Lymphocyte mediated cell lysis

Detection of a soluble form of the human adhesion receptor lymphocyte function-associated antigen-3 (LFA-3) in patients with chronic liver disease

BACKGROUND/AIMS

Multiple immune functions, such as cytotoxic reactions, B cell differentiation, and monocyte activation, are mediated via the adhesion receptor/ligand pairs CD2/lymphocyte function-associated antigen(LFA)-3 and LFA-1/ intercellular adhesion molecule(ICAM)-1. Since soluble forms of LFA-3 (sLFA-3) and ICAM-1 (sICAM-1) can interfere with these functions, we asked whether increased levels of sLFA-3 can be found in patients with different forms of chronic liver disease and/or hepatocellular carcinoma.

METHODS

sLFA-3 was measured in sera from 84 patients with chronic liver disease (39 with chronic viral liver disease, 30 with autoimmune liver disease, 12 with alcoholic cirrhosis, 3 with other causes of cirrhosis), 24 patients with hepatocellular carcinoma (15 with and 9 without cirrhosis), and 61 normal controls. From 36 of the patients with liver cirrhosis, arterial and hepatic venous serum samples were simultaneously obtained and tested for sLFA-3 and sICAM-1.

RESULTS

In comparison to controls, sLFA-3 levels were elevated in patients with liver cirrhosis due to autoimmune liver disease (p < 0.0001) and viral liver disease (p = 0.001), but not in patients with alcoholic cirrhosis. Increased sLFA-3 levels were also found in patients with hepatocellular carcinoma and liver cirrhosis. However, sLFA-3 was not significantly elevated in sera from patients with autoimmune liver disease, viral liver disease, and hepatocellular carcinoma without concomitant liver cirrhosis. No difference was found between arterial and hepatic venous serum levels of sLFA-3 and sICAM-1. sLFA-3 levels correlated positively with aspartate transaminase, alkaline phosphatase, bilirubin, sICAM-1, and inversely with albumin and cholinesterase.

CONCLUSIONS

Taken together, sLFA-3 serum concentrations of patients with liver cirrhosis due to autoimmune liver disease or viral liver disease and of patients with hepatocellular carcinoma and cirrhosis are significantly increased compared to controls. Elevated sLFA-3 and sICAM-1 levels might reflect the generalized inflammation in cirrhosis and by interference with cell-cell interactions sICAM-1 and sLFA-3 may limit the extent of inflammation.

Detection of soluble adhesion molecules in pleural effusions

PURPOSE

Multiple immune functions such as activation of T cells and monocytes or cytolysis of tumor cells are mediated via the adhesion receptor/ligand pairs CD2/LFA-3 and LFA-1/ICAM-1. Because soluble forms of LFA-3 (sLFA-3) and ICAM-1 (sICAM-1) can interfere with these functions, we asked whether increased levels of sLFA-3 and/or sICAM-1 can be found in malignant or inflammatory effusions compared with transudates.

METHODS

sLFA-3 and sICAM-1 levels were measured by enzyme-linked immunoassays in pleural effusions from 70 patients (6 transudates, 10 inflammatory, 47 malignant, and 7 other effusions). Twenty pleural fluid samples were tested in parallel for the complete sLFA-3 molecule or sLFA-3-domain 1 only.

RESULTS

Increased levels of sICAM-1 were found in all types of exudates compared with transudates. Highest levels of sICAM-1 were measured in malignant exudates, particularly in effusions caused by mesotheliomas, non-small lung cancers, and gynecologic malignancies. This was also true for sLFA-3. However, sLFA-3 levels were not increased in inflammatory effusions. sLFA-3 levels correlated significantly with protein, cholesterol, lactate dehydrogenase, and sICAM-1 levels. Comparison of sLFA-3-domain 1 and the complete sLFA-3 molecule revealed identical sLFA-3 levels, suggesting the absence of nonfunctional split products.

CONCLUSIONS

Elevated levels of the complete sLFA-3 molecule were found in malignant pleural effusions, while sICAM-1 level was elevated in both inflammatory and malignant effusions. Secretion of sICAM-1 and sLFA-3 by tumor cells might block T-cell-mediated immune functions such as tumor cytotoxicity. Alternatively, secretion of soluble adhesion molecules might reflect the generalized inflammation within the pleural space.

Apoptosis overview emphasizing the role of oxidative stress, DNA damage and signal-transduction pathways

Apoptosis (programmed cell death) is a central protective response to excess oxidative damage (especially DNA damage), and is also essential to embryogenesis, morphogenesis and normal immune function. An understanding of the cellular events leading to apoptosis is important for the design of new chemotherapeutic agents directed against the types of leukemias and lymphomas that are resistant to currently used chemotherapeutic protocols. We present here a review of the characteristic features of apoptosis, the cell types and situations in which it occurs, the types of oxidative stress that induce apoptosis, the signal-transduction pathways that either induce or prevent apoptosis, the biologic significance of apoptosis, the role of apoptosis in cancer, and an evaluation of the methodologies used to identify apoptotic cells. Two accompanying articles, demonstrating classic apoptosis and non-classic apoptosis in the same Epstein-Barr virus-transformed lymphoid cell line, are used to illustrate the value of employing multiple criteria to determine the type of cell death occurring in a given experimental system. Aspects of apoptosis and programmed cell death that are not covered in this review include histochemistry, details of cell deletion processes in the sculpting of tissues and organs in embryogenesis and morphogenesis, and the specific pathways leading to apoptosis in specific cell types. The readers should refer to the excellent books and reviews on the morphology, biochemistry and molecular biology of apoptosis already published on these topics. Emphasis is placed, in this review, on a proposed common pathway of apoptosis that may be relevant to all cell types.

