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Self-renewal of factor-dependent hemopoietic progenitor cell-lines derived from long-term bone marrow cultures
Abstract:
Long-term bone marrow cultures established from C57Ks/J mice have been shown to spontaneously release endogenous ecotropic RNA type-C virus (retrovirus). C57Ks/J marrow cultures produced granulocyte-macrophage progenitor cells (GM-CFUc) and immature and mature granulocytes for over 45 weeks. In contrast, NIH Swiss mouse marrow cultures failed to release detectable ecotropic virus and generated GM-CFUc and granulocytes for 25-35 weeks and established WEHI-3 conditioned medium (CM) dependent cell lines in vitro and did not establish permanent cell lines. To determine whether viral and/or cellular genes regulated the longevity of C57Ks/J marrow cultures, groups of cultures were established from the marrow of (NIH-Swiss X C47Ks/J) F1 hybrid, F2 hybrid, and (NIH Swiss X C47Ks/J) X NIH Swiss backcross generations. Release of endogenous ecotropic virus was measured weekly in each culture as was the duration of production of immature granulocytic cells and GM-CFUc over a 58-week period. The results demonstrated a complex pattern of inheritance of longevity of long-term in vitro hemopoiesis. Increased longevity did not absolutely correlate with detectable replication of the C57Ks/J N-tropic virus.
Insights
Long-term mouse bone marrow cultures showed differences in longevity, with C57Ks/J mice releasing retroviruses and lasting longer than NIH Swiss mice. Genetic analysis revealed complex inheritance patterns for this extended hematopoietic stem cell lifespan.
Area of Science:
- * Hematology
- * Virology
- * Genetics
Background:
- * Long-term bone marrow cultures (LTBMC) from C57Ks/J mice spontaneously release endogenous ecotropic retroviruses and maintain granulopoiesis for over 45 weeks.
- * In contrast, NIH Swiss mouse marrow cultures lack detectable virus release and have a shorter lifespan (25-35 weeks), failing to establish permanent cell lines.
- * This suggests a potential link between endogenous retroviral activity and the longevity of hematopoietic stem cells in vitro.
Purpose of the Study:
- * To investigate whether viral and/or cellular genes regulate the longevity of C57Ks/J mouse marrow cultures.
- * To determine the inheritance pattern of long-term in vitro hematopoiesis by analyzing hybrid and backcross generations.
Main Methods:
- * Establishment of LTBMC from C57Ks/J, NIH Swiss, (NIH-Swiss X C57Ks/J) F1 hybrid, F2 hybrid, and backcross generations.
- * Weekly measurement of endogenous ecotropic retrovirus release in all cultures.
- * Monitoring the duration of immature granulocytic cell and granulocyte-macrophage progenitor cell (GM-CFUc) production over a 58-week period.
Main Results:
- * A complex inheritance pattern for the longevity of LTBMC was observed across the different genetic crosses.
- * Increased longevity of hematopoiesis in vitro did not show an absolute correlation with the replication of the C57Ks/J N-tropic virus.
- * Differences in retroviral release and hematopoietic progenitor cell production were noted between the mouse strains and their genetic derivatives.
Conclusions:
- * The longevity of long-term in vitro hematopoiesis is regulated by multiple genetic factors, exhibiting a complex inheritance pattern.
- * While endogenous retroviral release is associated with longer culture lifespan in C57Ks/J mice, it is not the sole determinant of longevity.
- * Further research is needed to elucidate the specific viral and cellular genes controlling hematopoietic stem cell persistence in bone marrow cultures.