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While the sphingosine-1-phosphate (S1P)/sphingosine-1-phosphate receptor-1 (S1PR1) axis is critically important for lymphocyte egress from lymphoid organs, S1PR1-activation also occurs in vascular endothelial cells (ECs), including those of the high-endothelial venules (HEVs) that mediate lymphocyte immigration into lymph nodes (LNs). To understand the functional significance of the S1P/S1PR1-Gi axis in HEVs, we generated Lyve1;Spns2Δ/Δ conditional knockout mice for the S1P-transporter Spinster-homologue-2 (SPNS2), as HEVs express LYVE1 during development. In these mice HEVs appeared apoptotic and were severely impaired in function, morphology and size; leading to markedly hypotrophic peripheral LNs. Dendritic cells (DCs) were unable to interact with HEVs, which was also observed in Cdh5CRE-ERT2;S1pr1Δ/Δ mice and wildtype mice treated with S1PR1-antagonists. Wildtype HEVs treated with S1PR1-antagonists in vitro and Lyve1-deficient HEVs show severely reduced release of the DC-chemoattractant CCL21 in vivo. Together, our results reveal that EC-derived S1P warrants HEV-integrity through autocrine control of S1PR1-Gi signaling, and facilitates concomitant HEV-DC interactions.

Leukocyte microvilli are flexible projections enriched with adhesion molecules. The role of these cellular projections in the ability of T cells to probe antigen-presenting cells has been elusive. In this study, we probe the spatial relation of microvilli and T-cell receptors (TCRs), the major molecules responsible for antigen recognition on the T-cell membrane. To this end, an effective and robust methodology for mapping membrane protein distribution in relation to the 3D surface structure of cells is introduced, based on two complementary superresolution microscopies. Strikingly, TCRs are found to be highly localized on microvilli, in both peripheral blood human T cells and differentiated effector T cells, and are barely found on the cell body. This is a decisive demonstration that different types of T cells universally localize their TCRs to microvilli, immediately pointing to these surface projections as effective sensors for antigenic moieties. This finding also suggests how previously reported membrane clusters might form, with microvilli serving as anchors for specific T-cell surface molecules.

HEV LPA receptors differentially regulate lymphocyte recirculation, Naive lymphocytes continuously migrate from the blood into lymph nodes (LNs) via high endothelial venules (HEVs). To extravasate from the HEVs, lymphocytes undergo multiple adhesion steps, including tethering, rolling, firm adhesion and transmigration. We previously showed that autotaxin (ATX), an enzyme that generates lysophosphatidic acid (LPA), is highly expressed in HEVs, and that the ATX/LPA axis plays an important role in the lymphocyte transmigration across HEVs. However, the detailed mechanism underlying this axis’s involvement in lymphocyte transmigration has remained ill-defined. Here, we show that two LPA receptors, LPA4 and LPA6, are selectively expressed on HEV endothelial cells (ECs) and that LPA4 plays a major role in the lymphocyte transmigration across HEVs in mice. In the absence of LPA4 expression, lymphocytes accumulated heavily within the HEV EC layer, compared to wild-type (WT) mice. This accumulation was also observed in the absence of LPA6 expression, but it was less pronounced. Adoptive transfer experiments using WT lymphocytes revealed that the LPA4 deficiency in ECs specifically compromised the lymphocyte transmigration process, whereas the effect of LPA6 deficiency was not significant. These results indicate that the signals evoked in HEV ECs via the LPA4 and LPA6 differentially regulate lymphocyte extravasation from HEVs in the peripheral LNs.

In the lymphatic sinuses of draining lymph nodes, soluble lymph-borne antigens enter the reticular conduits in a size-selective manner and lymphocytes transmigrate to the parenchyma. The molecular mechanisms that control these processes are unknown. Here we unexpectedly found that PLVAP, a prototypic endothelial protein of blood vessels, was synthesized in the sinus-lining lymphatic endothelial cells covering the distal conduits. In PLVAP-deficient mice, both small antigens and large antigens entered the conduit system, and the transmigration of lymphocytes through the sinus floor was augmented. Mechanistically, the filtering function of the lymphatic sinus endothelium was dependent on diaphragms formed by PLVAP fibrils in transendothelial channels. Thus, in the lymphatic sinus, PLVAP forms a physical sieve that regulates the parenchymal entry of lymphocytes and soluble antigens.

