bluuebunny/crossref_metadata_2025 huggingface dataset:
Epithelioid cell granulomas in chronic hepatitis C: immunohistochemical character and histological marker of favourable response to interferon‐α therapy
Authors: Harada K , Minato H , Hiramatsu K , Nakanuma Y
Published: March 2003

Aims: The clinicopathological significance of intrahepatic epithelioid cell granulomas in chronic hepatitis C was determined.

Method and results

Granulomatous lesions were surveyed in 542 liver biopsy specimens and were immunohistochemically examined. We also tested whether this lesion is a marker of response to interferon‐α therapy in chronic hepatitis C. Granulomatous lesions in hepatic lobules and/or portal tracts were identified in 11/542 (2%) cases with chronic hepatitis C. Granulomas were positive for HLA‐DR and β2‐microglobulin, and were surrounded by T‐cells. Among them, three chronic hepatitis C cases showed portal granulomas with mild biliary epithelial damage. Bile ducts showing mild epithelial damage in chronic hepatitis C were positive for β2‐microglobulin, but negative for HLA‐DR, while both antigens were frequently expressed in damaged bile ducts in primary biliary cirrhosis (PBC). All five cases of chronic hepatitis C with granulomas who had interferon‐α therapy and were followed up and were found to have responded well.

Conclusion

Granulomas showed the same immunohistochemical phenotypes, though the expression of HLA‐DR on bile ducts in PBC but not in chronic hepatitis C suggests a different pathogenesis. Granulomas may predict a favourable response to interferon‐α therapy in chronic hepatitis C.
Loss of laminin‐5 in the epithelium–stroma interface: an immunohistochemical marker of malignancy in epithelial lesions of the breast
Authors: Henning  , Berndt  , Katenkamp  , Kosmehl
Published: March 2003

Aims

To demonstrate immunohistochemically the α3 and γ2 chain of laminin‐5 in benign epithelial and malignant lesions of the human breast.

Methods and results

The α3 chain was identified by the monoclonal antibody BM165 and the γ2 chain by GB3 in shock frozen samples using APAAP (alkaline phosphatase monoclonal anti‐alkaline phosphatase) technique. The pre‐existing breast epithelium, the 12 benign ductal and lobular proliferations and the three fibroadenomas showed a continuous immunostaining in the basement membrane region. In contrast to benign epithelial lesions, the 44 cases of invasive breast carcinoma showed a loss of the laminin‐5 chains in more than 50% of the carcinoma stroma interface. Twenty‐four out of the 44 invasive carcinomas revealed a complete loss of laminin‐5 immunostaining. Focal defects of the laminin‐5 immunostaining were also found in ductal carcinoma in situ in its pure form.

Conclusions

As recently described, the malignant transformation of breast epithelium with expression of an invasive phenotype is associated with a decrease of hemidesmosomes. The reduced immunostaining of laminin‐5 is in line with this finding because laminin‐5 represents the major component of the anchoring filaments attaching hemidesmosomes to the basement membrane. We feel that immunohistochemical demonstration of laminin‐5 may serve as a marker of benignity in epithelial breast lesions. While other carcinoma types exhibit an increased laminin‐5 deposition, which has been suggested as an invasion promoting factor, the loss of laminin‐5 in breast cancer supports the view that breast carcinomas do not utilize laminin‐5 for invasion.
Blastic transformation of mantle cell lymphoma: genetic evidence for a clonal link between the two stages of the tumour
Authors: László  , Matolcsy
Published: March 2003

Aims

The blastic variant of mantle cell lymphoma (MCL‐BV) may develop through histological transformation of mantle cell lymphoma (MCL). However, the clonal link between the tumour cells of MCL and transformed MCL‐BV has not been established at the genetic level. To investigate this link longitudinal molecular genetic studies have been performed in two cases of MCL that showed morphological transformation to MCL‐BV.

Methods and results

Polymerase chain reaction (PCR) and nucleotide sequence analyses of the complementary determining region 3 (CDR) of the immunoglobulin (Ig) heavy chain (H) gene were performed to identify clone‐specific rearrangements. In both cases, nucleotide sequence analysis revealed common clone‐specific IgH gene rearrangements in MCL and subsequent MCL‐BV.

Conclusions

These results provide genetic evidence for the common clonal origin of MCL and subsequently developed MCL‐BV.
The fraction of fields showing neoplastic tubules: a practical estimate of tubular differentiation in breast cancer
Authors: Kronqvist  , Kuopio  , Pirvu  , Collan
Published: March 2003

Aims

The purpose of the study is to evaluate histological measurement methods for quantitative assessment of the degree of tubular differentiation in breast cancer.

Methods and results

We evaluated tubular differentiation in 20 cases of invasive breast cancer by four different assessment methods. Method 1 was the traditional subjective evaluation of the amount of malignant tubules in each sample. Method 2 evaluated the fraction of fields presenting tubular differentiation by registering the presence or absence of neoplastic tubular structures in each microscopic field. In method 3 the area fraction of malignant epithelial cells presenting tubular differentiation was assessed field‐by‐field and expressed as an average of the whole tumour area. Method 4 applied point counting for evaluating the fraction of malignant epithelial cells in tubular structures. By correlation and reproducibility analyses, method 1 was inferior to the other methods. Method 4 was accurate but too laborious and time‐consuming for clinical use. Methods 2 and 3 were both efficient and reproducible and could be used interchangeably. With the time and effort used in the measurements taken into consideration method 2 was best applicable to clinical practice.

