فهرست مطالب

immunology - Volume:2 Issue: 2, Spring 2005

Iranian journal of immunology
Volume:2 Issue: 2, Spring 2005

  • 60 صفحه،
  • تاریخ انتشار: 1384/06/30
  • تعداد عناوین: 8
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  • The Jak - Stat Signaling Pathway of Interferons System: Snapshots
    Dr . Masoumeh Varedi Pages 67-77
    Interferons (IFNs) are a family of small regulatory glycoproteins that play a central role in the defense against viral infections. Although IFNs have been initially discovered as antiviral factors، today they are known as an integral part of the cytokine network that affect a wide range of biological processes. IFNs exert their pleiotropic effects through their multisubunit cell surface receptors in a species specific manner that is believed to be controlled at the receptor and the post-receptor levels. Although IFN-mediated signaling and transcription activation of cellular gene expression is currently best understood in the context of the JAK-STAT signal transduction، additional IFNs signaling pathways may also act in certain conditions. The Janus family of tyrosine kinase (JAK) enzymes and two families of transcriptional regulators، signal transducer and activator of transcription (STATS) and IFN regulatory factors (IRFs)، are the principal components of the JAK-STAT pathway. Overlapping subsets of JAKS are involved in signaling by type I (IFN- /ß) and type II (IFN- IFNs، indicating that the receptor subunits confer specificity for activating particular JAK family members. A considerable cross talk can exist between separate signaling pathways. The emergence of new tools and approaches for study of IFNs signaling has been an exercise in coming to respect the level of complexity of IFNs system. For many years، IFNs have been satisfactorily used in many clinical trials. However، their serious side effects remain as the major concern in clinical use of IFNs. A better understanding of the exact mechanism involved in IFNs signaling pathways and the structure-function relationships of the IFNs system components will allow researchers to improve and expand the therapeutic potential of these naturally occurring molecules. IFNs actions are mediated through multiple signaling pathways. However، due to the space limitation، this review will focus primarily on the IFNs-mediated JAK-STAT pathway.
    Abstract View Paper Original: Persian
  • Differential Immunohistochemical Expression Pattern of Galectin - 3 in Normal and Osteoarthritic Human Articuler Cartilage
    Mahmoud Orazizadeh, Donald M. Salter Pages 78-86
    Background
    Previous studies have shown that Galectin-3، a member of lectin family، is expressed in developing cartilage in mouse embryo and also in growth plate of long bones.
    Objective
    In the present work، the expression pattern of Galectin-3 in normal and various grades of osteoarthritic (OA) human articular cartilage has been studied.
    Methods
    Using immunohistochemistry and standard western blotting، the in vivo and in vitro expression pattern of Galectin-3 in normal and OA human articular cartilage were assessed.
    Results
    Immunohistochemical studies showed a similar pattern of Galectin-3 expression in normal and mild OA but severe OA showed different strong expression in all zones of human articular cartilage.
    Conclusion
    Increased expression pattern of Galectin-3 in advanced stages of OA may occur as a result of the imbalance of chondrocyte homeostasis that occurs in OA cartilage and provides a condition to modify normal chondrocyte to an OA chondroctye.
    Abstract View Paper Original: Persian
  • Prediction of Rejection in Ranal Transplantation by immune parameters
    Mahboob Lessan, Pezeshki, Ali Akbar Amirzargar, Nooshin Golabi, Mohammadreza Khatami, Behzad Einollahi, Vahid Pourfarziani, Farideh Khosravi, Hassaneh Tajerzadeh, Behrouz Nikbin Pages 87-90
    Methods
    16 non-diabetic kidney transplant candidates (4 females and 12 males، age = 20-65 yr، first time transplant) were selected. The transplanted patients were divided into two groups based on the rejection during 3 weeks post transplant: group I (n = 9) without rejection and group II (n = 7) with a rejection episode. Immune parameters including lymphocytes subpopulations (by flowcytometry) and immunoglobulin classes (IgM، IgG، IgA and IgE by nephlometric assay) before and 45 days after transplantation were determined.
    Results
    The results of this investigation showed that the level of immunoglobulin IgG، IgM، IgA and IgE decreased post transplantation due to immunosuppressive drugs. CD3، CD4، CD8 T cells count، CD56 NK cells count and CD20 B cells count pre- and post-transplantation did not show any significant differences. The amount of IgE (220 vs. 462 IU/ml)، CD3 (62% vs. 69. 7%) and CD4 (35% vs. 41. 3%) cells increased in group II during rejection episode pre-transplantation. In addition، IgA increased pretransplantation in group I those without rejection episode in comparison with group II with a rejection episode. Forty five days post transplantation IgA (209 vs. 152 mg/dl)، IgG (1009 vs. 703 mg/dl) and CD20 (15% vs. 10%) increased in group I patients.
    Conclusion
    It is suggestive that pre-transplantation increases IgE، CD3 and CD4 are predictive of acute rejection.
    Abstract View Paper Original: Persian
  • A Flowcytometry Study of CD55 and CD59 Expression on Erythrocytes in Rheumatoid Arthritis Patients
    Abbas Ali Pourazar, Ali Reza Andalib, Farzad Oreizy, Hamid Karimzadeh, Ahmd Ghavami, Nejad, Behshad Pournasr, Khakabaz Pages 91-97
    Background
    Inappropriate activation or blockage of the inhibition of complement system could cause tissue damages in autoimmune diseases particularly rheumatoid arthritis (RA). Defect in complement component regulation may cause damages to tissues، on the other hand، or the damaged tissue might affect the unnecessary activation of complement components.
    Objective
    To investigate the expression of CD55 and CD 59 complement regulatory proteins in RA patients. Subjects and
    Methods
    Fifty proved rheumatoid arthritis patients participated in this study and their blood were collected for investigations. CD55 and CD59 molecules expression on the erythrocytes was assayed using primary monoclonal antibody and secondary FITC conjugated Ab، then the prepared samples were run with a FACSCalibur flowcytometer (Becton-Dickinson) and the obtained data was analyzed using a Cell Quest software package. To evaluate the complement function، CH50 was performed using patient sera. All experiments were done with a matched healthy volunteer group.
    Results
    The mean fluorescence intensity for CD55 was 27. 6 ± 13. 4 arbitrary unit for patients and 68. 5 ± 10. 5 for healthy group. CD59 mean fluorescence intensity was 314 ± 83 in patient group and 508 ± 56 in healthy volunteers. In addition، there was a significant difference between CH50 in patients (54. 5 ± 15. 5) and in healthy group (110 ± 20). A significant correlation between CD55 and CD59 expansion on the patient erythrocytes was found (P = 0. 00، r = 0. 576). No association was found between CD59، or CD55 with CH50 (P > 0. 05).
    Conclusion
    The expression of CD55 and CD59 is down-regulated on erythrocytes of patients with RA. Change in expression of regulatory complement components in RA may be a useful key for the assessment of disease progression or in patients'' follow-up.
    Abstract View Paper Original: Persian
  • Lack of Association between ctla - 4A49G Polymorphism and Vitiligo
    Mohammad Javad Fattahi, Abbui Mohammad Pezeshkin, Marym Emad, Mohammad Hoseein Lohrasb, Azra Shamseddin Abbas Ghader, Mehrnoosh Doroudchi Pages 97-103
    Background

