Type 1 diabetes (T1D) is due to a selective loss of the insulin producing β-cells. However, the process responsible for this loss is still unknown. There is accumulating evidence that enteroviruses (EVs) are involved in T1D. In addition to direct virus-induced cytolysis, EVs could facilitate β-cell destruction by inducing inflammatory cytokines. Induction of such genes has previously been shown in EV-infected islets in vitro. Modulation of inflammatory mediators expressed in the islets could be a possible strategy to reduce β-cell destruction.In the first paper we screened uninfected isolated human islets for genes with the potential to induce or modulate an immune response. We found that several of the genes expressed in the islets encode proteins with a powerful biological activity, such as IL-1β, IL-8, MIP-2α, MCP-1 and MIF. This indicates that the islets themselves can express several triggers of inflammation, and if expressed in vivo these mediators would probably contribute to β-cell destruction.The vitamin B3 derivate, nicotinamide (NA), has been shown to modulate expression of factors important for coagulation and inflammatory responses. Addition of NA into isolated islet cultures resulted in a reduced expression of the pro-inflammatory chemokine MCP-1 and the coagulation activator tissue factor, suggesting…
Contents
Introduction
Background
Type 1 diabetes
Clinical features and epidemiology
Pathology
Immune-mediated destruction of -cells
Direct damage to -cells
Genetic factors
Environmental factors
Treatment and cure of type 1 diabetes
Human enterovirus
Classification of enterovirus
Clinical manifestation of enteroviral infections
Enterovirus lifecycle
Effect of viral replication on the host cell
Enterovirus infections in isolated human islets
Enterovirus and type 1 diabetes
Possible mechanisms of enterovirus-induced -cell destruction
Antiviral strategy to prevent type 1 diabetes
Aims
Paper I
Paper II
Paper III
Paper IV
Material and Methods
Cell culture
Human islet (papers I-IV)
Culture of human islets in the presence of various substances (paper II)
GMK cells (paper III and IV)
Microarray analysis (paper I)
The tubing loop system, blood and plasma analysis (paper II)
Viruses
Virus strains (paper III and IV)
Virus isolation (paper III)
Virus inoculations (paper III and IV)
Detection of virus replication (paper III and IV)
Immunostaining for EV (paper III)
Studies of cell morphology and viability of infected islets
Assessment of CPE (papers III and IV)
Electron microscopy (paper III)
Viability (paper III)
Glucose stimulation of infected islets (paper III)
Cytokine and chemokine measurement
TF and MCP-1 measurement (paper II)
IP-10 and MCP-1 measurement (paper IV)
Statistical analysis (paper II, III and IV)
Consideration regarding the research design and methods
Experiment using human islets (papers I, II, III and IV)
Microarray analysis (paper I)
The tubing loop system (paper II)
Virus infections of human islets (paper III and IV)
Results and Discussion
Paper I
Paper II
Paper III
Paper IV
Conclusions
Paper I
Paper II
Paper III
Paper IV
Acknowledgments
References
Author: Moell, Annika
Source: Uppsala University Library
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