Type 1 Diabetes Mellitus Is a Disease That Results from Autoimmune Destruction of The

Is there a receptor for Coxsackie- and Adenovirus on insulin-producing cells?

Asma Elshebani

Type 1 diabetes mellitus is a disease that results from the body’s own action of destroying of the insulin-producing cells in the pancreas. The disease is believed to be caused by a combination of inherited and environmental factors. Among environmental factors infections with virus, particularly viruses in the group Enteroviruses, for example Coxsackie B, are believed to have a significant role in initiation and development of the disease.

For a virus to infect a cell there must be a molecule on the cell surface that the virus can use to enter it, a receptor. Coxsackie B virus uses the same receptor as Adenovirus, which therefore is named the coxsackie and adenovirus receptor (CAR). In this project my aim was to investigate if the human gene encoding CAR is expressed in human insulin-producing cells, and in cells derived from a rat pancreas tumour. The latter cells were grown as monolayer cultures or as free-floating cell clusters. I used two methods, one that analyzed presence of mRNA transcribed from the CAR gene and one that analyzed the presence of the CAR protein. To detect the mRNA from the gene I used a very sensitive method that produced many DNA copies of the mRNA (“reverse transcription polymerase chain reaction, or RT-PCR). The product of the RT-PCR was analyzed by electrophoresis, where each DNA product formed a band migrating at a certain rate depending on its size. The DNA was then stained and quantified by measuring the amount of stain associated with each band. To detect the presence of CAR protein I used an immunological method where an anti-CAR antibody bound to the CAR protein, and then a second antibody bound to the anti-CAR antibody. This second antibody carried an enzyme the activity resulted in a red colour that could be visualized by a light microscope, providing a measure of the total amount of CAR present.

My results show that the receptor protein CAR was expressed in pancreatic insulin-producing cells of rat and human, suggesting that coxsackie virus can infect these cells and thereby possibly contribute to development of Type 1 diabetes.

Degree project in biology, University of Uppsala, spring 2004

Examensarbete i biologi, 10p

Department of Biology Education and Department of Women’s and Children’s Health

(Barnforskningslab), Uppsala University

Supervisor: Gun Frisk