Ontogenic development of proliferative and polyclonal antibody and autoantibody responses to staphylococcal peptidoglycan, protein A and cell walls in mice.

In the spleens of newborn mice, polyclonal IgM, IgG and IgA responses were low to protein A, cell walls (CW) and PWM, intermediate to peptidoglycan (PG), and high to LPS. Small, not significant increases in Ig responses to LPS (which occurred during the first 2 wks) were observed, whereas, the responses to PG, protein A, CW and PWM continued to increase for 8 wks, and the increases were high and significant. In most cases, there was no change in the dose response and kinetics patterns (characteristic for each stimulant) during ontogeny. Ontogenic development of autoantibody-secreting cells was different from the development of cells secreting all Ig and anti-SRBC antibodies. The increases in the numbers of cells secreting IgM anti-DNA and IgM anti-bromelin-treated mouse RBC antibodies in response to LPS and PG during postnatal development were larger than the increases of all IgM-secreting cells. In contrast, the increases of IgM anti-DNA secreting cells in response to protein A and PWM were smaller than the increases of all IgM-secreting cells. The frequencies of cells secreting anti-DNA antibodies in LPS- and PG-stimulated cultures were low in newborns and continued to increase until 8 wks of age, but they were high and did not change throughout ontogeny in protein A-stimulated cultures. Changes in the frequencies of anti-RBC antibody-secreting cells were less distinct and mostly insignificant. Postnatal changes in mitogenic responses were smaller and not correlated with the development of polyclonal Ig responses. Our data indicate different modes of ontogenic development of the ability of cells to produce polyclonal Ig, autoantibodies and heteroantibodies, and to synthesize DNA, in response to different stimulants.