ABSTRACT
Tuberculosis (TB) is one of the infectious diseases caused by the pathogen Mycobacterium tuberculosis that continuously threatens the global human health. Bacillus Calmette-Guérin (BCG) vaccine is the only vaccine that has been used clinically to prevent tuberculosis in recent centuries, but its limitations in preventing latent infection and reactivation of tuberculosis do not provide full protection. In this study, we selected the membrane-associated antigen Rv1513 of Mycobacterium. In order to achieve stable expression and function of the target gene, the prokaryotic expression recombinant vector pET30b-Rv1513 was constructed and expressed and purified its protein. Detection of IFN- γ levels in the peripheral blood of TB patients stimulated by whole blood interferon release assay (WBIA) and multi-microsphere flow immunofluorescence luminescence (MFCIA) revealed that the induced production of cytokines, such as IFN-γ and IL-6, was significantly higher than that in the healthy group. Rv1513 combined with adjuvant DMT (adjuvant system liposomes containing dimethyldioctadecylammonium bromide (DDA), monophospholipid A (MPL), and trehalose-660-dibenzoic acid (TDB)) was used to detect serum specific antibodies, cytokine secretion from splenic suprasplenic cell supernatants, and multifunctional T-cell levels in splenocytes in immunised mice. The levels of IFN-γ, TNF-α, and IL-2 secreted by mouse splenocytes were found in the Rv1513+DMT group and the BCG+Rv1513+DMT group. The serum levels of IgG and its subclasses and the number of IFN-γ+T cells, TNF-α+T and IFN-γ+TNF-α+T cells in the induced CD4+/CD8+T cells in mice were significantly higher than those in the BCG group, and the highest levels were found in the BCG+Rv1513+DMT group. These findings suggest that Rv1513/DMT may serve as a potential subunit vaccine candidate that may be effective as a booster vaccine after the first BCG vaccination.
Subject(s)
Mycobacterium tuberculosis , Th1 Cells , Tuberculosis Vaccines , Tuberculosis , Animals , Mycobacterium tuberculosis/immunology , Mycobacterium tuberculosis/genetics , Mice , Humans , Th1 Cells/immunology , Tuberculosis Vaccines/immunology , Tuberculosis Vaccines/genetics , Tuberculosis Vaccines/administration & dosage , Tuberculosis/immunology , Tuberculosis/prevention & control , Tuberculosis/microbiology , Female , Antigens, Bacterial/immunology , Antigens, Bacterial/genetics , Cytokines/metabolism , Cytokines/immunology , Bacterial Proteins/immunology , Bacterial Proteins/genetics , Interferon-gamma/immunology , Interferon-gamma/metabolism , Mice, Inbred BALB C , Antibodies, Bacterial/blood , Antibodies, Bacterial/immunology , Adjuvants, Immunologic/administration & dosage , AdultABSTRACT
Tuberculosis (TB) today remains the leading cause of global deaths due to infectious bacterial pathogens. The Bacillus Calmette-Guérin (BCG) vaccine is the only vaccine clinically used to prevent TB. However, its limitations in preventing latent infection and TB reactivation mean that it does not provide comprehensive protection. In this study, we successfully constructed and expressed the multistage fusion protein, SHR3, and used whole blood IFN-γ release assay (WBIA) with flow cytometry to detect antigen specificity, further confirmed by enzyme-linked immunosorbent assay (ELISA). SHR3 and its subfractional proteins stimulated the level of IFN-γ production by lymphocytes from M. tb-infected patients, inducing the production of single-positive and double-positive CD4+ and CD8+ T cells with IFN-γ and IL-2, at levels significantly higher than those of healthy controls. The fusion protein and complex adjuvant group (SHR3/DMT) induced mice to produce significantly higher levels of IgG antibodies and their subclasses, with IgG2a/IgG1 results showing a convergent Th1-type response; mice in the BCG + SHR3/DMT group induced secretion of the highest levels of IL-2, and TNF-α, irrespective of stimulation with purified protein derivative or SHR3. These findings suggest that SHR3/DMT could be a potential subunit vaccine candidate that may serve as an effective booster vaccine after BCG primary immunization.
