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Updated: Jun 22, 2026
Isolation and Cryopreservation of Highly Viable Human Peripheral Blood Mononuclear Cells From Whole Blood: A Guide for Beginners
Published on: October 25, 2024
Frequency of human T regulatory cells in peripheral blood is significantly reduced by cryopreservation
1Clinical Immunotherapy Laboratory, Department of Medical Oncology, University of Manchester, Wilmslow Road, Manchester M204BX, UK. eelkord@picr.man.ac.uk
Abstract:
Cryopreservation of peripheral blood mononuclear cells (PBMC) is essential for many clinical and research assays. Some studies reported consistent changes in PBMC phenotype following cryopreservation. We hypothesized that PBMC freezing may have a negative impact on estimation of the frequency of T regulatory cell (Treg). Treg levels were measured in 6 fresh PBMC samples isolated from 6 healthy donors and these levels were re-measured after freezing for three weeks. Herein, we report a significant reduction in Treg frequency in all samples following cryopreservation.
Insights
Cryopreservation significantly reduces T regulatory cell (Treg) frequency in peripheral blood mononuclear cells (PBMC). This finding impacts cell-based assays requiring accurate Treg quantification in research and clinical settings.
Area of Science:
- Immunology
- Cell Biology
- Cryobiology
Background:
- Cryopreservation of peripheral blood mononuclear cells (PBMC) is a standard procedure for numerous clinical and research applications.
- Previous research indicates that cryopreservation can alter PBMC phenotype.
- The specific impact on T regulatory cell (Treg) frequency remains a critical question for assay reliability.
Purpose of the Study:
- To investigate the effect of cryopreservation on the frequency of T regulatory cells (Tregs) within PBMC samples.
- To test the hypothesis that freezing PBMC negatively impacts Treg frequency estimation.
Main Methods:
- Isolation of PBMCs from six healthy donors.
- Measurement of Treg frequency in fresh PBMC samples.
- Re-measurement of Treg frequency after three weeks of cryopreservation.
Main Results:
- A significant reduction in Treg frequency was observed in all tested PBMC samples post-cryopreservation.
- The observed decrease in Treg levels was consistent across all samples.
Conclusions:
- Cryopreservation demonstrably reduces the quantifiable frequency of Tregs in PBMC samples.
- These findings highlight potential biases in studies relying on cryopreserved PBMCs for Treg analysis.
- Further research may be needed to develop cryopreservation protocols that preserve Treg integrity or to adjust for observed reductions.