    Vitiligo is an acquired skin disorder that selectively destroys melanocytes in epidermis with an unknown etiology.

    Objective

    To investigate the exon 1 A49G polymorphism of cytotoxic T lymphocyte antigen-4 (ctla-4) gene in vitiligo patients.

    Methods

    The A49G polymorphism was detected by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method in 101 patients and 208 normal healthy age/ethnicity matched individuals.

    Results

    The frequencies of heterozygote genotypes in patients and controls were found to be 42 (41. 6%) of 101 and 85 (40. 9%) of 208، respectively. The frequencies of homozygote A and G genotypes were 49 (48. 5%) and 10 (9. 9%) in 101 patients، whereas، these frequencies in 208 control individuals were 103 (49. 5%) and 20 (9. 6%)، respectively. There was no significant difference between the genotype (P = 0. 98) and allele (P = 0. 86) frequencies of A49G polymorphism in patients and normal healthy individuals.

    Conclusion

    Our results indicate that in contrast to several immune mediated disorders، there is no association between ctla-4 A49G gene polymorphism and vitiligo.

    Abstract View Paper Original: Persian
  • Level of Nitric Oxide in Bronchoalveolar Lavage Fluid Of Asthmatic Mice Model
    Alireza Salek Moghaddam, Mohammad Shabani, Farahdokht Fateminasag, Mohammad Reza Khakzab Pages 103-111
    Background

    Asthma is a chronic inflammatory disease with multifactorial and complicatedmechanisms. Elevated level of exhaled Nitric Oxide (NO) in asthma and other inflammatory lung diseases has led to many studies examining NO as a potential marker of airway inflammation.

