Related Experiment Videos
Kinetics of somatic mutation in lymph node germinal centres
E Källberg1, D Gray, T Leanderson
1Immunology Unit, Lund University, Sweden.
Scandinavian Journal of Immunology
|November 1, 1994
Summary
Somatic mutations in immunoglobulin V kappa genes occur early in the immune response, detected in B-cells within 4 days of immunization. These mutations appear before significant clonal expansion or selection, indicating rapid genetic changes in B-cells.
Area of Science:
- Immunology
- Molecular Biology
- Genetics
Background:
- B-cells undergo somatic hypermutation in immunoglobulin genes to enhance antibody diversity.
- The timing of somatic mutation induction relative to clonal expansion and selection is crucial for understanding immune responses.
Purpose of the Study:
- To investigate the early kinetics of somatic mutation in immunoglobulin V kappa genes during an immune response.
- To determine if somatic mutations occur before peak clonal expansion and selection.
Main Methods:
- Analyzing immunoglobulin V kappa genes from lymph node B-cells at various timepoints post-immunization.
- Utilizing polymerase chain reaction (PCR) and DNA sequencing to detect somatic mutations.
- Sequencing RNA from oxazolone-specific hybridomas to confirm mutations in expressed genes.
Main Results:
- Somatic mutations were detected in V kappa Ox1 genes as early as day 4 after immunization.
- Early mutations were predominantly found in B-cells with a germinal center phenotype.
- Evidence of population-level selection by apoptosis was not observed until day 7.
Conclusions:
- Somatic mutations can be induced very early in the immune response, preceding peak clonal expansion.
- These findings suggest a rapid process of genetic diversification in B-cells during the initial stages of immunization.
- The early occurrence of mutations highlights the dynamic nature of B-cell adaptation.