Related Experiment Video
Updated: Aug 9, 2026
Isolation Protocol of Mouse Monocyte-derived Dendritic Cells and Their Subsequent In Vitro Activation with Tumor Immune Complexes
Published on: May 31, 2018
Macrophage inflammatory protein-1beta induces migration and activation of human thymocytes
D J Dairaghi1, K Franz-Bacon, E Callas
1Department of Immunology, DNAX Research Institute, Palo Alto, CA, USA.
Insights
Macrophage inflammatory protein 1beta (MIP-1beta) activates human thymocytes, particularly CD4+ and CD8+ cells, via the CCR-5 receptor. This suggests a role in immune system development and potential HIV infectivity pathways.
Area of Science:
- Immunology
- Cell Biology
- Virology
Background:
- Macrophage inflammatory protein 1beta (MIP-1beta) is a CC chemokine known to chemoattract and activate T lymphocytes.
- Previous studies indicated MIP-1beta's chemoattractant properties for specific T cell subsets.
Purpose of the Study:
- To investigate the effect of MIP-1beta on human thymocytes.
- To elucidate the mechanism of MIP-1beta-mediated thymocyte activation.
- To identify the receptor involved in MIP-1beta's action on thymocytes.
Main Methods:
- Flow cytometry to analyze thymocyte subpopulations (DN, SP, DP) and cell activation markers.
- Intracellular calcium mobilization assays.
- Western blotting for phosphorylated tyrosine proteins and MAPK pathway activation.
- Radioligand binding assays to determine MIP-1beta binding affinity.
- RT-PCR to detect CCR-5 mRNA expression.
- Immunohistochemistry using anti-CCR-5 monoclonal antibody.
Main Results:
- MIP-1beta potently promoted migration of human thymocytes, primarily CD4+ and CD8+ single-positive (SP) and CD4+CD8+ double-positive (DP) populations.
- Thymocyte activation by MIP-1beta involved rapid intracellular calcium mobilization, increased tyrosine phosphorylation, and MAPK pathway activation.
- Specific, displaceable binding of MIP-1beta to thymocytes was observed, with a Kd of approximately 1 nmol/L.
- CCR-5 mRNA was detected in thymocytes, and CCR-5 expression was confirmed on DP and CD8+ SP subpopulations.
- MIP-1beta binding to thymocytes showed similar characteristics to binding on CCR-5-transfected cells.
Conclusions:
- MIP-1beta directly activates human thymocytes through a receptor-mediated mechanism, likely involving CCR-5.
- The findings suggest a role for MIP-1beta in human thymocyte development and activation.
- This interaction may represent a potential route for HIV infectivity in the developing immune system.
Abstract:
The CC chemokine macrophage inflammatory protein 1beta (MIP-1beta), has been shown to be a chemoattractant preferentially activating CD4(+) CD45RA+ T lymphocytes. Further analysis of chemokine action on lymphocytic cells has shown the potent migration-promoting capacity of MIP-1beta on human thymocytes. The responding cells were the CD4(+) and CD8(+) single-positive (SP), as well as the CD4(+) CD8(+) double-positive (DP) populations, with little if any migratory activity on the double-negative (DN) population. The activation of thymocytes by MIP-1beta appeared to be a direct, receptor-mediated event as evidenced by the rapid mobilization of intracellular calcium, increase in proteins phosphorylated on tyrosine, and activation of the mitogen-activated protein kinase (MAPK) pathway. Radioligand binding analyses showed specific and displaceable binding of MIP-1beta to thymocytes with a Kd of approximately 1 nmol/L, a profile that was comparable with MIP-1beta binding to CCR-5-transfected NIH 3T3 cells. In addition, CCR-5 mRNA was detected in total thymocyte populations indicating that activation of thymocytes by MIP-1beta may occur through binding to CCR-5. Further dissection of the subpopulations showed that only the DP and CD8(+) SP populations expressed CCR-5 and expression data on these two populations was confirmed using anti-CCR-5 monoclonal antibody. These data may be suggestive of a role for MIP-1beta in human thymocyte activation, and show a potential route for HIV infectivity in the developing immune system.
More Related Videos
07:55A Macrophage Reporter Cell Assay to Examine Toll-Like Receptor-Mediated NF-kB/AP-1 Signaling on Adsorbed Protein Layers on Polymeric Surfaces
Published on: January 7, 2020
06:38Macrophage Differentiation and Polarization into an M2-Like Phenotype using a Human Monocyte-Like THP-1 Leukemia Cell Line
Published on: August 2, 2021