Are B lymphocytes the principal antigen-presenting cells in vivo?

Abstract

Investigation of Ag presentation by B cells has resulted in a satisfying progression from in vitro analyses using purified and/or cloned reagents and cellular populations to studies of the requirements for in vivo Ag priming. I anticipate that the recent results implicating B cells as a critical participant in priming lymph node T cells to Ag will spur efforts to dissect the cellular components involved in Ag presentation in vivo, ultimately answering the question of whether the B lymphocyte is an APC of major physiologic relevance.