Apmis

Chidgey, Ann R.; Boyd, Richard L.

doi: 10.1111/j.1600-0463.2001.907801.xpmid: N/A

The intrathymic differentiation events leading to the development and export of mature T cells tolerant to self yet capable of responding to foreign peptide antigen in the context of self‐MHC are clearly both dynamic and complex. The changing phenotype of the developing thymocyte as it migrates through and interacts with the heterogeneous thymic microenvironment and the intracellular signalling events associated with such interactions are being extensively studied, yet many aspects remain poorly defined, such as the precise relationship between stromal cells and thymic selection. Positive and negative selection are crucial events in the development of T cells, leading to a diverse yet non‐autoreactive immune system. A breakdown in either of these processes could lead to either a reduced T cell repertoire or the escape into the periphery of autoreactive T cells – both clearly having deleterious consequences for the health of the individual. This review aims to summarise the current status of research in thymic positive selection with emphasis on the role of different cell types and peptides.

Klink, Magdalena; Sawierzko, Anna; SuLowska, Zofia

doi: 10.1111/j.1600-0463.2001.907802.xpmid: N/A

Conversion of hydroxylamine (HA) to nitric oxide (NO) has been studied in the presence or absence of human neutrophils with or without myristate acetate phorbol (PMA), catalase (CAT), hydrogen peroxide (H2O2), and superoxide dismutase (SOD) and nitric oxide synthase (NOS) inhibitors. The generation of NO from HA in the presence of neutrophils was higher than in the cell‐free system. We found that catalase did not influence the nitrite generation from HA in the cell‐free system and in the presence of neutrophils. The H2O2 enhanced the NO generation from HA in the presence of neutrophils only. When catalase and H2O2 were added together, a high increase of NO generation from HA in both systems was observed. The addition of SOD decreased whereas addition of PMA enhanced the NO generation from HA in the presence of neutrophils. The presented data show the possible role of oxygen radicals in the decomposition of HA to NO. The addition of NOS inhibitors to the culture of neutrophils decreased the generation of nitrite from HA. Our results suggest that NO generation from HA, which is an intermediate in NO production from L‐arginine, may be supported by an enzymatic pathway in which cellular NO synthase is involved.

Renkonen, Jutta; Räbinä, Jarkko; Mattila, Pirkko; Grenman, Reidar; Renkonen, Risto

doi: 10.1111/j.1600-0463.2001.907803.xpmid: N/A

Selectin‐dependent cell binding has importance in the extravasation of blood‐circulating tumor cells and in the generation of metastases. Cell surface glycoproteins decorated with sialylated, fucosylated epitopes, such as sialyl Lewisx (sLex), are ligands for selectins. Not only terminal sLex moieties but also proximal core structures contribute to the formation of binding epitopes for selectins. Core 2 β1,6‐N‐acetylglucosaminyltransferases (C2GnT) and α1,3‐fucosyltransferases (α1,3‐FucT) have been suggested to be the rate‐limiting enzymes in the synthesis of selectin ligands. We analyzed oral cavity epithelial carcinoma cell lines and showed their expression of RNA transcripts for C2GnT and α1,3‐FucT, identified α1,3‐FucT enzyme activities, and analyzed the cell surface sLex expression levels. Neither the pattern of expressed enzymes nor the α1,3‐FucT activity directly predicted the binding capacity of E‐selectin. However, only the sLex‐expressing cell lines were capable of binding to E‐selectin, but not to P‐selectin, thus putatively promoting the selectin‐mediated metastasis. These findings suggest that C2GnT in combination with α1,3‐Fuc‐T contribute to the selectin‐mediated metastasis in oral cavity carcinomas.

Byström, Jonas; Tenno, Taavo; Håkansson, Lena; Amin, Kawa; Trulson, Agneta; Högbom, Erik; Venge, Per

doi: 10.1111/j.1600-0463.2001.907804.xpmid: N/A

The eosinophil cationic protein (ECP) is a cytotoxic protein with ribonuclease activity, produced and stored in bone marrow eosinophil myelocytes. Mature circulating eosinophils contain about 10 pg ECP per cell. The aim of this study was to investigate the possibility that monocytes produce and store ECP. By results from flow cytometry and specific protein measurement it is shown that human monocytes contain ECP (monocytes about 10 fg ECP per cell). RT‐PCR analysis indicated the presence of mRNA coding for ECP in blood monocytes but not in alveolar macrophages. Furthermore, mRNA coding for ECP and low amounts of the protein were found in three myeloid cell lines representing different stages of monocytic differentiation. Differentiation of U‐937 cells to macrophages induced lowered transcription of the ECP gene and reduced protein production. Immunohistochemical staining of lung tissue indicated that lung macrophages do not contain ECP. It is concluded that ECP is produced to a low extent by human monocytes and that the production is shut down during macrophage differentiation. This might indicate an alternative transcriptional regulation of the ECP gene in the monocytic lineage compared to the eosinophil lineage.

