Heat shock response: presence and effects in burn patient neutrophils

Heat shock proteins (HSPs) are present in neutrophils (PMNs) from criticall y ill patients. We investigated whether HSPs were present in PMNs front bur n patients and whether heat shock contributed to the fuctional defects obse rved in burn PMNs. Using both flow cytometry and Western blot techniques it was observed that inducible HSP72 (iHSP72) was present in PMNs and leukocy tes front burn patients, especially in patients with inhalation injury. Sim ilar to burn PMNs, and in contrast to normal cells, heat shocked PMNs (43 d egrees C incubation) expressed iHSP72 and were unable to increase the expre ssion of CD11b/CD18 in response to pro-inflammatory stimuli, Degranulation after pro-inflammatory stimuli was decreased for both burn- and heat-shocke d PMNs when compared to normal controls, In burn PMNs these functional abno rmalities were mainly due to decreased quantities of proteins (CD11b, album in, B-12 binding protein, beta-glucuronidase) present within cytoplasmic gr anules, However, in heat-shocked PMNs the abnormalities were primarily rela ted to abnormal exocytosis. In conclusion, our data show that decreased qua ntities of cytoplasmic granule proteins and, to a smaller degree, defective exocytosis are involved in the functional abnormalities observed in burn P MNs.