Related Experiment Videos
Induction of leukemia cell differentiation and apoptosis by recombinant P48, a modulin derived from Mycoplasma
R E Hall1, S Agarwal, D P Kestler
1Department of Medicine, University of Tennessee Medical Center/ Graduate School of Medicine, Knoxville, Tennessee 37920, USA. rhall@utkux.utcc.utk.edu
Abstract:
P48 is a 48-kDa monocytic differentiation/activation factor which was originally identified in the conditioned medium of the Reh and other leukemia cell lines and has recently been shown to be a Mycoplasma fermentans gene product. Previously, conditioned medium P48 has been shown to induce differentiation of HL-60 (human promyelocytic leukemia) cells. Recently our laboratory isolated cDNA clones for P48 from Reh cells and genomic clones from Mycoplasma fermentans and expressed the recombinant protein as a maltose binding protein (MBP) fusion protein in E. coli. In this report we present the initial characterization of this recombinant P48 fusion protein (rP48-MBP). We show that rP48-MBP induces differentiation of HL-60, U937 (human histiocytic lymphoma), and M1 (mouse myeloid leukemia) cell lines. Interestingly, rP48-MBP also induces apoptosis of U937 and HL-60 cells as assessed by terminal transferase (TUNEL) assays. This is the first report of induction of apoptosis by a Mycoplasma gene product. P48 is a Mycoplasma-derived immunomodulatory molecule which has differentiation and apoptosis-inducing activities and may be important in the pathophysiology of Mycoplasma infections. The recombinant protein may be useful in studying the mechanisms of differentiation, cytokine production, and apoptosis in malignant and nonmalignant hematopoietic cells.
Insights
The Mycoplasma fermentans gene product P48 induces monocytic differentiation and apoptosis in leukemia cell lines. This recombinant protein offers insights into Mycoplasma infections and hematopoietic cell mechanisms.
Area of Science:
- Immunology
- Molecular Biology
- Cell Biology
Background:
- P48, a 48-kDa monocytic differentiation/activation factor, was identified in leukemia cell lines and is a Mycoplasma fermentans gene product.
- Previous studies showed conditioned medium P48 induces differentiation of HL-60 cells.
Purpose of the Study:
- To characterize the recombinant P48 fusion protein (rP48-MBP).
- To investigate the effects of rP48-MBP on hematopoietic cell lines.
Main Methods:
- Isolated cDNA clones for P48 from Reh cells and genomic clones from Mycoplasma fermentans.
- Expressed recombinant P48 as a maltose binding protein (MBP) fusion protein in E. coli.
- Assessed differentiation and apoptosis induction using cell line models and TUNEL assays.
Main Results:
- Recombinant P48-MBP induced differentiation of HL-60, U937, and M1 cell lines.
- rP48-MBP induced apoptosis in U937 and HL-60 cells, marking the first report of apoptosis induction by a Mycoplasma gene product.
- P48 is an immunomodulatory molecule with differentiation and apoptosis-inducing activities.
Conclusions:
- P48 is a Mycoplasma-derived molecule with significant immunomodulatory functions.
- The differentiation and apoptosis-inducing activities of P48 may play a role in Mycoplasma infection pathophysiology.
- Recombinant P48 protein is a valuable tool for studying differentiation, cytokine production, and apoptosis in hematopoietic cells.