The Centre for Research & Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.
Infect Immun. 2011 Jan;79(1):305-13. doi: 10.1128/IAI.00803-10. Epub 2010 Nov 1.
Melioidosis is a severe infectious disease caused by the saprophytic facultative intracellular pathogen Burkholderia pseudomallei. The disease is endemic in Southeast Asia and Northern Australia, and no effective vaccine exists. To describe human cell-mediated immune responses to B. pseudomallei and to identify candidate antigens for vaccine development, the ability of antigen-pulsed monocyte-derived dendritic cells (moDCs) to trigger autologous T-cell responses to B. pseudomallei and its products was tested. moDCs were prepared from healthy individuals exposed or not exposed to B. pseudomallei, based on serological evidence. These were pulsed with heat-killed B. pseudomallei or purified antigens, including ABC transporters (LolC, OppA, and PotF), Bsa type III secreted proteins (BipD and BopE), tandem repeat sequence-containing proteins (Rp1 and Rp2), flagellin, and heat shock proteins (Hsp60 and Hsp70), prior to being mixed with autologous T-cell populations. After pulsing of cells with either heat-killed B. pseudomallei, LolC, or Rp2, coculturing the antigen-pulsed moDCs with T cells elicited gamma interferon production from CD4(+) T cells from seropositive donors at levels greater than those for seronegative donors. These antigens also induced granzyme B (cytotoxic) responses from CD8(+) T cells. Activation of antigen-specific CD4(+) T cells required direct contact with moDCs and was therefore not dependent on soluble mediators. Rp peptide epitopes recognized by T cells in healthy individuals were identified. Our study provides valuable novel data on the induction of human cell-mediated immune responses to B. pseudomallei and its protein antigens that may be exploited in the rational development of vaccines to combat melioidosis.
类鼻疽是一种由腐生性兼性细胞内病原体伯克霍尔德菌假单胞菌引起的严重传染病。该疾病在东南亚和澳大利亚北部流行，目前尚无有效的疫苗。为了描述人类细胞介导的对伯克霍尔德菌假单胞菌的免疫反应，并确定疫苗开发的候选抗原，测试了抗原脉冲单核细胞衍生树突状细胞（moDC）触发自体 T 细胞对伯克霍尔德菌假单胞菌及其产物反应的能力。根据血清学证据，从接触或未接触过伯克霍尔德菌假单胞菌的健康个体中制备 moDC。用热灭活的伯克霍尔德菌假单胞菌或纯化抗原（包括 ABC 转运蛋白（LolC、OppA 和 PotF）、Bsa 型 III 分泌蛋白（BipD 和 BopE）、串联重复序列包含蛋白（Rp1 和 Rp2）、鞭毛蛋白和热休克蛋白（Hsp60 和 Hsp70）脉冲这些细胞，然后与自体 T 细胞群体混合。在用热灭活的伯克霍尔德菌假单胞菌、LolC 或 Rp2 脉冲细胞后，与 T 细胞共培养抗原脉冲 moDC 可从血清阳性供体的 CD4(+)T 细胞中诱导产生比血清阴性供体更高水平的γ干扰素。这些抗原还诱导 CD8(+)T 细胞产生颗粒酶 B（细胞毒性）反应。抗原特异性 CD4(+)T 细胞的激活需要与 moDC 直接接触，因此不依赖于可溶性介质。鉴定了健康个体中的 T 细胞识别 Rp 肽表位。我们的研究为诱导人类对伯克霍尔德菌假单胞菌及其蛋白抗原的细胞介导免疫反应提供了有价值的新数据，这可能有助于合理开发对抗类鼻疽的疫苗。
