bluuebunny/crossref_metadata_2025 huggingface dataset:
Giant cell arteritis localized to the colon associated with Crohn's disease
Authors: Colombat M , Imbert A , Bruneval P , Chatelain D , Gontier M‐F
Published: March 2003

Intestinal vasculitis is uncommon and usually accompanies systemic vasculitis. Although intestinal vascular changes including vasculitis have been studied intensively, and are found regularly in Crohn's disease, giant cell arteritis is distinctly unusual. We describe a case of giant cell arteritis localized to the colon of an 18‐year‐old girl suffering from Crohn's disease.

After three years of medical treatment, the patient underwent a proctocolectomy. The medium‐sized arteries of the mesocolon demonstrated striking changes characterized by intimal fibrous thickening and an inflammatory infiltrate with giant cells, most predominant at the intima–media junction. Epithelioid cells and sarcoid‐like granulomas were not observed. The internal elastic lamina was fragmented. Neither clinical symptoms nor laboratory findings showed evidence of systemic vasculitis. Neither the chest CT scan nor the echo‐Doppler of the temporal arteries, supra‐aortic and abdominal vessels revealed any abnormality.

This case illustrates an extremely rare feature in the spectrum of vascular lesions in Crohn's disease which have to be differentiated from temporal and Takayasu's arteritis.
Follicular lymphoid hyperplasia of the hard palate and oral mucosa: report of three cases and a review of the literature
Authors: Menasce L P , Shanks J H , Banerjee S S , Harris M
Published: March 2003

Follicular lymphoid hyperplasia of the hard palate and oral mucosa: report of three cases and a review of the literature

Aims: To bring to wider attention this uncommon, poorly understood entity which may closely resemble, clinically and morphologically, follicular lymphoma.

Methods and results: We report three cases of follicular lymphoid hyperplasia of the hard palate and oral mucosa which caused diagnostic difficulties for the referring pathologists. The clinicopathological features are described and integrated into a review of the 16 previously recorded cases. The condition most commonly presents as a slowly growing mass situated in the posterior hard palate but may present with multicentric oral lesions and lymphadenopathy. Morphologically, it is characterized by a dense follicular lymphoid infiltrate within the lamina propria which may show the classical features of benign reactive hyperplasia, but not uncommonly, indistinct germinal centres, ill‐defined mantles and a lack of tingible‐body macrophages are features which may lead to an erroneous diagnosis of follicular lymphoma.

Conclusions: Follicular lymphoid hyperplasia of the palate is a poorly recognized entity which is frequently confused with follicular lymphoma. Awareness of the entity combined with the use of immunohistochemistry for immunoglobulin light chains and bcl‐2 protein allows a correct diagnosis to be made avoiding extensive investigation and aggressive treatment to the patient.
Primary endometrioid adenocarcinoma of the large intestine arising in colorectal endometriosis
Authors: Petersen V C , Underwood J C E , Wells M , Shepherd N A
Published: March 2003

Primary eneometrioid adenocarcinoma of the large intestine arising in colorectal endometriosis

Aims: Three cases of endometrioid adenocarcinoma arising in colorectal endometriosis are described with discussion of their macroscopic and microscopic pathology and diagnosis, using immunohistochemistry.

Methods and results: Three middle‐aged women presented with symptoms and signs of colorectal mass effect. Two had a preceding history of gynaecological endometriosis and all three had either been on hormone replacement therapy or had functioning ovaries prior to presentation with colorectal disease. Each underwent resection of tumours of the distal large intestine. The definitive diagnosis was dependent on histological examination and immunohistochemistry, which was used to demonstrate an origin in endometriotic tissue.

Conclusions: Endometrioid adenocarcinoma is a rare complication of colorectal endometriosis, this report contributing to a total of 25 cases in the literature. Definitive diagnosis, aided by immunohistochemical studies, is important to enable the identification of the optimal management for this uncommon condition.
Multifocal distribution of pulmonary capillary haemangiomatosis
Authors: Erbersdobler A , Niendorf A
Published: March 2003

Multifocal distribution of pulmonary capillary haemangiomatosis

Aims: We investigated a case of pulmonary capillary haemangiomatosis, a rare condition, to determine the extent of the pathological changes within the lungs. Systematic histological sampling has not previously been performed in this condition.

Methods and results: A 52‐year‐old woman with a history of ischaemic cardiomyopathy suffered from repeated respiratory infections, which were attributed to chronic pulmonary congestion. She died suddenly of fulminant pulmonary thrombembolism. An autopsy was performed and lung tissue was sampled at multiple sites. Beside passive congestion, the lungs showed well‐circumscribed areas containing proliferations of small capillaries infiltrating the pulmonary septa and the walls of otherwise normal blood vessels and bronchi. The most severely affected areas were found to be in the periphery of both lower lobes. A diagnosis of pulmonary capillary haemangiomatosis was made.

Conclusions: This is the first case of pulmonary capillary haemangiomatosis in which systematic histological sampling has been performed. Mapping of lesions disclosed the multifocal distribution of pulmonary capillary haemangiomatosis in this patient.
Salivary duct carcinoma: cytokeratin 14 as a marker of in‐situ intraductal growth
Authors: De Araújo V C , Loducca S V L , Sobral A P V , Kowalski L P , Soares F , De Araújo N S
Published: March 2003

Aims:  The aim of this study was to determine the immunoprofile of salivary duct carcinoma and to differentiate intraductal growth from invasive growth.

Methods and results:  We applied a panel of antibodies (cytokeratins 7, 8, 13, 14, 19, vimentin and α‐smooth muscle actin) in five cases of salivary duct carcinoma. This panel is currently used for identification of different components of salivary gland tumours in our laboratory. All tumour cells were positive for cytokeratins 7 and 8. Few neoplastic structures expressed cytokeratin 14 in cells surrounding tumour islands.

