Infant 7-valent pneumococcal conjugate vaccine immunization alters young adulthood CD4T cell subsets in allergic airway disease mouse model

7-Valent pneumococcal conjugate vaccine (PCV7) immunization in adulthood can inhibit allergic asthma in mouse model. The aim of this study is to investigate the effects of infant PCV7 immunization on young adulthood CD4⁺T cell subsets in a murine allergic airway disease (AAD) model. Our study indicated that infant PCV7 immunization can inhibit young adulthood airway inflammation and airway hyperresponsiveness (AHR) by inducing the production of Foxp3⁺Treg, Th1 cells and their cytokines IL-10 and IFN-γ, inhibiting the production of Th2, Th17 cells and their cytokines IL-13 and IL-17A in BALB/c mice model. These results suggested that infant PCV7 immunization may serve as an effective measure to prevent young adulthood mice AAD.     

Oral vaccination with influenza hemagglutinin combined with human pulmonary surfactant-mimicking synthetic adjuvant SF-10 induces efficient local and systemic immunity compared with nasal and subcutaneous vaccination and provides protective immunity in mice

We reported previously that a synthetic mucosal adjuvant SF-10, which mimics human pulmonary surfactant, delivers antigen to mucosal dendritic cells in the nasal cavity and promotes induction of humoral and cellular immunity. The aim of the present study was to determine the effects of oral administration of antigen combined with SF-10 (antigen-SF-10) on systemic and local immunity. Oral administration of ovalbumin, a model antigen, combined with SF-10 enhanced ovalbumin uptake into intestinal antigen presenting MHC II⁺CD11c⁺ cells and their CD11b⁺CD103⁺ and CD11b⁺CD103^- subtype dendritic cells, which are the major antigen presenting subsets of the intestinal tract, more efficiently compared to without SF-10. Oral vaccination with influenza hemagglutinin vaccine (HAv)-SF-10 induced HAv-specific IgA and IgG in the serum, and HAv-specific secretory IgA and IgG in bronchoalveolar lavage fluid, nasal washes, gastric extracts and fecal material; their levels were significantly higher than those induced by subcutaneous HAv or intranasal HAv and HAv-SF-10 vaccinations. Enzyme-linked immunospot assay showed high numbers of HAv-specific IgA and IgG antibody secreting cells in the gastrointestinal and respiratory mucosal lymphoid tissues after oral vaccination with HAv-SF-10, but no or very low induction following oral vaccination with HAv alone. Oral vaccination with HAv-SF-10 provided protective immunity against severe influenza A virus infection, which was significantly higher than that induced by HAv combined with cholera toxin. Oral vaccination with HAv-SF-10 was associated with unique cytokine production patterns in the spleen after HAv stimulation; including marked induction of HAv-responsive Th17 cytokines (e.g., IL-17A and IL-22), high induction of Th1 cytokines (e.g., IL-2 and IFN-γ) and moderate induction of Th2 cytokines (e.g., IL-4 and IL-5). These results indicate that oral vaccination with HAv-SF-10 induces more efficient systemic and local immunity than nasal or subcutaneous vaccination with characteristically high levels of secretory HAv-specific IgA in various mucosal organs and protective immunity.     

Th17 cell accumulation is decreased during chronic experimental colitis by (n-3) PUFA in Fat-1 mice

During colon inflammation, Th17 cells and immunosuppressive regulatory T cells (Treg) are thought to play promotive and preventative roles, respectively. Dietary (n-3) PUFA favorably modulate intestinal inflammation in part by downregulating T-cell activation and functionality. We used the Fat-1 mouse, a genetic model that synthesizes long-chain (n-3) PUFA de novo, to test the hypothesis that (n-3) PUFA protect against colonic inflammation by modulating the polarization of Treg and Th17 cells during colitis. Male and female wild-type (WT) and Fat-1 mice were administered dextran sodium sulfate (DSS) in the drinking water (2.5%) to induce acute (5 d DSS) or chronic (3 cycles DSS) colitis and the percentage of Treg and Th17 cells residing locally [colonic lamina propria (cLP)] and systemically (spleen) was determined by flow cytometry. The percentage of Treg in either tissue site was unaffected by genotype (P > 0.05); however, during chronic colitis, the percentage of Th17 cells residing in both the spleen and cLP was lower in Fat-1 mice compared to WT mice (P < 0.05). Colonic mucosal mRNA expression of critical Th17 cell cytokines and chemokine receptors (IL-17F, IL-21, and CCR6) were lower, whereas expression of the Th17 cell suppressive cytokine, IL-27, was greater in Fat-1 mice compared to WT mice during chronic colitis (P < 0.05). Moreover, colon histological scores were improved in Fat-1 mice (P < 0.05). Collectively, these results demonstrate for the first time, to our knowledge, that (n-3) PUFA can modulate the colonic mucosal microenvironment to suppress Th17 cell accumulation and inflammatory damage following the induction of chronic colitis.     

