The in vitro growth and serial passage of RA 27/3 rubella vaccine virus in cord blood mononuclear leukocytes from normal babies

Abstract

Because of our inability to isolate rubella virus from peripheral blood lymphocytes from patients with chronic symptoms after rubella immunization we performed a series of experiments with cord blood mononuclear cells (CBL) to determine whether and to what extent these cells supported the growth of rubella virus in vitro. CBL were stimulated with phytohemagglutinin for 48-72 h, washed, and inoculated with 1000 tissue culture 50% infection dose of rubella virus and placed in RPMI1640 medium with 10% fetal bovine serum and IL-2. Approximately every 9 d the volume was halved, and new CBL were added. Aliquots at 2-to 9-d intervals were obtained and quantitatively cultured in African green monkey tissue culture. Rubella virus growth was determined by echovirus 11 challenge. Controls consisted of rubella virus in RPMI 1640 medium. Rubella virus persisted in CBL culture longer than in control medium in seven of 11 experiments, and in three instances there was evidence of productive infection. © 1995 International Pediatric Research Foundation, Inc.