DEVELOPMENT OF SPECIFIC £^£_ T CELL POPULATIONS IS CRITICALLY AFFECTED BY RECOMBINATION SIGNAL SEQUENCE-ASSOCIATED RESTRICTION ON TCR£_ GENE REARRANGEMENT
Open Access
- Author:
- Uche, Uzodinma Nnaemeka
- Graduate Program:
- Pathobiology
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- None
- Committee Members:
- Na Xiong, Thesis Advisor/Co-Advisor
Avery August, Thesis Advisor/Co-Advisor
Kumble Sandeep Prabhu, Thesis Advisor/Co-Advisor - Keywords:
- £^£_ T CELL
RSS
Rearrangement
Vg2
Vd7
C57Bl/6
129/svj
T cell Receptor
BWZ
Reporter Cell Line - Abstract:
- Abstract Preferential localization of gd T cells in the epidermis of the body suggests their roles in the first line of immune defense. However, little is known about the molecular mechanisms that regulate gd T cell development and tissue distribution. In wild type mice, Vg3+ T cells are exclusively found in the skin. However, in the absence of Vg3+ T cells, other subsets of gd T cells can substitute as skin gd T cells. Previous studies found that the development of substitute skin £^£_ T cells vary among different genetic backgrounds. Substitute skin ƒ×ƒÔ T cells were found in both Cƒ×1 and Vƒ×3 knockout mice of C57Bl/6 but not 129/svj background. Similarly, transgenic Vƒ×2+ ƒ×ƒÔ T cells were found in the skin of TCRV£^2TgCg1-/- mice of C57Bl/6 but not 129/svj background. The transgenic skin ƒ×ƒÔ T cells expressed Vg2 along with endogenous Vd7. As the V£_7 gene is present in the 129/svj genome it is unclear why it is not expressed on the 129/svj skin. Our analysis found that this is, at least in part, due to reduced rearrangement of TCRV£_7 gene in the 129svj strain. Furthermore, We found that recombination signal sequences (RSS) of the V£_7 gene is different between the C57Bl/B6 and 129/svj strains. The V£_7 RSS of 129/svj strain is identical to those of the other V£ genes of its family although the V£_7 RSS of B6 strain is unique in itself, suggesting that the recombination signal sequence might be responsible for the reduced V£_7 gene usage in TCR£_ gene assembly in the 129svj background. There is a possibility that the non expression of V£_7 in129/svj is due to the lack of a selection ligand. In order to investigate this possibility we have developed a reporter V£^2V£_7+ T cell-line. This V£^2V£_7+ reporter T cell-line has a construct containing the lac-Z gene under the control of the IL-2 promoter. Upon activation of the V£^2V£_7 TCR, NFAT should bind to the IL-2 promoter and lac-Z should be produced. Preliminary results show that the V£^2V£_7 reporter T cell line functions accordingly and can be applied in V£^2V£_7 ligand detection assays on C57Bl/6 and 129/svj mice.