Vol. 53, No. 2, 2005

Reginald M. Gorczynski (Toronto Hospital and University Health Network, Toronto, Ontario, Canada)

Abstract. Advances in the treatment of transplant rejection, autoimmune disease, allergy, and other conditions of altered immunoregulation have come from our improved knowledge of the multi-faceted nature of lymphocyte activation, incorporating not merely antigen triggering of specific receptors, but a myriad of other accessory signals, all operating within a defined environmental (cytokine) milieu. The review below focuses on just one aspect of this, the ability to manipulate costimulatory signals, or regulatory signals, as a means to induce long-standing immune suppression. Emphasis is placed on the dominant suppression mediated following activation of any one of a number of regulatory signals as a potentially more rational approach to clinical therapy, as the redundancy in costimulatory signals suggests that blockade of any one of these may be unlikely to produce permanent unresponsiveness. The role of regulatory T ceillis, induced following antigen presentation in the presence of immunoregulatory signals, is also discussed.

Keywords: tolerance; immunoregulation; costimulation; CD200

Ali Ouaissi¹ and Mehdi Ouaissi² (¹IRD, Research Unit No. 008, “The Pathogenesis of Trypanosomatides”, Montpellier, France ²Digestive and General Surgery Service, Hôpital Sainte Marguerite, Marseille, France)

Abstract. A number of features occurring during host-parasite interactions in Chagas disease caused by the protozoan parasite, Trypanosoma cruzi, and Leishmaniasis, caused by a group of kinetoplastid protozoan parasites are reminiscent of those observed in cancer diseases. In fact, although the cancer is not a single disease, and that T. cruzi and Leishmania are sophisticated eukaryotic parasites presenting a high level of genotypic variability, the growth of the parasites in their host and that of cancer cells share at least one common feature, that is their mutual capacity for rapid cell division. Surprisingly, the parasitic diseases and cancers share some immune evasion strategies. Consideration of these immunological alterations must be added to the evaluation of the pathogenic processes. The molecular and functional characterization of virulence factors and the study of their effect on the arms of the immune system have greatly improved understanding of the regulation of immune effectors functions. The purpose of this review is to analyze some of the current data related to the regulatory components or processes originating from the parasite that control or interfere with host cell physiology. Attempts are also made to delineate some similarities between the immune evasion strategies that parasites and tumors employ. The elucidation of the mode of action of parasite virulence factors toward the host cell allow not only provide us with a more comprehensive view of the host-parasite relationships but may also represent a step forward in efforts aimed to identify new target molecules for therapeutic intervention.

Keywords: trypanosomatids; virulence factors; cancer cells; immunoregulation

Tom Van Belle and Johan Grooten (Department for Molecular Biomedical Research, Flanders Institute for Biotechnology (VIB) and Laboratory for Molecular Biology, University of Ghent, Belgium)

Abstract. The cytokine IL-15 performs numerous functions, such as promotion of growth and survival, on a plethora of cell types from both the lymphoid and non-lymphoid compartments. Therefore, mice genetically engineered to either lack or overexpress functional IL-15 display reduced immunological responses and leukemia, respectively. Surprisingly, IL-15 protein is hardly found in serum or body fluids. Due to the lack of a clear demonstration of its presence as protein, IL-15 was often referred to as a “ghost cytokine”. Recently, however, membrane-bound IL-15 was detected in both a membrane-anchored form and an IL-15Ra-bound form on monocytes. Interestingly, the latter complex can be transpresented to cells expressing the intermediate-affinity IL-2/15Rß-g_C receptor and thereby support the survival and proliferation of T cells. Moreover, overlapping promoter elements indicate a model of co-regulation of IL-15 and IL-15Ra by which IL-15 activities are controlled in a cell-contact-dependent manner. In this review, recent reports on IL-15 are combined with previous observations and discussed in terms of their functional consequences for CD4⁺ T cell responses.