Chronic exposure to high glucose induces the expression of cystathionine gamma-lyase (CSE), a hydrogen sulfide-producing enzyme, in pancreatic beta-cells, thereby suppressing apoptosis. The aim of this study was to examine the effects of hydrogen sulfide on the onset and development of type 2 diabetes. Middle-aged (6-month-old) wild-type (WT) and CSE knockout (CSE-KO) mice were fed a high-fat diet (HFD) for 8weeks. We determined the effects of CSE knockout on beta-cell function and mass in islets from these mice. We also analyzed changes in gene expression in the islets. After 8weeks of HFD, blood glucose levels were markedly increased in middle-aged CSE-KO mice, insulin responses were significantly reduced, and DNA fragmentation of the islet cells was increased. Moreover, expression of thioredoxin binding protein-2 (TBP-2, also known as Txnip) was increased. Administration of NaHS, a hydrogen sulfide donor, reduced TBP-2 gene levels in isolated islets from CSE-KO mice. Gene levels were elevated when islets were treated with the CSE inhibitor dl-propargylglycine (PPG). These results provide evidence that CSE-produced hydrogen sulfide protects beta-cells from glucotoxicity via regulation of TBP-2 expression levels and thus prevents the onset/development of type 2 diabetes.

Lymph nodes (LNs) are highly confined environments with a cell-dense three-dimensional meshwork, in which lymphocyte migration is regulated by intracellular contractile proteins. However, the molecular cues directing intranodal cell migration remain poorly characterized. Here we demonstrate that lysophosphatidic acid (LPA) produced by LN fibroblastic reticular cells (FRCs) acts locally to LPA2 to induce T-cell motility. In vivo, either specific ablation of LPA-producing ectoenzyme autotaxin in FRCs or LPA2 deficiency in T cells markedly decreased intranodal T cell motility, and FRC-derived LPA critically affected the LPA2-dependent T-cell motility. In vitro, LPA activated the small GTPase RhoA in T cells and limited T-cell adhesion to the underlying substrate via LPA2. The LPA-LPA2 axis also enhanced T-cell migration through narrow pores in a three-dimensional environment, in a ROCK-myosin II-dependent manner. These results strongly suggest that FRC-derived LPA serves as a cell-extrinsic factor that optimizes T-cell movement through the densely packed LN reticular network. DOI: http://dx.doi.org/10.7554/eLife.10561.001, eLife digest Small organs called lymph nodes are found throughout the body and help to filter out harmful particles and cells. Lymph nodes are packed with different types of immune cells, such as the T-cells that play a number of roles in detecting and destroying bacteria, viruses and other disease-causing microbes. Within the lymph node, T-cells crawl along a meshwork made up of cells called fibroblastic reticular cells. The T-cells appear to move in random patterns, but the signals that drive this movement remain ill-defined. Now, Takeda et al. reveal that a lipid called lysophosphatidic acid (LPA), which is produced by the fibroblastic reticular cells, is responsible for regulating how T-cells move around inside the lymph nodes. T-cells are able to detect LPA via certain receptor proteins on their surface. Takeda et al. engineered mice that were either unable to produce a particular LPA receptor on their T-cells, or that produced less LPA than normal. The T-cells of these mice moved around less than T-cells in normal mice. Further experiments revealed that LPA signaling also affects the signaling pathway that alters how well the T-cells stick to nearby surfaces. This suggests that LPA helps to optimize T-cell movement to allow the cells to navigate the small spaces found between the fibroblastic reticular cells. In the future, targeting the processes involved in LPA signaling could help to develop new treatments for disorders of the immune system. DOI: http://dx.doi.org/10.7554/eLife.10561.002

Moesin is a member of the ezrin-radixin-moesin (ERM) family of cytoskeletal proteins. These proteins organize membrane domains by interacting with plasma membrane proteins and the actin cytoskeleton. Because of their high sequence similarity, ERM proteins are usually thought to be functionally redundant. Lymphocytes express two ERM proteins, ezrin and moesin. Whether each ERM plays a specialized role in lymphocytes, particularly in vivo, remains unknown. Here, we show that moesin has a crucial, non-redundant role in lymphocyte homeostasis. Moesin-deficient mice exhibited decreases in both T and B cells in the peripheral blood and lymph nodes, but not in the spleen. This phenotype was recapitulated in bone marrow (BM) chimeras with a hematopoietic moesin deficiency. Although the T and B cells apparently developed without major defects in the moesin-deficient mice, T cell egress from the thymus and immature B cell egress from the BM were impaired. In the periphery, both T and B cells showed delayed egress from lymphoid organs. We showed that moesin is the primary phosphorylated ERM subject to dynamic regulation during cell shape changes and migration. Our findings identify a previously unknown, non-redundant function of moesin in lymphocyte homeostasis in regulating lymphocyte egress from lymphoid organs.

