Effects of cryopreservation on immune responses. VIII. Enhanced secretion of interferon-gamma by frozen human peripheral blood mononuclear cells.
The effect of freezing on phytohemagglutinin-induced interferon-gamma (IFN-gamma) production by human peripheral blood mononuclear cells (PBMCs) was studied. The possible mechanisms responsible for the observed effects were also analyzed. Frozen PBMCs produced significantly larger quantities of IFN-gamma than fresh cells. Like the frozen cells, the monocyte- and natural killer cell-eliminated populations of fresh PBMCs also secreted significantly larger quantities of IFN-gamma. In contrast, the freezing process had no enhancing effect on IFN-gamma production by monocyte-depleted PBMCs. Irradiated PBMCs also secreted larger quantities of IFN-gamma. The results suggest that functional inactivation of a subset of cryosensitive suppressor monocytes is associated with an increase in IFN-gamma production by the T lymphocytes. The results provide further evidence that monocytes mediate their suppressive effect through the activation of a subset of radiosensitive, immuno-down-regulatory T cells. The ability of frozen cells to produce larger quantities of IFN-gamma should be of clinical importance. For instance, cancer patients receiving frozen PBMCs as stem cell support (after myeloablative radio/chemotherapy) should benefit from the increased IFN-gamma secretion because of its potent immunoregulatory, microbicidal, and antitumor activities.
Venkataraman
M
M
Department of Medicine, Mount Sinai Hospital Medical Center, Chicago, IL 60608, USA.
D001793:Blood Preservation; D002469:Cell Separation; D002478:Cells, Cultured; D015925:Cryopreservation; D006801:Humans; D007121:Immunocompetence; D007371:Interferon-gamma / Q000378:metabolism*; D007694:Killer Cells, Natural; D007963:Leukocytes, Mononuclear / Q000378:metabolism* / Q000528:radiation effects; D008213:Lymphocyte Activation; D009000:Monocytes; D010835:Phytohemagglutinins / Q000494:pharmacology
D010835:Phytohemagglutinins; D007371:Interferon-gamma