HUMAN LACTOFERRIN INDUCES PHENOTYPIC AND FUNCTIONAL-CHANGES IN MURINESPLENIC B-CELLS

The immunotropic activities of human lactoferrin were studied with res pect to phenotypic and functional changes in murine splenic B cells. P henotypic changes were induced by human lactoferrin in splenic B-cell fractions separated by buoyant density. B cells from 7-8-day-old BALB/ c mice isolated from a 50/60% Percoll gradient, gained characteriztic features of more mature B cells manifested by an increase of surface I gD and complement receptor expression. Incubation of the analogous B-c ell fraction from adult mice with human lactoferrin resulted in minor changes in relation to IgM and IgD expression. Besides induction of ph enotypic changes on immature B cells, human lactoferrin enabled B cell s from normal newborn and adult immunodeficient CBA/N mice to present antigen to an antigen-specific T-helper type 2 (Th2) cell line. We con clude that human lactoferrin acts as a maturation factor for B cells w ith regard to their phenotype and function.