Keywords: cytokines; T lymphocytes; IL-15; transpresentation; apoptosis

Zoltán Krasznai (Department of Biophysics and Cell Biology, Research Center for Molecular Medicine, Medical and Health Science Center, University of Debrecen, Hungary)

Abstract. Ion channels of a variety of cell types, such as cardiac and smooth muscle cells and neurons, serve as targets for many drugs used in therapy. T cells also express an assortment of ion channels that are in the focus of intensive research, as they may provide efficient ways to specifically manipulate T cell function and, consequently, immune responses. T cell activation relies on the operation of voltage-gated and Ca²⁺-activated potassium channels and Ca²⁺ release-activated Ca²⁺ channels. Many peptide toxin and small molecule blockers of these channels are known, but inhibitors of even higher affinity and selectivity would be needed for safe and effective clinical use. The recent discovery that the expression pattern of potassium channels in T cells is subset specific emphasizes the potential that these proteins have in immunomodulation. Compounds that could suppress T cells involved in autoimmunity without affecting T cells in normal immune responses would be of enormous value. In this paper the basic properties of these channels and compounds known to influence their operation are reviewed.

Keywords: T cell; activation; potassium channels; CRAC channels; channel blockers

Irma Kacprzak-Bergman¹ and Beata Nowakowska² (¹Department of Pediatric Infectious Diseases, Wrocław University of Medicine, Wrocław, Poland ²Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland)

Abstract. The association of genetic factors with hepatitis B virus (HBV) infection susceptibility, its different manifestations, and the different responses to hepatitis B antigen vaccination have been described by several authors. With regard to HLA class I molecules, association with HLA-B was especially observed. HLA-B35 and -B8 correlated with chronic active hepatitis (CAH) and with hepatitis B carriers. Correlation between HBV infection and HLA class II (loci DR and DQ) was also indicated, but results are not clear regarding the clinical pictures of the disease nor vaccination response. HLA class III (fourth complement component – C4, third complement component – C3, and properdin factor – BF) are associated with various manifestations of this disease. The gammaglobulin phenotype Gm(1, 2, 3, 10, 21) was more frequent in CAH. However, in only three publications was the impact of HLA on the efficacy of interferon therapy taken into account.

Keywords: HBV; genetics; HLA; C3; C4; BF; Gm; Inv

Irma Kacprzak-Bergman¹ and Beata Nowakowska² (¹Department of Pediatric Infectious Diseases, Wrocław University of Medicine, Wrocław, Poland ²Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland)

Abstract. The association of genetic factors with hepatitis B virus (HBV) infection susceptibility, its different manifestations, and the different responses to hepatitis B antigen vaccination have been described by several authors. With regard to HLA class I molecules, association with HLA-B was especially observed. HLA-B35 and -B8 correlated with chronic active hepatitis (CAH) and with hepatitis B carriers. Correlation between HBV infection and HLA class II (loci DR and DQ) was also indicated, but results are not clear regarding the clinical pictures of the disease nor vaccination response. HLA class III (fourth complement component – C4, third complement component – C3, and properdin factor – BF) are associated with various manifestations of this disease. The gammaglobulin phenotype Gm(1, 2, 3, 10, 21) was more frequent in CAH. However, in only three publications was the impact of HLA on the efficacy of interferon therapy taken into account.

Keywords: HBV; genetics; HLA; C3; C4; BF; Gm; Inv

Sunghee Choi¹ , Hae-Sim Park² , Myeong Sook Cheon¹ and Kyunglim Lee¹ (¹College of Pharmacy, Center for Cell Signaling Research and Division of Molecular Life Sciences, Ewha Women’s University, Seoul, Korea ²Department of Allergy and Rheumatology, Ajou University Hospital, Suwon, Korea)

Abstract. Introduction: Aspirin is a popular nonsteroidal anti-inflammatory drug, but some patients suffer from hypersensitivity to it. This prompted us to identify the factors or molecules related to these responses.
Materials and Methods: A commercially available DNA microarray was used to study changes in gene expression in human peripheral blood mononuclear cells (PBMCs) after aspirin treatment. The PBMCs were collected from a patient with aspirin-intolerant asthma and one normal healthy control.
Results: We identified 61 and 107 genes respectively induced and repressed by aspirin treatment in the PBMCs derived from the normal control. In the patient showing aspirin-induced asthma responses, 31 genes were up-regulated and 6 were down-regulated after aspirin treatment. Among these, 1 gene was expressed with the same pattern in the control and the patient. In contrast, 19 genes showed different expression patterns, and it turned out that most of them were involved in immune responses, cell growth/proliferation, transcription/ translation, and signaling pathways.
Conclusions:These results show the molecules involved in hypersensitivity to aspirin and may lead to a better understanding of adverse responses to aspirin. Furthermore, they can provide clues for identifying novel therapeutic and/or preventive molecular targets of the adverse effects of aspirin.