Subject(s)
Mycobacterium tuberculosis , Tuberculosis Vaccines , Tuberculosis , Humans , Animals , Mice , BCG Vaccine , CD8-Positive T-Lymphocytes , Interleukin-2/metabolism , Antigens, Bacterial/genetics , Tuberculosis/prevention & control , Adjuvants, Immunologic , Bacterial Proteins/geneticsABSTRACT
OBJECTIVES: Prior researches indicate that peripheral blood CD4 levels have an inverse correlation with distant tumor metastasis in non-small cell lung cancer (NSCLC). However, the linear relationship between CD4 and distant metastasis lacks clarity. Hence, the objective of this study was to ascertain the linear relationship between CD4 and distant metastasis in NSCLC patients. METHODS: This retrospective study analyzed clinical and laboratory data of NSCLC patients between March 2016 and July 2022 at the Cancer Hospital of Anhui University of Technology. The study first applied a generalized summation model and smoothing curve fitting to determine if there was a linear relationship between CD4 and NSCLC metastasis. Secondarily, univariate logistic analysis and multiple linear regression were used to analyze the odds ratio (OR) of CD4 as a continuous variable, dichotomous variable, and trichotomous variable when predicting NSCLC metastasis. In addition, stratified and subgroup analyses were conducted to assess the reliability of CD4 in different NSCLC patient populations. RESULTS: The study included a total of 213 NSCLC patients, among which 122 had distant metastasis and 91 had no metastasis. The smoothing curve fitting analysis revealed a U-shaped relationship between CD4 and NSCLC metastasis with a threshold effect. The univariate logistic analysis indicated that continuous CD4 expression was not significantly associated with NSCLC metastasis (P = 0.051); however, high levels of CD4 expression (≥ 35.06%) were found to be a protective factor against NSCLC metastasis when CD4+ T was a dichotomous variable (OR = 0.49, P = 0.010). Furthermore, multivariate linear regression models showed that low (< 32%) or high levels (> 44%) of CD4 significantly increased the risk of NSCLC metastasis compared to medium levels (32-44%) when CD4+ T was trichotomized. The significance was maintained in stratified analysis in relation to age, sex, type of pathology, smoke, PS, and T stage. CD4 levels were U-shaped in relation to different sites of distant metastases (bone, brain, liver), but not with lung metastases. CONCLUSIONS: A threshold effect is shown to exist between the peripheral blood CD4 and distant metastasis in NSCLC patients. It was revealed that the risk of distant metastasis is lower when CD4 is maintained between 32 and 44%, whereas low (< 32%) or high (> 44) levels of CD4 are associated with an increased risk of distant metastasis in NSCLC patients.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Carcinoma, Non-Small-Cell Lung/pathology , Lung Neoplasms/pathology , Retrospective Studies , Reproducibility of Results , PrognosisABSTRACT
The resuscitation of dormant Mycobacterium tuberculosis is an important cause of adult tuberculosis (TB) transmission. According to the interaction mechanism between M. tuberculosis and the host, the latency antigen Rv0572c and region of difference 9 (RD9) antigen Rv3621c were selected in this study to prepare the fusion protein DR2. Stimulating clinically diagnosed active tuberculosis infections (i.e., TB patients), latent tuberculosis infections, and healthy controls confirmed that T lymphocytes could recognize DR2 protein in the peripheral blood of TB-infected individuals more than subcomponent protein. The DR2 protein was then emulsified in the liposome adjuvant dimethyl dioctadecyl ammonium bromide, and imiquimod (DIMQ) was administered to C57BL/6 mice immunized with Bacillus Calmette-Guérin (BCG) vaccine to evaluate their immunogenicity. Studies have shown that DR2/DIMQ, a booster vaccine for BCG primary immunization, can elicit robust CD4+ Th1 cell immune response and predominant IFN-γ+ CD4+ effector memory T cells (TEM) subsets. Furthermore, the serum antibody level and the expression of related cytokines increased significantly with the extension of immunization time, with IL2+, CD4+, or CD8+ central memory T cells (TCM) subsets predominant in the long term. This immunization strategy showed matched prophylactic protective efficacy by performing in vitro challenge experiment. This result provides robust evidence that the novel subunit vaccine prepared by fusion protein DR2 combined with liposomal adjuvant DIMQ is a promising TB vaccine candidate for further preclinical trials as a booster vaccine for BCG.