Bregenholt, Søren; Ishøy, Torben; Skovgaard, Lene T.; Suadicani, Paul; Appleyard, Merethe; Guldager, Bernadette; Malte, Lone; Gyntelberg, Finn; Claesson, Mogens H.

doi: 10.1111/j.1600-0463.2001.907805.xpmid: N/A

Veterans who have participitated in the Gulf War suffer from a number of symptoms, collectively referred to as the Gulf War Syndrome. It has been hypothesized that a change in the systemic cytokine balance or other changes in immunological parameters could be responsible for some of the symptoms. We analyzed the peripheral blood natural killer (NK) cell activity of 686 Gulf War personnel who had been present in the Persian Gulf area during and immediately after the Gulf War as well as 231 gender and age‐matched controls. The test material included individual samples of frozen peripheral blood mononuclear cells kept at −139°C for a period of 50 to 380 days prior to NK cell analysis of freshly thrawed cells. Significant differences in NK‐cell activity were not observed by direct comparison of the levels of natural cytotoxic activity in the two groups. However, NK‐cell cytotoxicity as such decreased due to cryopreservation. Surprisingly, the NK cells obtained from control donors were significantly (p<0.0001) more sensitive to freezing conditions than cells from the Gulf War personnel, leaving the marginal comparison between the two groups untrustworthy, in particular because of the marked difference between the −139°C storage times used for the two groups. Freshly thawed samples of peripheral blood T lymphocytes (CD2+ cells) from 109 randomly selected Gulf War personnel and 68 gender‐ and age‐matched controls were stimulated for 3 days with phytohemagglutinin followed by 4 h activation by phorbol ester and ionomycin, and were stained for intracellular content of interleukin‐2, ‐5, ‐10 and interferon‐γ. As with natural cytotoxicity, the length of cell storage at −139 °C influenced the production of cytokines. No significant differences in the cytokine production between the two groups were observed when the influence of the storage period was taken into consideration. Together, these data suggest that no overall long‐term effects on NK‐cell function and T‐cell cytokine production are present in the Danish Gulf War personnel. Moreover, cryopreservation is a major potential source of bias when studying the physiology of thawed NK and T cells.

Törmänen‐Näpänkangas, U.; Soini, Y.; Pääkkö, P.

doi: 10.1111/j.1600-0463.2001.907806.xpmid: N/A

Aim: To test whether the number of tumour‐infiltrating mononuclear cells (MNC), namely T‐lymphocytes (TIL) and, to a lesser degree, B‐lymphocytes and macrophages, is associated with tumour cell apoptosis in non‐small cell lung carcinoma (NSCLC). Methods and results: Eighty‐four non‐small cell lung tumours were analysed with specific antibodies and the extent of apoptosis was determined using 3′‐end labelling of fragmented DNA (TUNEL). All parameters were determined from the same tumour areas. In general, adenocarcinomas showed a higher number of MNC than squamous cell carcinomas (p=0.04). The number of MNC increased concurrently with the grade of tumour, occurrence being highest in high grade (III) tumours (p=0.05). The number of apoptotic cells was significantly higher in tumours with a high number of CD3 + and CD8+ lymphocytes (p=0.01) and B‐cells (p=0.05). Tumours showing abnormal p53 protein expression had a significantly lower count of CD8 + T‐cells compared to p53‐negative tumours (p=0.03). Conclusions: Our results showed an association between lymphocytic infiltration and extent of apoptosis is NSCLC, suggesting that an attempt to suppress the growth of transformed tumour cells exists even when the tumour has reached an advanced stage.

