化酶免疫反应神经纤维在人免疫器官的分布

目的探讨人免疫器官突触体素、S-100蛋白和神经特异性烯醇化酶(NSE)免疫反应神经纤维的支配和免疫反应细胞的分布,为神经内分泌和免疫系统相互作用提供形态学资料.方法应用免疫组织化学ABC法观察正常免疫器官包括胸腺、脾脏、淋巴结各30例.10%福尔马林固定,石蜡包埋.结果胸腺,突触体素、S-100蛋白和NSE免疫反应神经纤维从胸腺被膜随小叶间隔和血管到胸腺皮质,再延伸到髓质形成神经纤维网,在胸腺组织散在分布突触体素、S-100蛋白和NSE免疫反应细胞.淋巴结,免疫反应神经纤维沿被膜和门部结缔组织小梁及血管进入皮质后主要分布于副皮质区环绕淋巴滤泡,进一步分支到达髓质.在髓质髓窦内有NSE免疫反应细胞.脾脏,免疫反应神经纤维沿着血管的各级分支进入脾实质,主要沿着脾动脉的分支而分布在白髓、红髓和边缘区,穿插于淋巴细胞之间.结论在人免疫器官可能存在神经内分泌免疫系统相互作用和调控.     

Myeloid‐Lymphoid Ontogeny in the Rhesus Monkey (Macaca mulatta)

Establishment of a functional immune system has important implications for health and disease, yet questions remain regarding the mechanism, location, and timing of development of myeloid and lymphoid cell compartments. The goal of this study was to characterize the ontogeny of the myeloid‐lymphoid system in rhesus monkeys to enhance current knowledge of the developmental sequence of B‐cell (CD20, CD79), T‐cell (CD3, CD4, CD8, FoxP3), dendritic cell (CD205), and macrophage (CD68) lineages in the fetus and infant. Immunohistochemical assessments addressed the temporal and spatial expression of select phenotypic markers in the developing liver, thymus, spleen, lymph nodes, gut‐associated lymphoid tissue (GALT), and bone marrow with antibodies known to cross‐react with rhesus cells. CD3 was the earliest lymphoid marker identified in the first trimester thymus and, to a lesser extent, in the spleen. T‐cell markers were also expressed midgestation on cells of the liver, spleen, thymus, and in Peyer's patches of the small and large intestine, and where CCR5 expression was noted. A myeloid marker, CD68, was found on hepatic cells near blood islands in the late first trimester. B‐cell markers were observed mid‐second trimester in the liver, spleen, thymus, lymph nodes, bone marrow spaces, and occasionally in GALT. By the late third trimester and postnatally, secondary follicles with germinal centers were present in the thymus, spleen, and lymph nodes. These results suggest that immune ontogeny in monkeys is similar in temporal and anatomical sequence when compared to humans, providing important insights for translational studies. Anat Rec, 297:1392–1406, 2014. © 2014 Wiley Periodicals, Inc.     

免疫组化技术分析人淋巴组织的多种分化抗原

用间接免疫过氧化物酶和PAP技术检测本室制备的31种抗人分化抗原单抗与淋巴组织的反应性.结果表明,CD3、CD5单抗与扁桃腺和淋巴结的T细胞、大部分成熟髓质胸腺细胞和脾白髓的中央动脉周围淋巴鞘呈非常强的反应.CD4~+细胞在扁桃腺的分布与CD3~+细胞类似,但数量稍少.只有少部扁桃腺和淋巴结T细胞与CD8单抗反应,CD8单抗主要染大部分胸腺皮质细胞,但抗CD8单抗与脾窦的内皮细胞呈强阳性交叉反应.Wu59单抗同时与扁桃腺、淋巴结和脾脏的T、B细胞呈非常强的膜染色,并与胸腺皮质和髓质细胞呈阳性反应,该单抗可能识别白细胞共同抗原或LFA-1.Wu 26.145单抗除与扁桃腺生发中心呈弱阳性反应外,还与脾红髓窦状结构内的血小板呈强阳性反应.此外,抗B细胞及其亚群单抗与扁桃腺、淋巴结、脾白髓生发中心呈强阳性反应.抗IL-2受体单抗与上述组织基本上呈阴性反应。     

