The in vitro B-cell response to pneumococcal polysaccharides in adults and neonates

Scand J Immunol. 1987 May;25(5):447-52. doi: 10.1111/j.1365-3083.1987.tb02215.x.


In order to gain insight into the relatively late appearance in ontogeny of responsiveness to T-cell independent (TI) antigens, the in vitro human B-cell response to type 4 pneumococcal polysaccharides (PS4, a human TI-2 antigen) was studied. B cells obtained from adults differentiate into anti-PS4 antibody forming cells upon culturing with PS4, but neonatal B cells obtained from cord blood fail to respond. The culture system used does, however, allow the differentiation of B cells reactive with TD antigens, for example ovalbumin. In order to evaluate the concept that in man the anti-PS4 response is derived from a particular B-cell subset we separated adult B cells on the basis of expression of the determinant recognized by the monoclonal antibody FMC7. The anti-PS4 response is found mainly, but not exclusively, in the FMC7+ subset. The selective unresponsiveness of neonatal B cells to TI-2 antigens is not, however, due to the absence of FMC7+ B cells because, unlike adult blood B cells of which about 50% are FMC7+, 100% of neonatal B cells are FMC7+.

MeSH terms

  • Adult
  • Antibodies, Bacterial / biosynthesis*
  • Antibodies, Monoclonal
  • Antigens, Surface / analysis
  • Antigens, T-Independent / immunology*
  • B-Lymphocytes / classification
  • B-Lymphocytes / immunology*
  • Humans
  • In Vitro Techniques
  • Infant, Newborn*
  • Polysaccharides, Bacterial / immunology*
  • Streptococcus pneumoniae / immunology*


  • Antibodies, Bacterial
  • Antibodies, Monoclonal
  • Antigens, Surface
  • Antigens, T-Independent
  • Polysaccharides, Bacterial