The natural abundance of lambda2-light chains in inbred mice

Area of Science:

• Immunology
• Molecular Biology
• Genetics

Background:

• The constant (C) domain of mouse myeloma protein M315 light chain is unique.
• Immunoglobulins (Igs) are crucial for immune response.

Purpose of the Study:

• To identify and characterize the L315 light chain in normal mouse serum.
• To investigate the presence and levels of lambda2 chains in various mouse strains.
• To explore the relationship between lambda2 chains and immune responses, particularly to dinitrophenyl (Dnp).

Main Methods:

• Serological analysis using antiserum to the C-domain of L315.
• Carboxypeptidase A analysis of normal light chains.
• Quantification of immunoglobulin levels in mouse serum.
• Immunization studies with Dnp-KLH and KLH.

Main Results:

• Approximately 1% of normal mouse serum Igs possess L315-type (lambda2) light chains.
• All 35 inbred mouse strains studied exhibited lambda2 chains, with varying serum levels.
• Mice immunized with Dnp-KLH showed a 3-5 fold increase in lambda2 compared to controls.
• Serum immunoglobulin molecules bearing the lambda2 variable region (VL315) were detectable and increased upon Dnp-KLH immunization.

Conclusions:

• Lambda2 chains are a distinct subset of mouse immunoglobulin light chains present across inbred strains.
• The presence and levels of lambda2 chains are influenced by immune stimulation, particularly with Dnp antigens.
• Lambda2 chains can be further categorized into subsets based on their variable (V) domain similarity to VL315, suggesting genetic and functional diversity.