Interferon-induced surface alterations in hairy cells. A review

Area of Science:

• Hematology
• Immunology
• Cell Biology

Background:

• Hairy cells (HCs) from hairy cell leukemia (HCL) patients exhibit characteristic ruffles and microvilli.
• In vitro culture of HCs leads to polarized surfaces with elongated microvilli and spiked ruffles.

Purpose of the Study:

• To investigate the in vitro effects of alpha-interferon (IFN) on the surface morphology and immunological profile of HCs from HCL patients.
• To correlate IFN-induced morphological changes with specific cell surface marker expression.

Main Methods:

• Immuno-scanning electron microscopy (immuno-SEM) was used to examine HCs from 11 HCL cases after in vitro IFN treatment.
• Monoclonal antibodies (MoAbs) and immuno-gold labeling were employed to assess cell surface marker expression (Leu-14, Leu-M5, HLA-DR, HLA-DQ).

Main Results:

• IFN treatment induced deformed surfaces with "bubbling" membranes and villous bud-like formations in up to one-third of HCs in 8 out of 11 cases.
• No significant changes in Leu-14 and Leu-M5 MoAb labeling were observed post-IFN treatment.
• A significant increase in HLA-DR and HLA-DQ labeling intensity was noted in HCs exhibiting IFN-induced membrane changes.

Conclusions:

• In vitro alpha-interferon induces distinct immuno-ultrastructural membrane alterations in hairy cells from HCL patients.
• These observed changes suggest a unique interferon-induced membrane reorganization process in malignant HCs.
• Increased expression of HLA-DR and HLA-DQ may serve as indicators of IFN response at the cellular level.