Bovine milk contains a variety of proteins and peptides that are
biologically
active (Ogra & Ogra, 1978; Duncan & McArthur, 1981; Newby et
al. 1982; Juto,
1985; Stoeck et al. 1989; Mincheva-Nilsson et al. 1990;
Watson, 1990; Barta et al.
1991; Politis et al. 1991; Fiat et al. 1993).
Our laboratory has a long-term interest in
some purified milk proteins, particularly lactoferrin (LF), lactoperoxidase
(LP) and
β-casein (β-CN), which have been shown to be immunologically
significant. Some of
our recent studies on these bovine milk proteins, particularly β-CN,
indicated that
their in vitro immunological effects did not
always parallel their in vivo activities
(Wong et al. 1996a, b;
1997a, b). This study was designed to investigate and
compare
the capacity of these purified bovine milk proteins to modulate a range
of
components that are vital to in vivo immune responses in sheep,
with a view to
providing further information on their potential in biomedical applications.
To
achieve this objective, a sensitive lymphatic cannulation model was employed
that
allows in vivo immune components and their functions to be measured
in lymph
collected under physiological conditions.