ANTIGEN-SPECIFIC T-CELL RESPONSES DURING PRIMARY AND SECONDARY LISTERIA-MONOCYTOGENES INFECTION

Although murine listeriosis is a widely used experimental model for th e analysis of cell-mediated immunity, there is little information abou t individual T-cell antigens of Listeria monocytogenes which are recog nized during primary and secondary infection. To study the antigen res ponses of L. monocytogenes-reactive T cells, somatic and secreted list erial proteins were separated by two-dimensional gel electrophoresis a nd subsequently divided into 480 liquid fractions. Antigen-specific T cells isolated from mice at different times of primary and secondary l isteriosis were tested for their capacity to proliferate with distinct protein fractions. Supernatants of these cultures were screened for t he production of gamma interferon, interleukin-4 (IL-4), and IL-10. Pr oliferation of antigen-specific T cells correlated with the production of high concentrations of gamma interferon, whereas IL-4 and IL-10 pr oduction in response to listerial protein fractions could not be detec ted. During both primary and secondary listeriosis, T cells recognized a multitude of somatic and secreted proteins rather than one or a few dominant antigens. Secreted proteins were recognized before somatic p roteins, and T cells recognized different fractions in secreted and so matic proteins.