Comparative analysis of mediastinal fat‐associated lymphoid cluster development and lung cellular infiltration in murine autoimmune disease models and the corresponding normal control strains

We previously discovered mediastinal fat‐associated lymphoid clusters (MFALCs) as novel lymphoid clusters associated with mediastinal fat tissue in healthy mice. However, no data about their morphology in immune‐associated disease conditions, and their relationship with lung infiltration, is available to date. In the present study, we compared the morphological features of MFALCs in 4‐month‐old male murine autoimmune disease models (MRL/MpJ‐lpr mice and BXSB/MpJ‐Yaa mice) with those of the corresponding control strains (MRL/MpJ and BXSB/MpJ, respectively). In addition, we analysed their correlation with lung infiltration. Furthermore, immunohistochemistry for CD3, B220, Iba1, Gr1 and BrdU was performed to detect T cells and B cells, macrophages, granulocytes and proliferating cells, respectively. The spleen weight to body weight ratios and anti‐double‐stranded DNA autoantibody titres were found to be significantly higher in the autoimmune models than in the control strains. Furthermore, the autoimmune model presented prominent MFALCs, with a significantly greater ratio of lymphoid cluster area to total mediastinal fat tissue area, and more apparent diffused cellular infiltration into the lung lobes than the other studied strains. Higher numbers of T and B cells, macrophages and proliferating cells, but fewer granulocytes, were observed in the autoimmune models than in the control strains. Interestingly, a significant positive Pearson's correlation between the size of the MFALCs and the density of CD3‐, B220‐ and Iba1‐positive cells in the lung was observed. Therefore, our data suggest a potentially important role for MFALCs in the progression of lung disease. However, further investigation is required to clarify the pathological role of MFALCs in lung disease, especially in inflammatory disorders.     

Peripheral tolerance through clonal deletion of mature CD4-CD8+ T cells.

Transgenic mice bearing the alpha beta transgenes encoding a defined T cell receptor specific for the male (H-Y) antigen presented by the H-2Db class I MHC molecule were used to study mechanisms of peripheral tolerance. Female transgenic mice produce large numbers of functionally homogeneous CD8+ male antigen-reactive T cells in the thymus that subsequently accumulate in the peripheral lymphoid organs. We have used three experimental approaches to show that male reactive CD8+ T cells can be eliminated from peripheral lymphoid organs after exposure to male antigen. (i) In female transgenic mice that were neonatally tolerized with male spleen cells, male reactive CD8+ T cells continued to be produced in large numbers in the thymus but were virtually absent in the lymph nodes. (ii) Injection of thymocytes from female transgenic mice into female mice neonatally tolerized with the male antigen, or into normal male mice, led to the specific elimination of male-reactive CD8+ T cells in the lymph nodes. (iii) Four days after male lymphoid cells were injected intravenously into female transgenic mice, male antigen-reactive CD8+ T cells recovered from the lymph nodes of recipient mice were highly apoptotic when compared to CD4+ (non-male reactive) T cells. These data indicate that tolerance to extrathymic antigen can be achieved through elimination of mature T cells in the peripheral lymphoid organs.     

Identification of dendritic cells,B cell and T cell subsets in Tasmanian devil lymphoid tissue; evidence for poor immune cell infiltration into devil facial tumors

The Tasmanian devil is under threat of extinction due to the transmissible devil facial tumor disease (DFTD). This fatal tumor is an allograft that does not induce an immune response, raising questions about the activity of Tasmanian devil immune cells. T and B cell analysis has been limited by a lack of antibodies, hence the need to produce such reagents. Amino acid sequence analysis revealed that CD4, CD8, IgM, and IgG were closely related to other marsupials. Monoclonal antibodies were produced against CD4, CD8, IgM, and IgG by generating bacterial fusion proteins. These, and commercial antibodies against CD1a and CD83, identified T cells, B cells and dendritic cells by immunohistochemistry. CD4⁺ and CD8⁺ T cells were identified in pouch young thymus, adult lymph nodes, spleen, bronchus‐ and gut‐associated lymphoid tissue. Their anatomical distribution was characteristic of mammalian lymphoid tissues with more CD4⁺ than CD8⁺ cells in lymph nodes and splenic white pulp. IgM⁺ and IgG⁺ B cells were identified in adult lymph nodes, spleen, bronchus‐associated lymphoid tissue and gut‐associated lymphoid tissue, with more IgM⁺ than IgG⁺ cells. Dendritic cells were identified in lymph node, spleen and skin. This distribution is consistent with eutherian mammals and other marsupials, indicating they have the immune cell subsets for an anti‐tumor immunity. Devil facial tumor disease tumors contained more CD8⁺ than CD4⁺ cells, but in low numbers. There were also low numbers of CD1a⁺ and MHC class II⁺ cells, but no CD83⁺ IgM⁺ or IgG⁺ B cells, consistent with poor immune cell infiltration. Anat Rec, 297:925–938, 2014. © 2014 The Authors. The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology Published by Wiley Periodicals, Inc.     

