486— Cell Cycle Effect on HLA expression in HTB-4 and MRC-5

Human Leukocyte Antigen (HLA) is a gene that codes for cell-surface proteins that are the basis of our bodies’ immune response. We observed two cell lines, HTB-4 and a non-cancerous cell line known as MRC-5. Our purpose for this experiment was to observe the effect of the cell cycle on HLA expression for these cell lines. Two flasks were prepared for each cell line: one confluent and one non-confluent. Flow cytometry analysis was performed for each of the four flasks. The flow cytometry results of the MRC-5 cells indicate increased HLA expression in the confluent flask, in the G1 phase of the cell cycle. A smaller amount of expression was found in the 48-hour group. Analysis of the HTB-4 cells revealed that there was more HLA expression in the confluent flask as well. These results show that for both cell lines, HLA appears to be expressed more in confluent cells that are not undergoing large amounts of proliferation. This suggests the cell cycle does have an effect on HLA expression for these cell lines. We would like to repeat it to verify our results and use this new information about HLA expression in drug treatment experimentation.