Chelvarajan R L, Raithatha R, Venkataraman C, Kaul R, Han S S, Robertson D A, Bondada S
Department of Microbiology and Immunology and Sanders-Brown Research Center on Aging, University of Kentucky, Lexington, KY 40536-0230, USA.
Eur J Immunol. 1999 Sep;29(9):2808-18. doi: 10.1002/(SICI)1521-4141(199909)29:09<2808::AID-IMMU2808>3.0.CO;2-E.
Neonates are very vulnerable to pathogenic encapsulated bacteria due to their inability to mount an antibody response to capsular polysaccharides, which are thymus-independent type 2 (TI-2) antigens (Ag). Oligodeoxynucleotides (ODN) containing unmethylated CpG dinucleotides induced neonatal B cells to proliferate to anti-IgM, a TI-2 stimulus. CpG ODN inhibited the spontaneous and B cell receptor-mediated apoptosis of neonatal B cells and reduced the amount of the pro-apoptotic Bcl-xS, strongly correlated with anti-IgM-induced apoptosis of neonatal B cells. CpG ODN protected neonatal B cells from apoptosis by down-regulation of the Bcl-xS protein. Neonatal B cells underwent polyclonal differentiation upon stimulation with CpG ODN, but unlike in adult B cells, this was not preceded by IL-6 secretion. CpG ODN stimulated neonatal B cells to mount an Ag-specific antibody response to TNP-Ficoll, another TI-2 Ag. Thus CpG ODN could provide a novel approach to induce the immune system in neonates to respond to harmful encapsulated bacteria.
