Long-lasting CD8 T cell memory in the absence of CD4 T cells or B cells.

The cellular basis of immunological memory has been a debated issue. It is not clear whether CD8 T cell memory is maintained by long-lived cells or by specific or nonspecific restimulation. Here, we have approached the question from a different angle, asking whether the cellular interactions that are required to maintain memory are the same as those necessary to activate cytotoxic T lymphocytes. We studied the CD8 memory response to the male antigen H-Y in mice deficient in CD4 cells, or B cells and found that memory in these mice was virtually unimpaired. These results suggest that CD8 memory is CD4 independent and that there is no requirement for long term retention of immune complexes on follicular dendritic cells, nor for B cells as antigen-presenting cells.