Autoimmunity. Thoughts for the millennium

Distinctive aspects of the immune status of the Kola Saami and Russians living in the Far North

OBJECTIVE

The level of immunological reactivity of the indigenous inhabitants of the Far North may depend on the extreme-discomfort factors of the climatic environment and genetic traits of the population. Therefore, the aim of this study was to identify the distinctive elements of the immune status of the Kola Saami and Russians living in the Far North (Murmansk Region).

METHODS

A complex immunological study of peripheral venous blood composition was performed and involved 67 Saami and 81 Russian inhabitants of the Far North (Murmansk Region) who were aged 21-55. Blood was collected from the cubital vein on an empty stomach in the morning. For the peripheral venous blood, we obtained a hemogram and phagocytic activity of neutrophils, determined the content of lymphocytes with CD4, CD8, CD16, and CD71 phenotypes by indirect immunoperoxidase reaction and flow cytometry using an Epics XL apparatus (Beckman Coulter, United States), obtained concentrations of IL-6, IFN-γ, IL-10, IgA, M, G, E, sCD54, and sCD62L, transferrin, and sCD71 by enzyme immunoassay using the "Evolis" enzyme immunoassay analyzer from Bio-RAD (Germany), and obtained circulating immune complexes by precipitation using 3.5%, 4.0%, and 7.5% PEG-6000. The sIgA content was determined in morning saliva, urine, and gastrointestinal tract secretions. The results were analyzed using descriptive statistics, independent sample t-criterion, and Pearson correlation coefficient.

RESULTS

A decrease in the total number of leukocyte cells in the Saami was associated with a high incidence of leukopenia, lymphopenia, and neutropenia. Deficiency in active phagocytes and serum IgA and sIgA concentrations was revealed as well as increased contents of CD4+ and CD8+ receptor lymphocytes, membrane and free adhesion molecules, and transferrin. Leukocytosis, lymphocytosis, neutrophilia, monocytosis, and eosinophilia with increased contents of natural killer cells, IL-6, and IL-10 were recorded more frequently in the Russians. High levels of IgE and IFN-γ, which have the most pronounced cytotoxicity and are indicative of strained immune mechanisms, were characteristic of the Saami and Russians.

CONCLUSION

The distinctive aspects of the immune status of the Kola Saami is related to the deficit in the active phagocyte and serum IgA and sIgA concentrations as well as the increase in the contents of cytotoxic lymphocytes, intercellular adhesion molecules, transferrin, and IFN-γ proinflammatory cytokines. The Russian inhabitants of the Far North are characterized by an adaptive response manifested by an increase in antibody-dependent cytotoxicity, involving IL-6 and IL-10.

State of humoral immunity in lactating sows and suckling piglets

The state of humoral immunity in lactating sows and its formation in suckling piglets in the conditions of a pig-breeding complex were studied. In sows after farrow, a high content of total immunoglobulins, the main classes of IgG, IgM and IgA, the concentration of which decreased in a day, followed by an increase in serum as lactation continued was detected in the serum and colostrum. In piglets at birth, the content of total immunoglobulins and the main Ig isotypes was insignificant, and at the age of twenty-four hours, as a result of absorption of colostral immunoglobulins in the small intestine, their amount in the serum was the highest, followed by a decrease in the concentration of IgG and IgA until the end of the suckling period, and IgM - up to day 14 with a further increase in its content, indicating the formation of a primary immune response. It has been detected that the dominant class of immunoglobulins in the serum and colostrum of sows and the serum of piglets is IgG, and in milk - IgA. An increase in the level of medium-dispersed circulating immune complexes (C4%) and their relation to giant (C3%) CICs was revealed, associated with an increase of the antigenic load in sows in the second half of lactation as a result of immunization, in milk - with a decrease in the content of the main classes of immunoglobulins, and in piglets, due to this, with a decrease in passive immunity.

A tribute to an outstanding immunologist - Ian Reay Mackay

The 11th Australasian Autoimmunity Workshop was held in Melbourne, Australia from July 6-8, 2007 organized by the Monash University Autoimmunity Network. The workshops, founded by the late Kevin Lafferty, are a chance for Australasians interested in research into autoimmune disease to present and discuss their work. This workshop also was a chance to acknowledge Ian Mackay, a pioneer clinician-scientist who has made major contributions to our understanding of autoimmune diseases. Friends, colleagues and former students attended the Workshop and acknowledged Ian's expertise and mentorship. This edition of the Journal of Autoimmunity pays tribute to Ian Mackay. It features articles from attendees at the workshop, and contributions from some of Ian's past students and past and current collaborators.

