Developments in conservative treatment for BCG-unresponsive non-muscle invasive bladder cancer.

INTRODUCTION: To reduce the risk of disease recurrence and progression of intermediate and high-risk Non-Muscle Invasive Bladder Cancers (NMIBCs), intravesical adjuvant treatment with Bacillus Calmette-Guerin (BCG) represents the standard of care, although up to 50% of patients will eventually recur and up to 20% of them will progress to Muscle Invasive Bladder Cancer (MIBC). Radical Cystectomy (RC) is the treatment of choice in this setting; however, this represents a major and morbid surgery, thus meaning that not all NMIBCs patient could undergo or may refuse this procedure or may refuse. The search for effective bladder sparing strategies in NMIBCs BCG-unresponsive patients is a hot topic in the urologic field. AREAS COVERED: We aimed to review the most important bladder-preserving strategies for BCG unresponsive disease, from those used in the past, even though rarely used nowadays (intravesical chemotherapy with single agents), to current available therapies (e.g. intravesical instillation with Gemcitabine-Docetaxel), and to future upcoming treatments (Oportuzumab Monatox). EXPERT OPINION: At present, bladder-preserving treatments in BCG-unresponsive patients are represented by the use of intravesical instillations, systemic immunotherapies, both with good short-term and modest mid-term efficacy, and numerous clinical trials ongoing, with encouraging initial results, in which patients could be recruited.

The mark of success: The role of vaccine-induced skin scar formation for BCG and smallpox vaccine-associated clinical benefits.

Skin scar formation following Bacille Calmette-Guérin (BCG) or smallpox (Vaccinia) vaccination is an established marker of successful vaccination and 'vaccine take'. Potent pathogen-specific (tuberculosis; smallpox) and pathogen-agnostic (protection from diseases unrelated to the intentionally targeted pathogen) effects of BCG and smallpox vaccines hold significant translational potential. Yet despite their use for centuries, how scar formation occurs and how local skin-based events relate to systemic effects that allow these two vaccines to deliver powerful health promoting effects has not yet been determined. We review here what is known about the events occurring in the skin and place this knowledge in the context of the overall impact of these two vaccines on human health with a particular focus on maternal-child health.

Evidence of innate training in bovine γδ T cells following subcutaneous BCG administration.

The Bacillus Calmette Guerin (BCG) vaccine has been shown to induce non-specific protection against diseases other than tuberculosis in vaccinated individuals, attributed to the induction of trained immunity. We have previously demonstrated that BCG administration induces innate immune training in mixed peripheral blood mononuclear cells and monocytes in calves. Gamma Delta (γδ) T cells are non-conventional T cells that exhibit innate and adaptive immune system features. They are in higher proportion in the peripheral blood of cattle than humans or rodents and play an essential role in bovine immune response to pathogens. In the current study, we determined if BCG administration induced innate immune training in bovine γδ T cells. A group of 16 pre-weaned Holstein calves (2-4 d age) were enrolled in the study and randomly assigned to vaccine and control groups (n=8/group). The vaccine group received two doses of 106 colony forming units (CFU) BCG Danish strain subcutaneously, separated by 2 weeks. The control group remained unvaccinated. Gamma delta T cells were purified from peripheral blood using magnetic cell sorting three weeks after receiving the 1st BCG dose. We observed functional changes in the γδ T cells from BCG-treated calves shown by increased IL-6 and TNF-α cytokine production in response to in vitro stimulation with Escherichia coli LPS and PAM3CSK4. ATAC-Seq analysis of 78,278 regions of open chromatin (peaks) revealed that γδ T cells from BCG-treated calves had an altered epigenetic status compared to cells from the control calves. Differentially accessible peaks (DAP) found near the promoters of innate immunity-related genes like Siglec14, Irf4, Ifna2, Lrrfip1, and Tnfrsf10d were 1 to 4-fold more accessible in cells from BCG-treated calves. MOTIF enrichment analysis of the sequences within DAPs, which explores transcription factor binding motifs (TFBM) upstream of regulatory elements, revealed TFBM for Eomes and IRF-5 were among the most enriched transcription factors. GO enrichment analysis of genes proximal to the DAPs showed enrichment of pathways such as regulation of IL-2 production, T-cell receptor signaling pathway, and other immune regulatory pathways. In conclusion, our study shows that subcutaneous BCG administration in pre-weaned calves can induce innate immune memory in the form of trained immunity in γδ T cells. This memory is associated with increased chromatin accessibility of innate immune response-related genes, thereby inducing a functional trained immune response evidenced by increased IL-6 and TNF-α cytokine production.

Macrophages directly kill bladder cancer cells through TNF signaling as an early response to BCG therapy.

The Bacillus Calmette-Guérin (BCG) vaccine is the oldest cancer immunotherapeutic agent in use. Despite its effectiveness, its initial mechanisms of action remain largely unknown. Here, we elucidate the earliest cellular mechanisms involved in BCG-induced tumor clearance. We developed a fast preclinical in vivo assay to visualize in real time and at single-cell resolution the initial interactions among bladder cancer cells, BCG and innate immunity using the zebrafish xenograft model. We show that BCG induced the recruitment and polarization of macrophages towards a pro-inflammatory phenotype, accompanied by induction of the inflammatory cytokines tnfa, il1b and il6 in the tumor microenvironment. Macrophages directly induced apoptosis of human cancer cells through zebrafish TNF signaling. Macrophages were crucial for this response as their depletion completely abrogated the BCG-induced phenotype. Contrary to the general concept that macrophage anti-tumoral activities mostly rely on stimulating an effective adaptive response, we demonstrate that macrophages alone can induce tumor apoptosis and clearance. Thus, our results revealed an additional step to the BCG-induced tumor immunity model, while providing proof-of-concept experiments demonstrating the potential of this unique model to test innate immunomodulators.