Evolution of T lymphocytes and cytokine expression in classical swine fever (CSF) virus infection

This study characterized the cell-mediated immune response in pigs inoculated with the Alfort 187 isolate of classical swine fever (CSF) virus. Quantitative changes in the T-lymphocyte population (CD3(+), CD4(+) and CD8(+)) and qualitative changes in cytokine expression (IL-2, IL-4 and IFNgamma) by these cells in serum, thymus and spleen were demonstrated. These changes coincided spatially and temporally with previously described quantitative and qualitative changes in monocyte-macrophage populations, thus demonstrating the contribution of the two cell populations to lymphoid depletion. Moreover, examination of cytokine expression in thymus and spleen samples revealed a type 1 cell-mediated immune response in the early and middle stages of the experiment, giving way to a type 2 immune response towards the end of the experiment; these findings, which accorded with the serological results and lymphopenia, may influence the delayed humoral response characteristic of CSF.     

Characterization of mouse CD6 with novel monoclonal antibodies which enhance the allogeneic mixed leukocyte reaction

Human CD6 is a cell surface protein expressed by thymocytes, mature T cells, a subset of B cells and certain cells of the brain. On human T cells, CD6 has been shown to act as a co-stimulatory molecule which modulates T cell receptor (TCR)-mediated T cell activation. To study further the recently identified mouse CD6 (mCD6), we generated and characterized a set of anti-mCD6 mAb. Anti-mCD6 mAb recognizing the mCD6 scavenger receptor cysteine-rich (SRCR) extracellular domains 1 and 3 were identified. mAb against SRCR domain 3, but not domain 1, inhibited the interaction of CD6 with a recently identified ligand, activated leukocyte cell adhesion molecule (ALCAM). Immunohistochemical analysis indicated that mCD6 expression was largely localized to the T cell areas of lymphoid tissue and, as previously reported in the human, CD6 was also expressed by neurons. CD6 was highly expressed on mouse T cells isolated from the spleen, lymph node and thymus as demonstrated by two-color immunofluorescence analysis. The CD4⁺ and CD8⁺ cells in these lymphoid compartments expressed similar levels of CD6. Immunoprecipitation studies showed that mouse thymocytes predominantly express a CD6 isoform of ～130 kDa, while splenocytes predominantly express a CD6 isoform of ～100 kDa. Anti-mCD6 mAb enhanced allogeneic mixed leukocyte reactions (MLR), indicating that CD6-ALCAM interactions may regulate the proliferative capacity of T cells.     

Differential expression of leukocyte common antigen in human fetal lymphoid organs.

To investigate the differential expression of various types of leukocyte common antigen (LCA) isoforms during development, we analyzed human fetal lymphoid organs, including the thymus, liver, spleen, and bone marrow from 14 weeks to 29 weeks of gestational age by immunohistochemical and flow cytometric methods. In fetal thymus, over 90% of thymocytes throughout the entire fetal life expressed CD45RO and CD45RB, while CD45RA was expressed only in less than 5% of thymocytes. This expression pattern of LCA isoforms was established by a gestational age of 14 weeks or earlier, and persisted throughout the fetal period. The tissue distribution was different from each isoform; CD45RO-positive thymocytes were found in both the cortex and medulla at the 14th week with low intensity, but was localized in the cortex with increasing fetal age. CD45RB-positive thymocytes distributed mainly in the medulla from early gestational age. Among extrathymic lymphoid organs, a small portion of lymphoid cells expressing leukocyte common antigens appeared first in the liver at 10-12 weeks of gestational age and was followed by a small number in the spleen and bone marrow by 13-15 weeks. All lymphoid cells in these extrathymic lymphoid organs at this stage were CD19+ B cells. The number of these CD19+ cells increased abruptly during the early period of mid-gestational age. The pattern of tissue distribution of each LCA isoform in the fetal liver and spleen correlated well with the patterns of quantitative analysis by flow cytometry. In summary we found that different LCA isoforms expressed in cell-type-specific pattern and showed different tissue distribution during the period of fetal development, and that LCA was the earliest antigen expressed by lymphocytes in the thymus and extrathymic lymphoid organs in our series.     

