The interaction between bone marrow immune suppression and hematopoiesis.

Area of Science:

• Immunology
• Hematology
• Cell Biology

Background:

• Murine bone marrow harbors a suppressor cell affecting in vitro immune responses.
• The in vivo function and identity of this suppressor cell remain largely unknown.
• Standard lymphocyte markers are absent on this bone marrow suppressor cell.

Purpose of the Study:

• To investigate the in vivo role of bone marrow suppressor cells.
• To identify factors that modulate the activity of bone marrow suppressor cells.
• To explore the relationship between hematopoiesis and immune suppression in bone marrow.

Main Methods:

• Characterization of bone marrow suppressor cells using lymphocyte markers.
• Detection and analysis of a suppressor-modifying cell in neonatal mice.
• Induction of anemia in adult mice to observe effects on marrow suppression.

Main Results:

• A Thy 1+ cell in neonatal mice was found to decrease the net effect of marrow suppression.
• Inducing anemia in adult mice via bleeding also reduced marrow suppression.
• The suppressor cell lacks common lymphocyte markers (Thy 1, Lyt 1, Lyt 2, Fc receptors, surface immunoglobulin).

Conclusions:

• A Thy 1+ suppression-modifying cell exists in neonatal mice, influencing bone marrow immune activity.
• Hematopoiesis and bone marrow immune suppression appear functionally linked.
• The Thy 1+ cell may play a role in mediating this functional link.