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Cellular Immune System (cellular + immune_system)
Selected AbstractsPathogenesis of Helicobacter pylori infectionHELICOBACTER, Issue 2002Markus Gerhard Five years after publication of the complete genome sequence of Helicobacter pylori, research interest is shifting from the descriptive association of virulence factors with clinical outcome in infected patients to the molecular mechanisms of virulence factor action. This is particularly noticeable for VacA and CagA, for both of which detailed understanding of the interaction with host signalling pathways has accumulated over the last year. The role of H. pylori Lewis antigens for clinical outcome was further substantiated. Various strategies of H. pylori to fool or evade the human immune system are described, which all lead to the dysfunction of specific compartments of the host cellular immune system. Finally, a number of animal models indicate that inflammation is a key factor for gastric carcinogenesis, which is finally supported by a large prospective study identifying corpus atrophy and intestinal metaplasia as precancerous conditions. [source] A quantitative study of epidermal Langerhans cells in cutaneous leishmaniasis caused by Leishmania tropicaINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 11 2004Simin Meymandi MD Objective, The purpose of this study was to characterize the number and distribution of epidermal Langerhans cells in different clinical forms of dry-type cutaneous leishmaniasis (CL). Methods, Sixteen cases of dry-type cutaneous leishmaniasis caused by Leishmania tropica were studied. These cases were classified clinically as five cases of acute leishmaniasis with indurated papules, nodules and plaques with central crust formation and duration < 2 years, six cases of lupoid leishmaniasis with characteristic papules around previous scars of cutaneous leishmaniasis with duration > 2 years, and five cases of chronic nonlupoid type with nonhealing lesions of duration > 2 years. Paraffin-embedded blocks were stained with hematoxylin and eosin (H&E) and stained immunohistochemically for CD1a. Results, The number of Langerhans cells per millimeter length of epidermis was increased in acute cases compared to chronic and lupoid cases. Conclusions, Lesions of acute leishmaniasis contain the greatest amounts of antigen for presentation, so Langerhans cells increase in number and in trafficking to present antigens derived from Leishman bodies to the cellular immune system. In chronic leishmaniasis, the Langerhans cell population is reduced, perhaps because of exhaustion of the source of Langerhans cells, or because of reduced response to modified antigen. [source] The large form of ADAR 1 is responsible for enhanced hepatitis delta virus RNA editing in interferon- , -stimulated host cellsJOURNAL OF VIRAL HEPATITIS, Issue 3 2006D. Hartwig Summary., Hepatitis delta virus (HDV) RNA editing controls the formation of hepatitis-delta-antigen-S and -L and therefore indirectly regulates HDV replication. Editing is thought to be catalysed by the adenosine deaminase acting on RNA1 (ADAR1) of which two different forms exist, interferon (IFN)- , -inducible ADAR1-L and constitutively expressed ADAR1-S. ADAR1-L is hypothesized to be a part of the innate cellular immune system, responsible for deaminating adenosines in viral dsRNAs. We examined the influence of both forms on HDV RNA editing in IFN- , -stimulated and unstimulated hepatoma cells. For gene silencing, an antisense oligodeoxyribonucleotide against a common sequence of both forms of ADAR1 and another one specific for ADAR1-L alone were used. IFN- , treatment of host cells led to approximately twofold increase of RNA editing compared with unstimulated controls. If ADAR1-L expression was inhibited, this substantial increase in editing could no longer be observed. In unstimulated cells, ADAR1-L suppression had only minor effects on editing. Inhibition of both forms of ADAR1 simultaneously led to a substantial decrease of edited RNA independently of IFN- , -stimulation. In conclusion, the two forms of ADAR1 are responsible almost alone for HDV editing. In unstimulated cells, ADAR1-S is the main editing activity. The increase of edited RNA under IFN- , -stimulation is because of induction of ADAR1-L, showing for the first time that this IFN-inducible protein is involved in the base modification of replicating HDV RNA. Thus, induction of ADAR1-L may at least partially cause the antiviral effect of IFN- , in