Immunogenic contaminants in mouse nerve-growth factor

Area of Science:

• Neuroscience
• Immunology
• Biochemistry

Background:

• Standard preparations of mouse nerve growth factor (NGF) are known to contain gamma-globulin.
• Antibodies in antisera to NGF can cross-react with these contaminating globulins.
• This cross-reactivity complicates accurate studies of NGF and its antibodies.

Purpose of the Study:

• To confirm the presence of gamma-globulin in mouse NGF preparations.
• To characterize antibodies against gamma-globulin in horse antisera to NGF.
• To develop methods for removing these antibodies without compromising NGF antiserum potency.

Main Methods:

• Gel filtration chromatography to purify the NGF beta subunit.
• Adsorption with soluble antigen to remove antibodies.
• Affinity chromatography using insolubilized antigen for antibody removal.
• In vitro and in vivo assays to assess antiserum potency.

Main Results:

• Gamma-globulin was confirmed in standard mouse 7-S NGF complex and beta subunit preparations.
• Horse antisera to mouse NGF contained antibodies against gamma-globulin.
• Adsorption and affinity chromatography effectively removed these antibodies.
• Antibody removal procedures did not diminish the NGF antiserum's potency.

Conclusions:

• Mouse NGF preparations are contaminated with gamma-globulin.
• Specific antibodies against this contaminant exist in NGF antisera.
• Effective purification strategies can yield immunochemically pure NGF beta subunit.
• These purification methods enable more accurate research on NGF and its antibodies.