Objective To investigate whether acupuncture treatment during superovulation process improves ovarian response and increases egg production. Methods ICR female mice aged 12-5 weeks were divided into control group, anaesthesia group and acupuncture group. Female mice were injected intraperitoneally with pregnant mare's serum gonadotropin (PMSG), followed by human chorionic gonadotropin (hCG) injection 56 h later. Anaesthesia group and acupuncture group were anaesthetized three times by injecting 10% nembutal solution according to 7.5-10.0 μl/g weight. Acupuncture group was treated three times with puncture Sanyinjiao Points(SP6) under anaesthesia. After 17 h of hCG injection, eggs were recovered and ovaries were isolated. Matured eggs were counted, ovarian histology and expression of follicle stimulating hormone receptor(FSH-R) in ovary were analyzed. Results Acupuncture treatment statistically increased the number of ovulated eggs. Histological section showed that some matured follicles left in the ovaries of control and anaesthesia groups after ovulation. On the contrary, all matured follicles ruptured and converted into corpus lutea in Acupuncture group. Expression of FSH-R in ovary was decreased in acupuncture group compared with those of the two others. Conclusion Acupuncture treatment during superovulation process improves ovarian response so as to increase egg production. The positive effect of acupuncture may be associated with regulated FSH-R expression.

【目的】免疫研究委員会の活動として、 臨床に携わる鍼灸師が持つ 「鍼灸と免疫」 に対する意識の現状分析を行い、 そこから示唆される今後の課題を提言することを目的とした。 【方法】東洋療法学校協会に加盟する専門学校43校、 および国内で鍼灸師の養成課程をもつ大学6校において勤務する鍼灸師を対象に無記名アンケートによる意識調査を行い、 単純集計により解析した。 【結果】調査対象校49校に総計960件のアンケートを送付し、 32校から263件の有効票を回収した。 鍼灸治療を受けている患者は一般に感染に対する抵抗力が高まっていると考える回答は56.4％、 また、 鍼灸は免疫力を高める予防医学の一つと考える回答は83.3％であり、 鍼灸は免疫に対して効果的と考える回答が多数を占めていた。 しかしながら、 実際の臨床現場において患者の免疫力を客観的に評価しているという回答は11.0％に留まり、 大多数が患者からの主観的な申告で判定しているという結果であった。 【結論】肯定的な回答が多かった鍼灸の免疫力向上作用について科学的検証を行うためにも、 鍼灸師が臨床現場で実施可能な非侵襲性かつ客観的な免疫力の評価方法を模索し導入していくことが重要と思われた。

Plasmacytoid dendritic cells (pDCs) are natural type I IFN-producing cells found in lymphoid tissues, where they support both innate and adaptive immune responses. They emigrate from the blood to lymph nodes, apparently through high endothelial venules (HEVs), but little is known about the mechanism. We have investigated the molecular mechanisms of pDC migration using freshly isolated DCs and HEV cells. We found that pDCs bound avidly to HEV cells and then transmigrated underneath them. Two observations suggested that these binding and migration steps are differentially regulated. First, treatment of pDCs with pertussis toxin blocked transmigration but not binding. Second, pDCs were able to bind but not to transmigrate under non-HEV endothelial cells, although the binding was observed to both HEV and non-HEV endothelial cells. Antibody inhibition studies indicated that the binding process was mediated by alphaL and alpha4 integrins on pDCs and by intercellular adhesion molecule (ICAM)-1, ICAM-2 and vascular cell adhesion molecule-1 on HEVs. The transmigration process was also mediated by alphaL and alpha4 integrins on pDCs, with junctional adhesion molecule-A on HEV cells apparently serving as an additional ligand for alphaL integrin. These data show for the first time that pDCs employ multiple adhesion molecules sequentially in the processes of adhesion to and transmigration through HEVs.

We previously demonstrated that electroacupuncture (EA) stimulation both produced antinociception and attenuated intrathecal (i.t.) morphine analgesia, suggesting that EA is capable of inducing two opposing systems, that is, opioid and anti-opioid mechanisms. This study examined the involvement of cholecystokinin (CCK) in the anti-opioid effects following EA in the spinal cord. EA was applied to commonly used acupoints for antinociception, ST-36 located 5-mm lateral to the anterior tubercle of the tibia, and analgesia was assessed by the hind-paw pressure test in male Sprague-Dawley rats. I.t. administration of CCK (0.01 – 10 µg) attenuated i.t. morphine analgesia (10 µg) dose-dependently. The attenuation of morphine analgesia following EA was reversed by i.t. proglumide, a CCK-receptor antagonist (0.01 µg). CCK-like immunoreactivity was increased in lamina I and II in the dorsal horn, and expression of spinal CCK mRNA increased after EA. Moreover, i.t. pretreatment with the neurokinin-1 (NK1)-receptor antagonist L-703,606 (18 µg) reversed both EA- and CCK-induced attenuation of morphine analgesia. These results suggest that CCK-mediated neural systems in the spinal cord may be involved in the attenuation of morphine analgesia following EA and that substance P-induced activation of NK1 receptors may be responsible for the downstream neuronal transmission of the CCK-mediated neuronal system. Keywords:: electroacupuncture, morphine, anti-opioid, cholecystokinin, neurokinin