Conclusion:  The finding of cytokeratin 14 was important to confirm the in‐situ intraductal growth, which probably characterizes this low‐grade neoplasm.
T‐cell/histiocyte‐rich large B‐cell lymphoma is a disseminated aggressive neoplasm: differential diagnosis from Hodgkin's lymphoma
Authors: Fraga M , García‐Rivero A , Sánchez‐Verde L , Forteza J , Piris M A
Published: March 2003

Aims:  An accurate diagnosis of T‐cell/histiocyte‐rich large B‐cell lymphoma needs to take into consideration those forms of Hodgkin's lymphoma also characterized by a predominance of small lymphocytes and histiocytes, i.e. nodular lymphocyte predominance Hodgkin's lymphoma and lymphocyte‐rich classical Hodgkin's lymphoma. We have studied the clinical, phenotypic and genetic features of a series of 12 cases of T‐cell/histiocyte‐rich large B‐cell lymphoma along with 18 cases of Hodgkin's lymphoma for comparative purposes.

Methods and results:  Of the Hodgkin's lymphoma cases, there were 11 lymphocyte predominance type and seven classic type. T‐cell/histiocyte‐rich large B‐cell lymphomas presented usually in advanced stages (III or IV in 11/12 cases), frequently with ‘B’ symptoms (6/9 cases), and followed a more aggressive course than Hodgkin's lymphoma (4/8 patients died due to the tumour in T‐cell/histiocyte‐rich large B‐cell lymphoma versus 0/15 in Hodgkin's lymphoma). T‐cell/histiocyte‐rich large B‐cell lymphoma cases showed diffuse effacement of the nodal architecture by a proliferation of scattered large atypical B‐cells obscured by a background of small T‐lymphocytes (more CD8+, TIA1+ than CD57+). Five cases showed also a prominent histiocytic component. The large B‐cells expressed CD45 and often EMA (6/10 cases). On the other hand, CD30, CD15 and latent infection by Epstein–Barr virus (EBV) were generally lacking. bcl6 and CD10 were, respectively, detected in 6/6 and 1/5 cases. Conventional polymerase chain reaction (PCR) showed monoclonal immunoglobulin heavy chain (IgH) gene rearrangements in all T‐cell/histiocyte‐rich large B‐cell lymphomas studied (5/5), but did not detect any case with t(14;18) involving the major breakpoint region (0/4).

Conclusions:  The differential diagnosis of T‐cell/histiocyte‐rich large B‐cell lymphoma from Hodgkin's lymphoma is facilitated by the integration of different immunophenotypic, molecular and clinical findings. T‐cell/histiocyte‐rich large B‐cell lymphoma is a monoclonal neoplasm of bcl6+ B‐cells with a phenotypic profile similar to lymphocyte predominance Hodgkin's lymphoma, suggesting a germinal centre origin andapossible relation to this disease. Therefore, in order to distinguish it from lymphocyte predominance Hodgkin's lymphoma, characterization of the reactive background, IgH gene rearrangement studies by conventional PCR and clinical features are more useful. In contrast, T‐cell/histiocyte‐rich large B‐cell lymphomacan be distinguished from classical Hodgkin's lymphoma thanks to the presence of monoclonal IgH rearrangement and the CD30–CD15–CD45+EMA+ immunophenotypic profile of the neoplastic cells in T‐cell/histiocyte‐rich large B‐cell lymphoma.
Lysis‐sensitive targets stimulate an elevation of cAMP in human natural killer cells
Authors: WHALEN  , GREEN
Published: March 2003

Natural killer (NK) cells are lymphocytes that are capable of destroying tumour cells and virally infected cells (cytolysis) without prior sensitization. When cAMP is artificially elevated in NK cells, it is a potent inhibitor of their cytolytic function. We investigated whether NK‐cell cAMP levels are modulated in response to tumour target cells to determine the potential of cAMP as a physiological regulator of NK cytotoxic function. When NK cells are exposed to a range of lysis‐sensitive (LS) tumour‐target cells there is an increase in intracellular cAMP levels in the NK cells over a 60‐min period. The peak increase in cAMP (200–400% above control) occurs at 30 min for all LS targets tested. There is no increase in NK‐cell cAMP in response to lysis‐resistant (LR) tumour‐target cells. The cAMP elevation may be dependent on both LS‐target‐stimulated adenylyl cyclase (AC) activation and LS‐target‐stimulated phosphodiesterase (PDE) inhibition. When the NK cells are pretreated with the protein tyrosine kinase (PTK) inhibitor, genistein (30 μg/ml), the AC‐activation component of the cAMP elevation is abolished. Thus, the AC‐activation component appears to require PTK activation. When NK cells are pretreated with the protein kinase C (PKC) inhibitor, chelerythrine chloride (10 μm) the cAMP elevation in response to LS targets was not diminished. This indicates that neither the AC‐activation component nor any PDE‐inhibition component require PKC activation.
Simultaneous cross‐linking of CD6 and CD28 induces cell proliferation in resting T cells
Authors: OSORIO  , ROTTENBERG  , JONDAL  , CHOW
Published: March 2003

