Page 691 - Veterinary Immunology, 10th Edition

antibodies against the pseudocapsule appears to be effective. This
VetBooks.ir pseudocapsule interferes with the ability of milk leukocytes to

phagocytose S. aureus. Antibodies induced by the vaccine promote
opsonization and destruction of the bacteria. A vaccine designed to

stimulate antibody production against staphylococcal α toxin, as
well as the pseudocapsule, is also effective. Encouraging results
have also been obtained by the use of a J5 mutant vaccine against
coliform bacteria (Chapter 26). The vaccine is given to cattle at

drying off, 30 days later, and at calving.
Colostrum is rich in macrophages and lymphocytes. These
macrophages can process antigen, and when cultured, their
supernatants can enhance IgA production from blood lymphocytes.

Milk lymphocytes survive for a short time in the intestine and
transfer cell-mediated immunity to the newborn animal (Chapter
23).

Immunity in the Respiratory Tract

The respiratory tract differs from other surfaces in that it is in
intimate connection with the interior of the body yet is required by
its very nature to allow unhindered access of air to the alveoli. The
system obviously requires a filter. Particles suspended in inhaled

air are largely removed by turbulence that directs them onto its
mucus-covered walls, where they adhere. The turbulence is caused
by the conformation of the turbinate bones, the trachea, and the

bronchi. This turbulence filter serves to remove particles as small as
5 µm before they reach the alveoli (Fig. 22.2).

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