CONTENTS
Review
- Effective Tumor Immunotherapy: Start the Engine, Release the Brakes, Step on the Gas, …and Get Ready to Face Autoimmunity
Inigo Tirapu, Guillermo Mazzolini, Mercedes Rodriguez-Calvillo, Ainhoa Arina, Belen Palencia, Izaskun Gabari and Ignacio Melero (Gene Therapy Division, Facultad de Medicina and Clinica Universitaria, Universidad de Navarra, Pamplona, Spain)Abstract. Cellular immune responses can destroy cancer cells, achieving the cure of experimental malignancies. An expanding wealth of knowledge on the molecular basis of how to prime and amplify a T cell response has fueled a number of strategies successful at treating established tumors (rather than merely preventing tumor grafting). The most efficacious approaches operate at different stages, including: 1) priming the immune response using tumor antigen-expressing dendritic cells or tumor cells transfected with genes that render them immunogenic, 2) sustaining and amplifying immunity using agonistic monoclonal antibodies against costimulatory molecules or immune-potentiating cytokines, and 3) eliminating mechanisms that self-regulate the strength of the immune response, such as inhibitory receptors or regulatory T cells. A rational combination of such approaches holds great hope for cumulative and synergistic effects, but there is also evidence that they can open the flood-gates for unwanted inflammatory reactions. The next decade can be envisioned as the time when the first reproducibly efficacious combination regimes for cancer immunotherapy will become available and widely used in the clinic, as clinicians learn the best strategies and try to harness their potentially damaging effects.
Keywords: immunotherapy; dendritic cells; costimulation; CTLA-4; 4-1BB; CD40; cytokines.
- Caspases – Their Role in Apoptosis and Other Physiological Processes as Revealed by Knock-Out Studies
Kenneth Sadowski-Debbing (Clinic for Craniomaxillofacial Surgery, Schloss Str. 1, D-48683 Ahaus, Germany), Johannes F. Coy (MTM Laboratories AG, Im Neuenheimer Feld 519, D-69120 Heidelberg, Germany), Walter Mier (Institute of Nuclear Medicine, University of Heidelberg, D-69120 Heidelberg, Germany), Hubert Hug (University Childrens Hospital, Prittwitzstr. 43, D-89075 Ulm, Germany), Marek Los (Department of Immunology and Cell Biology, University of Muenster, D-48149 Muenster, Germany)Abstract. Caspases are crucial mediators of apoptosis, a form of physiological cell death. Their activation is carefully controlled by a philogenetically conserved death program, which is indispensable for the homeostasis and development of higher organisms. Dysregulation of apoptosis contributes to the pathogenesis of many human diseases. As effectors of the apoptotic machinery, caspases are considered potential therapeutic targets. In vitro studies have demonstrated the requirement of caspases activity for both the triggering phase as well as the execution of apoptosis, thus providing a molecular base for the fine-tuning of this process by pharmacological agents. The precise roles of the individual caspases in vivo and their functional relation to each other have been best demonstrated in genetically modified animals. The generation of single caspase-deficient mice have confirmed most of the data obtained in vitro and exposed some new aspects previously undetected in the cell culture system. Interestingly, inactivation of many caspases revealed not only their expected participation in apoptotic events as well as in the maturation of cytokine, but also provided hints about the role of at least some caspases in cell differentation and stimulatory repsonses. In this review we will discuss what these studies have unveiled about the role of individual caspases in development, apoptosis, and inflammation, with particular focus on their role beyond the apoptotic process.
Keywords: caspases; cell death; development; cell cycle; inflammation.
- Emerging Concepts in the Molecular Pathogenesis of Systemic Lupus Erythematosus
Madhusoodana P. Nambiar, Yuang-Tuang Juang and George C. Tsokos (Department of Cellular Injury, Walter Reed Army Institute of Research, Building 503, Robert Grant Avenue, Silver Spring, MD 20910-7500, USA, Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA)Abstract. Systemic lupus erythematosus is a prototypic autoimmune disease that predominantly afflicts women during child-bearing age. The disease is characterized by the production of autoantibodies and immune complexes in association with a diverse array of clinical manifestations. Investigation into the etiopathogenesis has been directed at identifying the genes that provide susceptibility to the disease, the complex cellular and cytokine aberrations and the biochemical abnormalities that are responsible for them. Understanding the immune cell signaling and gene transcription abnormalities will help us tailor new strategies for efficient biotherapy of the disease.
Keywords: systemic lupus erythematosus; autoimmune diseases; pathogenesis.