In the present study, we showed that simultaneous ligation of the monoclonal antibodies (mAb) against CD6 and CD28 induces T‐cell proliferation in purified resting T lymphocytes in the absence of T‐cell receptor (TCR) occupancy. No cell proliferation was observed when the mAb were cross‐linked alone or used simultaneously in the soluble form. T‐cell proliferation mediated through CD6/CD28 is accompanied by the up‐regulation of interleukin‐2 (IL‐2) mRNA and expression of IL‐2 receptors on the cell surface. In the presence of IL‐2‐neutralizing mAb the proliferative response of the T cells induced through CD6/CD28 was inhibited dose dependently. Cross‐linking mAb to CD6 and CD28 alone or together did not down‐regulate the CD3/TCR complex. T‐cell proliferation mediated through CD6/CD28 was only partially blocked by the immunosuppressive drug, cyclosporin A (CsA), whereas anti‐CD28‐induced T‐cell proliferation in the presence of the phorbol ester, 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA), was unaffected. In sharp contrast T‐cell proliferation mediated by anti‐CD6 in the presence of TPA was efficiently blocked by CsA. In addition, two protein kinase C (PKC) inhibitors, GF 10 9203X and H‐7 dose‐dependently inhibited T‐cell proliferation mediated through CD6/CD28, suggesting that PKC activation may be involved. Furthermore, there was a marked differential dose‐dependent inhibitory effect of the PKC inhibitors on T‐cell proliferation mediated by the co‐ligation of anti‐CD6 or anti‐CD28 in the presence of anti‐CD3, with the former being more sensitive to PKC inhibition. Taken collectively, our results suggest that T‐cell activation can occur through an antigen‐independent pathway by cross‐linking the accessory molecules, CD6 and CD28, and that these two cell surface antigens may have distinct signalling pathways.
Lactic dehydrogenase virus infection enhances parasite egg production and inhibits eosinophil and mast cell responses in mice infected with the nematode Nippostrongylus brasiliensis
Authors: MORIMOTO  , YAMADA  , ARIZONO  , HAYASHI
Published: March 2003

The effects of lactic dehydrogenase virus (LDV) infection on the protective immune responses to the nematode Nippostrongylus brasiliensis were studied. Mice with chronic LDV infection showed significantly higher levels of parasite egg production than non‐LDV‐infected (control) mice after N. brasiliensis infection. Concurrent LDV infection also suppressed peripheral blood eosinophilia and the lung mastocytosis induced by this nematode. LDV infection showed higher expression levels of the interferon‐γ (IFN‐γ) mRNA in lymph nodes compared with control mice before N. brasiliensis infection. In addition, the IgG2a production in LDV‐infected mice was higher than that in control mice before and after N. brasiliensis infection. These results suggest that LDV infection modulates protective immune responses against N. brasiliensis infection by the activation of T‐helper type 1 cells.
Constitutive and regulated expression of the class Ib molecule Qa‐1 in pancreatic β cells
Authors: CHUN  , ALDRICH  , BALDEÓN  , KAWCZYNSKI  , SOLOSKI  , GASKINS
Published: March 2003

Enhanced major histocompatibility complex (MHC) class I expression is a prominent early feature of pancreatic β‐cell pathology in autoimm_une diabetes. The number and nature of class I MHC loci expressed by β cells are generally undefined and potentially critical to the onset and progression of insulitis. Mounting evidence indicates that the non‐classical MHC class Ib molecule Qa‐1, encoded by H2‐T23, is capable of presenting antigens to αβ and γδ T cells and that lymphocytes restricted to Qa‐1 may contribute imm_unoregulatory functions. We compared the expression of Qa‐1 and MHC class Ia in a β‐cell line (βTC6‐F7) before and after treatment with the insulitic cytokine interferon‐γ (IFN‐γ). Similar to MHC class Ia, Qa‐1 was expressed constitutively at a low level in βTC6‐F7 cells, with both T23b mRNA and cell surface Qa‐1b being up‐regulated following 24‐hr treatment with mouse IFN‐γ. Based on binding characteristics established for the predominant Qa‐1‐binding peptide, Qa‐1 determinant modifier (Qdm), we also examined the possibility that Qa‐1‐binding peptides may be encoded in the preproinsulin leader sequence. One nonameric peptide (Ins II; ALWMRFLPL) derived from the preproinsulin II leader sequence was recognized by a Qa‐1b‐specific cytotoxic T‐lymphocyte (CTL) clone. Specific binding of Ins II to Qa‐1b was confirmed by a CTL peptide‐blocking assay. Demonstration of IFN‐γ‐regulated Qa‐1 expression in β cells and identification of a Qa‐1‐binding peptide in the preproinsulin leader sequence invoke further consideration of possible roles of Qa‐1 in the progression of islet inflammation.
Modulation of alloimmune response in vitro by an IgM‐enriched immunoglobulin preparation (Pentaglobin)
Authors: Nachbaur D. , Herold M. , Gächter A. , Niederwieser D.
Published: March 2003

The mode of action of intravenous immunoglobulins (IVIG) in autoimmune and immunoregulatory disorders is still poorly understood. In vitro, direct effects of IVIG on cytokine release and on cytokine receptors have been described, as well as naturally occurring, neutralizing anti‐cytokine antibodies. The aim of our study was to investigate whether the enrichment in IgM and IgA would have any impact on the in vitro immunomodilatory capacity of IVIG. The preparation tested (Pentaglobin) contains 76% IgG and 12% IgM and IgA, respectively. We could demonstrate a significant inhibition of alloantigen‐induced proliferation in the mixed lymphocyte reaction (MLR) even at a Pentaglobin concentration of 1·0 mg/ml. About 10‐fold higher concentrations of standard 7S IVIG containing only trace amounts of IgM and IgA were necessary to achieve equivalent suppression of the alloimmune response. Similarly, phytohaemagglutinin (PHA)‐induced lymphocyte proliferation was more effectively inhibited by Pentaglobin than by standard 7S IVIG. Cytokine analyses in culture supernatants of MLR provide evidence that Pentaglobin not only modulates interleukin‐2 (IL‐2), which has already been observed with standard 7S IVIG, but, moreover, modulates interferon‐γ production with a subsequent impact on monocyte‐derived tumour necrosis factor‐α and IL‐6 release. Based on these results we conclude that in vitro the IgM‐ and IgA‐enriched Pentaglobin has a more potent immunomodulatory capacity than conventionally used standard 7S IVIG.