Conclusion

Accurate evaluation of tubular differentiation in breast cancer is possible by defining the presence or absence of tubular differentiation in microscopic fields of a histological section. Assessment of the fraction of fields with tubular differentiation (FTD) is simple, unambiguous, objective and fast − even a large sample can be screened in less than 10 min. In our results, FTD has clear advantages over subjective or point counting‐based evaluation methods of tubular differentiation.
Frequent presence of neuroendocrine small cells in thymic carcinoma: a light microscopic and immunohistochemical study
Authors: Kuo T‐t
Published: March 2003

Aims

Neuroendocrine differentiation has been described in conventional carcinomas of various organs. Small cells postulated to be neuroendocrine cells were observed previously in some thymic carcinomas. This study was conducted to confirm and characterize the presence of neuroendocrine small cells in thymic carcinomas by light microscopy and immunohistochemistry.

Methods and results

Twenty‐two thymic carcinomas were studied by light microscopy to detect the presence of small neuroendocrine‐like cells. They were found in four of 10 squamous cell carcinomas (SCC) and seven of eight adenosquamous carcinomas (ASC). No small cells were observed in three lymphoepithelioma‐like carcinomas (LELC) and one adenocarcinoma. The small cells were located within the tumour nests and constituted less than 1% of the entire tumour. In one case, small cells also extended outside the tumour nests. Rosette formation was seen in three cases. They were proved to be neuroendocrine cells by their immunoreactivity to neuron‐specific enolase, chromogranin A, and/or synaptophysin. A few scattered neuroendocrine small cells were found only by immunohistochemistry in one case each of SCC, ASC, and LELC. The small cells were also strongly positive for cytokeratin (CK) 8 and CK18 but negative for CK19 and CK20. The predominant carcinoma cells other than the neuroendocrine small cells also displayed neuroendocrine markers in 68% of the cases studied.

Conclusions

Neuroendocrine small cells can be recognized by light microscopic examination in approximately 61% of thymic SCC and ASC. Neuroendocrine markers, CK8 and CK18 can aid in confirming their presence. The neuroendocrine small cells present in thymic carcinomas are different from the main carcinoma cells displaying immunohistochemical neuroendocrine markers. The presence of neuroendocrine small cells could be an useful marker for the differentiation of thymic carcinomas from thymomas and carcinomas of other sites.
Interrelationship between Epstein–Barr virus infection in gastric carcinomas and the expression of apoptosis‐associated proteins
Authors: Ishii H , Gobé G , Kawakubo Y , Sato Y , Ebihara Y
Published: March 2003

Aims:

Epstein–Barr virus (EBV) and its associated proteins may be protective against the occurrence of apoptosis that would normally inhibit cancer development and progression. Alternatively, the viral infection may cause altered or mutated expression of oncogenes or tumour suppressor genes that are necessary for tumour development, an action that may also involve apoptosis. In this study, a relationship was sought between occurrence of EBV infection, expression of apoptosis‐associated proteins (tumour suppressor gene p53 and oncogenes c‐myc and bcl‐2) and levels of cell death (apoptosis or necrosis) in 119 cases of gastric carcinoma.

Methods and results:

The EBV status of the gastric carcinomas (using the EBV‐encoded small RNA I (EBER‐1) and in‐situ hybridization), stage and grade of tumour and sex of patients were compared for bcl‐2, p53 and c‐myc expression patterns. EBER‐1 was detected in approximately 20% of cases studied. There was no significant correlation between levels of cell death in the tumour tissue and EBV status. In the protein analyses, development and progression of gastric carcinoma, with or without EBV infection, was independent of bcl‐2 expression. However, in gastric cancers with EBV infection, p53 overexpression was inhibited and c‐myc expression was increased in early stage cancers, in comparison with decreased c‐myc expression in late stage cancers.

Conclusions:

The p53 and c‐myc expression patterns indicate that EBV‐infected gastric carcinomas are less likely to have a natural regression via apoptosis at an early stage and explain, in part, the resistance to treatment of late stage of gastric cancers.
Increased microvessel density in malignant and borderline mammary phyllodes tumours
Authors: Tse G M K , Ma T K F , Chan K‐F , Law B K B , Chen M‐H , Li K‐H , Chan E C K , Mak M K F
Published: March 2003

Increased microvessel density in malignant and borderline mammary phyllodes tumours

Aims: Tumour vascularity is considered a prognostic indicator in breast carcinoma, but its utility in mammary phyllodes tumour has not been explored. The authors report the correlation between intratumoral microvessel density and the histological grade of phyllodes tumour.

Methods and results: Forty cases of phyllodes tumour were reviewed for stromal cellularity, overgrowth, cytological pleomorphism, mitotic count and margin pattern. Using established criteria, these were diagnosed as benign (n=28), borderline (n=10) and malignant (n=2). Microvessel density was counted on CD31‐stained slides as the number of vessels per high power field. For benign phyllodes tumour, the range was 7–26.2 (mean 13.1); for borderline phyllodes tumour the range was 17.2–32.5 (mean 22.4); for malignant phyllodes tumour the range was 25.9–33.3 (mean 29.6). The difference between the benign and borderline groups was significant (P < 0.0001) but that between the borderline and malignant groups was not, due to the small number of malignant cases.

Conclusions: There is a significant difference in stromal microvessel density between benign and borderline phyllodes tumour. Although the small number of cases of malignant phyllodes tumour limits further interpretation, we believe that microvessel density can be used as an additional objective histological parameter in the evaluation of phyllodes tumour.
Morphometric assessment of gastric antral atrophy: comparison with visual evaluation
Authors: Ruiz B , Garay J , Johnson W , Li D , Rugge M , Dixon M F , Fiocca R , Genta R M , Hattori T , Lechago J , Price A B , Sipponen P , Solcia E , Watanabe H , Correa P
Published: March 2003

Morphometric assessment of gastric antral atrophy: comparison with visual evaluation

Aims: As part of a multinational effort to reach a consensus in the definition and evaluation of atrophic gastritis, we applied morphometric techniques to 22 antral biopsy specimens examined visually by 12 experienced gastrointestinal pathologists.