Keywords: aspirin; asthma; human peripheral blood mononuclear cells; microarray

Stanisław Moskalewski , Anna Osiecka-Iwan , Anna Hyc and Justyna Niderla (Department of Histology and Embryology, Medical University of Warsaw, Warsaw, Poland)

Abstract. Introduction: The aim of the study was to discover the mechanism of rejection of chondrocyte transplants introduced into articular cartilage defects.
Materials and Methods: Chondrocytes from 3–5-day-old Lewis or WAG rats were liberated by enzymatic digesandtion from articular-epiphyseal cartilage complexes and implanted into defects made in the subpatellar region of the femur condyle of naive Lewis rats. Syngeneic transplants were also done aftersensitization of the recipients with allogeneic chondrocytes injected intramuscularly. The transplants and synovial membrane were studied in periodate-lysineparaformaldehyde- fixed material with antibodies against B lymphocytes, CD4⁺ and CD8⁺ cells, NK cells, and macrophages. For detection of humoral response, chondrocyte lysates were subjected to protein electrophoresis and Western blotting with sera from the transplant recipients.
Results: Cartilage produced in intracartilaginous transplants of syngeneic chondrocytes did not show any signs of rejection. CD8⁺ lymphocytes and macrophages accumulated in the vicinity of cartilage produced by similar transplants in animals sensitized with intramuscular transplants of allogeneic WAG chondrocytes or bearing transplants of allogeneic WAG chondrocytes. CD8⁺ cells penetrated into the peripheral part of the cartilage, while macrophages advanced much more deeply. No specific anti-chondrocyte antibody was detected. The synovium from rats bearing intracartilaginous transplants of allogeneic chondrocytes or syngeneic chondrocytes after sensitization contained macrophages and CD8⁺ cells.
Conclusions: The rejection of cartilage formed by syngeneic chondrocyte transplants in sensitized animals argues in favor of a chondrocyte-specific antigen expression. The involvement of the synovial membrane during transplant rejection suggests that it should be included in observations of the behavior of chondrocyte transplants introduced into articular cartilage.

Keywords: chondrocyte transplants rejection; synovium; CD8⁺ cells; macrophage

Jacek Madeja¹, Ewa Wypasek², Barbara Plytycz²,Krzysztof Sarapata³ and Krystyna Harmata¹(¹Institute of Botany, Jagiellonian University, Krakow, Poland ²Institute of Zoology, Jagiellonian University, Krakow, Poland ³Department of Bioinformatics and Telemedicine, Medical College, Jagiellonian University, Krakow, Poland)

Abstract. Introduction: Birch (Betula sp.) pollen grains are the main cause of seasonal allergies in northern andcentral Europe. The allergen particles released from the grains are often well distributed in the air. Due to their size, airborne protein particles can easily penetrate into the lower parts of the respiratory airways and may lead to symptoms of asthma. The purpose of this paper was to quantify both Betula sp. pollen grains and allergens in the air.
Materials and Methods: Materials for the investigation were collected in the spring of 2003 with two Hirst-type pollen volumetric traps. Tapes from one trap served for routine birch pollen grain counts, while those from the second for the immunodetection of birch allergens. As birch pollen allergen concentration is seen as dark spots on X-ray films densitometric measurements of the spots were used to quantify birch-pollen antigen concentrations in the air.
Results: In most instances, birch pollen counts corresponded with birch pollen allergen levels. However, on several occasions outside the pollen season, only grains or only allergens were detected. Apart from sampling variability, this could be due to faulty/dead pollen grains or submicronic airborne allergen particles.
Conclusions: Counting intact pollen grains and antibody-based detection of allergen molecules are efficient tools in controlled allergen avoidance.