Lymphocyte trafficking to lymph nodes (LNs) is initiated by the interaction between lymphocyte L-selectin and certain sialomucins, collectively termed peripheral node addressin (PNAd), carrying specific carbohydrates expressed by LN high endothelial venules (HEVs). Here, we identified a novel HEV-associated sialomucin, nepmucin (mucin not expressed in Peyer's patches [PPs]), that is expressed in LN HEVs but not detectable in PP HEVs at the protein level. Unlike conventional sialomucins, nepmucin contains a single V-type immunoglobulin (Ig) domain and a mucin-like domain. Using materials affinity-purified from LN lysates with soluble L-selectin, we found that two higher molecular weight species of nepmucin (75 and 95 kD) were decorated with oligosaccharides that bind L-selectin as well as an HEV-specific MECA-79 monoclonal antibody. Electron microscopic analysis showed that nepmucin accumulates in the extended luminal microvillus processes of LN HEVs. Upon appropriate glycosylation, nepmucin supported lymphocyte rolling via its mucin-like domain under physiological flow conditions. Furthermore, unlike most other sialomucins, nepmucin bound lymphocytes via its Ig domain, apparently independently of lymphocyte function–associated antigen 1 and very late antigen 4, and promoted shear-resistant lymphocyte binding in combination with intercellular adhesion molecule 1. Collectively, these results suggest that nepmucin may serve as a dual-functioning PNAd in LN HEVs, mediating both lymphocyte rolling and binding via different functional domains.

Although dendritic cells (DCs) located in the small intestinal lamina propria (LP-DCs) migrate to mesenteric lymph nodes (MLNs) constitutively, it is unclear which chemokines regulate their trafficking to MLNs. In this study we report that LP-DCs in unperturbed mice require CCR7 to migrate to MLNs. In vitro, LP-DCs expressing CCR7 migrated toward CCL21, although the LP-DCs appeared morphologically and phenotypically immature. In MLNs, DCs bearing the unique LP-DC phenotype (CD11chighCD8αintCD11blowαLlowβ7high and CD11chighCD8α−CD11bhighαLlowβ7high) were abundant in wild-type mice, but were markedly fewer in CCL19-, CCL21-Ser-deficient plt/plt mice and were almost absent in CCR7-deficient mice, indicating the critical importance of CCR7 in LP-DC trafficking to MLNs. Interestingly, CCR7+ DCs in MLNs with the unique LP-DC phenotype had numerous vacuoles containing cellular debris in the cytoplasm, although MLN-DCs themselves were poorly phagocytic, suggesting that the debris was derived from the LP, where the LP-DCs ingested apoptotic intestinal epithelial cells (IECs). Consistent with this, LP-DCs ingested IECs vigorously in vitro. By presenting IEC-associated Ag, the LP-DCs also induce T cells to produce IL-4 and IL-10. Collectively, these results strongly suggest that LP-DCs with unique immunomodulatory activities migrate to MLNs in a CCR7-dependent manner to engage in the presentation of IEC-associated Ags acquired in the LP.

平成16年度に発足した免疫研究委員会では、過去に国内外で発表された鍼灸と免疫に関する全ての基礎研究論文の記載内容を精査する目的でWeb上のデーターベースからキーワード検索により724論文を選び、そこから実験動物対象の原著論文52編とヒト対象の原著論文42編 (そのうち英文論文72編、邦文論文22編) を抽出した。それら94論文に記載された鍼灸刺激方法や実験対象、測定された免疫学的パラメーターなどについて詳細な検討を加えた結果、本領域の報告は極めて多様な実験条件設定の下で実施されていることが明らかとなり、今後のこの領域の基礎研究では相互に比較検討が可能な再現性の高いデータを蓄積しなければならないことが示唆された

The E-cadherin-based adherens junction (AJ) is essential for organogenesis of epithelial tissues including the liver, although the regulatory mechanism of AJ formation during development remains unknown. Using a primary culture system of fetal hepatocytes in which oncostatin M (OSM) induces differentiation, we show here that OSM induces AJ formation by altering the subcellular localization of AJ components including E-cadherin and catenins. By retroviral expression of dominant-negative forms of signaling molecules, Ras was shown to be required for the OSM-induced AJ formation. Fetal hepatocytes derived from K-Ras knockout (K-Ras-/-) mice failed to form AJs in response to OSM, whereas AJ formation was induced normally by OSM in mutant hepatocytes lacking both H-Ras and N-Ras. Moreover, the defective phenotype of K-Ras-/- hepatocytes was restored by expression of K-Ras, but not by H-Ras and N-Ras. Finally, pull-down assays using the Ras-binding domain of Raf1 demonstrated that OSM directly activates K-Ras in fetal hepatocytes. These results indicate that K-Ras specifically mediates cytokine signaling for formation of AJs during liver development.