- Interferon Tau and Its Immunobiological Role in Ruminant Reproduction
Anna Chełmońska-Soyta (Department of Veterinary Prevention and Immunology, Faculty of Veterinary Medicine, Agriculture University of Wrocław, Norwida 31, 50-375 Wrocław, Poland)Abstract. Interferon tau (IFN-tau) is an key cytokine in maintaining pregnancy in ruminants. It is produced by the ruminant conceptus around the time of implantation. IFN-tau belongs to the type I interferon family but, unlike the other members of this group, it is not virus inducible and its expression is temporal and restricted to the trophoblast cells of the ruminant conceptus. The main target of the paracrine action of this cytokine is the endometrium. It changes the prostaglandin metabolism and secretory function of the cells by upregulating the secretion of several proteins. It also presents immunomodulatory action towards leukocytes by changing their proliferative responses and cytokine production. This cytokine activity in reproductive biology and immunology has been intensively explored for the last ten years. It has been regarded as a potential tool in improving the performance and biotechnological processes in ruminant reproduction. Additionally, its high antiviral potency and low cytotoxicity in comparison with IFN-tau has placed this cytokine in the group of possible therapeutics in human and animal medicine.
Keywords: interferon tau; cytokine; ruminants; reproduction; pregnancy.
- The Role of the Innate and Adaptive Immune Responses in Acanthamoeba Keratitis
Jerry Y. Niederkorn (Department of Ophthalmology, University of Texas Southwestern Medical Center Dallas, Texas 75390-9057, USA)Abstract. Infections of the corneal surface are an important cause of blindness. Protozoal, viral, bacterial, and helminthic infections of the cornea account for up to nine million cases of corneal blindness. Free-living amoebae of the genus Acanthamoeba produce a progressive infection of the cornea called Acanthamoeba keratitis. Disease is usually transmitted by Acanthamoeba trophozoites bound to soft contact lenses. Infection of the cornea is initiated when the parasite binds to the corneal epithelial surface. Recrudescence can occur and suggests that the adaptive immune response is not aroused by corneal Acanthamoeba infections. Systemic immunization with Acanthamoeba antigens elicits robust Th1 cell-mediated immunity and serum IgG antibody, yet fails to prevent the development of Acanthamoeba keratitis. However, immunization via mucosal surfaces induces anti-Acanthamoeba IgA antibodies in the tears and provides solid protection against the development of Acanthamoeba keratitis. Unlike other immune effector mechanisms that rely on cytolysis, inflammation, release of toxic molecules, or the induction of host cell death, the adaptive immune apparatus prevents Acanthamoeba infections of the cornea by simply preventing the attachment of the parasite to the epithelial surface. The beauty of this mechanism lies in its exquisite simplicity and efficacy.
Keywords: cornea; Acanthamoeba keratitis; corneal blindness.
Immunochemistry
- Thermal Glycation of Proteins by D-Glucose and D-Fructose
Urszula Kańska and Janusz Boratyński (Department of Tumor Immunology, Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 12 Weigla, 53-114 Wroclaw, Poland)Abstract. The dry thermal glycation method was used to conjugate D-glucose and D-fructose with bovine serum albumin. Reactions were conducted at 50-104oC for 30 min. Depending on temperature, different levels of substitution were achieved. In the case of D-glucose average substitution level of up to 53 mol glucose/mol BSA were obtained. D-Fructose turned out to be less reactive than D-glucose. The pH of the reaction mixture was also found to affect the efficiency of the glycation reaction. The levels of substitution were estimated using matrix assisted laser desorption/ionisation time of flight mass spectrometry (MALDI-TOF) and SDS-polyacrylamide gel electrophoresis. Glycated molecules, and a process of glycation itself are implicated in diabetes complications. Hypothetically bovine spongiform encephalopathy (BSE) was also derived from glycation.
Keywords: glycation; BSA; D-glucose; D-fructose; conjugate.