Kitaura, Hideki; Ohara, Naoya; Kobayashi, Kazuhide; Yamada, Takeshi

doi: 10.1111/j.1600-0463.2001.907807.xpmid: N/A

Mycobacterial infection is a common occurrence in patients with acquired immune deficiency syndrome. Incubation of U1, a chronically HIV‐1‐infected human promonocytic cell line, with Mycobacterium smegmatis, M. avium, M. bovis BCG and M. tuberculosis resulted in enhancement of p24 antigen release in the supernatant, indicating that these mycobacteria could activate HIV replication from this cell line. The amount of p24 in the culture infected with M. smegmatis was higher than in cultures infected with other mycobacteria. The amounts of p24 release in cultures infected with M. avium and M. bovis BCG were intermediate. M. tuberculosis slightly stimulated HIV replication. The amount of TNF‐α produced by U1 cells was correlated with the amount of p24 antigen release. The IL‐β and IL‐6 levels in the supernatant from cultures infected with all species were the same. The antibody to TNF‐α inhibited p24 release induced by mycobacterial infections. The anti‐IL‐1β and anti‐IL‐6 antibodies, however, scarcely influenced stimulation of HIV replication by mycobacterial infection. These data suggested that activation of HIV replication by mycobacteria mainly occurred by secondary release of cytokine TNF‐α.

Tollersrud, Tore; Berge, Torunn; Andersen, Svein Rune; Lund, Arve

doi: 10.1111/j.1600-0463.2001.907808.xpmid: N/A

The surfaces of four strains of Staphylococcus aureus, which differed in their expression of capsular polysaccharides, were examined using atomic force microscopy. The images show that it is possible to get information about surface characteristics of S. aureus using atomic force microscopy (AFM) following simple preparation. Strains Smith Diffuse (serotype 2), Reynolds (serotype 5), Wood‐46 (capsule negative) and JL243 (capsule negative) were grown on medium known to promote the expression of capsular polysaccharides. The bacteria were air‐dried prior to being imaged using tapping‐mode AFM. Differences in the appearance of the bacterial surfaces were evident between the strains. The two capsule‐negative strains exhibited a smooth regular surface, as opposed to the mucoid appearance of the two strains having polysaccharide capsules. Moreover, comparison of images of the heavily encapsulated serotype 2 strain and the serotype 5 strain indicates that a type 2 capsule can be distinguished from a type 5 microcapsule.

Mikami, Yoshiki; Maehata, Kenichiro; Fujiwara, Keiichi; Manabe, Toshiaki

doi: 10.1111/j.1600-0463.2001.907809.xpmid: N/A

We report a case of adenomyoma of endocervical type arising in a 44‐year‐old female. Grossly, a well‐circumscribed tumor protruding from the right side of the uterine cervix was seen which was assumed to be an ovarian tumor by imaging studies carried out preoperatively. The tumor was composed of a mixture of proliferating glands of endocervical type and fascicles of smooth muscle cells. There was no distinct nuclear anaplasia in the proliferating glands, there were no architectural abnormalities, and there was no evidence of destructive stromal invasion such as desmoplasia. Minimal deviation adenocarcinoma, which shows a gastric phenotype with immunoreactivity for M‐GGMC‐1 and predominantly PAS‐positive neutral mucin, was a serious diagnostic possibility, but the lesion was well‐circumscribed, cytologic and architectural abnormalities were absent, and staining for M‐GGMC‐1 was negative, which suggested a diagnosis of endocervical adenomyoma. An increased Ki‐67 labeling index by up to 20%, the presence of predominantly PAS‐positive neutral mucin, and membranous immunoreactivity for CEA in limited areas were diagnostic pitfalls, which could lead to an erroneous diagnosis of minimal deviation adenocarcinoma of the uterine cervix. Therefore, the results of these ancillary techniques should be interpreted with caution and combined with gross and light microscopic features.

Wang, Mei; Adawi, Diya; Molin, Göran; Pettersson, Bertil; Jeppsson, Bengt; Ahrne, Siv

doi: 10.1111/j.1600-0463.2001.907810.xpmid: N/A

The bacterial flora of the intestine and the bacteria found in liver, mesenteric lymph nodes, portal and arterial blood after D‐galactosamine‐induced liver injury, with and without pretreatment with Lactobacillus plantarum DSM 9843, were studied in the rat. Dominating representatives were identified to species level by 16S rDNA sequencing and typed by randomly amplified polymorphic DNA (RAPD) and by restriction endonuclease analysis (REA) for strain definition. It was proven that bacterial strains from the intestine occur at extraintestinal sites after liver injury. Lactobacillus spp. dominated the intestinal flora and were also the most frequently found genus in the liver and the mesenteric lymph nodes. Some of the blood isolates, identified as Staphylococcus aureus, Proteus vulgaris and Bacteroides merdae, were not found as a dominating part of the mucosal flora. Treatment with L. plantarum before liver injury decreased translocation and made the intestinal flora increasingly dominated by lactobacilli.