Intracellular trafficking and killing of Streptococcus pneumoniae by human alveolar macrophages are influenced by opsonins
Intracellular trafficking and killing of Streptococcus pneumoniae by human alveolar macrophages are influenced by opsonins
Human alveolar macrophages (HAM) are the major resident phagocytic cells of the gas-exchanging areas of the lung. Following contact with macrophages, bacteria enter phagosomes, which gradually acquire the characteristics of terminal phagolysosomes, with incorporation of lysosome-associated membrane protein (LAMP). We measured the binding of type 1 Streptococcus pneumoniae to the surface of HAM and then measured subsequent internalization and phagosomal incorporation of LAMP-1 under various opsonic conditions. Opsonization with serum containing immunoglobulin resulted in significantly greater binding of pneumococci to HAM compared with opsonization with immunoglobulin G (IgG)-depleted serum containing complement, which in turn resulted in marginally increased binding over that observed in the absence of opsonization. Internalization of opsonized S. pneumoniae gradually increased to a maximum of 20% of bound bacteria by 120 min of warm incubation, with 20% of internalized pneumococci being localized within LAMP-containing compartments by 80 min. Internalization of opsonized S. pneumoniae by HAM correlated with a reduction of bacterial viability. When inocula were adjusted so that pneumococcal binding under different conditions was equalized, subsequent internalization, trafficking to LAMP-containing compartments, and reduction of bacterial viability were less efficient in the absence of opsonization than that observed following opsonization with adsorbed or IgG-replete adsorbed serum. Once bound to the surface of HAM, pneumococci opsonized with adsorbed serum with or without IgG were internalized, processed, and killed equally well. In conclusion, binding, intracellular trafficking, and killing of S. pneumoniae by HAM are each significantly increased by opsonization with serum containing immunogloblin and/or complement.
Antigens, CD, Bacterial Adhesion, Bronchoalveolar Lavage Fluid, Cells, Cultured, Colony Count, Microbial, Humans, Immunoglobulin G, Kinetics, Lysosome-Associated Membrane Glycoproteins, Macrophages, Alveolar, Membrane Glycoproteins, Microscopy, Fluorescence, Opsonin Proteins, Phagocytosis, Pneumonia, Pneumococcal, Receptors, Complement 3b, Streptococcus pneumoniae, Time Factors, Journal Article, Research Support, Non-U.S. Gov't
2286-2293
Gordon, S.B.
d004fb35-bf59-4028-a55f-56eb478706a2
Irving, G.R.
c1c55856-0645-4d1a-aa73-2125a76b4a4e
Lawson, R.A.
5fc693d8-4211-454c-aab8-cb71af0d1507
Lee, M.E.
cc9ac703-7b07-40ae-8778-e0e5df37c9f8
Read, R.C.
b5caca7b-0063-438a-b703-7ecbb6fc2b51
April 2000
Gordon, S.B.
d004fb35-bf59-4028-a55f-56eb478706a2
Irving, G.R.
c1c55856-0645-4d1a-aa73-2125a76b4a4e
Lawson, R.A.
5fc693d8-4211-454c-aab8-cb71af0d1507
Lee, M.E.
cc9ac703-7b07-40ae-8778-e0e5df37c9f8
Read, R.C.
b5caca7b-0063-438a-b703-7ecbb6fc2b51
Gordon, S.B., Irving, G.R., Lawson, R.A., Lee, M.E. and Read, R.C.
(2000)
Intracellular trafficking and killing of Streptococcus pneumoniae by human alveolar macrophages are influenced by opsonins.
Infection and Immunity, 68 (4), .
(doi:10.1128/IAI.68.4.2286-2293.2000).
Abstract
Human alveolar macrophages (HAM) are the major resident phagocytic cells of the gas-exchanging areas of the lung. Following contact with macrophages, bacteria enter phagosomes, which gradually acquire the characteristics of terminal phagolysosomes, with incorporation of lysosome-associated membrane protein (LAMP). We measured the binding of type 1 Streptococcus pneumoniae to the surface of HAM and then measured subsequent internalization and phagosomal incorporation of LAMP-1 under various opsonic conditions. Opsonization with serum containing immunoglobulin resulted in significantly greater binding of pneumococci to HAM compared with opsonization with immunoglobulin G (IgG)-depleted serum containing complement, which in turn resulted in marginally increased binding over that observed in the absence of opsonization. Internalization of opsonized S. pneumoniae gradually increased to a maximum of 20% of bound bacteria by 120 min of warm incubation, with 20% of internalized pneumococci being localized within LAMP-containing compartments by 80 min. Internalization of opsonized S. pneumoniae by HAM correlated with a reduction of bacterial viability. When inocula were adjusted so that pneumococcal binding under different conditions was equalized, subsequent internalization, trafficking to LAMP-containing compartments, and reduction of bacterial viability were less efficient in the absence of opsonization than that observed following opsonization with adsorbed or IgG-replete adsorbed serum. Once bound to the surface of HAM, pneumococci opsonized with adsorbed serum with or without IgG were internalized, processed, and killed equally well. In conclusion, binding, intracellular trafficking, and killing of S. pneumoniae by HAM are each significantly increased by opsonization with serum containing immunogloblin and/or complement.
This record has no associated files available for download.
More information
Accepted/In Press date: 20 December 1999
e-pub ahead of print date: 1 April 2000
Published date: April 2000
Keywords:
Antigens, CD, Bacterial Adhesion, Bronchoalveolar Lavage Fluid, Cells, Cultured, Colony Count, Microbial, Humans, Immunoglobulin G, Kinetics, Lysosome-Associated Membrane Glycoproteins, Macrophages, Alveolar, Membrane Glycoproteins, Microscopy, Fluorescence, Opsonin Proteins, Phagocytosis, Pneumonia, Pneumococcal, Receptors, Complement 3b, Streptococcus pneumoniae, Time Factors, Journal Article, Research Support, Non-U.S. Gov't
Identifiers
Local EPrints ID: 416852
URI: http://eprints.soton.ac.uk/id/eprint/416852
ISSN: 0019-9567
PURE UUID: 5457ff6e-be5d-4cdf-9fe8-9821a5ca16e1
Catalogue record
Date deposited: 11 Jan 2018 17:30
Last modified: 16 Mar 2024 04:10
Export record
Altmetrics
Contributors
Author:
S.B. Gordon
Author:
G.R. Irving
Author:
R.A. Lawson
Author:
M.E. Lee
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics
