Ability of the polysaccharide chitosan to inhibit in vitro and in vivo the proliferation of CD4 lymphocytes from mucosal inductive sites

PORPORATTO CARINA; CANALI M MAGDALENA; BIANCO ISMAEL D; CORREA SILVIA G

CELL PROLIFERATION

Blackwell Publishing

Lugar: UK; Año: 2009 vol. 42 p. 780 - 787

0960-7722

Objective: After oral administration of chitosan (a copolymer of glucosamine and N-acetylglucosamine), mesenteric lymph node (MLN) lymphocytes exhibited traits of anergy, a process coupled with inability of mature T cells to proliferate. We wondered whether biological activity of chitosan could be affecting division of lymphocytes at the mucosal inductive sites. Materials and methods: We studied the effect of chitosan on proliferation of carboxyfluorescein diacetate- labelled MLN lymphocytes stimulated with concanavalin A in vitro. We assessed expression of CD25 and CD71 activation markers and pro-apoptotic molecule CD95L. Moreover, we studied the effect of chitosan ex vivo, in carboxyfluorescein diacetatelabelled MLN cells isolated after feeding single or repetitive doses of the polysaccharide, and we evaluated cell cycle parameters. Results: Chitosan suppressed cell proliferation and down-modulated expression of CD25 in these MLN CD4+ cells isolated from normal rats. After in vivo contact, chitosan inhibited proliferation of MLN cells and reduced secretion of interferon-gamma. Furthermore, sustained feeding produced reduction in percentage of CD4+ cells in S phase of the cell cycle. Conclusion: Here we demonstrate the ability of chitosan to suppress proliferation of CD4+ lymphocytes from mucosal inductive sites in vivo and in vitro This effect could be relevant in modulatory activity of chitosan in the intestinal microenvironment.