IFN-?, but not IL-17A,is required for survival during secondary pulmonary Francisella tularensis Live Vaccine Stain infection

IL-17 and IFN-? production by Th17 and Th1 cells, respectively, is critical for survival during primary respiratory infection with the pathogenic bacterium, Francisella tularensis Live Vaccine Strain (LVS). The importance, however, of these T cell subsets and their soluble mediators is not well understood during a secondary or memory response. We measured the number of CD4⁺ T cells producing IFN-? or IL-17 in the spleen and lungs of vaccinated mice on day four of the secondary response using intracellular cytokine staining in order to identify protective T cell subsets participating in the memory response. Few bacteria were present in spleens of vaccinated mice on day four and a T cell response was not observed. In the lung, where more bacteria were present, there was a robust Th1 response in vaccinated mice but Th17 cells were not present at higher numbers in vaccinated mice compared to unvaccinated mice. These data show that the lung is the dominant site of the secondary immune response and suggest that Th17 cells are not required for survival during secondary challenge. To further investigate the importance of IFN-? and IL-17 during the secondary response to F. tularensis, we neutralized either IFN-? or IL-17 in vivo using monoclonal antibody treatment. Vaccinated mice treated with anti-IFN-? lost more weight and had higher bacterial burdens compared to vaccinated mice treated with isotype control antibody. In contrast, treatment with anti-IL-17A antibody did not alter weight loss profiles or bacterial burdens compared to mice treated with isotype control antibody. Together, these results suggested that IFN-? is required during both primary and secondary respiratory F. tularensis infection. IL-17, on the other hand, is only critical during the primary response to respiratory F. tularensis but dispensable during the secondary response.     

Intranasal boosting with MVA encoding secreted mycobacterial proteins Ag85A and ESAT-6 generates strong pulmonary immune responses and protection against M. tuberculosis in mice given BCG as neonates

Bacille-Calmette-Guerin (BCG) has variable efficacy as an adult tuberculosis (TB) vaccine but can reduce the incidence and severity of TB infection in humans. We have engineered modified vaccinia Ankara (MVA) strain vaccine constructs to express the secreted mycobacterial proteins Ag85A and ESAT-6 (MVA-AE) and evaluated their immunogenicity and protective efficacy as mucosal booster vaccines for BCG given subcutaneously in early life. Intranasal delivery of MVA-AE to young adult mice induced CD4⁺ and CD8⁺ T cell responses to both Ag85A and ESAT-6 in lung mucosae. These responses were markedly enhanced in mice that had been primed neonatally with BCG prior to intranasal MVA-AE immunization (BCG/MVA-AE), as evidenced by numbers of pulmonary Ag85A-, ESAT-6-, and PPD-specific CD4⁺ and CD8⁺ T cells and by their capacity to secrete multiple antimicrobial factors, including IFNγ, IL-2 and IL-17. Moreover, MVA-AE boosting generated multifunctional lung CD4⁺ T cells responding to ESAT-6, which were not, as expected, detected in control mice given BCG, and elevated Ag85A-specific circulating antibody responses. After aerosol challenge with M. tuberculosis H37Rv (Mtb), the BCG/MVA-AE group had significantly reduced mycobacterial burden in the lungs, compared with either BCG primed mice boosted with control MVA or mice given only BCG. These data indicate that intranasal delivery of MVA-AE can boost BCG-induced Th1 and Th17-based immunity locally in the lungs and improve the protective efficacy of neonatally-administered BCG against M. tuberculosis infection.     