Peroxiredoxins are novel peroxidases that exhibit divergent biological functions. The fourth member, Prx4, is synthesized with a signal sequence and, after processing, secreted as a 27-kDa form in most tissues. A 31-kDa Prx4 which corresponds to the unprocessed, membrane-bound form is found only in testis. This study was undertaken in order to investigate the role of the membrane-bound Prx4 during spermiogenesis in rats. The Prx4 transcript was observed in testes at 14 days of age, the age before puberty, and its level increased only slightly during aging. Only the secretable form of Prx4 was present before 30 days of age, but the membrane-bound Prx4 became detectable in adult testes, although sum of the two forms appeared to be the same after 21 days old. While weak immunoreactivity to the Prx4 antibody was detected in spermatogenic cells for all ages, a strong immunoreactivity was observed in the elongating spermatid and residual body of adult testis. Prx4 was present in the lumen of the endoplasmic reticulum, Golgi bodies, and the perinuclear space in young rat testes. However, the localization of Prx4 was restricted to membranes of the acrosomal vesicle of the elongated spermatid and was not detected in spermatozoon. Once spermiogenesis is accomplished, vesicles containing the membrane-bound Prx4 were released into the residual body, along with residual membranous components. Thus the conversion of the soluble form to the membrane-bound form may have a role in the acrosome formation during vesicular reorganization during spermiogenesis.

Lymphocyte extravasation from the high endothelial venules (HEVs) of lymph nodes is crucial for the maintenance of immune homeostasis, but its molecular mechanism remains largely unknown. In this article, we report that lymphocyte transmigration across the basal lamina of the HEVs is regulated, at least in part, by autotaxin (ATX) and its end-product, lysophosphatidic acid (LPA). ATX is an HEV-associated ectoenzyme that produces LPA from lysophosphatidylcholine (LPC), which is abundant in the systemic circulation. In agreement with selective expression of ATX in HEVs, LPA was constitutively and specifically detected on HEVs. In vivo, inhibition of ATX impaired the lymphocyte extravasation from HEVs, inducing lymphocyte accumulation within the endothelial cells (ECs) and sub-EC compartment; this impairment was abrogated by LPA. In vitro, both LPA and LPC induced a marked increase in the motility of HEV ECs; LPC’s effect was abrogated by ATX inhibition, whereas LPA’s effect was abrogated by ATX/LPA receptor inhibition. In an in vitro transmigration assay, ATX inhibition impaired the release of lymphocytes that had migrated underneath HEV ECs, and these defects were abrogated by LPA. This effect of LPA was dependent on myosin II activity in the HEV ECs. Collectively, these results strongly suggest that HEV-associated ATX generates LPA locally; LPA, in turn, acts on HEV ECs to increase their motility, promoting dynamic lymphocyte–HEV interactions and subsequent lymphocyte transmigration across the basal lamina of HEVs at steady state.

Interleukin-3 (IL-3) is a potent growth factor for hematopoietic cells. IL-3 transmits its signal through a specific cell surface receptor which consists of a primary binding alpha subunit (IL-3R alpha) and a signaling beta subunit that is shared by the IL-5 and GM-CSF receptors. Here, we describe the expression of the alpha and beta subunit of the IL-3 receptor in mouse testis and testicular cell lines both at nucleic acid and protein levels. Our data indicate that IL-3R alpha is expressed on the cell surface of testicular Leydig cells and a Leydig cell tumor cell line I-10. Expression of the beta subunit mRNA was only faintly detected in testis, but not in I-10 cells. Immunoelectron microscopy has revealed that IL-3R alpha is present on cell membrane and microvilli.

We report on 2 cell lines (designated OVAK-I and OVAK-II) established from an adenosarcoma, a rare variant of a malignant Mullerian mixed tumor, of the ovary. OVAK-I was not tumorigenic in nude mice and showed no responsiveness to transforming growth factor (TGF)-beta1, whereas OVAK-II was tumorigenic and had various biological properties. Light- and electron-microscopic studies showed that the morphology of the cells was converted from an epithelial to a mesenchymal form by TGF-betaI. Furthermore, the protein and mRNA expressions of the epithelial marker carcinoembryonic antigen and the mesenchymal marker vimentin were down- and up-regulated, respectively, by TGF-beta1. These findings suggested that TGF-beta1 plays a role in epithelial-mesenchymal transformation and support the single-stem-cell theory which explains the origin of malignant Mullerian mixed tumors: that the epithelial and mesenchymal components of these tumors are of common stem-cell origin.

