“Newly arrived” vs “old” cell surface MHC class I molecules - membrane distribution and role in inhibitory NK cell recognition.

Supervisor: Prof. Dr. Klas Kӓrre, Karolinska Institute, Stockholm, Sweden.

Established systems to study how stabilization of recently arrived, unstable MHC class I molecules on the surface of TAP deficient cells can augment MHC class I expression, and to study how this affects inhibition of NK cell activation and killing.   Experiments established protocols for up-regulation of MHC class I expression by peptides in the TAP-deficient mutant cell line, RMA-S and also established protocols to generate NK effector cells that can attack RMA-S cells. These protocols were then applied in experiments where peptides were used to augment MHC class I expression and induce protection from NK killing of RMA-S cells. A key result was that the protection from NK cell killing could be induced in RMA-S cells by pre-incubation with Kb binding peptide SIINFEKL at 26°C as well as at 37 °C, even when the pre-incubation was very short or when peptides were just present in the cytotoxicity assay. This could be due to uptake of the peptide either by “old” MHC class I molecules present since long on the surface or the “new, recently arrived” MHC class I molecules stabilized by the peptides. Although these studies begin to view the “old” and “new” MHC class I molecules and distinguish them based on their functional and structural aspects, much more investigations and studies should be carried out.

                                 

A mouse model of myasthenia gravis with antibodies against Muscle Specific Tyrosine Kinase (MuSK)

Supervisor: Dr.Anna Rosetdt Punga, Uppsala University Hospital, Uppsala, Sweden.

Immunization of mice with the protein MuSK to elicit an autoimmune response  check  the Gene expression level and gene amplification level using RT PCR also study the nerve stimulation at different frequencies to analyze the neuromuscular transmission in so called Repetitive Nerve Stimulation (RNS) and  compare with the recordings of normal mice to we get information about neuromuscular signalling.The model was successful since the mice developed Ab against MuSK (ie.,) They developed autoimmune MG. No significant change in Dok-7 transcription was observed. RNS confirmed fatigue in the MG mouse.  

 

Study on the evaluation of growth, Dye Uptake and stability analysis of newly isolated high dye bioaccumulating Ochrobacterum  pseudintermedium. 

Supervisor: Seenuvasan, Madha Engineering College, Chennai, India.

The work involves isolation and identification of bioaccumulating microbe from sewage water plant, design and running a bioreactor, study of the microbial growth by varying conditions, analysis of the rate of dye uptake and its stability using response surface methodology(RSM). The rate of dye uptake increases with increase in time.