Methods and results: Atrophy was defined as loss of glands. Each pathologist graded atrophy with both non‐standardized and standardized approaches. Discriminant function analyses of morphometric measurements were conducted to validate and grade atrophy. Kappa statistics were used to compare the performance of each pathologist against the group mode and against the discriminant functions’ grading of atrophy. Three morphometric indexes showed significant differences among categories of atrophy utilizing non‐standardized as well as standardized visual atrophy grades: (i) the ratio of glandular length to total mucosal thickness; (ii) the proportion of the secretory compartment area occupied by glands; and (iii) the number of glandular cross sections per 40× microscopic field. The discriminant function analyses verified all cases classified visually as either non‐atrophic, or moderately/severely atrophic; it verified as mildly atrophic 40% of the cases classified visually as mildly atrophic; and classified the remaining 60% as moderately or severely atrophic. The κ statistics were good or excellent for the majority of pathologists.

Conclusions: The evaluation of antral atrophy, simply defined as loss of glands, can be reliable and reproducible. The visual grading of atrophy as absent, moderate and severe is entirely consistent with objective morphometric observations.
Capsular intravascular endothelial hyperplasia: a peculiar form of vasoproliferative lesion associated with thyroid carcinoma
Authors: Tse L L Y , Chan I , Chan J K C
Published: March 2003

Capsular intravascular endothelial hyperplasia: a peculiar form of vasoproliferative lesion associated with thyroid carcinoma

Aims: Florid vasoproliferative processes are uncommon in the thyroid gland. We report three cases of an unusual vasoproliferation involving the capsular blood vessels of thyroid carcinoma.

Methods and results: The histological diagnoses of the three cases were made on conventional histological sections. Two cases were minimally invasive follicular carcinomas and one case was an encapsulated variant of papillary carcinoma. Some blood vessels in the tumour fibrous capsule were filled with spindly cellular proliferations forming irregular vascular clefts and papillae. Immunohistochemical studies for CD31, CD34 and muscle‐specific actin confirmed that the spindly cells were mostly endothelial cells variably supported by pericytes.

Conclusion: This peculiar intravascular endothelial hyperplasia by itself should not be mistaken for vascular invasion by tumour, but evidence of malignancy must be diligently sought by extensive sampling because the lesion has thus far been consistently associated with malignant thyroid neoplasms.
Prichard’s structures of the fossa ovalis are not histogenetically related to cardiac myxoma
Authors: Acebo E , Val‐Bernal J F , Gómez‐Román J J
Published: March 2003

Prichard’s structures of the fossa ovalis are not histogenetically related to cardiac myxoma

Aims: Cardiac myxomas are neoplasms of unknown histogenesis. They are thought to arise from hypothetical subendothelial vasoformative reserve cells or from primitive cells which reside in the fossa ovalis and surrounding endocardium. In 1951 Prichard described a kind of microscopic endocardial structure with a predilection for the interatrial septum, which were suggested to be related to cardiac myxomas. To confirm the existence of Prichard’s structures and to clarify their role in the genesis of cardiac myxomas, we examined histologically the fossa ovalis and we performed an immunohistochemical study of the endocardial abnormalities that were found.

Methods and results: A prospective histological study of 100 interatrial septa and an immunohistochemical study of three out of the 12 endocardial abnormalities that were detected, as well as of four conventional cardiac myxomas were accomplished. Antibodies were used to vimentin, CD31, CD34, α‐smooth muscle actin, S100 protein, thrombomodulin, calretinin and c‐kit (CD117), a tyrosine kinase growth factor receptor for stem cell factor usually expressed by embryonic/fetal endothelium. Structures similar to the ones described by Prichard were found in 12% of septa, most of them in the left side of the fossa ovalis. The hearts with these structures were from patients 10 years older than the ones without them (72 ± 10 versus 62 ± 16 years, P=0.006). Immunohistochemically the cells comprising Prichard’s structures were positive for vimentin, CD31, CD34 and thrombomodulin, and negative for α‐smooth muscle actin, S100 protein, calretinin and c‐kit. Therefore these cells seem to be mature endothelial cells, but not primitive multipotential mesenchymal cells. Furthermore, these cells were not found in the atrial tissue from the bases of any of the conventional cardiac myxomas.

Conclusions: Our study suggests that there is no apparent relation between Prichard’s structures and cardiac myxomas, and that Prichard’s minute endocardial deformities are age‐related phenomena.
Lymphadenoma: a report of three cases of an uncommon salivary gland neoplasm
Authors: Ma J , Chan J K C , Chow C W , Orell S R
Published: March 2003

Aims: Lymphadenoma of the salivary gland is a rare neoplasm that has not been properly characterized. This study describes the clinicopathological features of three cases.

Methods and results: All three patients were males, ranging in age from 13 to 57 years. Two presented with a parotid mass, and one a preauricular mass. The tumours were well circumscribed, comprising anastomosing trabeculae, solid tubules, glands or basaloid islands of epithelium with or without cyst formation, accompanied by a prominent lymphoid stroma lacking sinuses. Large reactive lymphoid follicles were found in two cases. The epithelial cells were bland‐looking to mildly atypical. Immunostaining demonstrated dual luminal cell and abluminal basal cell differentiation, with the former being often subtle and highlighted only by immunostaining for epithelium membrane antigen or CAM 5.2, and the latter being highlighted by p63 immunostain.

