Differential expression of Ia molecules by human monocytes
The Journal of Clinical Investigation
|September 1, 1984
Summary
Human peripheral blood monocytes exhibit distinct expression patterns of HLA-DR and HLA-DC molecules. While all monocytes express HLA-DR, only half express HLA-DC, indicating two distinct monocyte populations regulated by gamma interferon.
Area of Science:
- Immunology
- Cell Biology
Background:
- Human immune response genes encode Ia molecules, including HLA-SB, HLA-DC, and HLA-DR.
- HLA-DR's tissue distribution and function are well-established, unlike HLA-DC.
Purpose of the Study:
- To investigate the expression of HLA-DR and HLA-DC molecules on human peripheral blood monocytes.
- To determine if monocyte populations can be distinguished based on HLA-DC expression.
- To examine the regulatory effects of gamma interferon (IFN-gamma) on HLA-DR and HLA-DC expression.
Main Methods:
- Monoclonal antibodies were used to detect HLA-DR and HLA-DC on monocytes.
- Monocytes were separated into HLA-DC+ and HLA-DC- populations.
- Cells were cultured in autologous serum and treated with recombinant IFN-gamma.
Main Results:
- All monocytes expressed detectable HLA-DR, but only 50% expressed detectable HLA-DC.
- Monocyte populations were divided into HLA-DR+, HLA-DC+ and HLA-DR+, HLA-DC-.
- IFN-gamma treatment restored expression of both HLA-DR and HLA-DC after a decrease induced by serum culture.
Conclusions:
- Human peripheral blood monocytes can be classified into two populations based on differential expression of HLA-DC and HLA-DR.
- Both HLA-DR and HLA-DC expression are regulated by IFN-gamma, suggesting a common signaling pathway.
- Monocyte surface marker MAC 120 expression is modulated by IFN-gamma similarly to Ia antigens.
