Monolayer destruction by leukocytes from patients with multiple sclerosis

Area of Science:

• Immunology
• Neuroscience
• Cell Biology

Background:

• Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system.
• The etiology of MS is not fully understood, with potential roles for viral infections and immune system dysregulation.
• Previous studies have suggested immune cell involvement in MS pathogenesis.

Purpose of the Study:

• To investigate the cytotoxic effects of lymphoid cells from MS patients on tissue-culture monolayers.
• To explore potential causative agents, such as viruses or specific cell types, contributing to this observed cytotoxicity in MS.

Main Methods:

• Co-cultivation of separated lymphoid cells from MS patients and healthy controls with various cell lines.
• Electron microscopy to detect viral particles in positive co-cultures.
• Immunofluorescent techniques to test for measles and herpes viruses.
• Comparative analysis with co-cultivations from stroke patients, including granulocyte manipulation.

Main Results:

• Over 80% of co-cultivations with MS lymphoid cells showed monolayer destruction, compared to less than 5% with normal cells.
• No viral particles were detected by electron microscopy, and measles/herpes viruses were negative via immunofluorescence.
• While stroke patient leukocytes caused destruction, this was abrogated by reducing granulocyte contamination, unlike the MS samples.
• The cytotoxic effect in MS was not attributed to lymphotoxin.

Conclusions:

• Lymphoid cells from MS patients possess a potent, intrinsic cytotoxic activity against tissue-culture cells.
• This MS-associated cytotoxicity is not mediated by common viral infections or granulocytes.
• The findings suggest a unique, non-viral, non-granulocyte-dependent mechanism contributing to MS pathogenesis.