Page 146 - Veterinary Immunology, 10th Edition

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FIG. 5.13 A scanning electron micrograph of a bovine milk
neutrophil ingesting Streptococcus agalactiae. Note how a film of
neutrophil cytoplasm appears to flow over the surface of the
bacterium. Original magnification ×5000.

In complement-mediated phagocytosis, particles sink into the

neutrophil without lamellipod formation, suggesting that the
ingestion process is fundamentally different from that mediated by
antibodies (type 2 phagocytosis). The bacterium is eventually
drawn into the cell, and as it is engulfed, it is enclosed in a vacuole

called a phagosome. The ease of ingestion depends on the
properties of the bacterial surface. Neutrophils readily flow over
lipid surfaces so that hydrophobic bacteria, such as Mycobacterium
tuberculosis, are readily ingested. In contrast, Streptococcus

pneumonia has a hydrophilic capsule. It is poorly phagocytosed
unless made hydrophobic by opsonization. A third type of
ingestion occurs with bacteria such as Legionella pneumophila and
Borrelia burgdorferi, where a single lamellipod may wrap itself

several times around the organism. This is called coiling
phagocytosis.

Destruction

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