Page 842 - Veterinary Immunology, 10th Edition
P. 842
patients. Conversely, mice are nocturnal mammals that would not
VetBooks.ir be expected to have high vitamin D levels and must rely on other
pathways.
FIG. 26.1 Immunity to tuberculosis is governed in many species by
the availability of vitamin D. The vitamin D receptor is upregulated
on activated macrophages. Binding of vitamin D to this receptor
upregulates vitamin D hydroxylase, which in turn increases
production of the antibacterial cathelicidins and enhances disease
resistance.
When activated, platelets release antibacterial peptides and
reactive oxygen species (ROS). They also bind to neutrophils to
form aggregates and enhance neutrophil activities. Horse platelets
exposed to bacterial lipopolysaccharide from Escherichia coli and
lipoteichoic acid from Staphylococcus aureus are activated and can
inhibit E. coli growth as a result of the release of ROS.
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