A Novel LNP-Based <i>Chlamydia</i>Subunit Vaccine Formulation That Induces Th1 Responses without Upregulating IL-17 Provides Equivalent Protection in Mice as Formulations That Induced IL-17 and Th1 Cytokines

• 作者: Julie M. Skinner
• 来源期刊: 疫苗(英文)
• 学科: 医学
• 关键词: LNP Chlamydia IL-17 Mouse Model Th1 Cytokines
• 年，卷（期）: 2020,（4）
• 页码范围: 55-75
• 页数: 21页
• 分类号: R73

摘要

We evaluated novel Chlamydial vaccines, consisting of major outer membrane protein (MOMP) alone or in combination with polymorphic membrane proteins D (PmpD) and G (PmpG) using a C57BL/6 mouse model. Native MOMP (nMOMP) isolated from <em>C</em>. <em>muridarum</em> elementary bodies (EBs) and recombinant PmpD and PmpG proteins were adjuvanted with Monophosphoryl lipid A (MPLA), with either lipid nanoparticles (LNPs) or the cationic lipid dimethyldioctadecylammonium bromide (DDA). Antibody titers to <em>C</em>. <em>muridarum</em> nMOMP, and EBs were evaluated by ELISA, and T-cell responses were analyzed by intracellular cytokine staining (ICS). Protection from challenge was determined by qPCR. Vaccine immunized mice showed significantly higher antibody titers to nMOMP (P < 0.001) and <em>C</em>. <em>muridarum</em> EBs (P < 0.001), when compared to the adjuvant alone group. Antibody titers in vaccine groups with Monophosphoryl lipid A (MPLA) + LNP were higher as compared to the MPLA + DDA group (P < 0.001) except for (Cm nMOMP + PmpG + PmpD p73 + PmpD p82 + MPLA + DDA) vs (Cm nMOMP + PmpG + PmpD p73 + PmpD p82 + MPLA + LNP) for both <em>C</em>. <em>muridarum</em> EBs and PmpG. ICS analysis showed more robust CD4 + T-cell responses (IFN-<em>γ</em>/IL-2/TNF-a) in the DDA and LNP groups compared to the adjuvant alone group. The DDA + MPLA gave robust Th17 responses in comparison to MPLA and LNP group. Mice immunized with <em>Chlamydia</em> antigens also showed protection from <em>C</em>. <em>muridarum</em> challenge, by reduction in bacterial shedding for all groups (P < 0.003) compared to shedding from the adjuvant control. Both vaccine formulations generated robust immunological responses, and both were protective by reducing bacterial shedding after challenge. This data indicates equal protection can be achieved without the induction of Th17 responses.