Subject(s)
Mycobacterium bovis , Mycobacterium tuberculosis , Tuberculosis , Animals , Mice , BCG Vaccine , Liposomes , Antigens, Bacterial/genetics , Mice, Inbred C57BL , Tuberculosis/prevention & control , Adjuvants, Immunologic , Immunization, SecondaryABSTRACT
Tuberculosis (TB) is recognized as a highly infectious disease worldwide, and Bacille Calmette-Guerin (BCG) remains the only TB vaccine licensed for clinical use. As there is little evidence that BCG is effective in adults, there is an urgent need for a safe and effective vaccine to control TB in adults. In this study, we tested the immunomodulatory efficiency of the fusion protein AR2. whole blood IFN-γ release assay (WBIA) was used to detect antigen specificity. The immunogenicity of the vaccine was tested in C57BL/6 mice, and confirmed by enzyme-linked immunosorbent assay (ELISA), flow cytometry, and qRT-PCR. The fusion protein AR2 was successfully constructed and expressed. The level of IFN-γ in the peripheral blood of subjects stimulated by AR2 was significantly higher than in those induced by all subcomponent proteins. AR2-specific IgG and the Th1 cytokines IFN-γ, TNF-α, and iNOS were significantly increased in the group treated with the fusion protein and compound adjuvant (AR2+DMC). Likewise, the number of IFN-γ+ CD4+, IFN-γ+CD8+, and IL-4+ CD8+ T lymphocytes increased significantly. The combination of the fusion protein and the compound adjuvant (AR2+DMC) may be a suitable candidate for an enhanced TB vaccine. This study provides theoretical and experimental support for future research to enhance the effectiveness of TB vaccines and provides an experimental basis for evaluating the influence of different adjuvants on vaccine efficacy.
Subject(s)
Mycobacterium tuberculosis , Tuberculosis Vaccines , Tuberculosis , Mice , Animals , BCG Vaccine , Antigens, Bacterial , CD4-Positive T-Lymphocytes , Mice, Inbred C57BL , Adjuvants, ImmunologicABSTRACT
The dormancy survival regulator (DosR) antigens upgraded during latency and resuscitation-promoting factors (Rpfs) expressed over the reactivation from dormant Mycobacterium tuberculosis (M. tuberculosis) could be used to diagnose tuberculosis (TB) at different stages. We performed a retrospective cohort study based on four groups, including healthy controls (HCs), active tuberculosis infections (ATBs), latent tuberculosis infections (LTBIs), and relapse tuberculosis infections (RTBs) enrolled between November 2020 and June 2021. Compared to the fusion protein E6-C10, combined with early secreted antigenic target 6 kDa (ESAT-6) and culture filtrate of 10 kDa (CFP-10), the DosR- or Rpf-encoded antigens could not elicit significant IFN-γ concentration for the diagnosis of ATB. Of note, the DosR antigens produce significantly more antigen-specific IFN-γ in LTBIs than Rpfs, and the levels of antigen-specific IFN-γ elicited in RTBs stimulated by Rpfs were higher than the DosR antigens. Among the DosR antigens, Rv2003c was the most immunogenic in diagnosing LTBIs, followed by Rv2007c and Rv2005c. As far as Rpfs are concerned, Rv0867c was the best antigen to identify RTBs, followed by Rv2389c and Rv1009. Both Rv2450c and Rv1884c showed relatively limited IFN-γ concentration in RTBs. Besides, the selected DosR antigens and Rpfs showed ideal specificity and inadequate sensitivity, which could have been enhanced by the fusion antigens prepared by the DosR antigens or Rpfs, respectively. The results of this study can provide more accurate detection methods for LTBIs and RTBs and could be used for screening the dormant M. tuberculosis throughout reactivation.
Subject(s)
Latent Tuberculosis , Mycobacterium tuberculosis , Tuberculosis , Antigens, Bacterial , Bacterial Proteins , Humans , Latent Tuberculosis/diagnosis , Latent Tuberculosis/microbiology , Recurrence , Retrospective Studies , Tuberculosis/epidemiologyABSTRACT
COVID-19 has affected the progress made in the prevention and treatment of tuberculosis (TB); hence, the mortality of tuberculosis has risen. Different strategies-based novel TB vaccine candidates have been developed. This study identifies strategies to overcome the limitations of Bacille Calmette-Guérin (BCG) in preventing latent infection and reactivation of TB. The latency antigen Rv0572c was selected based on the mechanism of interaction between Mycobacterium tuberculosis and its host. The rRv0572c protein was used to stimulate whole blood samples derived from patients with clinically diagnosed active TB (ATBs) or latent TB infections (LTBIs) and healthy control (HCs) donors, confirming that this protein can be recognized by T cells in patients with TB, especially LTBIs. C57BL/6 mice were used to investigate the immunogenicity of the rRv0572c protein emulsified in the liposome adjuvant dimethyldioctadecylammonium [DDA], monophosphoryl lipid A [MPLA], trehalose-6, 6'-dibehenate [TDB] (DMT). The results demonstrated that rRv0572c/DMT could boost BCG-primed mice to induce antigen-specific CD4+ T cell production and generate functional T cells dominated by antigen-specific CD8+ T cells. The rRv0572c/DMT vaccine could also trigger limited Th2 humoral immune responses. These findings suggest that rRv0572c/DMT is a potential subunit vaccine candidate that can be used as a booster vaccine for BCG.