Determining the Precursor Frequency of HBV Nucleocapsid Antigen-Specific T Cells

The measurement of the precursor frequency of cells present in a population that are participating in a given immune function has been widely done by limiting dilution assays (LDAs). These have been used for measuring proliferative and cytotoxic responses and cytokine production by lymphocytes in the peripheral blood population. They are particularly well suited to the identification of rare cells; bulk culture is not quantitative at the cellular level and, if a low frequency of responder cells is present, misleading negative results may be obtained. Another advantage of an LDA over conventional bulk culture is that it minimizes the cross-regulatory influence between cells. In this chapter a method for measuring the precursor frequency of T cells proliferating in response to nucleocapsid antigen is described.