Although there is growing evidence showing that the involvement of chemokines in the pathogenesis of neuropathic pain is associated with neuroinflammation, the details are unclear. We investigated the C-X-C chemokine ligand type 2 [macrophage inflammatory protein 2 (MIP-2)]/C-X-C chemokine receptor type 2 (CXCR2) axis and epigenetic regulation of these molecules in neuropathic pain after peripheral nerve injury. Expression of MIP-2 and CXCR2 were up-regulated and localized on accumulated neutrophils and macrophages in the injured sciatic nerve (SCN) after partial sciatic nerve ligation (PSL). Perineural injection of MIP-2-neutralizing antibody (anti-MIP-2) or the CXCR2 antagonist N-(2-bromophenyl)-N'-(2-hydroxy-4-nitrophenyl)urea (SB225002) prevented PSL-induced tactile allodynia and thermal hyperalgesia. Perineural injection of recombinant MIP-2 elicited neuropathic pain-like behaviors. Anti-MIP-2 suppressed neutrophil accumulation in the SCN after PSL. Neutrophil depletion by intraperitoneal injection of Ly6G antibody attenuated PSL-induced neuropathic pain. Both anti-MIP-2 and SB225002 suppressed up-regulation of inflammatory cytokines and chemokines in the injured SCN. In addition, acetylation of histone H3 [lysine (Lys9)-acetylated histone H3 (AcK9-H3)] on the promoter region of MIP-2 and CXCR2 was increased in the injured SCN after PSL. Expression of AcK9-H3 was observed in the nuclei of neutrophils and macrophages surrounding the epineurium. Administration of the histone acetyltransferase inhibitor anacardic acid suppressed the up-regulation of MIP-2 and CXCR2 in the SCN after PSL and resulted in the prevention of PSL-induced neuropathic pain. Taken together, these results show that augmentation of the MIP-2/CXCR2 axis by hyperacetylation of histone H3 on the promoter region of MIP-2 and CXCR2 located in the injured peripheral nerve elicits chronic neuroinflammation through neutrophil accumulation, leading to neuropathic pain.

Lymphocyte trafficking into lymph nodes and Peyer's patches is mediated primarily by specifically differentiated venules, called high endothelial venules (HEVs), located in the tissue parenchyma. HEVs have a unique morphology and phenotype, which enables them to interact with circulating lymphocytes efficiently. That is, the HEV endothelial cells have a tall and plump appearance, and constitutively express multiple adhesion molecules and chemokines on their surface. These molecules can interact with cognate receptors on circulating lymphocytes, thereby mediating the stepwise and sequential lymphocyte adhesion and transendothelial migration (TEM) at the HEV endothelial luminal surface. This review summarizes the fine morphological aspects of the unique HEV endothelial cells, with special reference to the spatial distribution of the adhesion molecules and chemokines that regulate lymphocyte migration.

We developed a new monoclonal antibody (mAb), named 1E9, which recognizes the immunoglobulin (Ig) M-like molecule of the insectivore laboratory animal, the suncus. This mAb was developed in order to investigate the distribution of surface Ig (sIg)-bearing lymphocytes in the lymphoid tissues of this animal. Immunohistochemically, the distribution of 1E9+ lymphocytes in the follicles of peripheral lymphoid tissues showed homology with such distribution in rodents. However, the lymphocytes in the follicles of the mucosal lymphoid tissues were not recognized by the mAb. These data suggest that from a comparative immunological viewpoint, our newly developed 1E9 mAb is useful for the characterization of sIg+ lymphocytes in the peripheral and mucosal lymphoid tissues of the suncus.

Nepmucin/CLM-9 is an Ig domain-containing sialomucin expressed in vascular endothelial cells. Here we show that, like CD31, nepmucin was localized to interendothelial contacts and to vesicle-like structures along the cell border and underwent intracellular recycling. Functional analyses showed that nepmucin mediated homotypic and heterotypic cell adhesion via its Ig domain. Nepmucin-expressing endothelial cells showed enhanced lymphocyte transendothelial migration (TEM), which was abrogated by anti-nepmucin mAbs that block either homophilic or heterophilic binding. Notably, the mAbs that inhibited homophilic binding blocked TEM without affecting lymphocyte adhesion. These results suggest that endothelial nepmucin promotes lymphocyte TEM using multiple adhesion pathways.

The leukocyte adhesion molecule L-selectin mediates the recruitment of lymphocytes to secondary lymphoid organs and is involved in the accumulation of neutrophils at sites of inflammation. In this study, we report the identification of novel isoforms of the mouse L-selectin gene, termed L-selectin-v1 and L-selectin-v2. Sequence analysis revealed that these isoforms are generated by alternative splicing: the L-selectin-v2 transcript includes a previously unknown exon of 100 bp located between the 7th and 8th exons of the mouse L-selectin gene, while the L-selectin-v1 transcript contains the first 49-bp sequence of this new exon. The insertion of each new sequence adds a downstream reading frame, giving rise to predicted proteins that differ in their carboxyl-terminal tails. These splice variants were found in cells that express conventional L-selectin, termed L-selectin-c, including B and T lymphocytes and granulocytes. Functionally, like L-selectin-c, both L-selectin-v1 and L-selectin-v2 expressed in cultured cells underwent phorbol ester-induced shedding, although L-selectin-v1 and L-selectin-v2 were shed to a greater and lesser degree, respectively, than L-selectin-c. Under flow conditions, both L-selectin-v1 and L-selectin-v2 mediated faster cell rolling than did L-selectin-c. In addition, ligation of L-selectin-c and L-selectin-v1, but not L-selectin-v2, induced p38 mitogen-activated protein kinase phosphorylation. These results suggest that alternative splicing is one mechanism for generating functional diversity in L-selectin.

