Aliphatic aldehydes inhibit the proliferative response of human peripheral blood lymphocytes to phytohemagglutinin and alloantigens.

The effect of methyl glyoxal (MG) and various 4-hydroxyalkenals on the response of human peripheral blood lymphocytes (PBL) to phytohemagglutinin (PHA) or allogeneic cells has been investigated. Pretreatment of PBL with aldehydes significantly reduced the percentage of blast-transformed cells and [3H]thymidine incorporation into DNA in both PHA- and alloantigen-stimulated cultures, hydroxyalkenals being more effective than MG. Further experiments showed that these aldehydes also affected the proliferation of pre-activated lymphocytes. The percentage of blasts as well as [3H]thymidine incorporation into DNA were significantly decreased when the aldehydes were added until 72 h after application of the mitogenic stimulus.