Lysosomal Storage Disorders and Malignancy.

Area of Science:

• Immunology
• Genetics
• Biochemistry

Background:

• Lysosomal storage disorders (LSDs) disrupt cellular degradation, with Gaucher disease (GD) being a common lipidosis.
• Patients with Gaucher disease exhibit increased frequencies of polyclonal and monoclonal gammopathies.
• Accumulated lipids in GD, such as β-glucosylceramide (βGL1-22) and glucosylsphingosine (LGL1), are recognized by specific NKT cells.

Purpose of the Study:

• To investigate the mechanism linking Gaucher disease lipid accumulation to gammopathies.
• To explore the role of NKT cells in the immune dysregulation observed in Gaucher disease.
• To determine if targeting lipid accumulation can ameliorate associated gammopathies.

Main Methods:

• Analysis of NKT cell recognition of GD-specific lipids (βGL1-22, LGL1).
• In vivo studies in a Gaucher disease mouse model to assess NKT cell phenotypes and downstream immune responses.
• Investigation of immunoglobulin specificity in human monoclonal gammopathies.
• Evaluation of substrate reduction therapy in ameliorating GD-associated gammopathy.

Main Results:

• GD-associated lipids (βGL1-22, LGL1) activate specific NKT cells, promoting T-follicular helper (TFH) phenotype.
• Activation leads to germinal center B cells, hypergammaglobulinemia, and anti-lipid antibodies in mice.
• Human monoclonal gammopathies show specificity for lysolipids (LGL1, LPC).
• Substrate reduction therapy reduced gammopathy in Gaucher disease mice.

Conclusions:

• Chronic antigenic stimulation by abnormal lipid storage in GD drives immune dysregulation, leading to gammopathies.
• NKT cell activation by accumulating lipids is a key mechanism in GD-associated immune abnormalities.
• Investigating rare diseases like GD offers insights into common conditions with similar underlying mechanisms.