VH and VL gene elements that encode human antibodies to DNA

Area of Science:

• Immunology
• Molecular Biology
• Genetics

Background:

• Antibodies against DNA are crucial in autoimmune diseases.
• Previous research suggested antigen-driven affinity maturation for high-affinity anti-DNA antibodies.

Purpose of the Study:

• To determine the cDNA sequence of variable regions of heavy and light chains of low-affinity DNA-binding antibodies.
• To investigate the genetic basis of antibody reactivity to DNA.

Main Methods:

• cDNA sequencing of antibody variable heavy and light chains.
• Analysis of Variable Heavy (VH) and Variable Light (VL) gene element utilization.
• Comparison of gene usage in low-affinity versus high-affinity anti-DNA antibodies.

Main Results:

• Identified specific VH gene elements (VH26, VH1.9III) in low-affinity anti-DNA antibodies, associated with novel D gene-encoded CDR3s.
• Discovered previously unidentified VL gene elements in these antibodies.
• Found that only a subset of high-affinity anti-DNA antibodies utilize these low-affinity VH genes.

Conclusions:

• The limited repertoire of VH genes in low-affinity anti-DNA antibodies suggests most relevant VH gene elements have been identified.
• The data indicates that DNA is unlikely to be the sole driving antigen for high-affinity antibody development, challenging previous assumptions.