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Mediation of macrophage reactions in immune tissue injury
Abstract:
The chemotactic specificity of three types of macrophage chemotactic factors (MCF) -a, -b, and -c, from delayed hypersensitivity reaction (DHR) skin sites in guinea pigs, was analysed. MCF-c shared common antigenicity with the macrophage chemotactic lymphokine released from bovine gamma globulin (BGG) and horse radish peroxidase (HRPO) -stimulated lymphocytes, using an immunoadsorbent column conjugated with anti-MCF-c antibody. These purified lymphokines were very similar, or possibly identical in terms of physicochemical and serological properties. BCG-induced lymphokine seemed to exist as complexes with serum protein at the skin site. A change in the proportion of each MCF was observed during the development of DHR. Furthermore, MCF-a and -b attracted Ia- M1 cell line cells, while MCF-c attracted Ia+ cells. Moreover, the responsive guinea-pig monocytes were divided mainly into two distinctive migrating subpopulations. One subpopulation was responsive to MCF-a and -b, and the majority of responding cells were "Ia-negative". The second subpopulation was responsive to MCF-c and the predominant cell type was "Ia-positive". The data suggest that macrophage reactions in the DHR are mediated by MCF-a, -b, and -c and that MCF-c attracts Ia bearing accessory macrophages and MCF-a and b- attract Ia negative macrophages.
Insights
Three macrophage chemotactic factors (MCF-a, -b, -c) mediate delayed hypersensitivity reactions (DHR) in guinea pigs. MCF-c attracts Ia-positive cells, while MCF-a and -b attract Ia-negative cells, indicating distinct macrophage subpopulations.
Area of Science:
- Immunology
- Cell Biology
Background:
- Delayed hypersensitivity reactions (DHR) involve complex cellular interactions.
- Macrophage chemotactic factors (MCF) play a crucial role in directing macrophage migration during DHR.
Purpose of the Study:
- To analyze the chemotactic specificity of MCF-a, -b, and -c from DHR skin sites in guinea pigs.
- To investigate the relationship between MCFs and distinct macrophage subpopulations.
Main Methods:
- Analysis of MCFs from DHR skin sites using guinea pigs.
- Immunoadsorbent column chromatography for lymphokine purification.
- Cellular assays to determine the chemotactic response of macrophage subpopulations to different MCFs.
Main Results:
- MCF-c exhibited shared antigenicity with lymphokines from stimulated lymphocytes.
- A shift in MCF proportions was observed during DHR development.
- MCF-a and -b attracted Ia-negative cells, whereas MCF-c attracted Ia-positive cells, defining two monocyte subpopulations.
Conclusions:
- Macrophage recruitment in DHR is mediated by distinct MCFs.
- MCF-c specifically targets Ia-bearing accessory macrophages.
- MCF-a and -b target Ia-negative macrophages, suggesting differential roles in DHR pathogenesis.