Horwitz M A
J Clin Invest. 1983 Jun;71(6):1686-97. doi: 10.1172/jci110923.
Previous studies from this laboratory have suggested a role for cell-mediated immunity in host defense against Legionella pneumophila. In this paper, cell-mediated immunity to L. pneumophila in patients recovered from Legionnaires' disease was studied by examining patient mononuclear cell responses to L. pneumophila antigens. Patient mononuclear cells were assayed both for their capacity to respond to L. pneumophila antigens with the production of cytokines that activate monocytes, as measured by monocyte inhibition of L. pneumophila multiplication, and for their capacity to respond with proliferation, as measured by [(3)H]thymidine incorporation. Patient mononuclear cells incubated with formalin-killed L. pneumophila generated cytokines (supernatants) that were capable of activating in vitro freshly explanted monocytes from a person without historical or serological evidence of L. pneumophila infection (nonpatient). Such activated nonpatient monocytes inhibited the intracellular multiplication of L. pneumophila, and the degree of inhibition was proportional to the concentration of supernatant added. Patient mononuclear cells incubated with 5 x 10(6) - 5 x 10(8) formalin-killed L. pneumophila/ml for 4 d produced maximally potent supernatants; supernatants generated in flat-bottomed wells were equivalent in potency to supernatants generated in cone-shaped wells. Patient L. pneumophila-induced mononuclear cell supernatants were less potent than patient concanavalin A-induced mononuclear cell supernatants. Patient mononuclear cells also responded to formalin-killed L. pneumophila with proliferation (lymphoproliferation). Patient mononuclear cells responded more strongly to L. pneumophila antigens than mononuclear cells of age- and sex-matched nonpatients, as measured by both assays; responses to concanavalin A were comparable. Mononuclear cells from patients recovered from Legionnaires' disease responded more strongly to L. pneumophila than to Mycobacterium leprae antigens, whereas mononuclear cells from patients with tuberculoid leprosy responded more strongly to M. leprae antigens. These findings indicate that cell-mediated immunity to L. pneumophila develops in patients with Legionnaires' disease and, taken together with previously reported findings, that cell-mediated immunity plays a major role in host defense against L. pneumophila. The monocyte activation assay described in this paper has general applicability for the study of monocyte and mononuclear cell effector functions in selected patients. The assay may be used to study (a) the capacity of a patient's monocytes to be activated to an antimicrobial potential by a standard preparation of cytokines and (b) the capacity of a patient's mononuclear cells to generate such monocyte-activating cytokines in response to a mitogen or antigen.
该实验室先前的研究表明，细胞介导的免疫在宿主抵御嗜肺军团菌的防御中发挥作用。在本文中，通过检测患者单核细胞对嗜肺军团菌抗原的反应，研究了从军团病康复的患者对嗜肺军团菌的细胞介导免疫。对患者单核细胞进行了两种检测，一是检测其对嗜肺军团菌抗原作出反应并产生激活单核细胞的细胞因子的能力（通过单核细胞对嗜肺军团菌增殖的抑制来衡量），二是检测其增殖反应能力（通过[³H]胸腺嘧啶核苷掺入来衡量）。用福尔马林灭活的嗜肺军团菌孵育患者单核细胞，可产生能够在体外激活来自无嗜肺军团菌感染病史或血清学证据的人的新鲜分离单核细胞（非患者）的细胞因子（上清液）。这种被激活的非患者单核细胞抑制了嗜肺军团菌的细胞内增殖，且抑制程度与添加的上清液浓度成正比。用5×10⁶ - 5×10⁸福尔马林灭活的嗜肺军团菌/毫升孵育患者单核细胞4天，可产生最大效力的上清液；平底孔中产生的上清液效力与锥形孔中产生的上清液相当。患者嗜肺军团菌诱导的单核细胞上清液的效力低于患者伴刀豆球蛋白A诱导的单核细胞上清液。患者单核细胞对福尔马林灭活的嗜肺军团菌也有增殖反应（淋巴细胞增殖）。通过两种检测方法均发现，患者单核细胞对嗜肺军团菌抗原的反应比对年龄和性别匹配的非患者的单核细胞反应更强；对伴刀豆球蛋白A的反应相当。从军团病康复的患者的单核细胞对嗜肺军团菌的反应比对麻风分枝杆菌抗原的反应更强，而结核样麻风患者的单核细胞对麻风分枝杆菌抗原的反应更强。这些发现表明，军团病患者会产生针对嗜肺军团菌的细胞介导免疫，并且与先前报道的结果一起表明，细胞介导免疫在宿主抵御嗜肺军团菌的防御中起主要作用。本文所述的单核细胞激活检测方法对于研究特定患者的单核细胞和单核细胞效应功能具有普遍适用性。该检测方法可用于研究：（a）患者单核细胞被标准细胞因子制剂激活至抗菌潜能的能力；（b）患者单核细胞响应丝裂原或抗原产生此类单核细胞激活细胞因子的能力。
