IMMUNOGLOBULINS
COMPLEMENT SYSTEM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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factor P
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factor H
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factor B
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all of the above
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Detailed explanation-1: -Factor P acts as a pattern recognition molecule to bind selectively to specific surfaces upon which it recruits C3b or C3(H2O) to direct and trigger alternative pathway. Factor P can bind early apoptotic T cells, which promotes their phagocytic uptake by macrophages and dendritic cells.
Detailed explanation-2: -Properdin, a 50 kDa protein, is found at 4–25 g/ml in plasma and, under physiological conditions, forms mainly cyclic dimers (P2), trimers (P3) and tetramers (P4) in a 26:54:20 ratio via head-to-tail association of its monomers (Pangburn, 1989; Smith, et al., 1984).
Detailed explanation-3: -The complement cascade can be activated via innate or specific immune responses. The innate response involves neither antibodies nor T-cell receptors; a molecule on the surface of a pathogen (e.g., a set of sugars) activates the cascade directly.