Keywords: pollen allergy; pollen allergen release; immunodetection; pollen traps; birch allergens; Betula

Ewa Jabłońska¹, Wioletta Pużewska¹, Magdalena Marcińczyk¹ , Zyta Grabowska2 and Jakub Jabłoński^{1 1} Department of Immunology, Medical University, Białystok, Poland (¹Department of Oral and Maxillofacial Surgery, Medical University, Białystok, Poland ¹Department of Toxicology, Medical University, Białystok, Poland)

Abstract. Introduction: The tumor-polymorphonuclear neutrophil (PMN) relationship can be altered by the release of toxic molecules, such as nitric oxide (NO). The aim of the present study was to examine the expression of the inducible synthase of NO (iNOS) and NO production by human neutrophils of patients with oral cavity cancer. For comparison we performed similar examinations in autologous peripheral blood mononuclear cells (PBMCs).
Materials and Methods: PMNs and PBMCs were isolated from the whole blood of 27 patients with squamous cell carcinoma of the oral cavity. iNOS protein expression in these cells was detected by Western blot. Total nitrite as an indicator of NO concentrations in the culture supernatants and the serum of patients was measured using a colorimetric assay.
Results: The PMNs of oral cavity cancer patients showed a significantly lower intensity of iNOS expression than those of healthy controls. The PBMCs of patients showed a more intensive expression of iNOS than the PMNs, but a lower intensity than the PBMCs of the controls. The expression of iNOS in rhIL-6 and rhIL-15-stimulated PMNs and PBMCs of patients increased in comparison with unstimulated cells. We observed lower productions of NO by PMNs and PBMCs of patients than those of the control group.
Conclusions: The results revealed that altered iNOS expression and NO production are more characteristic of PMNs than of PBMCs of patients with oral cavity cancer. Additionally, this study provided new information about IL-6 and IL-15 activity in a tumor-bearing host.

Keywords: neutrophils; peripheral blood mononuclear cells; squamous oral cavity cancer; nitric oxide; inducible synthase of nitric oxide

Tadeusz Orłowski¹ , Ewa Godlewska¹ , Magda Tarchalska², Joanna Kinasiewicz¹ , Magda Antosiak1 and Marek Sabat² (¹Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland ²Transplantation Institute, Warsaw University of Medicine, Warsaw, Poland)

Abstract. Introduction: The aim of this study was to determine the influence activating of the recipient immune system on the function of microencapsulated islet xenografts.
Materials and Methods: The skin of WAG or Fisher rats and WAG free or encapsulated (APA) Langerhans islets were transplanted to healthy or to streptozotocin diabetic BALB/c mice. Skin grafts were performed following the method of Billingham and Medawar. Rat islets were isolated from pancreas by the Lacy and Kostianovsy method and encapsulated with calcium alginate- poly-L-lysine-alginate according to the 3-step coating method of Sun.
Results: The transplantation of encapsulated WAG islets, despite activation of the host immune system, restored euglycemia for over 180±100 days. A subsequent skin graft taken from the same donor was rejected in the second set mode, but euglycemia persisted. In diabetic recipients, impaired immune response was corrected by successful encapsulated islet transplantation. In diabetic mice, strong stimulation with 2-fold skin transplantation induced primary non-function of grafted islets despite their encapsulation.
Conclusions: The survival of an islet xenograft depends on the level of activation of the recipient immune system. The immune response of diabetic mice was impaired, but increased after post-transplant restitution of euglycemia. Microencapsulation sufficiently protected grafted islets, and remission of diabetes was preserved. However, after strong specific or non- -specific stimulation of the host immune system, non-function of xenografted islets developed despite their encapsulation. Therefore, islet graft recipients should avoid procedures which could stimulate their immune systems. If absolutely necessary, the graft should be protected by exogenous insulin therapy at that time

Keywords: islet xenograft; islet encapsulation; type l diabetes mellitus