Pacini María F, Balbi Camila Bulfoni, Dinatale Brenda, González Florencia B, Prochetto Estefania, De Hernández María A, Cribb Pamela, Farré Cecilia, Espariz Martín, Blancato Víctor S, Magni Christian, Marcipar Iván, Pérez Ana R
Instituto de Inmunología Clínica y Experimental de Rosario (IDICER-CONICET-UNR), Argentina.
Laboratorio de Tecnología Inmunológica, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina.
Acta Trop. 2023 May;241:106889. doi: 10.1016/j.actatropica.2023.106889. Epub 2023 Mar 7.
Trypanosoma cruzi, the agent of Chagas disease, can infect through conjunctive or oral mucosas. Therefore, the induction of mucosal immunity by vaccination is relevant not only to trigger local protection but also to stimulate both humoral and cell-mediated responses in systemic sites to control parasite dissemination. In a previous study, we demonstrated that a nasal vaccine based on a Trans-sialidase (TS) fragment plus the mucosal STING agonist c-di-AMP, was highly immunogenic and elicited prophylactic capacity. However, the immune profile induced by TS-based nasal vaccines at the nasopharyngeal-associated lymphoid tissue (NALT), the target site of nasal immunization, remains unknown. Hence, we analyzed the NALT cytokine expression generated by a TS-based vaccine plus c-di-AMP (TSdA+c-di-AMP) and their association with mucosal and systemic immunogenicity. The vaccine was administered intranasally, in 3 doses separated by 15 days each other. Control groups received TSdA, c-di-AMP, or the vehicle in a similar schedule. We demonstrated that female BALB/c mice immunized intranasally with TSdA+c-di-AMP boosted NALT expression of IFN-γ and IL-6, as well as IFN-β and TGF-β. TSdA+c-di-AMP increased TSdA-specific IgA secretion in the nasal passages and also in the distal intestinal mucosa. Moreover, T and B-lymphocytes from NALT-draining cervical lymph nodes and spleen showed an intense proliferation after ex-vivo stimulation with TSdA. Intranasal administration of TSdA+c-di-AMP provokes an enhancement of TSdA-specific IgG and IgG plasma antibodies, accompanied by an increase IgG/IgG ratio, indicative of a Th1-biased profile. In addition, immune plasma derived from TSdA+c-di-AMP vaccinated mice exhibit in-vivo and ex-vivo protective capacity. Lastly, TSdA+c-di-AMP nasal vaccine also promotes intense footpad swelling after local TSdA challenge. Our data support that TSdA+c-di-AMP nasal vaccine triggers a NALT mixed pattern of cytokines that were clearly associated with an evident mucosal and systemic immunogenicity. These data are useful for further understanding the immune responses elicited by the NALT following intranasal immunization and the rational design of TS-based vaccination strategies for prophylaxis against T. cruzi.
克氏锥虫是恰加斯病的病原体，可通过结膜或口腔黏膜感染。因此，通过疫苗接种诱导黏膜免疫不仅与触发局部保护有关，还与刺激全身部位的体液免疫和细胞介导免疫反应以控制寄生虫传播有关。在先前的一项研究中，我们证明了基于转唾液酸酶（TS）片段加黏膜STING激动剂c-di-AMP的鼻用疫苗具有高度免疫原性，并具有预防能力。然而，基于TS的鼻用疫苗在鼻相关淋巴组织（NALT）（鼻内免疫的靶位点）诱导的免疫谱仍然未知。因此，我们分析了基于TS的疫苗加c-di-AMP（TSdA + c-di-AMP）产生的NALT细胞因子表达及其与黏膜和全身免疫原性的关联。疫苗通过鼻内给药，分3剂，每剂间隔15天。对照组按相似的时间表接受TSdA、c-di-AMP或赋形剂。我们证明，用TSdA + c-di-AMP鼻内免疫的雌性BALB/c小鼠增强了NALT中IFN-γ和IL-6以及IFN-β和TGF-β的表达。TSdA + c-di-AMP增加了鼻腔以及远端肠黏膜中TSdA特异性IgA的分泌。此外，来自NALT引流的颈部淋巴结和脾脏的T淋巴细胞和B淋巴细胞在用TSdA进行体外刺激后显示出强烈的增殖。鼻内给予TSdA + c-di-AMP可增强TSdA特异性IgG和IgG血浆抗体，同时IgG/Igg比率增加，表明存在Th1偏向的免疫谱。此外，来自接种TSdA + c-di-AMP的小鼠的免疫血浆在体内和体外均具有保护能力。最后，TSdA + c-di-AMP鼻用疫苗在局部给予TSdA攻击后也会促进强烈的足垫肿胀。我们的数据支持TSdA + c-di-AMP鼻用疫苗触发了NALT中细胞因子的混合模式，这与明显的黏膜和全身免疫原性明显相关。这些数据有助于进一步了解鼻内免疫后NALT引发的免疫反应以及基于TS的预防克氏锥虫疫苗接种策略的合理设计。
