Lymphocyte surface markers and cytotoxicity following cryopreservation

Area of Science:

• Immunology
• Cell Biology
• Cryobiology

Background:

• Cryopreservation (CP) is crucial for preserving biological samples, including peripheral blood lymphocytes (PBL).
• Understanding the impact of CP on lymphocyte subpopulations and function is vital for accurate immunological assessments.

Purpose of the Study:

• To evaluate the effects of cryopreservation on lymphocyte subpopulation distribution.
• To assess the functional activity of cryopreserved lymphocytes in blastogenic and cytotoxicity assays.

Main Methods:

• Peripheral blood lymphocytes (PBL) from 12 healthy donors were divided into fresh and cryopreserved groups.
• Lymphocyte subpopulations were analyzed using rosette-forming cell assays.
• Functional assays included blastogenesis (response to alloantigens and unstimulated controls) and various cytotoxicity tests (MLC-induced CML, NK, ADCC, LDCC, and 18h assay against melanoma cells).

Main Results:

• Cryopreservation led to a significant reduction in E, EA gamma, and EA mu rosette-forming cells, with a reciprocal increase in EAC rosette-forming cells.
• Blastogenic response to alloantigens remained stable, but spontaneous blastogenesis was significantly reduced.
• Cryopreservation significantly diminished MLC-induced CML, NK, ADCC, and LDCC activities, but not cytotoxicity in an 18-hour assay against melanoma targets.

Conclusions:

• Cryopreservation significantly alters lymphocyte subpopulation percentages and impairs various functional immune activities.
• The impact of cryopreservation is assay-dependent, with some cytotoxic functions showing resilience.
• These findings highlight the need for careful consideration of cryopreservation effects in immunological studies and clinical applications.