HMGN2: a novel antimicrobial effector molecule of human mononuclear leukocytes?
Leukocytes are a central cellular element of innate-immune defense in mammals. In addition to the generation of toxic oxygen radicals and nitric oxide, leukocytes express and secrete a broad array of antimicrobial proteins and peptides. In the study, an antimicrobial polypeptide was isolated and purified from human peripheral blood mononuclear leukocytes in the presence of interleukin (IL)-2. Microsequencing provided that its N-terminal amino sequence was PKRKAEGDAK, which was identical to high mobility group nucleosomal-binding domain 2 (HMGN2). Mass spectrometric value and Western blot also indicated its individual character of HMGN2. The antimicrobial assays showed that the Escherichia coli-based production of HMGN2 had a potent antimicrobial activity against E. coli ML-35p, Pseudomonas aeruginosa ATCC 27853, and to some extent, against Candida albicans ATCC 10231. The HMGN2 alpha-helical domain had the same antimicrobial activity as HMGN2. The immunocytochemistry staining, enzyme-linked immunosorbent assay, and Western blot revealed that HMGN2 was present in the cytoplasm of mononuclear leukocytes and released to the extracellular environment when stimulated with IL-2. These results suggest that HMGN2 would be a novel antimicrobial effector molecule of human mononuclear leukocyte.
Feng
Yun
Y
Research Unit of Infection and Immunity, West China Medical Center, Sichuan University, Chengdu, PR China.
Huang
Ning
N
Wu
Qi
Q
Wang
Boyao
B
D000890:Anti-Infective Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D024242:HMGN2 Protein / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000737:chemistry* / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012016:Reference Values
D000890:Anti-Infective Agents; D024242:HMGN2 Protein; D007376:Interleukin-2; D010455:Peptides