Enhancement of Antigen-Presenting Function of Dendritic Cells with Culture Supernatants of Mouse Peritoneal Macrophages Stimulated with Certain Particulate Substances

Abstract

The production from murine resident peritoneal macrophages (Mφ) of a soluble factor, which was capable of enhancing the antigen-presenting (AP) function of dendritic cells (DC), was examined. The supernatants of peritoneal Mφ (Mφ sup) were prepared by culturing peritoneal Mφ with particles, i.e., zymosan A, latex, and sheep red blood cells (SRBC), or antigen-antibody (Ag-Ab) complexes such as keyhole limpet hemocyanin (KLH)-anti-KLH, ovalbumin (OVA)-anti-OVA, and SRBC-anti-SRBC complexes. When exposed to Mφ sup during antigen pulsing DC induced a marked antigen-specific T cell proliferation, relative to DC treated with the supernatants from Mφ cultured without stimuli (control sup). On the other hand, Mφ sup-treated splenic Mφ stimulated antigen-specific T cell activation to almost the same extent as did splenic Mφ treated with control sup. These results indicated that peritoneal Mφ elaborated a soluble factor which preferentially enhanced the AP capacity of DC when stimulated with particles or Ag-Ab complexes. Analytical gel filtration of Mφ sup revealed that the factor had an apparent molecular weight of 27, 000 daltons which was distinct from interleukin 1.