A simplified and rapid limiting dilution assay of T lymphocytes

Area of Science:

• Immunology
• Cell Biology

Background:

• T lymphocytes (T cells) play a crucial role in immune responses.
• Accurate assessment of T cell proliferative capacity is essential for understanding immune function and recovery.

Purpose of the Study:

• To develop and validate an alternative limiting dilution assay (LDA) for quantifying T cell progenitor frequency.
• To assess the utility of this LDA in evaluating T cell proliferative activities in clinical settings.

Main Methods:

• Peripheral blood mononuclear cells were stimulated with PHA and cultured with recombinant interleukin-2.
• Microwell cultures were assessed for T cell proliferation after 4 days.
• Clonal expansion was modeled using the single-hit Poisson distribution.

Main Results:

• The progenitor frequency (f) in normal donors was determined for mononuclear cells (0.082 ± 0.025) and E-rosette-positive cells (0.236 ± 0.029).
• A significant decrease in progenitor frequency was observed in patients following marrow-ablative chemotherapy and autologous stem cell transplantation.
• The assay demonstrated that T cell clonal expansion follows the single-hit Poisson model.

Conclusions:

• The developed LDA provides a reliable method for evaluating T cell proliferative activity.
• This assay is valuable for assessing immune recovery post-chemotherapy and autologous transplantation.
• The LDA system is suitable for routine clinical use in monitoring T cell function.