Expression of a gp33/27,000 MW activation inducer molecule (AIM) on human lymphoid tissues. Induction of cell proliferation on thymocytes and B lymphocytes by anti-AIM antibodies.

We have recently described several monoclonal antibodies (mAb) that recognize a heterodimeric structure (gp33/27,000 MW) expressed on the surface of human peripheral blood T lymphocytes upon activation with different mitogenic stimuli. Such mAb, when used in combination with submitogenic doses of phorbol ester, were capable of triggering T-cell proliferation. The antigen has been designated as activation inducer molecule (AIM). In the present study we have investigated the expression of the AIM in different lymphoid and non-lymphoid tissues. In addition, we have analysed the ability of lymphocyte subsets derived from thymus and tonsil to proliferate in response to anti-AIM mAb. The presence of AIM on subpopulations of lymphoid cells from thymus, tonsil, lymph node and spleen has been demonstrated by immunoprecipitation, flow cytometry and immunoperoxidase staining of tissue sections. By contrast, non-lymphoid cells from tissue such as brain, kidney, liver, lung or skin did not react with anti-AIM mAb. In thymus, the AIM expression was restricted to a subset of CD3+ medullary thymocytes, whereas CD1+ CD3- cortical thymocytes did not express this antigen. Nevertheless, the majority of both purified CD1- and CD3- thymocytes expressed AIM antigen after treatment with PMA. In tonsil and lymph node, a strong staining of a subset of CD3+ T lymphocytes located in the germinal centre was observed by immunohistochemical labelling with anti-AIM mAb. Certain T cells from the paracortical zone and CD19+ B lymphocytes from mantle region were also reactive. Both purified tonsillar T and B lymphocytes strongly expressed AIM after activation with PMA. The anti-AIM mAb was able to induce a strong proliferative response on purified CD1- thymocytes as well as on both purified tonsillar T and B lymphocytes in the presence of submitogenic doses of PMA. By contrast, no proliferative response was induced through the AIM in the CD3- immature thymocyte subset.     

过氧化物酶体增殖剂激活受体α对小鼠T、B细胞发育的影响

目的研究过氧化物酶体增殖剂激活受体α(PPARα)与小鼠免疫系统功能和发育的关系。方法喂养含过氧化物酶体增殖剂(PP)的食物后,观察野生型C57Bl/6小鼠和PPARα缺陷型小鼠胸腺、脾脏的重量及胸腺细胞、脾细胞数量的变化。用抗小鼠CD3、CD4、CD8a、CD19、IgM或CD45R/220单克隆抗体(mAb)进行细胞免疫荧光染色后,用流式细胞术分析骨髓细胞、胸腺细胞和脾细胞的表型变化。用刀豆蛋白A(ConA)和脂多糖(LPS)分别刺激小鼠的脾细胞,用3H-TdR掺入法检测淋巴细胞增殖活性的变化。用RT-PCR检测小鼠骨髓、胸腺和脾脏中PPARαmRNA的表达。结果与野生型小鼠相比较,PP对PPARα缺陷型小鼠胸腺、脾脏的重量和细胞数,以及ConA和LPS刺激对淋巴细胞增殖反应的影响很小。PP可致野生型小鼠胸腺中CD4 CD8 T细胞数,骨髓中B220 B细胞总数和原/前B细胞数明显减少,但对PPARα缺陷型小鼠的上述T、B细胞亚群无显著影响。PPARαmRNA在小鼠胸腺和脾脏中呈低表达,在骨髓中不表达。结论PPARα在PP诱导的免疫调节中起主要作用,其可通过间接途径影响T、B细胞的发育。