BMT, bone marrow transplantation, GVHD, graft‐versus‐host diseaseIFN, interferonIL, interleukinIVIG, intravenous immunoglobulinMLRmixed lymphocyte reactionPHA, phytohaemagglutininTNF, tumour necrosis factor.
Lymphocyte surface marker and cytokine expression in peripheral and mucosal lymph nodes
Authors: PREMIER R. R. , MEEUSEN E. N. T.
Published: March 2003

Lymphocyte populations, adhesion molecule and cytokine expression were determined in lymph nodes draining peripheral (popliteal and prescapular) or mucosal (abomasal and jejunal) tissue sites using flow cytometry analysis, immunostaining and cytokine‐specific reverse‐transcription–polymerase chain reaction (RT–PCR). Similar proportions of lymphocyte subpopulations were present in all lymph nodes except for immunoglobulin A+ (IgA+) B cells which were only present in significant numbers in the gastrointestinal lymph nodes. Peripheral lymph nodes contained a significantly higher number of CD4+ cells expressing l‐selectin and β1‐integrin than mucosal lymph nodes while the α4‐integrin chain was expressed at similar levels in all lymph nodes. The peripheral node adressin recognized by the MECA 79 monoclonal antibody (mAb) was mainly expressed on peripheral lymph node vessels. RT–PCR analysis showed that interleukin (IL)‐10 and IL‐4 were preferentially induced in the gastrointestinal lymph nodes while IL‐2 and interferon‐γ (IFN‐γ) were induced in all lymph nodes after polyclonal stimulation. These results indicate that there are substantial differences in the cell populations and microenvironments of lymph nodes draining mucosal and peripheral tissue sites in adult sheep.
Characterization of E‐selectin‐binding epitopes expressed by skin‐homing T cells
Authors: PRIEST  , BIRD  , MALHOTRA
Published: March 2003

The glycoprotein counter‐receptors for E‐selectin borne on skin‐homing T cells are poorly defined. In this study we have used flow cytometry to investigate the surface expression of potential carbohydrate ligands for E‐selectin on HUT78, a skin‐homing cutaneous T‐cell lymphoma. These cells possessed high surface expression of the KM‐93 epitope but not HECA 452 or CSLEX1 epitopes. The KM‐93 antibody also blocked the binding of HUT78 cells to E‐selectin. All these antibodies are reported to recognize sialyl Lewis X (sLex)‐like molecules. Using an E‐selectin affinity matrix, the main glycoprotein isolated from HUT78 cells was a molecular species of 90 000 MW. Other minor species of molecular weights 40 000, 60 000, 100 000, 120 000 and 200 000 were also identified as potential counter‐receptors for E‐selectin. Four of the purified counter‐receptors (90 000, 100 000, 120 000 and 200 000 MW) stained positive with the KM‐93 antibody. Immunoblot analysis of these purified glycoproteins established the identity of the 90 000 MW glycoprotein as l‐selectin. Furthermore, an anti‐l‐selectin antibody inhibited the binding of HUT78 cells to E‐selectin, probably by steric inhibition of the carbohydrate ligand for E‐selectin that is borne on the C‐type lectin domain of l‐selectin. These results suggest that a carbohydrate epitope on l‐selectin may act as a ligand for E‐selectin on skin‐homing T cells.
The regulation of superoxide generation and nitric oxide synthesis by C‐reactive protein
Authors: RATNAM  , MOOKERJEA
Published: March 2003

Activated macrophages utilize both reactive oxygen intermediates and reactive oxynitrogen intermediates for defence against microbes. However, simultaneous generation of superoxide (O− 2˙) and nitric oxide (NO) could be harmful to host cells due to the production of peroxynitrite, nitrogen dioxide and hydroxyl radicals. Therefore, the regulation of the production of these molecules is critical to host survival. During periods of inflammation or infection, the level of serum C‐reactive protein (CRP) increases in many species. Human and rat CRP have been shown to bind and interact with phagocytic cells. Since many of the interactions of CRP involve the binding to the phosphocholine ligand, we studied the role of CRP in O− 2˙ and NO generation through the modulation of phosphatidylcholine (PC) metabolism in macrophages. This study has shown that, while rat CRP inhibited phorbol myristate acetate‐ (PMA) induced release of O− 2˙ by rat macrophages, CRP‐treated macrophages released NO in a time‐ and dose‐dependent manner. CRP increased inducible nitric oxide synthase (iNOS) enzyme as well as iNOS mRNA levels in rat macrophages. Tricyclodecan‐9‐yl‐xanthogenate (D609), an inhibitor to PC phospholipase C (PC‐PLC), suppressed iNOS induction but enhanced PMA‐induced release of O− 2˙. These data indicate that an increased level of CRP during periods of inflammation may result in differential regulation of macrophage NADPH oxidase and iNOS activity. Increased hepatic synthesis of CRP may contribute to the mechanism by which phagocytic cells avoid simultaneous O− 2˙ and NO synthesis, and this could possibly be mediated through the regulation of PC‐PLC.
Direct and rapid induction of migration in human CD4+ T lymphocytes within three‐dimensional collagen matrices mediated by signalling via CD3 and/or CD2
Authors: NIKOLAI*  , NIGGEMANN*  , WERNER†  , ZÄNKER*  , FRIEDL*‡
Published: March 2003

