MCB9808724 Owen, Judith Abstract The project is part of an ongoing effort to determine how the repertoire of antigen-specific surface receptors displayed by populations of lymphocytes changes during the course of an ongoing immune response. This is a central issue of immunology that defines how lymphocytes differentiate and adapt in a way that optimizes their antigen specificity during an immune response. This project focuses on the specific question of whether there is a maturation of the receptor repertoire in cytotoxic T lymphocytes (CTLs), those cells responsible for cellular immune responses, that is similar to what is observed for the B lymphocytes, those lymphocytes responsible for making secreted antibodies. The first part of the project will be a comparison of the sequence repertoires of the two polypeptide chains of CTL receptors to a specific antigen to determine if there are differences in the repertoires in primary and secondary (memory) responses. Differences will be related to the way the genetic elements responsible for the receptors are selected and rearranged during cell differentiation. The effect of antigen concentration on repertoires and possible differences in receptor density on the surface of cells will also be explored. The second part of the project is a study of B lymphocytes to determine if subpopulations of this class of cells can be identified that would account for preferential expression of certain receptor structures by these cells. A third part of the project is to initiate a survey of B lymphocyte genes to identify those genes that are differentially expressed during cell selection and maturation in response to antigen. The project has a major educational component to train undergraduates in cell biological research through their direct involvement in the planned studies.