外周血Th17和Th22细胞在呼吸机相关性肺炎患者中的水平变化及临床意义

目的 观察外周血Th17和Th22细胞在呼吸机相关性肺炎（VAP）中的水平变化及临床意义。方法 选取2014年01月至2019年01月于本院行机械辅助通气治疗的患者810例作为研究对象。采用流式细胞术检测患者外周血Th17和Th22细胞水平;酶联免疫吸附法检测相关炎性细胞因子（IL-17、IL-22）水平,绘制受试者工作曲线（ROC曲线）,评价外周血Th17和Th22细胞水平对VAP患者预后的曲线下面积（AUC）和最佳截断值。结果 VAP组患者外周血Th17、Th22细胞水平及IL-17和IL-22水平高于非VAP组（t=66.050,P<0.001;U=54.630,P<0.001;t=27.530,P<0.001;t=28.500,P<0.001）;高危组VAP患者中上述指标水平最高,中危组次之,低危组最低,差异比较具有统计学意义（F=39.440,P<0.001;F=71.400,P<0.001;F=50.640,P<0.001;F=94.510,P<0.001）。死亡组患者上述指标水平高于存活组（t=3.098,P=0.002;t=4.322,P<0.001;t=4.825,P<0.001;t=4.122,P<0.001）。VAP患者外周血Th22细胞与Th17细胞、IL-22及APACHEⅡ评分呈正相关（r1=0.8200,P1<0.001;r2=0.895,P2<0.001;r3=0.752,P3<0.001）;同时外周血Th17细胞与IL-17、APACHEⅡ评分呈正相关（r1=0.832,P1<0.001;r2=0.710,P2<0.001）。ROC曲线分析显示,外周血Th22细胞曲线下面积为0.874 (0.813~0.935),其最佳工作点为7.92,此时评估VAP患者预后不佳的敏感性和特异性分别为79.49%和78.93%,优于外周血Th17细胞,但差异无统计学意义（Z=0.810,P=0.310）。 结论 外周血Th17和Th22细胞水平在VAP患者中显著升高,对于VAP患者预后的评估,具有一定的临床应用价值。     

Incorporation of immunostimulatory motifs in the transcribed region of a plasmid DNA vaccine enhances Th1 immune responses and therapeutic effect against Mycobacterium tuberculosis in mice

T-helper type 1 (Th1) immune response is involved in the development of protective immunity against Mycobacterium tuberculosis. Thus, an increase in Th1 and cellular immune responses should lead to enhanced anti-mycobacterial activity. In this study, we aimed to improve Th1 immune responses to a DNA vaccine by adding potentially immunostimulatory nucleotide sequences into the transcribed region downstream of the antigen. The Mycobacterium leprae gene for hsp65, codon-optimized for expression in mammalian cells, was inserted into pVAX1 with and without 3′-sequences containing CpG and dsRNA motifs. When the plasmid contained both motifs, transfected murine macrophage-like RAW264.7 cells showed markedly increased levels of mRNA for immune molecules of Th1 (IFN-α, IL-12) and Th17 (IL-17, IL-23 and IL-6) responses and for T cell co-stimulatory molecules (CD80 and CD86) but not for a Th2 response (IL-4 and IL-10). Immunized mice showed substantially increased serum anti-Hsp65 IgG2a antibody levels and IFN-γ production by spleen cells, confirming enhancement of the Th1 response in vivo. Furthermore, when non-vaccinated mice were infected with H37Rv by low-dose aerosol challenge, and then 4 weeks later were treated with plasmids by intramuscular injection, the mice that had been treated with plasmids containing immunostimulatory motifs showed an enhanced reduction in mycobacterial loads in lung and spleen. We conclude that DNA vaccines may be made more highly immunogenic and more effective for treatment by including transcribed stimulatory sequences.     

Intestinal Mucosal Barrier Improvement with Prebiotics: Histological Evaluation of Longish Glucomannan Hydrolysates-Induced Innate T Lymphocyte Activities in Mice

Use of prebiotics is a growing topic in healthcare. A lightweight molecule and water-soluble fiber ingredient, longish glucomannan hydrolysates (LGH), has been developed to improve the intestinal mucosal barrier and confer gut health benefits. This study aims to investigate the implications of continuous LGH intervening in intestinal epithelium integrity and protective immunity against chemical dextran sodium sulfate (DSS)-induced colitis. Twelve male BALB/c mice were randomly arranged into four groups. The LGH/DSS group had results in bodyweight variance, epithelial cell density, and aberrancy score as good as the LGH group, and both were equivalent to the control group. LGH consumption effectively protects the distal intestinal epithelium by activating innate T lymphocytes. Meanwhile, T-cell subsets in subepithelial interspersion take a bystander role in these microenvironmental alterations. Under this stress, the cluster of differentiation 3 (CD3)⁺ T cells infiltrate the epithelium, while CD4⁺ T cells inversely appear in submucosal large lymphoid aggregates/isolated lymphoid follicles (ILFs) in which significant CD3⁺, CD4⁺, and CD8⁺ T-cell populations agglomerate. Moreover, forkhead box P3 (Foxp3) and interleukin 17 (IL-17) are observed in these ILFs. Agglomerated CD4⁺ T-cell lineages may have roles with proinflammatory T helper 17 cells and anti-inflammatory regulatory T cells in balancing responses to intraluminal antigens. Collectively, LGH administration may function in immune modulation to protect against DSS-induced inflammation.     