Specific activation of T cells requires stable cell–cell interaction; however, little is known how the transition from a previously motile state into a sessile state following activation is achieved. We investigated the direct effect of T‐cell receptor (TCR)/CD3 complex engagement and/or stimulation of the accessory molecule CD2 on the locomotion of peripheral human T cells within three‐dimensional (3‐D) collagen lattices. Simultaneous engagement of CD3 and CD2 very potently stimulated T‐cell migration, resulting in the recruitment of previously sessile cells (about 24% of the total population was additionally recruited) as well as an increase in the mean duration of active locomotion. This induction of migration was accompanied by an increased tyrosine phosphorylation of a 125 000 MW substrate corresponding to the focal adhesion kinase. Using confocal laser scanning microscopy we detected antibody‐induced receptor capping into the uropod of migrating T cells whereas untreated control cells displayed an even distribution of CD3 and CD2 on the cell surface. Less pronounced induction of locomotion was achieved following triggering of CD3 or CD2 alone. Thus, in 3‐D collagen lattices specific T‐cell activation did not lead to cessation of cellular migration but rather induced cytoskeletal activity that ultimately resulted in vigorous locomotory activity.
Involvement of both donor cytotoxic T lymphocytes and host NK1.1+ T cells in the thymic atrophy of mice suffering from acute graft‐versus‐host disease
Authors: ONOE  , HARADA  , TAMADA  , ABE  , LI  , TADA  , NOMOTO
Published: March 2003

It has been reported that a dramatic decrease in the number of thymocytes (thymic atrophy) in mice suffering from acute graft‐versus‐host disease (GVHD) is ascribed to glucocorticoids. In this study, we examined the possibility that cellular immune responses may thus be involved in thymic atrophy. In contrast to chronic GVHD mice, acute GVHD (C57BL/6 X DBA/2) F1 (BDF1) hybrid mice, which were injected intravenously with both spleen and lymph node cells from C57BL/6 mice, showed a dramatic decrease in the number of CD4 CD8 double‐positive thymocytes 2 or 3 weeks after the induction of GVHD. A flow cytometric analysis revealed the donor‐derived T cells with either CD4 or CD8 molecules to infiltrate the thymus of the mice undergoing acute GVHD for 10 days. In a cytolytic assay, such thymus‐containing cells exhibited a cytolytic activity specific to the host cells. In addition, anti‐H‐2d cytolytic T cells showed a high level of cytolytic activity against BDF1 (H‐2bXd) thymocytes, whereas they also showed a low level of cytolytic activity against C57BL/6 (H‐2b) thymocytes, thus suggesting that the thymus‐infiltrating donor‐derived T cells killed the host thymocytes through both anti‐H‐2d‐specific and non‐specific mechanisms. Interestingly, a flow cytometric analysis revealed both the percentage and the absolute cell number of host‐derived NK1.1+ CD3+ cells to increase in the thymus of mice suffering from acute GVHD for 10 days. In addition, they also showed the cytolytic activity against YAC‐1 cells and the mRNA expression of interleukin‐12 (IL‐12) in the thymus to be also significantly augmented on day 7 after the induction of acute GVHD. Collectively, our results indicate that the cellular immune responses such as donor cytotoxic T lymphocytes and host NK1.1+ T cells are therefore involved in the thymic atrophy of mice suffering from acute GVHD.
Encephalitogenicity of myelin‐associated oligodendrocytic basic protein and 2′,3′‐cyclic nucleotide 3′‐phosphodiesterase for BALB/c and SJL mice
Authors: MÄÄTTÄ§  , KÄLDMAN  , SAKODA  , SALMI  , HINKKANEN
Published: March 2003

In search of new encephalitogenic myelin antigens, the 2′,3′‐cyclic nucleotide 3′‐phosphodiesterase (CNP) and 19 000 MW isoform of myelin‐associated oligodendrocytic basic protein (MOBP) were obtained as recombinant proteins by the baculovirus expression system in Spodoptera frugiperda cells and purified to homogeneity by immobilized metal chelate affinity chromatography (IMAC). The purified MOBP was soluble in water and showed retarded migration on sodium dodecyl sulphate–polyacrylamide gel electrophoresis similar to myelin basic protein (MBP). MOBP induced experimental autoimmune encephalomyelitis (EAE) in nine of 15 susceptible SJL OlaHsd mice, causing death in two animals, whereas three of 14 BALB/c mice showed mild symptoms of EAE, manifested as transient weakness of hind limbs. In both mouse strains, periventricular infiltrates of mononuclear cells were observed. In addition, both 46 000 MW and 48 000 MW CNP isoforms were shown to be non‐encephalitogenic for both mouse strains.
Strong intrinsic biases towards mutation and conservation of bases in human IgVH genes during somatic hypermutation prevent statistical analysis of antigen selection
Authors: DUNN‐WALTERS  , SPENCER
Published: March 2003

Immunoglobulin V region genes acquire point mutations during affinity maturation of the T‐cell‐dependent B‐cell response. It has been proposed that both selection by antigen and characteristics of the DNA sequence are involved in determining the distribution of mutations along the genes. There is a tendency for replacement mutations to occur in the complementarity‐determining regions and for silent mutations to accumulate in the framework regions of used genes. By analysing a group of highly mutated human IgVH4‐34 (VH4.21) and family 5 genes derived from human gut‐associated lymphoid tissues, which were out‐of‐frame between VH and JH (and therefore not used) we have investigated the distribution of mutations acquired in the absence of selection. We observed that these genes may show the statistical hallmarks of selected genes, suggesting that intrinsic biases alone may be enough to give the appearance of selection. These data suggest that analysis of the distribution of mutations in IgVH genes cannot be used reliably to state whether antigenic selection of the B‐cell carrying the genes occurred. In‐frame genes had more silent mutations than the out‐of‐frame genes and lacked stop codons. These characteristics were considered to be indicative of selection in the in‐frame genes derived from human gut‐associated lymphoid tissue.
Enrichment of c‐kit+ Lin− haemopoietic progenitor cells that commit themselves to extrathymic T cells in in vitro culture of appendix mononuclear cells
Authors: KOYA  , HONDA  , NARITA  , WATANABE  , ARAKAWA  , ABO
Published: March 2003

