Natural antibodies (nABs) are a part of innate immunity. Their presence in human blood is not associated directly with previous immunization. The origin and mechanism of nABs formation are of particular interest because of a number of their functions, including protection against infections, maintenance of metabolic clearance and transformed cells.
At the present work serum samples of healthy infants (age 3 days, 3, 6, and 12 months) with different types of nutrition, their mothers and sera from cord blood were analyzed using glycochip, containing ~ 400 glycans (constituents of mammalian glycoproteins and glycolipids) and 150 bacterial O-polysaccharides.
The repertoire of own anti-glycan ABs found to form at early stage of human development and by the age of 1 year contains the antibodies that will be constantly present in blood during the lifetime. The IgG and IgM dynamics have an opposite direction through this time: IgM level is increased whereas IgG - decreased. Changes in anti-glycan repertoire are closely related to nutritive factor: antibodies to different glycan sets were detected in serum of infants with different types of nutrition. Interestingly, the narrowest repertoire of anti-glycan ABs was observed in the group of breast fed infants, that is caused, probably, by antigenic compatibility of mother and infant.
Taken together, the glycochip data, structures of O-polysaccharides and literature data for dynamics of child microflora formation extend our understanding of mechanism of nABs formation.
