Related Experiment Videos
Identification and molecular characterization of macrophage-associated antigens of the rat
Abstract:
Rabbit antiserum to rat peritoneal exudate (PE) macrophage (M phi) antigens was prepared and its reactivity with cell surface proteins of M phi, granulocytes, and lymphocytes was studied by one- and two-dimensional polyacrylamide gel electrophoresis (PAGE). A total of 14 membrane antigens were identified of which three were found to be expressed only by M phi and granulocytes. By one-dimensional analysis, a protein with an approximate m.w. of 105,000 was present on splenic and PE M phi and on splenic lymphocytes. Two-dimensional analysis revealed that this band was heterogeneous and contained at least three species, one of which was restricted to expression on M phi and granulocytes. A second protein of 150,000 daltons was resolved into two species by two-dimensional analysis. Both of these species were present on M phi and granulocytes but not on lymphocytes. Both the 105,000- and 150,000-dalton proteins were glycosylated. Because the 105,000- and 150-000-dalton proteins expressed by M phi were also expressed by granulocytes, is is likely that these are differentiation antigens whose expression is a characteristic property of cells within both monocytoid and myeloid lineages. All three 105,000-dalton species and one of the two 150,000-dalton species were detected on mouse M phi, indicating their expression is not unique to the rat.
Insights
Researchers identified novel macrophage and granulocyte cell surface proteins using rabbit antiserum. These proteins, including glycosylated species of 105,000 and 150,000 daltons, may represent differentiation antigens shared across myeloid lineages.
Area of Science:
- Immunology
- Cell Biology
- Proteomics
Background:
- Macrophages (M phi) are key immune cells involved in phagocytosis and antigen presentation.
- Understanding macrophage-specific and shared antigens is crucial for immunology and disease research.
Purpose of the Study:
- To characterize cell surface antigens on rat peritoneal exudate macrophages.
- To identify antigens shared between macrophages, granulocytes, and lymphocytes.
Main Methods:
- Preparation of rabbit antiserum against rat peritoneal exudate macrophage antigens.
- Analysis of antigen reactivity using one- and two-dimensional polyacrylamide gel electrophoresis (PAGE).
Main Results:
- Identification of 14 distinct membrane antigens.
- Three antigens were exclusively expressed on macrophages (M phi) and granulocytes.
- Proteins of 105,000 and 150,000 daltons were identified on M phi and granulocytes, with some species also found on lymphocytes.
- Both 105,000- and 150,000-dalton proteins were found to be glycosylated.
- Expression of these antigens was also detected in mouse macrophages, suggesting conserved function.
Conclusions:
- The identified antigens, particularly the 105,000- and 150,000-dalton proteins, are likely differentiation antigens.
- These antigens are characteristic of both monocytoid and myeloid lineages.
- The findings provide insights into immune cell differentiation and potential therapeutic targets.