Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX 77555-0435, USA.
Immunol Cell Biol. 2012 Sep;90(8):796-801. doi: 10.1038/icb.2012.3. Epub 2012 Mar 6.
Immunosuppressive neutrophils (PMN-II) appearing in association with burn injury have a role on the increased susceptibility of burn patients to various infections. In the present study, the role of PMN-II on the production of human β-defensins (HBDs), important molecules on host antimicrobial innate immunities, by human keratinocytes was studied. Normal human epidermal keratinocytes (NHEKs) were cultured with neutrophils (PMNs) isolated from burn patients or healthy volunteers in dual-chamber transwells. Culture fluids harvested 24 h after cultivation were assayed for HBDs using enzyme-linked immunosorbent assay. Also, these culture fluids were assayed for their antimicrobial activities by a standard colony-counting method using Pseudomonas aeruginosa. In the results, PMNs isolated from peripheral blood of burn patients were confirmed as PMN-II, because these cells produced CC-chemokine ligand 2 (CCL2), but not interleukin (IL)-12 and CC-chemokine ligand 3 (CCL3). Culture fluids of NHEK transwell-cultured with healthy PMNs exhibited strong killing activities against P. aeruginosa (96% inhibition), however, the growth of bacteria was not dramatically inhibited by the culture fluids of NHEK transwell-cultured with burn-patient PMNs (36% inhibition). IL-12 and CCL3 containing culture fluids of healthy PMNs stimulated with the bacterial antigen or rCCL3 and rIL-12 enhanced the production of HBD2 and HBD3 by NHEK, whereas CCL2 containing culture fluids of burn-patient PMN stimulated with the antigen or rCCL2 inhibited the HBD production by NHEK. These results indicate that PMN-II appearing in association with burn injury contribute to the decreased production of HBDs in thermally injured patients.
与烧伤相关的免疫抑制性中性粒细胞（PMN-II）会增加烧伤患者易感染各种感染的易感性。在本研究中，研究了 PMN-II 对人角质形成细胞产生人β防御素（HBDs）的作用，HBDs 是宿主抗菌先天免疫的重要分子。将正常的人表皮角质形成细胞（NHEK）与从烧伤患者或健康志愿者中分离出的中性粒细胞（PMN）在双层 Transwell 中共同培养。培养 24 小时后，通过酶联免疫吸附试验（ELISA）测定培养上清液中的 HBDs。此外，还通过使用铜绿假单胞菌的标准菌落计数法测定这些培养上清液的抗菌活性。结果表明，从烧伤患者外周血中分离出的 PMN 被确认为 PMN-II，因为这些细胞产生 C 趋化因子配体 2（CCL2），但不产生白细胞介素（IL）-12 和 C 趋化因子配体 3（CCL3）。与健康 PMN 共培养的 NHEK Transwell 培养物的培养上清液对铜绿假单胞菌表现出强烈的杀伤活性（抑制 96%），而与烧伤患者 PMN 共培养的 NHEK Transwell 培养物的培养上清液对细菌的生长抑制作用不明显（抑制 36%）。用细菌抗原或 rCCL3 和 rIL-12 刺激健康 PMN 产生的含 IL-12 和 CCL3 的培养上清液增强了 NHEK 对 HBD2 和 HBD3 的产生，而用抗原或 rCCL2 刺激烧伤患者 PMN 产生的含 CCL2 的培养上清液抑制了 NHEK 的 HBD 产生。这些结果表明，与烧伤相关的 PMN-II 的出现会导致烧伤患者 HBDs 产生减少。