Conclusions: Although there is some variation in the histological pattern from case to case, lymphadenoma is a morphologically recognizable salivary gland adenoma characterized by a dense lymphoid infiltrate. Lack of familiarity with this tumour may lead to misdiagnosis as myoepithelial sialadenitis, lymphoma, metastatic carcinoma in lymph node or lymphoepithelial carcinoma.
Human HER‐2/neu protein immunization circumvents tolerance to rat neu: a vaccine strategy for ‘self’ tumour antigens
Authors: DISIS  , SHIOTA  , CHEEVER
Published: March 2003

Many newly defined tumour antigens are ‘self’ proteins. Immunizing cancer patients against these antigens may be difficult due to tolerance. The HER‐2/neu oncogenic protein is such a ‘self’ tumour antigen. Rat neu is homologous with human HER‐2/neu and provides a model system for studying vaccination strategies. Rats are tolerant to rat neu. Vaccination with this ‘self’ protein elicits no detectable immune response. The current studies evaluated whether tolerance to rat neu can be circumvented by immunizing with the highly homologous foreign human HER‐2/neu protein. Rats were immunized with human HER‐2/neu intracellular domain (hICD) protein that is 92% homologous to rat neu ICD. Animals immunized with hICD developed significant antibody and T‐cell responses that were specific for both human HER‐2/neu and rat neu. Neu‐specific antibodies were present in titres of greater than 1:200 000. Analysis of the specificity of the antibody response using synthetic peptides demonstrated substantial reactivity to an epitope with 100% homology between rat and human protein. Significant T‐cell responses (stimulation index>10) to hICD and rat neu protein (stimulation index>4) were detected. The T cells also responded to both human and rat ICD. The results imply that immunization with foreign proteins, which are highly homologous to ‘self’ tumour antigens, may be an effective vaccine strategy for ‘self’ tumour antigens.
γδ T cells in infection‐induced and autoimmune‐induced testicular inflammation
Authors: MUKASA  , YOSHIDA  , KOBAYASHI  , MATSUZAKI  , NOMOTO
Published: March 2003

In a previous report, we investigated inflammatory responses induced by injecting Listeria monocytogenes into one testis of a mouse. We demonstrated that the contralateral testis also developed an orchitis despite the absence of bacteria, indicating that the inflammation on the uninfected, contralateral side was of autoimmune character. In both infected and autoimmune testes, γδ and αβ T cells infiltrated during the inflammation. In this paper, we present the data of a comparison of the character of γδ T cells of the infected and autoimmune testes. In both testes, γδ T cells appeared to be activated, as assessed by high CD44 and low l‐selectin expression. Analysis of T‐cell receptor (TCR) usage in both inflammation types revealed the same γδ TCR repertoire. Finally, the semi‐quantitative reverse transcriptase‐polymerase chain reaction (RT‐PCR) demonstrated that γδ T cells in both types of inflammation were capable of producing interleukin‐2 (IL‐2), IL‐4, interferon‐γ (IFN‐γ), IL‐10 and transforming growth factor‐β (TGF‐β). These results imply that γδ T cells present in infected‐induced and autoimmunity‐induced inflammation have the same characteristics and could work as immunoregulatory cells.
An in vivo comparison of bacillus Calmette–Guérin (BCG) and cytokine‐secreting BCG vaccines
Authors: SLOBBE  , LOCKHART  , O’DONNELL  , MACKINTOSH  , DE LISLE  , BUCHAN
Published: March 2003

A recombinant bacillus Calmette–Guérin (BCG) vaccine has been developed, which constitutively secretes interleukin (IL)‐2. Groups of deer were immunized with either normal BCG (Pasteur 1173 P2 strain) or recombinant BCG (rBCG/IL‐2) and their immune responses were monitored over 3 months. Animals gained weight over this period and showed no signs of adverse reactions to either vaccine. Lymphocyte transformation responses did not differ significantly between the two groups. No antibody that was specific for BCG was detected in any animal. Intradermal skin‐test responses to BCG antigens showed that the rBCG/IL‐2 induced a smaller delayed‐type hypersensitivity response than the normal BCG. Cytokine transcription was determined by reverse transcription–polymerase chain reaction (RT–PCR). While IL‐2 and interferon‐γ (IFN‐γ) levels did not differ significantly between the two groups, the level of IL‐4 was found to be lower in the group given rBCG/IL‐2. This resulted in a strong interferon‐γ:IL‐4 ratio, suggesting a skewing of the immune response towards a Type 1 response. The rate at which the vaccine was eliminated from the host was the same regardless of whether BCG or rBCG was used. At autopsy (3 months after vaccination) 99·99% of the organisms had been eliminated. The small number of organisms isolated from the draining lymph node of animals given rBCG/IL‐2 were grown in antibiotic‐containing media. They were shown to still contain the shuttle plasmid and to secrete biologically active IL‐2, indicating that the plasmid was stably maintained despite the host’s immune response and in the absence of antibiotic selection.
The polymorphisms S503P and Q576R in the interleukin‐4 receptor α gene are associated with atopy and influence the signal transduction
Authors: KRUSE  , JAPHA  , TEDNER  , SPARHOLT  , FORSTER  , KUEHR  , DEICHMANN
Published: March 2003