DNA mismatch repair protein expression and microsatellite instability in primary mucosal melanomas of the head and neck

AIMS

To examine the expression of DNA mismatch repair (MMR) proteins and the presence of microsatellite instability (MSI) in seven primary mucosal melanomas of the head and neck (MMHN).

METHODS AND RESULTS

Haematoxylin and eosin staining and immunohistochemical analysis for routine diagnostic markers and for MMR proteins were performed. Six cases were examined for MSI. Four cases were monomorphous and three cases were pleomorphic type MMHN. Melanocytic markers were positive in all cases. Immunoreactivity for MMR proteins was weak in normal epithelium. The neoplastic tissue in six cases showed positivity for all MMR proteins with different percentages. One case showed weak positivity for hMSH2 and hMSH6 and no immunoreactivity for hMLH1 or hPMS2. Staining intensity was higher in tumour cells than in matched normal mucosa in three cases for hMSH2 and hMLH1 and in two cases for hPMS2. None of the examined cases showed MSI.

CONCLUSIONS

Expression of hMSH2 and hMLH1 proteins was up-regulated in three cases, whereas in two cases that of hPMS2 was increased. hMSH6 expression was comparable to that of normal cells in all cases. The percentage of positive neoplastic cells and the intensity of staining seemed to be greater in pleomorphic melanomas. Six cases were MMR-proficient and microsatellite stable.

Microsatellite instability is not related to response to cisplatin-based chemotherapy in cervical cancer

This study investigates whether microsatellite instability (MSI) due to defects of the mismatch repair (MMR) system could be associated with response to cisplatin-based neoadjuvant chemotherapy (NACT) and if cisplatin exposure could select MSI-positive cell clones in cervical cancer. Microsatellite analysis was performed by polymerase chain reactions using six microsatellite markers, while hMLH1 protein expression was investigated by immunohistochemistry. We found that 1 tumor out of 20 (5%) NACT-responding patients and 1 tumor out of 18 (6%) nonresponding patients showed MSI. The analysis of tumor specimens collected after NACT revealed no change in the banding pattern as compared to each corresponding pre-NACT tumor at each locus tested. hMLH1 staining was observed in at least > or =80% of cells in all tumors examined except the two exhibiting MSI. Our data showed that MSI due to defects of the MMR system seems not to play a crucial role in the biology of human cervical cancer cells and that MSI seems not to be related to response to chemotherapy. Moreover, cisplatin exposure did not seem to select for MMR-deficient tumor clones in cervical cancer.

Primary biliary cirrhosis: does X mark the spot?

Primary biliary cirrhosis (PBC) is an autoimmune disease of unknown etiology leading to progressive destruction of intrahepatic bile duct, with cholestasis, cirrhosis, and eventually liver failure. Epidemiological data indicate that environmental factors trigger autoimmunity in genetically susceptible individuals, although no definitive association of PBC with specific genes has been found. Further, no convincing explanation has been provided for the strong female predominance observed in the prevalence of PBC. However, we recently suggested that the enhanced monosomy X in peripheral white blood cells, and particularly in lymphocytes, of affected women might play a role in the induction of PBC. Such observations appear independent from the degree of cholestasis and specific for PBC. In this review we discuss the implications of these findings and their immunological implications.

Antitumor activity of irofulven against human ovarian cancer cell lines, human tumor colony-forming units, and xenografts