Clostridium tyrobutyricum Protects against LPS-Induced Colonic Inflammation via IL-22 Signaling in Mice

This study aimed to investigate the effects of Clostridium tyrobutyricum (C. tyrobutyricum) on colonic immunity and the role of IL-22 in the protective function of C. tyrobutyricum. Mice were supplemented with 10⁸ CFU/mL C. tyrobutyricum daily for 20 days, followed by injecting with LPS for 24 h. In vivo interference of IL-22 via injecting with an adeno-associated virus was conducted to elucidate the role of IL-22 in C. tyrobutyricum attenuating colonic inflammation. The results showed that C. tyrobutyricum decreased the mRNA expression of IL-6 and IL-1β. C. tyrobutyricum enhanced the mRNA expression of IL-22 and the expression of MUC2 in the colon. The in vivo interference results showed that C. tyrobutyricum enhanced the mRNA expression of IL-6 and IL-1β while decreased the expression of MUC2 after knocking down IL-22. The flow cytometric analysis showed that C. tyrobutyricum decreased the proportions of macrophages, DCs, and mast cells and effectively regulated the proportion of Th17 cells, indicating that C. tyrobutyricum may stimulate the expression of IL-22 via regulating Th17 cells. Our study concluded that C. tyrobutyricum protected against LPS-induced colonic barrier dysfunction and inflammation via IL-22 signaling, suggesting that C. tyrobutyricum could be a potential probiotic in regulating colonic health.     

脓毒症患儿外周血Th17细胞水平的变化 及其临床意义

摘要:目的　探讨外周血辅助性T 细胞17（Th17）细胞水平在儿童脓毒症发病中的作用及临床价值。方法　选取脓毒症患儿36例;健康儿童20例为正常对照组。分离外周淋巴细胞后,分别采用流式细胞仪检测Th17细胞比例;实时荧光定量PCR（qRT-PCR）技术检测Th17细胞特异性转录因子即维甲酸受体相关孤儿受体γt（RORγt）mRNA 表达水平;酶联免疫吸附法（ELISA）检测血清IL-6,IL-17及IL-23的含量。结果　与健康对照组比较,脓毒症患儿组外周血Th17细胞比例增高（t＝3.68,P＜0.05）;脓毒症患儿组RORγt mRNA 表达水平也显著高于健康对照组（t＝8.32,P＜0.05）;同时脓毒症患儿组细胞因子含量（IL-6,IL-17,IL-23）明显高于健康对照组（P＜0.05）。此外,脓毒症死亡组患儿外周血Th17细胞水平（2.2±0.5）%显著高于存活组（0.8±0.3）%（t＝4.67,P＜0.05）,外周血Th17细胞比例与患儿死亡率呈正相关（r＝0.24,P＜0.001）。结论　Th17细胞参与了脓毒症的炎症反应,检测Th17细胞水平有助于儿童脓毒症的早期诊断、治疗及预后的判断。     

Protective role of Th17 cells in pulmonary infection

Th17 cells are characterized as preferential producer of interleukins including IL-17A, IL-17F, IL-21 and IL-22. Corresponding receptors of these cytokines are expressed on number of cell types found in the mucosa, including epithelial cells and fibroblasts which constitute the prime targets of the Th17-associated cytokines. Binding of IL-17 family members to their corresponding receptors lead to modulation of antimicrobial functions of target cells including alveolar epithelial cells. Stimulated alveolar epithelial cells produce antimicrobial peptides and are involved in granulepoesis, neutrophil recruitment and tissue repair. Mucosal immunity mediated by Th17 cells is protective against numerous pulmonary pathogens including extracellular bacterial and fungal pathogens. This review focuses on the protective role of Th17 cells during pulmonary infection, highlighting subset differentiation, effector cytokines production, followed by study of the binding of these cytokines to their corresponding receptors, the subsequent signaling pathway they engender and their effector role in host defense.     