Modulated expression of human leucocyte antigen class I and class II determinants in hyperplastic and malignant human prostatic epithelium

OBJECTIVES

To determine whether human prostatic carcinoma cells express Class I and/or Class II major histocompatibility complex (MHC) determinants and whether they might thus be immune-competent targets for cell-mediated cytotoxicity.

MATERIALS AND METHODS

Immunohistochemistry, performed both before and after neuraminidase digestion, was employed to compare 13 benign prostatic hyperplasias with 42 primary and 44 metastatic prostatic carcinomas obtained from the United Kingdom and from the United States of America. Expression of beta 2-microglobulin was used as the marker of Class I and HLA-DR as the marker of Class II expression.

RESULTS

Before desialylation, Class I MHC determinants were expressed in all of the benign hyperplasias, in 26% of primary carcinomas and in 14% of lymph node metastases. Cells expressing Class II determinants were identified in 69% of benign hyperplasias and in 2% of primary carcinomas, but in none of the lymph node metastases. After desialylation. Class I determinants were expressed in 100% of benign hyperplasias. 59% of primary carcinomas and 34% of the lymph node metastases. Class II determinants were expressed in 100% of benign hyperplasias, but only 19% of primary carcinomas and 5% of the lymph node metastases. While more than 50% of epithelial cells in each of the benign hyperplasias expressed MHCs, < 5% of the tumour cell populations in the positive malignant tissues (primary and metastatic) expressed MHCs, even after neuraminidase digestion. No correlation was found between expression of Class I or Class II MHC and Gleason morphological grade.

CONCLUSIONS

Failure to express Class I and/or Class II MHC determinants is a common feature of the majority of human prostatic carcinoma cells. Absence of these recognition molecules may be associated with avoidance of immune-surveillance and contribute to the metastatic dissemination of this malignancy.

Mucosal immune defence mechanisms in enterocolitis complicating Hirschsprung's disease

Enterocolitis remains an important cause of morbidity and mortality in Hirschsprung's disease. The aetiology of enterocolitis is uncertain-ischaemic and bacterial causes and recently, rotavirus infections, have been suggested. Bowel tissue from 12 patients with Hirschsprung's disease who underwent Swenson's operation (five of whom had clinical evidence of enterocolitis) and colon from six controls subjects were examined to investigate possible immunopathological mechanisms associated with the disease. IgA, IgM, and J chain (but not IgG) containing plasma cells were significantly increased in the lamina propria along the entire length of resected bowel in enterocolitis patients, compared with non-enterocolitis patients and controls (p less than 0.01). Luminal secretory component staining of the anganglionic segment of colon from enterocolitis patients was considerably reduced. Lamina propria CD68 positive monocyte/macrophages and CD45RO positive leukocytes were increased in enterocolitis patients compared with non-enterocolitis patients (p less than 0.01). CD57 positive natural killer (NK) cells showed a unique distribution pattern compared with other cell types. Patients with enterocolitis showed a significant increase in CD57 positive NK cells in the lamina propria of ganglionic bowel only (p less than 0.05). NK cell values in ganglionic bowel of non-enterocolitis patients and in aganglionic bowel in all patients were similar to controls. The diversity of altered local immune response seen in this study may reflect a multifactorial microbial aetiology in enterocolitis associated with Hirschsprung's disease.

Immunohistochemical study of adhesion molecules in liver inflammation

Using monoclonal antibodies and in situ immunohistochemistry, we studied the distribution of "accessory" adhesion molecules (i.e., intercellular adhesion molecule-1 and leukocyte function-associated antigen-3) in 114 liver biopsy specimens with various inflammatory liver diseases and in 12 control liver biopsy samples without inflammation. The distribution of these adhesion molecules was compared with the presence on inflammatory cells of their natural ligands, lymphocyte function-associated antigen-1 and cluster of differentiation antigen-2, respectively. In normal liver, intercellular adhesion molecule-1 and leukocyte function-associated antigen-3 reacted weakly with sinusoidal lining cells, portal vessel endothelium and scattered mononuclear inflammatory cells, whereas hepatocytes were constantly negative. In contrast, all 114 biopsy samples of acute or chronic liver diseases revealed strong expression of intercellular adhesion molecule-1 and leukocyte function-associated antigen-3 on sinusoidal lining cells and on hepatocytes in areas of inflammation. Hepatocellular membrane positivity resulted in a "honeycomb pattern" of staining , which was panacinar in acute hepatitis and focal in chronic persistent or aggressive hepatitis. In various other chronic liver diseases, a multifocal periportal and intraacinar honeycomb pattern was detected. In all cases, a close topographical correlation was found between hepatocellular expression of intercellular adhesion molecule-1 and leukocyte function-associated antigen-3 on one hand and the presence of inflammatory cells expressing lymphocyte function-associated antigen-1 and cluster of differentiation antigen-2 on the other.(ABSTRACT TRUNCATED AT 250 WORDS)