Naso-oropharyngeal Brucella Infections and Mucosal Immune Protection

摘要 人间布鲁氏菌病在8种被忽视的人畜共患病中居第3位， 未经巴氏灭菌的乳制品。革兰氏阴性布鲁氏菌具有高度传染性，据信， 肺部感染需要CFU。感染主要发生在粘膜暴露后， 以流感样症状为表现的全身性疾病。尽管进行了积极的抗生素治疗， 反复出现的后遗症表现为波状热和关节炎布鲁氏菌在宿主体内的存活与其 逃避细胞内识别的能力，因此，允许它们在各种组织中隔离。虽然人类 疾病主要是通过粘膜暴露获得的，很少有研究检查粘膜免疫， 布鲁氏菌病部分原因是口服灌胃法效率低，需要大量的 布病来诱导感染有鉴于此，我们设计了一种口腔感染方法，称为ad bibitum， 口腔粘膜和引流头颈淋巴结（HNLN）的感染 人类自然感染。因此，我们假设，鼻口咽组织的粘膜免疫 将使用我们的新型减毒羊种布鲁氏菌（BM）菌株推导出保护性免疫所需的相关性。 这种方法将允许比较哪种免疫细胞类型是保护所需的， 逆转野生型（wt）BM感染，使其不产生调节应答，以逃避检测。后续 对于免疫，减毒的BM突变体刺激产生IFN-γ和TNF-α的CD 4+和CD 8+的增加， T细胞，它可以有效地消除布鲁氏菌。为了进一步开展这些研究，提出了三个具体目标。 特定目标1的研究将建立一种粘膜鼻咽疫苗接种方案， 对抗强毒布鲁氏菌的粘膜攻击。具体目标2的研究将确定哪些T细胞亚群是 负责保护粘膜和全身隔室。具体目标3的研究将建立 粘膜记忆性CD 8 + T细胞在更有效地增强对强毒布鲁氏菌攻击的保护中的作用 CD 4 + T细胞。这些研究将进一步加深我们对如何在鼻- 口咽粘膜，并将有助于制定策略，以规避BM的逃避方法。这项工作将 最终定义什么构成保护，以及需要哪些T细胞来防御wt BM挑战。

ABSTRACT Human brucellosis ranks third among 8 neglected zoonotic diseases, and is contracted as a result of ingesting unpasteurized dairy products. The Gram-negative Brucella is highly infectious, and is believed that less than 2000 CFUs are needed for pulmonary infection. Infection primarily occurs following a mucosal exposure causing a systemic disease manifested by its flu-like symptoms. Despite aggressive antibiotic treatment, it can still persist in a recurring sequelae evident as undulant fever and arthritis. Brucellae survival within the host is linked to its ability to evade intracellular recognition, thus, allowing them to sequester in various tissues. Although human disease is mostly acquired via a mucosal exposure, few studies have examined mucosal immunization for brucellosis. In part, this is attributed to the inefficiency of oral gavage methods requiring an enormous amount of brucellae to induce an infection. Bearing this, we have devised an oral infection method, termed ad bibitum, that retains the infection to the oral mucosa and draining head and neck lymph nodes (HNLNs) recapitulating natural human infections. Hence, we hypothesize that mucosal immunization of the naso-oropharyngeal tissues will derive the required correlates of protective immunity using our novel attenuated Brucella melitensis (BM) strain. Such approaches will allow for the comparison of which immune cell types are needed for protection and to reverse wild-type (wt) BM infection from mounting regulatory responses in order to evade detection. Subsequent to immunization, the attenuated BM mutant stimulates increases in IFN-g- and TNF-a-producing CD4+ and CD8+ T cells, which can effectively eliminate the brucellae. To further these studies, three Specific Aims are proposed. Studies in Specific Aim 1 will establish a mucosal naso-oropharyngeal vaccination regimen that confers protection against mucosal challenge with virulent Brucella. Studies in Specific Aim 2 will determine which T cell subsets are responsible for protection in the mucosal and systemic compartments. Studies in Specific Aim 3 will establish the role for mucosal memory CD8+ T cells in augmenting protection against virulent Brucella challenge more effectively than CD4+ T cells. These studies will further our understanding of how to induce immunity in the naso- oropharyngeal mucosa, and will aid in devising strategies to circumvent BM' evasion methods. This work will ultimately define what constitutes protection and which T cells are needed to guard against wt BM challenges.