Differences in N-acetylmuramyl-L-alanine amidase and lysozyme in serum and cerebrospinal fluid of patients with bacterial meningitis.
N-acetylmuramyl-L-alanine amidase (NAMLAA) specifically degrades peptidoglycan, a major component of bacterial cell walls. Lysozyme degrades peptidoglycan differently by hydrolyzing the aminosugar backbone of peptidoglycan. In another study, it was shown that the two enzymes act synergistically to inactivate the inflammatory properties of peptidoglycan. The presence of lysozyme and NAMLAA was determined in serum and cerebrospinal fluid (CSF) of patients with bacterial meningitis. High concentrations of lysozyme were found in CSF while, surprisingly, NAMLAA was not present. To explain this phenomenon, the degranulation pattern of neutrophils in CSF was compared with that of neutrophils from blood. Specific granules contain lysozyme and the azurophil granules contain both lysozyme and NAMLAA. CD66b expression on the cell surface, indicative for fusion of the specific granules with the cell membrane, was higher in CSF than in blood, while the marker for the azurophil granules was lower.
Hoijer
M A
MA
Department of Immunology, Erasmus University Rotterdam, Sophia Children's Hospital/University Hospital Rotterdam, The Netherlands.
de Groot
R
R
van Lieshout
L
L
Jacobs
B C
BC
Melief
M J
MJ
Hazenberg
M P
MP
D000293:Adolescent; D000328:Adult; D000368:Aged; D015703:Antigens, CD; D000951:Antigens, Neoplasm; D015815:Cell Adhesion Molecules; D015550:Cell Degranulation; D002462:Cell Membrane / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D005260:Female; D005434:Flow Cytometry; D058851:GPI-Linked Proteins; D006192:Haemophilus Infections / Q000097:blood / Q000134:cerebrospinal fluid; D006801:Humans; D007223:Infant; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis / Q000378:metabolism; D016920:Meningitis, Bacterial / Q000097:blood* / Q000134:cerebrospinal fluid*; D008585:Meningitis, Meningococcal / Q000097:blood / Q000134:cerebrospinal fluid; D008875:Middle Aged; D009113:Muramidase / Q000032:analysis*; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000032:analysis*; D018375:Neutrophil Activation; D009504:Neutrophils / Q000502:physiology; D011008:Pneumococcal Infections / Q000097:blood / Q000134:cerebrospinal fluid
D015703:Antigens, CD; D000951:Antigens, Neoplasm; C504120:CEACAM8 protein, human; D015815:Cell Adhesion Molecules; D058851:GPI-Linked Proteins; D008562:Membrane Glycoproteins; D009113:Muramidase; D009238:N-Acetylmuramoyl-L-alanine Amidase