Paediatric Virology and its interaction between basic science and clinical practice (Review)

Mammas, Ioannis N.; Greenough, Anne; Theodoridou, Maria; Kramvis, Anna; Rusan, Maria; Melidou, Angeliki; Korovessi, Paraskevi; Papaioannou, Georgia; Papatheodoropoulou, Alexia; Koutsaftiki, Chryssie; Liston, Maria; Sourvinos, George; Spandidos, Demetrios A.

Prolonged human breast feeding (>6 months) has been documented to have a beneficial effect on the avoidance of viral infections, e.g., norovirus-and rotavirus-related infections, which can potentially be lethal for newborn babies (7) . It has also been shown that it reduces the risk of developing certain malignant tumours arising in early childhood, e.g., acute lymphoblastic leukemia (ALL), or in young adolescence, e.g., Hodgkin's disease (HD). Apparently, specific sugars in human milk modify the receptors blocking the uptake of noroviruses and rotaviruses during the breast feeding phase. The maturation of the immune system during this period, subsequently, facilitates an effective immune response during the weaning period. The uptake of specific sialic acids, not produced in humans, but present in cow milk and meat products, beginning during the weaning time, results in their incorporation into the cell surface glycoproteins and gangliosides. The resulting modification of cell surface receptors alters their susceptibility to specific viral infections, e.g., human polyomavirus type 9 and others. Current analyses suggest that these receptors now permit the binding of infectious agents present in dairy cattle serum and milk products, leading to their longtime persistence and latency and their potential pathogenicity under conditions of reactivation. Thus, the protective effects of breast feeding, which allows for the maturation of the immune response during the first years of life, emerges as critical period, which determines the uptake and latency of specific infections (7).