Interleukin‐4 (IL‐4) plays a major role in immunoglobulin E (IgE) production. Its signal is conferred to effector cells through binding to the α chain of the IL‐4 receptor (IL‐4Rα). We present further evidence for polymorphisms in the IL‐4Rα gene having an effect on IgE regulation. For two of four common polymorphisms, S503P and Q576R, we found an association with lowered total IgE concentrations (P=0·0008 if occurring together). The polymorphism S503P has not yet been described and is located within the I4R motif of the receptor. In vitro analyses using synthetic peptides of this region showed that the tyrosine kinase Janus kinase 1 (JAK1), as well as IRS‐1 and IRS‐2 bind to the I4R motif irrespective of the polymorphism or a tyrosine phosphorylation. In vivo immunoassays using T cells of four different groups of individuals (S503/Q576; P503/Q576; S503/R576; P503/R576) revealed that only in case of both polymorphisms the phosphorylation of IRS‐1 and IRS‐2, but not JAK1 was increased. We found no binding of STAT6 to the I4R synthetic peptides; however, the phosphorylation was reduced in the presence of any of the two polymorphisms, including P503 alone. We discuss possible conformational changes of the receptor leading to the observed effects on the phosphorylation status of IRS‐1, IRS‐2 and STAT6, in addition to previous findings that Q576R alters STAT6 binding. We conclude that P503 and R576 influence the signal transduction pathways through the IL‐4Rα, an effect that is magnified by the presence of both polymorphisms. This could explain the observed association effects with lowered total IgE concentrations.
Increased inducible apoptosis in CD4+ T lymphocytes during polymicrobial sepsis is mediated by Fas ligand and not endotoxin
Authors: AYALA  , CHUNG  , XU  , EVANS  , REDMOND  , CHAUDRY
Published: March 2003

Recent studies suggest that increased lymphocyte apoptosis (Ao) detected in peripheral blood T cells from burn patients appears to contribute to decreased lymphocyte immunoresponsiveness. However, while it is known that sepsis induces a marked depression in the splenocyte immune response (i.e. decreased interleukin‐2, interferon‐γ production and proliferation) in response to the T‐cell mitogen concanavalin A (Con A), it is unknown whether this depression is associated with an increase in inducible Ao and if so, which mediators control this process. To assess this, splenocytes were harvested from mice at 24 hr (a period associated with decreased Con A response) after the onset of polymicrobial sepsis [caecal ligation and puncture (CLP)] or sham‐CLP (Sham) and then stimulated with 2·5 μg Con A/ml (24 hr). Septic mouse splenocytes stimulated with Con A, while not showing a change in their phenotypic make‐up, did exhibit a marked increase in the percentage of splenocyte that were Ao+ which was associated with altered cytokine release. This appears to be due to an increase in the percentage of Ao+ cells in the CD4+ CD8− population and was associated with enhanced Fas antigen expression as well as an increase in mRNA for the Fas–FasL gene family. To determine if the changes in Ao are due to either endotoxin (a product of Gram‐negative bacteria seen in CLP mice) or the expression of Fas ligand (FasL; a mediator of activation‐induced lymphocyte Ao), a second set of studies examining Con A‐inducible Ao was performed with splenocytes harvested from septic endotoxin‐tolerant C3H/HeJ and the FasL‐deficient C3H/HeJ‐Fasl gld mice. The results show that increased splenocyte Ao detected following CLP is due to a FasL‐mediated process and not to endotoxin. Thus the inadvertent up‐regulation of FasL‐mediated splenocyte Ao may contribute to the depression of splenocyte immune responses seen during polymicrobial sepsis.
In vitro treatment of human transforming growth factor‐β1‐treated monocyte‐derived dendritic cells with haptens can induce the phenotypic and functional changes similar to epidermal Langerhans cells in the initiation phase of allergic contact sensitivity reaction
Authors: Aiba S. , Manome H. , Yoshino Y. , Tagami H.
Published: March 2003

Human monocyte‐derived dendritic cells (MoDCs) obtained from peripheral blood monocytes (PBMC) cultured with granulocyte–macrophage colony‐stimulating factor (GM‐CSF) and interleukin‐4 (IL‐4) can be activated in vitro by a variety of simple chemicals such as haptens and several metals. Recently, it has been demonstrated that transforming growth factor‐β1 (TGF‐β1) can induce further differentiation of MoDCs to the cells that share some characteristics with epidermal Langerhans cells, i.e. they contain Birbeck granules and express E‐cadherin. In this study, using such TGF‐β1‐treated dendritic cells (TGF‐β1+ DCs), we examined the in vitro effects of representative haptens, i.e. NiCl2 and dinitrochlorobenzene (DNCB), on their phenotypic and functional characteristics, comparing with those reported in vivo in epidermal Langerhans cells during the sensitization phase of a contact sensitivity reaction. Treatment of TGF‐β1+ DCs with NiCl2 increased their expression of the molecules related to antigen presentation such as CD86, major histocompatibility complex class I and class II, and CD83, although weakly, in addition to that of those essential for their migration to the regional lymph nodes, such as CD49e, CD44 and its variant 6, while it down‐regulated the expression of the molecules required for homing to the skin and staying in the epidermis, such as cutaneous leucocyte antigen (CLA) and E‐cadherin. It also increased the production of tumour necrosis factor‐α, but not that of IL‐1β or IL‐12. DNCB also increased their CD86 expression and down‐regulated E‐cadherin and CLA, but did not affect other phenotypic changes that were observed in TGF‐β1+ DCs treated with NiCl2. TGF‐β1+ DCs treated with either NiCl2 or DNCB increased their allogeneic T‐cell stimulatory function. In addition, reverse transcribed polymerase chain reaction revealed augmented expression of chemokine receptor 7 mRNA by TGF‐β1+ DCs when treated with either NiCl2 or DNCB. Moreover, consistent with this data, TGF‐β1+ DCs treated with these chemicals chemotactically responded to macrophage inflammatory protein‐3β. These data suggest the possibility that TGF‐β1+ DCs present a good in vitro model to study the biology of epidermal Langerhans cells.
Adherent dendritic cells expressing high levels of interleukin‐10 and low levels of interleukin‐12 induce antigen‐specific tolerance to experimental autoimmune encephalomyelitis
Authors: Yang J.‐S. , Xu L.‐Y. , Huang Y.‐M. , Van Der Meide P. H. , Link H. , Xiao B.‐G.
Published: March 2003