natural immune response to HDV as well as in case of therapeutic administration of IFN. [source] Neopterin and interleukin-8 , prognosis in alcohol-induced cirrhosisLIVER INTERNATIONAL, Issue 6 2000Christian Homann Abstract:Background: Neutrophil cytotoxity and activated macrophages have been implicated in the pathogenesis of alcohol-induced liver disease. The aim of this study was to relate plasma levels of neopterin, a marker of activation of the cellular immune system, and IL-8, a neutrophil chemotactic factor, with severity of liver disease and prognosis in patients with alcohol-induced cirrhosis. Methods: Plasma concentrations of neopterin and IL-8 were assessed in 81 patients with alcohol-induced cirrhosis admitted to the Department of Medicine B, Bispebjerg Hospital, Copenhagen, Denmark, and in 16 healthy controls. After a median follow-up period of 5 years, mortality and death causes were registered. The patients were divided into groups according to the major contributing cause of death: infection, upper gastrointestinal bleeding or hepatic coma. Results: Neopterin and IL-8 levels were increased in the cirrhosis patients, but not significantly related to Child-Pugh classification. Five-year mortality was 67%. High neopterin levels (>upper quartile) were an independent predictor of death (p=0.01, Log rank and p<0.02, Cox). High IL-8 levels (>upper quartile) were of no significant prognostic value for overall mortality. Causes of death related mortality were as follows (Log rank): Neopterin; p=0.009, p=0.84 and p=0.94, and IL-8; p=0.36, p=0.002 and p=0.27, respectively, according to infection, bleeding and coma as causes of death. Conclusions: Neopterin and IL-8 plasma levels are raised in patients with alcohol-induced cirrhosis, and are predictive of mortality associated with infections and upper gastrointestinal bleeding, respectively. [source] T-lymphocyte subsets, thymic size and breastfeeding in infancyPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 2 2004Dorthe L. Jeppesen We followed the changes in concentration of T-lymphocyte subsets (CD4+ and CD8+ cells) in peripheral blood and thymus size during infancy. Previous studies have found increased thymus size in breastfed infants. The present study analyzed the association between breastfeeding and the number of CD4+ and CD8+ cells. Two different populations of infants between birth and 1 year of age were examined. Study Group I: infants with a variable duration of breastfeeding. Study Group II: long-term breastfed infants. In both groups a correlation was found between CD8+ cells and the thymic index at 10 months of age. In Group I, infants still breastfed at the 8-month examination had a higher CD8% than formula-fed infants (p = 0.05), and infants breastfed at the 4-month examination had a higher CD4% at 10 months of age (p=,0.03). Group II showed an increase in the absolute number of CD4+ and CD8+ cells from 8 to 10 months of age; and a positive correlation between the number of breastfeedings per day at 8 months of age, and an increase in CD4+ cells from 8 to 10 months of age (p <0.01). In conclusion, a correlation was found between thymus size and CD8+ cells. Breastfeeding might have both a current and long-term immune-modulating effect on the developing cellular immune system. [source] Pulmonary Tuberculosis and Cutaneous Mycobacterial Infection in a Patient with Incontinentia PigmentiPEDIATRIC DERMATOLOGY, Issue 6 2004Nilgün Senturk M.D. Lupus vulgaris following bacille Calmette-Guérin (BCG) vaccination is a rare entity. Incontinentia pigmenti is an X-linked dominant genodermatosis in which vesicular, verrucous, and pigmented lesions are associated with various developmental defects. There is evidence of altered immunologic reactivity in some patients with incontinentia pigmenti. A 12-year-old girl hospitalized for pulmonary tuberculosis presented with bizarre-shaped brown macules following Blaschko lines on the left deltoid area, compatible with incontinentia pigmenti, which had appeared following BCG vaccination at the age of 7 years. Histopathologic examination found noncaseated granulomas in the dermis. Antituberculous treatment for pulmonary and cutaneous tuberculosis was initiated along with genetic counseling. Immunologic abnormalities have been reported in conjunction with incontinentia pigmenti. Simultaneous occurrence of pulmonary and cutaneous tuberculosis in our patient might be either coincidental or indicate derangements in the cellular immune system. [source] | |||||||||||||||||||