The appendix as well as the small intestine have recently been found to carry c‐kit+ stem cells which give rise to extrathymic T cells. In this study, the properties of c‐kit+ stem cells in the appendix of mice were further characterized. When appendix mononuclear cells (MNC) were cultured in the presence of stem cell factor, interleukin‐3, interleukin‐6 and erythropoietin on a methylcellulose culture plate, the population of c‐kitdull Lin− and that of c‐kithi Lin− cells expanded. Morphological study revealed that these c‐kithi Lin− cells were basophilic granular cells (possibly mast cells). Both populations of cultured appendix MNC were then injected into severe combined immunodeficient mice or cultured with Tst‐4 thymic stroma cells. These in vivo and in vitro studies demonstrated that c‐kitdull Lin− cells were oligopotent haemopoietic progenitor cells which gave rise to extrathymic T cells, while c‐kithi Lin− cells lacked haemopoietic progenitor cell activity. In contrast to c‐kit+ stem cells in the bone marrow, those in the appendix did not give rise to myeloid cells and conventional thymic T cells under any of the conditions tested. The present results suggest that the appendix primarily comprises c‐kit+ cells which give rise to basophilic granular cells and extrathymic T cells and that such c‐kit+ cells have the ability to replicate themselves in culture in vitro.
Interleukin‐3 and granulocyte–macrophage colony‐stimulating factor enhance the generation and function of dendritic cells
Authors: STOROZYNSKY  , WOODWARD  , FRELINGER  , LORD
Published: March 2003

Dendritic cells, well‐known for their potent antigen‐presenting activity, are generally present at very low frequency in the spleens of naive mice. We examined the ability of mice to generate functional dendritic cells (DC) following exposure to the cytokines interleukin‐3 (IL‐3) and granulocyte–macrophage colony‐stimulating factor (GM‐CSF). Tumours secreting these cytokines provided a continuous stimulus resulting in a greatly increased number and frequency of DC in the spleen. These cells were purified by conventional DC isolation techniques and were found to exhibit many of the characteristics of DC from unmanipulated mice, including high allo‐stimulatory activity in mixed lymphocyte reactions and expression of many similar cell surface markers. Using ovalbumin‐peptide specific class I‐ and class II‐restricted hybridomas containing the lacZ reporter gene, we found that these cytokine‐generated DC had a greatly increased efficacy in the uptake and processing of particulate antigen. These cells appear to have retained the ability to ingest antigen that is generally associated with immature DC, but also exhibit the peptide/major histocompatibility complex (MHC)‐presenting capabilities of mature DC. Development of an assay to measure the activity of a single DC revealed that these dual activities were the properties of the majority of the cytokine‐generated DC. These findings indicate that exposure in vivo to the cytokines IL‐3 and GM‐CSF can result in the generation of large numbers of DC with increased capability of stimulating T cells. Thus, these cells may be important in vivo in the process of cross‐priming and the subsequent generation of tumour‐reactive cytotoxic T lymphocytes (CTL).
The production of interleukin‐1β from human fetal membranes is not obligatory for increased prostaglandin output
Authors: Alvi  , Rajasingam  , Brown  , Elder  , Bennett  , Sullivan
Published: March 2003

Bacterial endotoxin increased the expression of mRNA (maximal after 4 hr) for interleukin‐1β (IL‐1β) and the release of mature protein from intact human fetal membranes. In contrast, the change in expression of mRNA for type 2 cyclo‐oxygenase (COX‐2) was biphasic, with peaks after 0·5–1 hr and after 8 hr of culture. An antibody to IL‐1β was without effect after 4 hr of culture, inhibited endotoxin‐stimulated prostaglandin E2 (PGE2) production after 8 hr of culture, and caused a parallel decrease in the expression of mRNA for COX‐2. We conclude that endotoxin induced the expression of COX‐2 through IL‐1β‐independent and IL‐1β‐dependent mechanisms, and these differences are time dependent. Corticotrophin‐releasing hormone (CRH) or platelet‐activating factor (PAF) also increased the expression of mRNA for IL‐1β and the release of IL‐1β from some, but not all, fetal membranes. The antibody to IL‐1β did not affect CRH‐stimulated or PAF‐stimulated PGE2 production or COX‐2 expression. We conclude that CRH and PAF can induce the expression of IL‐1β, but this is not obligatory for increased PGE2 release, and the effect of these stimuli on COX‐2 expression is a direct, IL‐1β‐independent effect.
Influence of the μ‐chain C‐terminal sequence on polymerization of immunoglobulin M
Authors: Getahun  , Lundqvist  , Middleton  , Warr  , Pilström
Published: March 2003

Immunoglobulin (IgM) is found in various states of covalent polymerization (μL)n, where n is typically 8, 10, or 12. The usual form of IgM of bony fish is tetrameric (8 μL units) as compared to the pentameric form (10 μL units) observed in cartilaginous fish and mammals. Two hypotheses were tested in this study. First, that the length of the μ‐chain C terminus following Cys575 determines whether an IgM polymerizes as a tetramer or as a pentamer. This was tested by examining the covalent polymerization state of mouse IgM mutated to contain a series of μ‐chain C‐termini from bony and cartilaginous fish. The results proved this hypothesis wrong: mouse IgM bearing the C‐terminal sequence of shark, salmon and cod μ‐chain behaved identically to native mouse IgM, forming predominantly (μL)10 and (μL)12 forms. The second hypothesis was that an additional Cys residue near the C terminus of the μ‐chain is responsible for the multiple covalent structures seen in IgM of the channel catfish. The addition of a catfish C terminus to the mouse μ‐chain resulted, as predicted, in the production of a series of covalently bonded forms, with the major species being (μL)4. When a Ser‐Cys unit was removed from the catfish C terminus added to the mouse μ‐chain, this resulted in production of IgM indistinguishable in structure from that of wild‐type mouse IgM.
Immune responses to Plasmodium falciparum–merozoite surface protein 1 (MSP1) antigen, II. Induction of parasite‐specific immunoglobulin G in unsensitized human B cells after in vitro T‐cell priming with MSP119
Authors: Garraud  , Diouf  , Holm  , Perraut  , Longacre
Published: March 2003

