EXPRESSION OF THE ADHESION MOLECULE CD11B AND POLYMERIZATION OF ACTINBY POLYMORPHONUCLEAR GRANULOCYTES OF PATIENTS ENDANGERED BY SEPSIS

The integrin CD11b is an important adhesion molecule mediating the tra nsendothelial migration of circulating polymorphonuclear granulocytes into an inflammatory region. The expression of CD11b is closely relate d to the ability to polymerize actin, a major component of the cytoske leton within the phagocyte. In this study we compared the CD11b expres sion as well as the polymerization of actin of isolated neutrophils fr om patients endangered by sepsis with cells from healthy donors. The p atient population was subdivided into a group of patients with severe thermal injuries and a group of patients who were admitted to an inten sive care unit on suspicion of sepsis. The following results were obta ined: (1) cells from burn patients, but not from non-burn patients, sh owed a reduced basal expression of CD11b during the first week after t he burn trauma; (2) stimulation with the chemotactic peptide formyl-Me t-Leu-Phe (FMLP) led to a strong overexpression of CD11b on the cells from burn patients, the effect was not observed using cells of the sec ond subgroup; (3) the content of polymerized actin was reduced within resting and stimulated cells from burn patients during the first 2 wee ks postinjury, non-burn patient cells showed an enhanced F-actin conte nt within the first week; (4) the ability of burn and non-burn patient cells ro polymerize actin after stimulation with FMLP was slightly im paired during the first week post injury/admission. The results demons trate that cells from patients endangered by sepsis show dysfunctions on the level of adhesion molecule expression and the strong related ac tin polymerization. There are remarkable differences between patients with burn injuries and patients who were endangered by sepsis due to o ther injuries or diseases.