    Objective

    This study was designed to determine the level of NO in Bronchoalveolar Lavage (BAL) fluid during early and late stages of asthmatic attack in mouse model.

    Methods

    In this study male BALB/c mice were used. The level of NO was determined in BAL fluid of asthmatic mice five minutes، six and sixteen hours after challenge with methacholine، as irritant and smoke and 5% ovalbumin as allergens، using colorimetric assay.

    Results

    The level of NO increased upon exposure to all three irritants used in this study (52. 3 M for smoke and 49. 5 Mfor methacholine) as compared to 22. 8 M for the baseline. Our results showed that NO levels were increased during early phase of asthmatic condition and reached to its maximum level after six hours and decreased at the late stage of asthma (16hrs) possibly by activating a feedback regulatory loop. In addition، high level of NO led to the hypertrophy of smooth muscle that can account for the pathological changes associated with asthma.

    Conclusion

    Thus، NO is an inflammatory marker in asthma and its measurement، as a non-invasive method during asthmatic attack is suggested. A careful development of specific inhibitors for iNOS enzyme during asthmatic attack is also necessary.

    Abstract View Paper Original: Persian
  • Increased Natural Killer Cell Activity in Schizophrenic Patients
    Mohammad Vodjgani, Hedieh Matloubi, Abbas Ali Nasehi, Mohammad Hossein Niknam, Anoushirvan Kazemnejad, Eisa Salehi, Tahereh Aboufazeli, Zahra Gheflat Pages 111-117
    Background
    Schizophrenia has been associated with altered immunity. Different studies regarding natural killer cell activity (NKA) in schizophrenic patients have shown inconsistent results.
    Objectives
    To evaluate NK cell activity in schizophrenic patients in comparison with healthy control individuals.
    Methods
    30 medication-free schizophrenic patients and 41 healthy sex، age and smoking status matched individuals were included in this study. NK cell activity of case and control subjects was measured by Methyl-Thiazol-Tetrazolium (MTT) test. Statistical analysis of the data was done using SPSS 11. 5 software.
    Results
    NK activity of patients and normal subjects had a mean of 36. 94 ± 26. 15 (Mean ± SD) and 22. 31 ± 17. 92، respectively. A significant increase in NK activity in schizophrenic patients compared to controls (P = 0. 011). Among patients، NK activity of smokers was significantly lower than that of non-smokers (P = 0. 02). Other demographic factors didn''t show any influence on NK activity.
    Conclusion
    The higher activity of NK cells in the schizophrenic patients as compared with the control population could explain the low incidence of cancer in these patients. Decreasing the effect of smoking on NK activity in the patients could be one of the responsible factors for the inconsistency in the results of different studies.
    Abstract View Paper Original: Persian
  • Flowcytometric Analysis of Tumor Associated Macrophages in Invasive Ductal Cacinoma of Breast
    Dawar Amani, Zohair Mohammad Hassan, Fatemeh Ravangard, Susan Fraznab, Mojtaba Karim Zadeh Pages 117-124
    Background
    Invasive ductal carcinoma is the most common type of breast cancer in Iran. Impaired immune responses occur frequently in cancer patients، but the mechanisms of the induced immune defects remain poorly understood. It is believed that infiltrated immune cells، especially macrophages، may provide help for tumor cell growth and metastasis.
    Objective
    To analyze the status of tumor associated macrophages (TAM) by immunophenotyping method.
    Methods
    Twenty-three women suffering from breast cancer were examined; nineteen of them were confirmed histologically to have invasive ductal carcinoma. Tumor cell suspensions from biopsy specimens and peripheral blood mononuclear cells from patients and matched controls were processed for analysis by flow cytometry.
    Results
    No significant changes in the percentages of intra-tumor leukocytes and macrophages in the different stages of tumor were observed. There were no significant differences in the percentages of leukocytes (CD45+)، monocytes (CD45+/CD14+) and activated monocytes (CD14+/HLA-DR+ and CD14+/CD16+) in the peripheral blood of patients and controls.
    Conclusion
    The results of this study indicated that human breast cancer contain substantial، although variable numbers of macrophages، however، the activation status of these macrophages remain to be elucidated.
    Abstract View Paper Original: Persian