We have previously shown that tolerance can be induced against acute experimental autoimmune encephalomyelitis (EAE) in Lewis rats by bone marrow‐derived dendritic cells (DC) that have been pulsed in vitro with encephalitogenic myelin basic protein peptide 68–86 (MBP 68–86), and injected subcutaneously into healthy rats prior to immunization with MBP 68–86 plus complete Freund's adjuvant. To elucidate better the properties of tolerogenic DC, we here compared plastic‐adherent DC with floating, non‐adherent DC, which were cultured for 7 days in the presence of granulocyte–macrophage colony‐stimulating factor plus interleukin‐4 (IL‐4). Adherent DC expressed high levels of IL‐10 mRNA and protein, and low levels of IL‐12 mRNA and showed high expression of CD54 compared with floating DC. Proliferation, nitrite concentration and capacity for antigen presentation were lower in adherent DC than in floating DC. There were no differences between adherent and floating DC regarding expression of CD11c, OX62, major histocompatibility complex class II, CD80, or CD86. Most importantly, we observed that adherent DC induced tolerance to EAE in vivo when injected subcutaneously into Lewis rats prior to immunization, while floating DC did not. Adherent DC‐mediated tolerance to EAE was associated with augmented proliferation, nitric oxide production and frequency of apoptotic cells as well as with up‐regulation of transforming growth factor‐β (TGF‐β) ‐expressing cells in T‐cell areas of lymph nodes. Tolerance induction by adherent DC seems to be related to a nitric oxide–apoptosis pathway and to up‐regulation of TGF‐β‐expressing cells.
Molecular signals and genetic reprogramming in peripheral T‐cell differentiation
Authors: Noble A.
Published: March 2003

Rearrangement of gene segments occurs in T lymphocytes during thymic development as the T‐cell receptor (TCR) is first expressed, allowing T cells to become central regulators of antigen specificity in the acquired immune system. However, further development of T cells occurs after population of peripheral lymphoid tissues, which can result in T‐cell expansion and differentiation into effectors of various immune function, or progression to memory T cells, anergic cells or death by apoptosis. This review focuses on more recent developments concerning the choices that peripheral T cells make between first encountering antigen through TCR recognition and death. These decisions are associated with a process of genetic reprogramming that alters the behaviour of cells so that immune responses are appropriately regulated.
Complement‐mediated lipopolysaccharide release and outer membrane damage in Escherichia coli J5: requirement for C9
Authors: O'Hara A. M. , Moran A. P. , Würzner R. , Orren A.
Published: March 2003

Lipopolysaccharides (LPS) are major antigenic components of the outer membrane of Gram‐negative bacteria and can stimulate activation of the complement system. Such activation leads to formation of the complement membrane attack complex (MAC) on the cell walls, LPS release and, in serum‐sensitive strains, to cell death. In this study, Escherichia coli J5 strains, which incorporate exogenous galactose exclusively into LPS, were used to generate target strains with different LPS chemotypes, and the LPS of the strains was labelled with tritium (3H‐LPS). The ability of normal human serum (NHS) and human complement‐deficient sera to release LPS was subsequently monitored. NHS‐induced release of 64–95·7% of 3H‐LPS within 30 min; overall, no significant difference was observed between release of LPS from E. coli J5 strains with different LPS chemotypes. In functional assays, maximum LPS release had occurred by 30 min and before maximum bacterial killing. Electron microscopy revealed NHS‐induced outer‐membrane disruption in the form of blebs at 15 min; at this time‐point the inner membrane remained intact. Background LPS release and no bactericidal activity were detected in heat‐inactivated serum or human sera deficient in C6, C7 or C8. The C9‐deficient (C9D) serum had low bactericidal activity and failed to induce LPS release; however, addition of purified human C9 reconstituted its ability to release LPS. This study demonstrated the need for functional C9 molecules for LPS‐releasing activities in serum‐sensitive E. coli J5 strains.
Neutralization of interferon‐γ in neonatal SOCS1−/− mice prevents fatty degeneration of the liver but not subsequent fatal inflammatory disease
Authors: Bullen Denise V. R. , Darwiche Rima , Metcalf Donald , Handman Emanuela , Alexander Warren S.
Published: March 2003

Mice lacking the suppressor of cytokine signalling‐1 (SOCS1) die within weeks of birth with extensive fatty degeneration of the liver, consistent with acute hepatic toxicity to interferon‐γ (IFN‐γ), and inflammation of multiple organs. We show here that treatment for 1 week from birth with neutralizing antibody to IFN‐γ rescues SOCS1−/− mice from lethal liver disease but the mice subsequently succumb to chronic inflammatory lesions characterized by T‐lymphocyte infiltration of skeletal muscle, pancreas, lung, liver and skin. Elevated blood levels of eosinophils, neutrophils and platelets were also observed and the thymic lymphocyte population was depleted of CD4+ CD8+ T cells and showed a reduced CD4 : CD8 ratio. All T‐cell populations in thymus, spleen and lymph node exhibited an increased proportion of cells bearing the activation marker CD44. These data suggest an important role for SOCS1 in T‐lymphocyte regulation.
The lipopolysaccharide co‐receptor CD14 is present and functional in seminal plasma and expressed on spermatozoa
Authors: Harris Claire L. , Vigar Miriam A. , Rey Nores Julia E. , Horejsi Vaclav , Labeta Mario O. , Morgan B. Paul
Published: March 2003

