Human immunoglobulin variable region gene analysis by single cell RT-PCR.

Area of Science:

• Immunology
• Molecular Biology
• Genetics

Background:

• Understanding human immunoglobulin V region usage is crucial for B cell repertoire analysis.
• Existing methods for V region analysis can introduce bias due to variable mRNA levels.
• A need exists for a precise and efficient method to study single B cell V region expression.

Purpose of the Study:

• To describe a protocol for single-cell reverse transcription polymerase chain reaction (RT-PCR) applied to human immunoglobulin V region usage.
• To provide a method that avoids biases associated with traditional cDNA library construction.
• To enable detailed analysis of V region gene expression at the single-cell level.

Main Methods:

• Peripheral blood mononuclear cells (PBMC) are isolated and stained with anti-CD19 antibody.
• B cells are sorted by flow cytometry, with single cells deposited into individual tubes.
• Single-cell cDNA synthesis is followed by nested PCR amplification of antibody variable regions (VH and/or VL).
• PCR products are sequenced and aligned to germline and Genbank databases.

Main Results:

• The protocol enables direct sequencing and analysis of V region genes from single human B cells.
• Nested PCR enhances specificity and quantity of V region PCR products.
• This method provides a fast and convenient way to analyze V region gene expression without library construction bias.

Conclusions:

• Single-cell RT-PCR is a powerful tool for unbiased analysis of human immunoglobulin V region usage.
• The method facilitates the study of B cell antibody repertoires at an unprecedented resolution.
• Generated PCR products are suitable for cloning into expression vectors for recombinant protein domain production.