- Glycoforms of Six Serum Glycoproteins in a Patient with Congenital Disorder of Glycosylation Type I
Mirosława Ferens-Sieczkowska, Iwona Kątnik-Prastowska (Deptartment of Chemistry and Immunochemistry, Wrocław Medical University, Bujwida 44A, 50-345 Wrocław, Poland), Krzysztof Zwierz (Department of Pharmaceutical Biochemistry), Alina Midro (Department of Clinical Genetics, Medical Academy, Mickiewicza 2A, 15-222 Białystok, Poland)Abstract. In this paper the occurrence and relative content of defectively glycosylated serum glycoforms in transferrin (Tf), a1-acid glycoprotein (AGP), haptoglobin (Hp), a1-antitrypsin (a1-AT), a2-macroglobulin (a2-MG) and ceruloplasmin (Cpl) in the serum of a patient with congenital disorder of glycosylation type I are reported. Blood samples were taken when the patient was 14 years old and then after a one-year interval. The patterns of glycoforms in both samples were compared. In 4 out of 6 examined glycoproteins, glycoforms lacking one and two oligosaccharide chains occurred. „Underglycosylated” glycoforms of a2-MG and Cpl were not clearly detectable. Tf was shown to be affected with this defect to a higher extent than other glycoproteins, containing only 30% properly glycosylated molecules and also as much as 30% of the molecules lacking two glycan units. In Hp and a1-AT the proportions of properly and defectively glycosylated forms were similar. This properly glycosylated form comprised 47% of the Hp and 51–55% of the a1-AT molecules. As in AGP and Tf, about 30% the of molecules lacked one glycan unit. Twenty-one percent of the Hp molecules were devoid of two glycans, and this amount slightly increased in the course of the year. In a1-AT, 19 and 17% of the molecules lacked two glycans in both samples, respectively. Only in AGP we did find a substantial difference between the two blood samples. In the course of the year, the amount of the form lacking 2-chains decreased from 12 to 3%, resulting in a simultaneous increase in the forms lacking one chain and the properly glycosylated. Our work also indicates, that applying a simple method of biochemical analysis such as SDS-PAGE/Western-blotting could be helpful in preliminary diagnosis and could improve the identification of congenital disorders of glycosylation.
Keywords: glycosylation; congenital disorders of glycosylation; a1-acid glycoprotein; a1-antitrypsin; haptoglobin; transferrin; a2-macroglobulin; ceruloplasmin.
Clinical Immunology
- Comparison of Leukocyte Populations from Bronchoalveolar Lavage and Induced Sputum in Evaluation of Cell Composition and Nitric Oxide Production in Patients with Bronchial Asthma
Małgorzata Bieńkowska-Haba, onika Cembrzyńska-Nowak, Iwona Siemieniec (Laboratory of Virology, Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Weigla 12, 53-114 Wrocław, Poland), Jerzy Liebhart, Rafał Dobek, Ewa Liebhart, Bernard Panaszek, Andrzej Obojski, Józef Małolepszy (Department of Internal Medicine and Allergology, Wrocław Medical University, Traugutta 57/59, 50-454 Wrocław, Poland)
Abstract. Bronchoalveolar lavage (BAL) or induced sputum (IS) techniques may provide leukocytes for the evaluation of airway inflammatory response in bronchial asthma. The aim of the present study was to compare features of leukocyte populations obtained by the two different methods regarding the cell types and their activity in patients with bronchial asthma. The nitric oxide (NO) level released from the cells was measured as a marker of their activity. Pulmonary leukocytes were obtained from the BAL and IS of 11 asthmatic patients in stable condition at the time of the study. The BAL and IS leukocyte populations varied in cell count and NO production. Macrophages were the predominant leukocyte population in BAL (Me = 83.0%, range 67.9-88.4%), whereas sputum sediments were found to consist mainly of neutrophils (Me = 55.7%, range 29.0-64.9%). The IS leukocytes released much more NO (p = 0.0022) than the BAL leukocytes. In spite of these quantitative differences, a similar pattern of NO production was observed in BAL and in IS cells. Both BAL and IS leukocyte populations produced almost the same amounts of NO before and after lipopolysaccharide stimulation (p = 0.9063, p = 0.4801, respectively). Furthermore, a slight positive correlation (RS = 0.5578, p=0.0594) was noticed between the neutrophil percentages and NO levels produced by BAL cells, whereas in IS a statistically significant correlation between the percentage of neutrophils and the levels of NO (RS = 0.6643, p = 0.0184) was observed. In conclusion, the BAL and IS leukocyte populations are different in cell type, their size and activity. Depending on the asthma severity and the type of cells needed in a study, either BAL or IS specimens may be chosen as a source of pulmonary leukocytes. The use of IS as a noninvasive technique is supposed to be potential value particularly in the study of the airway inflammatory response mediated mainly by neutrophils, i.e. during and/or after exacerbation of the disease. Based on our results, a possible contribution of neutrophils in the production of NO in the airways of asthmatic patients can be proposed apart from other cells such as macrophages.
Keywords: bronchoalveolar lavage, induced sputum, pulmonary leukocytes, nitric oxide, neutrophils, macrophages, eosinophils, bronchial asthma