The human palatine tonsils and the nasopharyngeal tonsil were considered the defense mechanism against ingested or inhaled foreign pathogens. The current findings suggest that the tubal tonsils possess abilities of active transportation of foreign antigens, and will act as inductive and effector sites in the mucosal immune system. Our results also indicated a significant difference in roles of immune responses among individual tonsillar organs, suggesting functional sub-compartmentalization.To address the function of tonsils in inducing local immune responses, we evaluated the antigen uptake of tubal tonsils and the induction of specific immune responses in a small laboratory animal with both tubal and palatine tonsils, i.e. Suncus murinus.S. murinus were injected with 2 x 10(6) CFU of FITC-labeled Staphylococcus aureus via the right tympanic cavity. The distribution of the FITC-labeled S. aureus was examined under a fluorescent microscope. S. murinus were also immunized with 100 microg of ovalbumin (OVA) mixed with 2 microg of cholera toxin (CT) via the right external ear meatus every 2 days for 2 weeks. One week after the final immunization, sera, pairs of tubal and palatine tonsils, and the neck lymph nodes were obtained to evaluate the induction of specific immune responses.The FITC-labeled S. aureus particles were detected in tubal tonsils and also in cervical lymph nodes. Total IgA-producing cells and OVA-specific antibody-producing cells were identified in the immunized tubal tonsils. Trans-external ear meatus immunization of tubal tonsils also evoked systemic antibody responses.

BACKGROUND AND PURPOSE: The patency of intracranial perforating arteries after stent placement is unknown despite the general clinical use of intracranial arterial stenting. METHODS: We deployed stainless steel stents in the abdominal aorta across the lumbar artery in eight normal rabbits in which the diameters of the abdominal arterial vessels were similar to those of human intracranial arteries. We evaluated the patency via angiographic and scanning electron microscopic methods 3 months after stent placement. Histopathologic evaluation was also performed for one rabbit. RESULTS: The lumbar arteries were patent, even when stent struts crossed the ostium, except in one rabbit in which intimal dissection occurred intraoperatively. The scanning electron microscopy showed that the regenerative endothelium had grown onto the strut at the ostium of the lumbar artery. CONCLUSION: We confirmed the patency of the lumbar arteries in this study by using normal rabbits. Thus, intracranial stenting may not pose a risk of occluding perforating arteries of the same diameter of the lumbar artery, even if stent struts cover the ostium.

Morphological changes of the dermal blood vessels of moxibustion-stimulated rat skin were examined with reference to the lymphocyte migration. After long-term stimulation with direct moxibustion to the acupoint Tsu-San-Li (St-36), peculiar vessels that possess immunohistological features of high endothelial venules could be observed in the moxa-stimulated acupoint dermis. Endothelial cells of the vessels had well-developed Golgi apparatus in their plump cytoplasms, and they strongly expressed intercellular adhesion molecule-l on the luminal surface. These data suggest that the appearance of the peculiar vessels in the dermis acts toward the active infiltration of blood-lymphocytes into the acupoint skin.

我々は, 艾が活性酸素の一つであるスーパーオキシドの生成を抑制することを報告したが, 今回 1, 1-diphenyl-2-picrylhydrazyl を用いてラジカル除去作用について検討を行なった。その結果, 艾にラジカル除去作用があり, その活性は艾の種類によって異なることが確認された。

The milk ejection reflex is mediated by the release of pituitary oxytocin and its interaction with specific receptors within the mammary gland. Although up-regulation of the oxytocin receptor during lactation has been shown for the rat mammary gland by ligand binding assay, investigation of the receptor expression in human breast at the molecular level has not yet been carried out in detail. Here we report the expression and immunolocalization of the oxytocin receptor in the human breast. It appears that the expression level of the receptor-specific mRNA is not significantly elevated during lactation and the protein remains at a relatively low level. However, this lack of increase may be only a dilution effect because of the high level of milk protein expression. Immunohistochemistry and immunoelectron microscopy using three anti-oxytocin receptor antibodies raised against different epitopes of the receptor indicated the presence of receptor immunoreactivity only to a very limited extent in the myoepithelial cells; more specific expression appeared to occur in the ductal/glandular epithelium in both the non-lactating as well as lactating breast. This finding was also confirmed in a New World monkey, the common marmoset (Callithrix jacchus). These results suggest that, at least for human and marmoset, in addition to--or even instead of--myoid cells, the ductal/glandular epithelium is also a target for oxytocin action, not only during lactation but also in the non-lactating breast. Thus, there may be other physiological effects of oxytocin besides direct myoid cell contraction in the breast.

