Function of bone marrow stromal cell lines derived from nude mice

Area of Science:

• Immunology
• Developmental Biology
• Hematopoiesis

Background:

• X-linked immune deficiency (xid) is characterized by B cell development defects.
• Previous studies indicated potential stromal cell deficiencies in nude and nude.xid mice affecting B cell maturation.
• Progenitors from nude.xid bone marrow differentiated on normal stromal cells, suggesting a stromal defect.

Purpose of the Study:

• To investigate the capacity of bone marrow stromal cells from nude and nude.xid mice to support B cell lymphopoiesis.
• To determine if nude and nude.xid stromal cells can support the maturation of X-linked immune deficiency (xid) B cells.
• To assess the functional capabilities of bone marrow stromal cells in supporting B cell development in immunodeficient mouse models.

Main Methods:

• Generation of primary stromal cell layers and immortalized stromal cell lines from nude and nude.xid mice.
• Co-culture experiments involving B cell progenitors and stromal cells.
• Flow cytometry analysis to assess B cell differentiation stages (CD43+/CD45-, CD45+/IgM-, surface IgM+).
• Detection of cytokine expression (IL-7, IGF-I) in supporting stromal cell lines.

Main Results:

• Primary stromal cells from nude mice supported xid B cell differentiation in vitro.
• Derived stromal cell lines from nude and nude.xid mice supported B cell differentiation from early progenitors to surface IgM+ B cells.
• Supporting stromal cell lines expressed Interleukin-7 (IL-7) and Insulin-like Growth Factor I (IGF-I).
• Frequencies of supportive stromal cells were comparable across normal, xid, nude, and nude.xid mice.

Conclusions:

• Bone marrow stromal cells from nude and nude.xid mice possess normal capabilities to support B cell maturation.
• The stromal microenvironment in nude and nude.xid mice is not deficient in supporting B cell lymphopoiesis.
• These findings resolve previous questions regarding stromal cell function in these immunodeficient models.