A sensitive ELISPOT assay to detect low-frequency human T lymphocytes

Area of Science:

• Immunology
• Cellular Biology

Background:

• The ELISPOT assay is crucial for quantifying antigen-specific immune responses.
• Detecting rare or low-frequency T lymphocytes presents a significant challenge in immunological studies.

Purpose of the Study:

• To enhance the sensitivity of the ELISPOT assay for detecting rare T lymphocytes.
• To improve the objective quantitation and flexibility of the ELISPOT assay.

Main Methods:

• Incorporated an antigen-driven proliferation step before restimulation with antigen and antigen-presenting cells (APCs).
• Utilized ELISA-grade plates and video computer imaging software for improved signal-to-noise ratio and objective quantitation.
• Applied the modified assay to analyze peripheral blood mononuclear cells (PBMC) from multiple sclerosis (MS) patients.

Main Results:

• The modified ELISPOT assay demonstrated a >10-fold increase in detecting myelin basic protein (MBP)-responsive T cells in MS patients.
• Achieved significantly higher spot-forming cell (SFC) counts compared to the standard ELISPOT assay.
• The assay successfully utilized frozen PBMC, allowing for greater sample processing flexibility.

Conclusions:

• The modified ELISPOT assay offers superior sensitivity for detecting rare T lymphocytes compared to standard methods.
• This enhanced assay provides a more flexible and accurate tool for immunological research and clinical applications.
• Potential applications include analyzing cytokine profiles, identifying T lymphocyte donors, and assessing therapeutic efficacy.