CD14 is a 54 000‐molecular weight (MW) glycolipid‐anchored membrane glycoprotein, expressed on myeloid cells, which functions as a member of the lipopolysaccharide (LPS) receptor complex. Soluble forms of CD14 have been reported in plasma, cerebrospinal fluid, amniotic fluid and breast milk. In plasma and breast milk, soluble CD14 has been implicated as a regulator of T‐ and B‐cell activation and function. Expression of CD14 in the male reproductive system has not previously been investigated. We here show that soluble CD14 is present in seminal plasma at levels comparable to those in serum. Spermatozoa expressed CD14 on their membranes, as demonstrated by fluorescence microscopy and flow cytometry. Post‐vasectomy, the levels of seminal plasma CD14 (spCD14) were much reduced, implying an origin distal to the point of transection of the vas deferens. Ultracentrifugation analyses demonstrated that spCD14 was not associated with lipid complexes, indicating that it lacks the glycolipid anchor. Purified spCD14 mediated activation by LPS of CD14‐negative cells. These findings suggest that CD14 may play a hitherto unexplored role in immune defence and cell activation in the male reproductive tract.
Contribution of conformational stability of hen lysozyme to induction of type 2 T‐helper immune responses
Authors: So Takanori , Ito Hiro‐O. , Hirata Masato , Ueda Tadashi , Imoto Taiji
Published: March 2003

It is important to identify characteristics that confer on proteins the potential to induce allergenic sensitization and allergenic disease. Protein allergens carry T‐cell epitopes that are capable of inducing a type 2 T helper (Th2) cell response. There is limited information regarding factors that govern the allergenicity of proteins. We previously reported that a decrease in the conformational stability of hen‐egg lysozyme (HEL) enhanced its capacity to activate HEL‐specific T cells owing to the increased susceptibility to intracellular antigen processing. To determine whether the conformational stability of HEL makes for a critical contribution to allergenic sensitization in vivo, we immunized BALB/c mice with HEL derivatives of different conformational stability, but which retained a similar three‐dimensional structure. The magnitude of in vivo T‐cell responses, evaluated by ex vivo proliferative responses of lymph node T cells from mice primed with various HEL derivatives, was inversely correlated with conformational stability, as was interferon‐γ (IFN‐γ) and interleukin‐4 (IL‐4) production by splenic T cells in response to HEL. Immunization of the least stable derivative led to a potent IL‐4 response and to immunoglobulin E (IgE) antibody production. We propose that the intrinsic allergenicity of proteins can be determined by the degree of conformational stability.
Immune privilege and FasL: two ways to inactivate effector cytotoxic T lymphocytes by FasL‐expressing cells
Authors: Li Jie‐Hui , Rosen Dalia , Sondel Paul , Berke Gideon
Published: March 2003

The theory that Fas ligand (FasL)‐expressing tumours are immune‐privileged and can directly counterattack Fas‐expressing effector T lymphocytes has recently been questioned and several alternative mechanisms have been proposed. To address this controversial issue, we analysed the impact of FasL‐expressing tumours on in vivo‐primed cytotoxic T lymphocytes (CTLs) and the mechanisms involved. CTLs were obtained from the peritoneal cavity (PEL) after in vivo priming with syngeneic or allogeneic murine tumour cells. We have found that PEL populations undergo Fas‐based apoptotic cell death when co‐cultured with FasL‐expressing tumour cells and that PEL destruction of cognate targets in a 51Cr‐release assay was markedly inhibited by the pre‐exposure to either cognate or non‐cognate tumour cells expressing FasL. Furthermore, cytocidal function of PEL was markedly inhibited by preincubation with FasL‐negative tumour cells, if and only if they were the cognate targets of the CTL; this CTL inhibition involved FasL–Fas interactions. The killing function of ‘bystander’ PELs, reactive to a third‐party target cell, was inhibited by co‐cultivation with PELs mixed with their cognate target. This activation‐induced CTL fratricide was not influenced by the expression of FasL on the cognate target cells. These studies demonstrate the existence of two distinct pathways whereby FasL‐expressing cells inhibit in vivo‐primed FasL‐ and Fas‐expressing CTLs: first, by FasL‐based direct tumour counterattack, and second, by FasL‐mediated activation‐induced cell death of the CTLs, which is consistent with the concept that FasL expression in vivo could play a role in inducing immune privilege.
Glycoprotein B from strain 17 of herpes simplex virus type I contains an invariant chain homologous sequence that binds to MHC class II molecules
Authors: Sievers Elisabeth , Neumann Jürgen , Raftery Martin , SchÖnrich Günther , Eis‐Hübinger Anna Maria , Koch Norbert
Published: March 2003

