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Quantification of Intracellular Growth Inside Macrophages is a Fast and Reliable Method for Assessing the Virulence of Leishmania Parasites
Published on: March 16, 2018
Leishmania promastigotes require opsonic complement to bind to the human leukocyte integrin Mac-1 (CD11b/CD18)
D M Mosser1, T A Springer, M S Diamond
1Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140.
The Journal of Cell Biology
|January 1, 1992
Summary
Leishmania parasites bind to macrophages via Mac-1, a leukocyte integrin. This interaction requires complement component 3 (C3) for parasite entry into host cells.
Area of Science:
- Immunology
- Cell Biology
- Parasitology
Background:
- Leishmania spp. are known to interact with macrophages.
- Previous studies suggest binding involves Mac-1 (CD11b/CD18), a leukocyte integrin.
Purpose of the Study:
- To investigate the specific binding mechanism between Leishmania promastigotes and leukocyte integrins.
- To determine the role of complement in Leishmania-Mac-1 interactions.
Main Methods:
- Testing Leishmania promastigote binding to purified and cloned leukocyte integrins (Mac-1, LFA-1).
- Utilizing serum, monoclonal antibodies against Mac-1, and complement component 3 (C3) in binding assays.
- Assessing binding in the presence and absence of complement opsonization.
Main Results:
- Leishmania promastigotes specifically bind to Mac-1 in a dose-dependent manner requiring serum.
- Binding to Mac-1 is inhibited by anti-Mac-1 antibodies.
- Leishmania binding to Mac-1 is dependent on complement component 3 (C3) and does not occur without it.
Conclusions:
- Leishmania parasites utilize complement component 3 (C3) to bind to Mac-1 on macrophages.
- This interaction facilitates parasite entry into macrophages by subverting the Mac-1/iC3b adhesion pathway.
- Understanding this mechanism offers insights into host-pathogen interactions and immune evasion.
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