Using an immunoelectron microscopic technique, we demonstrated the distinctive localization of L-selectin, alphaL and beta2 integrins (LFA-1) on lymphocytes adhering to high endothelial venules (HEVs) of peripheral lymph nodes. Immunogold staining clearly demonstrated the preferential localization of L-selectin on the faintly adherent microvilli to endothelial surfaces. Often, the particles of L-selectin were found around those microvilli with a dispersed distribution. Examination by antibody-coated latex beads showed that the localization of L-selectin was not restricted to the lymphocyte surface but also found on endothelial cells. These data suggest the molecular shedding from lymphocytes and its transfer to the HEV surface as the 'molecular footprints' of rolling cells. Concomitant with the dispersion of L-selectin, the gold particles of alphaL, and beta2 integrins showed significant capping and clustering images on the adherent border of lymphocytes. This redistribution of LFA-1 may be important for inducing the transition of the molecule into the active state to facilitate effective binding to its endothelial ligands. These morphological findings revealed the characteristic behavior of L-selectin and LFA-1 on lymphocytes, and they confirm their respective molecular roles in the current adhesion cascade model between lymphocytes and HEVs.

The beige rat is an animal model of the Chédiak-Higashi syndrome. Since mast cells can be easily purified from the peritoneal cavity of rats, we investigated the function of beige rat mast cells with giant granules by using quantitative methods. Beige and normal rat mast cells were sensitized with anti-dinitrophenol (DNP) IgE antibodies and stimulated by DNP conjugated with human serum albumin. The proportion of histamine released to total histamine was significantly greater in beige rat mast cells than in normal rat mast cells. Since the supernormal histamine release of beige rat mast cells was observed after treatment with 12-O-tetradecanoylphorbol 13-acetate, calcium ionophore A23187, substance P or compound 48/80, it appeared to be attributable to the enlargement in granules in beige rat mast cells. Spontaneous cytotoxic activity of mast cells was assayed by incubating purified mast cells with 51Cr-labelled WEHI-164 cells. Both beige and normal rat mast cells showed significant cytotoxic activity, but no significant difference was detectable between beige and normal rat mast cells. Even after IgE-mediated stimulation, no significant difference in cytotoxic activity was detectable between beige and normal rat mast cells either. Giant granules of beige rat mast cells did not appear to influence the cytotoxic activity of mast cells.

An ultrastructural study was made of the postnatal development of the tonsillar crypt epithelium in the musk shrew, Suncus murinus. On day 3 after birth, a particular kind of large lymphoid cell was first seen to move through the basement membrane into the epithelium. The next migration was that of lymphocytes, which passed through holes in the basement membrane. On days 5 to 7, the lymphocytes formed clusters, and pale epithelial cells of low electron density appeared. The cell clusters and pale epithelial cells fused on day 10. By day 14, these epithelial cells extended cytoplasmic projections to the surface of the epithelium, which had many heterophagic vacuoles and some microvilli-like structures. These findings suggest that the lymphoepithelial relationship is important for the organization of the immunological microenvironment in tonsillar crypt epithelium of the neonatal musk shrew.

During a sparrow-pecking and twisting-needle manipulation to the acupoints BL 23, 24 and 25 for an induction of "Qi", it was found that some transparent materials were binding to the needles after removed from the volunteer's skin. Electron-microscopical analysis of the transparent materials revealed that they corresponded to the injured fascia made up of collagen fibers, elastic fibers, fibroblasts, adipocytes and mast cells. Rarely were nerve fiber-like structures observed in the materials. Immunohistochemically, calcitonin gene-related peptide-positive nerve fibers could be demonstrated in the acupoint BL 24 associated fascia. A possible functional relationship between the needle manipulation and the induction of Qi-sensation is discussed along with the acupoint tissue constitution.

Ultrastructures of the electro-acupunture or moxibustion stimulated skin and regional lymph nodes in experiment animals were examined by scanning and transmission electron microscopy. In the scanning electron microscopy, small numbers of infiltrating erythrocytes and lymphocytes were found in the vicinity of the penetrated acupunture needle in the acupunture-stimulated skin, whereas moxibustion-treated instances revealed a large number of immunocyte infiltrations in the region. Transmission electron microscopically revealed that immunocytes consisted of lymphocytes, monocytes and some granulocytes and mast cells. In addition, the moxibustion-stimulated regional lymph nodes increased in weight after the stimulation and induced numerous immunocyte influx through afferent lymphatics. The acupunture-stimulated nodes, however, revealed no remarkable change in the weight and morphology. A functional significance of the acupunture and moxibustion-stimulated skin and regional nodes was discussed in reference to previous immunohistological descriptions of immune-reacted lymph node of the same animals.