Major histocompatibility complex class I (MHCI) molecules are major targets of virus evasion strategies because they introduce antigens from the biosynthesis pathway into the antigen‐processing and presentation pathways for immune recognition by CD8+ T cells. Little is known about viral strategies that interfere with the MHC class II (MHCII) antigen presentation pathway. We identified a six amino acid sequence from type I herpes simplex virus (HSV‐1) glycoprotein B (gB) that is identical to a sequence of human leucocyte antigen D (HLA‐D) ‐associated invariant chain (Ii). In addition, this gB sequence is adjacent to a highly conserved HLA‐DR1 binding motif. Both viral sequences together resemble the class II binding site of human Ii, consisting of a MHCII groove binding segment and a promiscuous binding site. We cloned gB from HSV‐1 strain 17 and demonstrate association of the virus envelope protein to three HLA‐DR allotypes. With chimeric Ii/gB fusion proteins we identified gB sequences that mediate promiscuous or allotype‐specific binding to the HLA‐DR peptide‐binding domain. Mutation of two Lys residues in the viral segment of Ii/gB abolished promiscuous binding to HLA‐DR heterodimers. The result indicates promiscuous binding of the virus sequence to HLA‐DR molecules and suggests a potential for HSV‐1 to manipulate antigen processing and presentation.
Insufficient interleukin‐2 production from splenic CD4+ T cells causes impaired cell proliferation and early apoptosis in SAMP1, a strain of senescence‐accelerated mouse
Authors: Nishimura Yasumitsu , Hosokawa Tomohide , Hosono Masamichi , Baba Mitsuo , Hosokawa Masanori
Published: March 2003

We examined the proliferative and cytokine‐producing activities of CD4+ T cells from young mice of the senescence‐accelerated mouse strain SAMP1, which had shown markedly low T‐dependent antibody‐producing responses. When splenic T cells were cultured with concanavalin A (Con A), the percentage of CD4+ cells decreased earlier in SAMP1 than in C3H/He mice. At 40 hr of culture, the percentage of BrdU‐labelled proliferating CD4+ cells increased strongly in C3H/He, but only slightly in SAMP1. When purified CD4+ T cells were cultured with Con A, the percentage of 5‐bromo‐2′‐deoxyuridine (BrdU)‐labelled cells peaked at around 48 hr of culture in both strains, but decreased significantly at 64 hr in SAMP1. The production of interleukin (IL)‐2 but not IL‐4 or interferon‐γ (IFN‐γ) was significantly lower in SAMP1 than in C3H/He at 48 hr of culture. IL‐2 production was also markedly low in SAMP1, even under the stimulation of anti‐CD3 with anti‐CD28 antibodies. The frequency of cells producing IL‐2 was significantly lower in SAMP1 than in C3H/He at 6–24 hr of culture with Con A. The percentage of annexin‐positive and propidium iodide (PI)‐negative apoptotic cells was significantly higher in SAMP1 than in C3H/He at 96 hr of culture. Exogenous IL‐2 prevented the decrease in BrdU‐labelled cells and the increase in apoptotic cells in the SAMP1 cell culture. These results indicate that SAMP1 CD4+ T cells cannot produce IL‐2 at levels sufficient to support cell proliferation and survival. This may account for the weak T‐dependent antibody response in SAMP1 mice.
A blood‐borne antigen induces rapid T–B cell contact: a potential mechanism for tolerance induction
Authors: Gütgemann Ines , Darling Jama M. , Greenberg Harry B. , Davis Mark M. , Chien Yueh‐Hsiu
Published: March 2003

Understanding the difference between the development of a productive T‐cell response and tolerance is central to discerning how the immune system functions. Intravenous injection of soluble protein is thought to mimic the presentation of self‐serum and orally introduced antigens. It is generally toleragenic. The current view is that this outcome reflects the failure of ‘immunogenic’ dendritic cells to relocate to the T‐cell zone of the secondary lymphoid tissues. Here, using a peptide/I‐Ek tetramer and antibodies to stain splenic sections, we showed that antigen‐specific T cells were activated in the spleen within hours of injection or feeding of protein. The activated T cells were found to be located at the T–B junction, the bridging zone and the B‐cell area, interacting directly with B cells. In addition, B cells gain the ability to present antigen. Our results suggest a way for T cells to be stimulated by blood‐borne antigen presented by naïve B cells, a potential mechanism of tolerance induction.
γδ T cells contribute to the systemic immunoglobulin E response and local B‐cell reactivity in allergic eosinophilic airway inflammation
Authors: Svensson Linda , Lilliehöök Bo , Larsson Roland , Bucht Anders
Published: March 2003

Allergic airway inflammation induced in mice is T‐cell dependent and recruitment of eosinophils to airspaces requires both αβ and γδ T cells. From previous studies it is evident that αβ T cells are essential for the allergic T helper type 2 (Th2)‐like response, while the mechanistic contribution of γδ T cells is still unclear. In this study, we have investigated the role of γδ T cells in allergic airway eosinophilia induced by ovalbumin hypersensitivity. By comparing the responsiveness to sensitizing allergen of wild‐type mice with that of T‐cell receptor γδ knockout mice (TCRγδ KO) we demonstrated that mice lacking γδ T cells are defective in the systemic ovalbumin‐specific immunoglobulin E (IgE) response. Furthermore, after aerosol challenge with allergen, γδ T‐cell deficient mice exhibited a significantly decreased migration of B cells and natural killer cells to airways and reduced levels of allergen‐specific IgG and IgA in bronchoalveolar lavage fluid. The role for B cells in the airway inflammation was indicated by the impaired ability of mice lacking functional B cells to evoke an eosinophilic response. The diminished eosinophilia in TCRγδ KO mice could not be explained by a defective Th2 activation since these mice displayed a normal IgG response in serum and an unaffected IG2b/IgG1 ratio in airways. Analysis of immunoregulatory cytokines in isolated lung tissue, thoracic lymph nodes and spleen further supported the notion that these mice are able to evoke a sufficient activation of T helper cells and that γδ T cells are not required for maintaining the Th2 profile. These results indicate that γδ T cells contribute to allergic airway inflammation by pathways separate from classical Th2 immune activation.