CD5(+) B Cell Lymphomas of Mice

Area of Science:

• Immunology
• Oncology
• Genetics

Background:

• Spontaneous murine lymphomas frequently originate from CD5 B cells, appearing late in life.
• Lymphoma development involves an early commitment to neoplasia followed by a long indolent phase.
• The immunoglobulin V gene repertoire in these lymphomas is not random, showing specific VH and VK gene associations.

Purpose of the Study:

• To investigate the origins and developmental processes of spontaneous murine lymphomas.
• To understand the role of immunoglobulin gene repertoire skewing in lymphomagenesis.
• To characterize the specific V gene usage and antibody specificities associated with CD5 B cell lymphomas.

Main Methods:

• Analysis of immunoglobulin (Ig) V gene repertoire in spontaneous murine lymphomas.
• Comparison of lymphoma Ig V gene usage with that of normal CD5 B cells.
• Investigation of CD5 B cell development and repertoire selection in mice.

Main Results:

• The unbalanced Ig V gene repertoire in lymphomas mirrors that of normal CD5 B cells, indicating lymphomagenesis occurs after repertoire establishment.
• CD5 B cell repertoire skewing happens early in post-natal life, driven by antigen selection, primarily self-antigens.
• A subset of CD5 B cells and lymphomas express VH11/VH12 genes with specific VK genes, producing anti-phosphatidylcholine antibodies, a specificity not found in conventional B cells.

Conclusions:

• Murine CD5 B cell lymphomas arise from a pre-established, skewed V gene repertoire.
• Antigen-driven selection by self-antigens during early post-natal development shapes the CD5 B cell repertoire and predisposes to lymphomagenesis.
• Specific VH gene usage and antibody specificities characterize these lymphomas, highlighting a distinct B cell subset involved in lymphomagenesis.