Antigen-speciļ¬c antibodies
The titer of the serum anti-OVA IgG Abs was increased in the groups
treated with Morus alba L. and OVA or CT compared to the OVA-only
treated group (Fig. 3). A comparable immune response was produced when
an antigen mixed with CT was used as a positive control. To determine
the immunoglobulin patterns induced by oral Morus alba L.
administration, OVA-specific serum IgG1 and IgG2a anti-OVA Abs were
measured. The oral immunization of OVA and CT induced a predominantly
antigen-specific IgG1 response, with little IgG2a. Co-administration of
OVA with Morus alba L. increased the levels of both the IgG1 and
IgG2a Abs two-fold (Fig. 3 C, D). No change in the IgE content was
observed. CT induced the secretion of IgE Abs two-fold compared to OVA
(Fig. 3E).
We further determined whether oral tolerance affected the mucosal Ab
responses in serum, saliva, and the intestine. The oral immunization of
OVA plus CT as an adjuvant elicited significant antigen-specific mucosal
IgA Ab responses. The serum and intestinal responses were significantly
increased in the Morus alba L. or CT combination groups compared
to the OVA group (Fig. 3 F, H). There was no effect on salivary IgA
responses (Fig. 3G).