A baculovirus recombinant antigen corresponding to the C‐terminal 19 000 MW fragment of Plasmodium falciparum merozoite surface protein 1 (MSP119), has been used to prime T cells from individuals with no previous exposure to malaria, to provide help for the induction of a parasite specific antibody response in vitro. Although MSP119 alone could induce a small but detectable T‐cell response, which included interleukin‐4 (IL‐4) secretion, this response was significantly increased by the presence of IL‐2. In addition, IL‐4 was shown to synergize with IL‐2 for the induction of antigen‐specific T‐cell responses. If interferon‐γ (IFN‐γ), IL‐12, or neutralizing anti‐IL‐4 antibody was present at the time of priming, the T‐cell responses were abolished. Parasite‐specific immunoglobulin G (IgG) could be detected after secondary restimulation with MSP119, IL‐10 and anti‐CD40 monoclonal antibody in cultures containing MSP119 primed T cells, autologous B cells, IL‐2 and IL‐4. No antibody was secreted in the absence of primed T cells in this B‐cell culture assay. These data show that recombinant MSP119, a leading malaria vaccine candidate, can prime non‐immune human lymphocytes under defined in vitro experimental conditions, which include regulatory cytokines and/or other costimulatory molecules. This is a complementary approach for exploring immunogenic mechanisms of potential vaccine candidates such as P. falciparum antigens in humans.
Activation, survival and apoptosis of CD45RO+ and CD45RO− T cells of human immunodeficiency virus‐infected individuals: effects of interleukin‐15 and comparison with interleukin‐2
Authors: Naora  , Gougeon
Published: March 2003

HIV infection is associated with increased representation of T cells bearing an activated, memory (CD45RO+) phenotype. Although administration of antiretroviral agents and interleukin‐2 (IL‐2) augment depleted CD4+ T‐cell numbers, such therapies have been preferentially beneficial for CD45RO+ T cells. Interleukin‐15 (IL‐15) exhibits many biological activities in common with IL‐2, including promoting T‐cell survival and proliferation. The present study found that these two cytokines differed in their ability to induce proliferation, enhance survival, and control apoptosis of CD45RO+ and CD45RO− T‐cell populations of human immunodeficiency‐ (HIV) infected individuals. When used at equivalent concentrations in vitro, IL‐15 was more potent than IL‐2 in activating and stimulating proliferation of CD4+CD45RO+, CD8+CD45RO+ and CD8+CD45RO− cells, but failed to be more effective than IL‐2 in reducing apoptosis. Poor activation of CD4+CD45RO− cells by IL‐15 and to IL‐2 appeared to be attributable to low expression of the β receptor chain utilized by both cytokines. However, IL‐15 was more effective than IL‐2 in enhancing survival of the CD4+CD45RO− population, suggesting a greater protective effect of IL‐15 for naive CD4+ T cells, which are preferentially lost in HIV‐infected individuals.
Depletion of CD8+ cells abolishes memory in acquired immunity against Chlamydia pneumoniae in BALB/c mice
Authors: Penttilä  , Anttila  , Varkila  , Puolakkainen  , Sarvas  , Mäkelä  , Rautonen
Published: March 2003

The importance of T cells in Chlamydia pneumoniae infection in mice was assessed by comparing wild‐type BALB/c mice with nude mice and mice depleted in vivo of either CD4+ or CD8+ T cells. Whereas wild‐type mice cleared the primary infection in 3 weeks, nude mice were only able to restrict the infection and could not clear it during the observation period of 56 days. Nude mice exhibited a greater number of macrophages in their lungs and the pulmonary cells secreted a higher level of tumour necrosis factor‐α (TNF‐α) than wild‐type mice. Depletion of CD4+ cells did not change the overall infection kinetics of the primary infection. However, depletion of CD8+ cells resulted in a slightly impaired clearance of the bacteria in the late stages of primary infection. To assess the role of the two T‐cell subsets in the acquired immunity that develops during primary infection in wild‐type BALB/c mice, in vivo depletions were performed during reinfection. Prior to reinfection, immunocompetent wild‐type mice were infected and natural immunity was allowed to form. During reinfection, depletion of CD4+ cells did not have any effect on infection kinetics, whereas depletion of CD8+ cells abolished the protection, reverting the infection kinetics and bacterial load to the same levels found in wild‐type mice during primary infection. These results show that T cells are necessary for clearing C. pneumoniae infection in mice. Furthermore, whereas neither of the two main T‐cell subsets, separately, were essential for clearance of primary infection, the induced protective immunity was strongly CD8 dependent.
H‐2Dd engagement of Ly49A leads directly to Ly49A phosphorylation and recruitment of SHP1
Authors: Daws  , Eriksson  , Öberg  , Ullén  , Sentman
Published: March 2003

