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Serum Amyloid P‐Component‐Mediated Inhibition of the Uptake of Mycobacterium tuberculosis by Macrophages, In Vitro
Author(s) -
Kaur S.,
Singh P. P.
Publication year - 2004
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/j.0300-9475.2004.01412.x
Subject(s) - in vitro , mycobacterium tuberculosis , microbiology and biotechnology , chemistry , tuberculosis , serum amyloid p component , amyloid (mycology) , mycobacterium , biology , immunology , medicine , biochemistry , pathology , inflammation , c reactive protein , inorganic chemistry
The effect of purified mouse serum amyloid P‐component (SAP) treatment of mouse alveolar macrophages (AMs) on their uptake of Mycobacterium tuberculosis Erdman was investigated, in vitro . SAP (0.5–50.0 µg/ml), in a concentration‐dependent manner, inhibited the M. tuberculosis uptake by the AMs; maximum inhibition (33.43%) occurred at 10.0 µg/ml. The inhibition of uptake could be observed as early as 30 min after the incubation of AMs with 10.0 µg/ml SAP; however, an incubation of 60 min induced maximum inhibition beyond which the response became static. The SAP‐mediated decreased uptake of M. tuberculosis also resulted in their reduced intramacrophage growth as determined by colony‐forming unit counts. SAP inhibited the uptake of mycobacteria in the presence of Ca 2+ , and at pH = 5.6, the inhibition was abrogated. Deglycosylation of purified SAP with N ‐glycanase, and not with O ‐glycanase, blocked the SAP‐mediated inhibition of the uptake. Heat‐inactivated (80 °C; 1 h; pH 7.0) SAP did not inhibit the uptake of M. tuberculosis by AMs. These data, apparently for the first time, indicate that purified mouse SAP, in a divalent cation‐ and N ‐linked oligosaccharide glycosylation‐dependent manner, inhibited the in vitro uptake of M. tuberculosis Erdman by mouse AMs, which was also associated with their reduced intracellular growth.