The objective of this study was to investigate the cytotoxic activity of irofulven (HMAF, MGI 114), a unique chemotherapeutic agent currently under clinical investigation, in various preclinical models of ovarian cancer. Antiproliferative effects of irofulven in ovarian cancer cell lines and ovarian tumor specimens were characterized in vitro using sulforhodamine B and human tumor colony-forming assays, respectively. Irofulven demonstrated marked activity against a panel of ovarian tumor cell lines, including IGROV1, OVCAR-3, OVCAR-4, OVCAR-5, OVCAR-8, and SK-OV-3, all of which exhibit various drug resistance mechanisms. In human tumor cloning assays, irofulven inhibited colony formation in surgically derived ovarian tumors at concentrations as low as 0.001 micro g /ml and indicated superior activity in comparison with paclitaxel when tested against the same tumor specimens. The antitumor activity of irofulven compared to that of paclitaxel was also examined using the SK-OV-3 xenograft model. In mice bearing subcutaneously implanted SK-OV-3 tumors, treatment with paclitaxel failed to inhibit tumor growth; whereas mice treated with maximum tolerated doses of irofulven had a 25% partial shrinkage rate, and the remaining animals had a mean tumor growth inhibition of 82%. The potent activity of irofulven against ovarian tumors in vitro and in vivo supports the evaluation of its clinical activity in ovarian cancer.

Significance of Mismatch Repair Protein Expression in the Chemotherapeutic Response of Sporadic Invasive Ductal Carcinoma of the Breast

The mismatch repair (MMR) gene plays a key role in the correction of DNA damage, and the loss of MMR has been implicated in resistance to a variety of chemotherapeutic drugs. The purpose of this study was to assess whether the reduced expression of hMLH1 and/or hMSH2 affects the chemotherapeutic responsiveness of sporadic invasive ductal carcinoma of the breast. Immunohistochemical studies were performed on 71 histologic specimens of breast cancer taken from the patients treated with surgery and subsequent cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) or cyclophosphamide, Adriamycin, and 5-fluorouracil (CAF) chemotherapy for stage II or III primary breast cancer. Single-strand conformational polymorphism polymerase chain reaction (PCR-SSCP) and sequencing were carried out in 16 patients. A combined immunoreactivity score (hMLH1-IS and hMSH2-IS) was calculated by multiplying the staining grade by the intensity score. Positive expression (>4) of hMLH1-IS and hMSH2-IS were 57.7% and 60.6%, respectively, and complete losses of hMLH1 and hMSH2 were observed in 4.2% of patients. Of the patients with advanced cancer with lymph node metastasis, those having a low hMLH1-IS had a significantly higher failure rate with the CMF regimen than those having a high hMLH1-IS (p = 0.03). No significant difference was noted in chemotherapeutic response according to hMLH1 and hMSH2 expression in the CAF group. Both hMLH1-IS (p = 0.03) and progesterone receptor (PR) status (p = 0.03) were well correlated with CMF chemotherapy response in breast cancers with lymph node metastasis. Our study shows that a lack of hMLH1 expression may play a role in drug resistance, especially in the CMF group, and immunohistochemical assay for MMR protein can be used as a convenient tool for evaluating chemotherapeutic response in patients with breast cancer.

Are virus infections triggers for autoimmune disease?

Viruses have been implicated in the initiation, progression, and exacerbation of several human autoimmune diseases, including multiple sclerosis. However, no single virus has been demonstrated as the etiologic agent. Multiple different infections may be involved, first in priming the immune system for autoimmunity and then in triggering the actual disease. A model based on experimental allergic encephalomyelitis, an animal model of multiple sclerosis, has been developed, which shows that an initial early infection with a virus having molecular mimicry to self-epitopes can prime for disease that occurs after a subsequent non-specific immunologic stimulus, such as a different infection. The role of multiple infections in the development of autoimmune disease may explain why no one virus has been implicated.

Xenobiotic considerations for the development of autoimmune liver diseases: bad genes and bad luck

The etiologic origins of autoimmune disease remain an enigma. Although considerable information on the mechanisms of immunopathology has been acquired, in part from murine models, such mechanisms have yet to be substantiated in human autoimmune disease. This absence of validation is especially true for organ-specific diseases like those affecting the liver. In this review we focus on the putative role of xenobiotics as inducing agents for autoimmune liver pathology. In particular, we discuss the autoantibody immune response, the humoral hallmark of autoimmune disease, as well as cellular immune responses. We believe that exposure to environmental factors, namely xenobiotics, is the initiating straw that breaks the camel's back, leading to the loss of tolerance to self proteins in genetically susceptible hosts. The end result is a perpetuating process that is determined by the governing features of the genetics of the host and by exposure to the inciting environmental agent. Interestingly, the liver, an organ that plays a major role in immune tolerance, can itself become the target of autoreactivity and immune destruction.