We have used a number of in vitro and in vivo techniques to identify the molecules that can bind to the cytoplasmic tail of the Ly49A receptor. Affinity chromatography using peptides corresponding to the N‐terminal 18 amino acids of Ly49A allowed the recovery of a number of proteins that bound preferentially to the tyrosine‐phosphorylated peptide, including SH2‐containing phosphatase‐1 (SHP1) and the SH2‐containing inositol 5′ phosphatase (SHIP). In another approach, using the entire cytoplasmic domain of the Ly49A receptor, we found that SHP2 also interacted with the tyrosine‐phosphorylated form of the Ly49A cytoplasmic tail. Using BIACORE®2000 analysis, we determined that both SHP1 and SHP2 bound to the tyrosine‐phosphorylated cytoplasmic tail of Ly49A with affinities in the nanomolar range, whilst SHIP showed no binding. Mutation of tyrosine‐36 to phenylalanine did not significantly affect the affinities of these proteins for the tyrosine‐phosphorylated cytoplasmic tail of Ly49A. In addition, using a whole‐cell system with T‐cell lymphoma cell lines that expressed the Ly49A receptor or its H‐2Dd ligand, we determined that engagement of Ly49A by its major histocompatibility complex (MHC) ligand leads to tyrosine‐phosphorylation events and recruitment of SHP1. Recruitment of SHP1 was rapid and transient, reaching a maximum after 5 min. These data suggest that mechanisms for the inhibitory signal are generated following receptor engagement. They also provide direct evidence that ligand engagement of the Ly49A receptor is responsible for recruitment of downstream signalling molecules.
Expression of the RelB transcription factor correlates with the activation of human dendritic cells
Authors: Clark  , Gunningham  , Troy  , Vuckovic  , Hart
Published: March 2003

The RelB gene product is a member of the nuclear factor (NF)‐κB family of transcription factors. It has been identified recently within mouse antigen‐presenting cells and human monocyte‐derived dendritic cells (DC). Disruption of the mouse RelB gene is accompanied, amongst other phenotypes, by abnormalities in the antigen‐presenting cell lineages. In order to define RelB expression during human DC differentiation, we have analysed RelB mRNA by reverse transcriptase–polymerase chain reaction and RelB protein by intracellular staining in CD34+ precursors and different types of DC preparations. RelB mRNA was not detected in CD34+ precursor populations. Fresh blood DC (lineage−human leucocyte antigen‐DR+ (lin−HLA‐DR+)) lacked RelB mRNA and cytoplasmic RelB protein but a period of in vitro culture induced RelB expression in blood DC. Purified Langerhans’ cells (LC) (CD1a+ HLA‐DR+) failed to express RelB mRNA. Immunocytochemical staining identified RelB protein in human skin epithelium. RelB protein was expressed in a very few CD1a+, CD83+ or CMRF‐44+ dermal DC but was not present in CD1a+ LC. Tonsil DC (lin−HLA‐DR+ CMRF‐44+) were positive for RelB mRNA and RelB protein. Intestinal DC (HLA‐DR+) also lacked immunoreactive RelB protein. The majority of interdigitating CD83+, CMRF‐44+, CMRF‐56+ or p55+ DC located in paracortical T‐lymphocyte areas of lymph node and tonsil contained RelB protein. The expression of RelB mRNA and RelB protein correlates with the activated phase of blood DC and the postmigration cell (activated) stage of tissue DC development.
Mechanisms of binding of cutaneous lymphocyte‐associated antigen‐positive and αeβ7‐positive lymphocytes to oral and skin keratinocytes
Authors: Brown  , Furness  , Speight  , Thomas  , Li  , Thornhill  , Farthing
Published: March 2003

Intraepithelial lymphocytes (IEL) utilize the integrin αeβ7 on their surface to bind to E‐cadherin on epithelial cells in the gut and breast. In oral mucosa and skin IEL express αeβ7 and the cutaneous lymphocyte‐associated antigen (CLA) but the mechanisms of adhesion of these subsets to keratinocytes are unknown. Levels of αeβ7 and CLA were up‐regulated on peripheral blood lymphocytes (PBL) by transforming growth factor‐β (TGF‐β) and interleukin‐12 (IL‐12), respectively, and both groups of lymphocytes adhered onto oral and skin keratinocytes. Adhesion of IL‐12‐activated PBL was totally abolished by anti‐lymphocyte‐associated function antigen type 1 (anti‐LFA‐1) antibodies but was unaffected by anti‐αeβ7 antibodies indicating that adhesion of the CLA‐positive subset is mediated via LFA‐1 interaction with intercellular adhesion molecule‐1 (ICAM‐1). Adhesion of TGF‐β‐activated PBL to E‐cadherin‐positive oral and skin keratinocytes was partially inhibited by anti‐αeβ7 antibodies but was unaffected by the blocking antibody E4.6 against E‐cadherin which detects the binding site for αeβ7‐positive lymphocytes in breast and gut epithelium. TGF‐β‐activated PBL also bound to an E‐cadherin‐negative oral keratinocyte cell line and adhesion was inhibited by anti‐αeβ7 antibodies. These results strongly suggest that in oral epithelium and epidermis αeβ7‐positive lymphocytes do not bind to E‐cadherin and there may be a novel second ligand for the αeβ7 integrin.
Immunomodulatory effect of a plasmid expressing CD40 ligand on DNA vaccination against human immunodeficiency virus type‐1
Authors: Ihata A. , Watabe S. , Sasaki S. , Shirai A. , Fukushima J. , Hamajima K. , Inoue J. , Okuda K.
Published: March 2003

CD40 ligand is a costimulatory molecule which acts a potent immunomodulator. We found the mice inoculated with human CD40 ligand expression plasmid (pMEhCD40L) combined with human immunodeficiency virus type‐1 (HIV‐1) DNA vaccine exhibited both humoral and cellular antigen‐specific immunological enhancement. The expression of hCD40L induced predominantly antigen‐specific immunoglobulin G (IgG) antibody response while it failed to induce mucosal IgA response. Delayed‐type hypersensitivity (DTH) and cytotoxic T lymphocyte (CTL) activity were induced in a dose‐dependent manner. Examination of the relative levels of the two IgG subclasses showed that co‐injection of pMEhCD40L enhanced IgG2a response without suppressing IgG1 response. Similarly, the expression of pMEhCD40L enhanced not only T helper 1 (Th1)‐ but also Th2‐type cytokine production. In conclusion, co‐inoculation of pMEhCD40L with DNA vaccine was shown to be a useful way to enhance CTL responses without suppressing the humoral immune response in acquired immune deficiency syndrome (AIDS) patients.