慢性乙型肝炎患者外周血SOCS3 mRNA的表达及其与Th17的关系

 目的 研究慢性乙型肝炎(CHB)患者外周血辅助性T细胞17(Th17)以及细胞因子信号转导抑制因子3(SOCS3) mRNA的表达状况,探索CHB患者SOCS3 mRNA表达与Th17的关系。方法 选取2021年2—8月于某院门诊就诊的30例CHB患者为研究对象,并选取同期正常体检者15例为对照组。采用流式细胞术(FCM)检测外周血Th17细胞频数,酶联免疫吸附试验(ELISA)检测血清细胞因子IL-17A和IL-23表达水平,实时荧光定量逆转录聚合酶链反应(qRT-PCR)法测定外周血SOCS3、维甲酸相关孤儿核受体γt (RORγt) mRNA表达水平,并比较两组患者的检测结果。结果 CHB患者外周血Th17细胞频数及其效应分子IL-17A、IL-23表达水平高于对照组(均P＜0.05),Th17细胞频数、IL-17A与HBV DNA水平之间存在正相关(r值分别为0.570、0.563,均P＜0.005)。CHB患者外周血SOCS3、RORγt mRNA表达水平高于对照组(均P＜0.05),两者与HBV DNA水平正相关(r值分别为0.662、0.561,均P＜0.05)。CHB患者SOCS3 mRNA与RORγt mRNA、Th17细胞频数、IL-17A之间存在正相关(r值分别为0.552、0.626、0.826,均P＜0.05)。结论 CHB患者外周血SOCS3 mRNA的异常高表达,可能通过调节RORγt mRNA的表达来影响Th17的分化及其效应分子的分泌。     

Immunization with PCEP microparticles containing pertussis toxoid, CpG ODN and a synthetic innate defense regulator peptide induces protective immunity against pertussis

We investigated the efficacy of a novel microparticle (MP) based vaccine formulation consisting of pertussis toxoid (PTd), polyphosphazene (PCEP), CpG ODN 10101 and synthetic cationic innate defense regulator peptide 1002 (IDR) against Bordetella pertussis in mice. We studied whether encapsulation of these IDR-CpG ODN complexes into polyphosphazene-based microparticles further enhanced their immunomodulatory activity compared to soluble formulations containing PCEP (SOL), or without PCEP (AQ). In vitro stimulation of murine macrophages showed MP induced significantly higher levels of pro-inflammatory cytokines. When assessed in a B. pertussis infection challenge model, a single immunization with MP formulation led to significantly lower bacterial loads compared to other formulations and non-vaccinated animals. ELISPOT of splenocytes showed that MP group mice had significantly higher number of antigen-specific IL-17 secreting cells. The cytokine profile in lung homogenates of MP group mice after challenge showed significantly higher amounts of MCP-1, TNF-α, IFN-γ, IL-12 and IL-17 and significantly lowered IL-10 levels suggesting a strong Th1 shift. Protection was observed against challenge infection with B. pertussis. On the other hand protective immune responses elicited in Quadracel^® immunized mice were Th2 skewed. Hence, we conclude that formulation of PTd, PCEP, CpG ODN and IDR into MP generates a protective immune response in mice against pertussis emphasizing the potential of MP as a delivery vehicle for the potential development of single-shot vaccines.     

Intradermal vaccination with a Pseudomonas aeruginosa vaccine adjuvanted with a mutant bacterial ADP-ribosylating enterotoxin protects against acute pneumonia

Respiratory infections are a leading cause of morbidity and mortality globally. This is partially due to a lack of effective vaccines and a clear understanding of how vaccination route and formulation influence protective immunity in mucosal tissues such as the lung. Pseudomonas aeruginosa is an opportunistic pathogen capable of causing acute pulmonary infections and is a leading cause of hospital-acquired and ventilator-associated pneumonia. With multidrug-resistant P. aeruginosa infections on the rise, the need for a vaccine against this pathogen is critical. Growing evidence suggests that a successful P. aeruginosa vaccine may require mucosal antibody and Th1- and Th17-type CD4⁺ T cells to prevent pulmonary infection. Intradermal immunization with adjuvants, such as the bacterial ADP-Ribosylating Enterotoxin Adjuvant (BARE) double mutant of E. coli heat-labile toxin (dmLT), can direct protective immune responses to mucosal tissues, including the lungs. We reasoned that intradermal immunization with P. aeruginosa outer membrane proteins (OMPs) adjuvanted with dmLT could drive neutralizing antibodies and migration of CD4⁺ T cells to the lungs and protect against P. aeruginosa pneumonia in a murine model. Here we show that mice immunized with OMPs and dmLT had significantly more antigen-specific IgG and Th1- and Th17-type CD4⁺ memory T cells in the pulmonary environment compared to control groups of mice. Furthermore, OMPs and dmLT immunized mice were significantly protected against an otherwise lethal lung infection. Protection was associated with early IFN-γ and IL-17 production in the lungs of immunized mice. These results indicate that intradermal immunization with dmLT can drive protective immunity to the lung mucosa and may be a viable vaccination strategy for a multitude of respiratory pathogens.