Pharmacologic marrow purging in murine T cell leukemia

Area of Science:

• Biochemistry
• Immunology
• Cell Biology

Background:

• Malignant T cells pose a significant challenge in bone marrow transplantation.
• Effective purging of contaminating tumor cells is crucial for successful engraftment and patient survival.

Purpose of the Study:

• To investigate the efficacy of deoxycoformycin (dCF) in combination with deoxyadenosine for purging 6C3HED malignant T cells from murine marrow.
• To evaluate the safety and efficacy of this purging strategy in a murine bone marrow rescue model.

Main Methods:

• Murine 6C3HED malignant T cells were incubated with deoxycoformycin (10(-6) mol/L) and deoxyadenosine (10(-4) mol/L) for 12 hours.
• Cellular adenosine deaminase activity, nucleotide levels (ATP, dATP), and NAD levels were assessed.
• The purged marrow was used to rescue lethally irradiated syngeneic mice, with tumor cell contamination and long-term survival monitored.

Main Results:

• Incubation with dCF ablated adenosine deaminase activity in 6C3HED cells.
• Tumor cells accumulated dATP, depleted NAD and ATP, leading to cell death.
• Over 5 logs of 6C3HED cells were killed, with no interference to normal marrow cell rescue.
• 12 out of 14 mice receiving contaminated marrow treated with dCF and deoxyadenosine survived long-term.

Conclusions:

• Deoxycoformycin and deoxyadenosine combination is a potent method for purging malignant T cells from murine marrow.
• This purging strategy is compatible with bone marrow rescue and offers potential for clinical application in T-cell malignancies.
• The developed murine model is valuable for assessing strategies to purge malignant T cells from bone marrow for transplantation.