A nuclear antigen associated with cell proliferation and blast transformation

Area of Science:

• Immunology
• Cell Biology
• Molecular Biology

Background:

• Autoantibodies against nuclear antigens are common in systemic lupus erythematosus (SLE).
• Proliferating cell nuclear antigen (PCNA) is a nuclear antigen linked to cell proliferation and blast transformation.
• Previous studies identified autoantibodies recognizing PCNA in SLE patients' sera.

Purpose of the Study:

• To investigate the distribution of PCNA during the cell cycle and blast transformation.
• To utilize anti-PCNA autoantibodies as a reagent for cellular localization studies.
• To explore the association of PCNA with DNA synthesis events in proliferating cells.

Main Methods:

• Immunofluorescence staining using anti-PCNA autoantibodies.
• Analysis of synchronized B lymphoid cell lines (WiL-2).
• Study of mitogen-induced blast-transformed lymphocytes.

Main Results:

• PCNA exhibited speckled nucleoplasmic staining throughout G1, S, and G2 phases in WiL-2 cells.
• PCNA was detected in the nucleolus during late G1 and early S phases.
• In lymphocytes, PCNA appeared in the nucleolus before DNA synthesis initiation and subsequently localized to the nucleoplasm.

Conclusions:

• PCNA's distribution correlates with cell cycle progression and blast transformation.
• PCNA localization, including nucleolar presence, is linked to DNA synthesis.
• Anti-PCNA autoantibodies are valuable tools for studying cell proliferation markers.