Regional disparities in BCG vaccination coverage and tuberculosis incidence in infants among Brazilian states.

Bacillus Calmette-Guerin (BCG) vaccination and tuberculosis (TB) incidence in children under 1 year of age are critical public health indicators in Brazil. The coronavirus disease 2019 pandemic disrupted vaccination coverage (VC), potentially impacting TB incidence. Understanding regional disparities in VC and TB incidence can inform targeted interventions. We conducted an observational and ecological study using BCG vaccination data (2019-21) and TB incidence (2020-22) for all births in Brazil. Data were collected from public health databases, stratified by state, and analyzed using descriptive and analytical statistics to explore VC and TB incidence. Between 2019 and 2021, average BCG VC was 79.59%, with significant variation among states (P < .001). Only four states achieved minimum recommended coverage (>90%). TB incidence varied significantly among states (P = .003). There was a notable decline in VC from 2019 (90.72%) to 2021 (78.67%) (P < .001). This study highlights regional disparities in BCG VC and TB incidence among Brazilian states. Lower VC post-pandemic may increase TB incidence, requiring targeted interventions in states with inadequate coverage. The findings underscore the importance of sustaining vaccination programs amidst public health crises and implementing strategies to enhance access and uptake.

X-linked severe combined immunodeficiency complicated by disseminated bacillus Calmette-Guérin disease caused by a novel pathogenic mutation in exon 3 of the IL2RG gene: a case report and literature review.

X-linked severe combined immunodeficiency (X-SCID), caused by mutations in the gamma-chain gene of the interleukin-2 receptor (IL2RG), is a prevalent form of SCID characterized by recurrent and fatal opportunistic infections that occur early in life. The incidence of disseminated bacillus Calmette-Guérin (BCG) disease among children with SCID is much higher than in the general population. Here, we report the case of a 4-month-old male infant who presented with subcutaneous induration, fever, an unhealed BCG vaccination site, and hepatosplenomegaly. Metagenomic next-generation sequencing in blood, and the detection of gastric juice and skin nodule pus all confirmed the infection of Mycobacterium tuberculosis. Lymphocyte subset analysis confirmed the presence of T-B+NK immunodeficiency. Whole-exome and Sanger sequencing revealed a novel microdeletion insertion mutation (c.316_318delinsGTGAT p.Leu106ValfsTer42) in the IL2RG gene, resulting in a rare shift in the amino acid sequence of the coding protein. Consequently, the child was diagnosed with X-SCID caused by a novel mutation in IL2RG, complicated by systemic disseminated BCG disease. Despite receiving systemic anti-infection treatment and four days of hospitalization, the patient died three days after discharge. To the best of our knowledge, this specific IL2RG mutation has not been previously reported. In our systemic review, we outline the efficacy of systemic anti-tuberculosis therapy, hematopoietic stem cell transplantation, and gene therapy in children with SCID and BCG diseases caused by IL2RG gene mutation.

Comparison of Lowenstein Jensen Media and Ogawa Media Usage for Viability Test of BCG Vaccine Pasteur P11732 and Russian (Moscow) - 384 sub-strains.

The BCG vaccines on the market have employed a Mycobacterium bovis (M. bovis) sub-strains derived from the initial strain. To date, there has been no recommendation regarding the sub-strains with the highest effectiveness when administered to humans. Because it remains the standard for Tuberculosis treatment, the quality of the BCG vaccine must be verified. The viability test is one of the parameters for BCG vaccine quality control. The culture method has become the gold standard for viability testing with various testing media. The present study aimed to evaluate the performance of Lowenstein Jensen (LJ) and Ogawa media for the viability test of Pasteur 1173P2 and Russian (Moscow) - 384 sub-strains of M. bovis in the BCG vaccine. The number of culturable particles of each sub-strain in the BCG vaccine was estimated and statistically evaluated using the t-test. The colonies of the Pasteur 1173P2 have characteristics; tended to clump on both mediums with tiny, rough, and pale yellow/cream colors. Although the colony character of the Russian (Moscow) - 384 generally has similar feature, it did not cluster and had a smooth texture. In terms of growth rate, LJ and Ogawa media performed similarly for Pasteur 1173P2 and Russian (Moscow) - 384 sub-strains. Maximum growth is reached by the fifth week. The culturable particles of Pasteur P1173P2 sub-strains did not differ between mediums. Whereas the growth of the Russian (Moscow) - 384 sub-strains was statistically better on Ogawa media. The results of this study reveal that the performance of the media used for determining the number of culturable particles is based on the sub-strains of M. bovis present in the BCG vaccine.

Miliary TB in children and adolescents: a scoping review.

To summarise the available literature regarding clinical presentation, immunological and microbiological diagnosis, treatment, and outcomes of miliary TB in children and adolescents.Four databases were searched from 1 January 1950 to 31 January 2023. "Miliary" and "disseminated" TB were the main search concepts.Of 257 studies, 1,883 patients with miliary TB were included. Bacille Calmette-Guérin (BCG) vaccination was confirmed in 223/549 (40.6%) children. Central nervous system (CNS) involvement was reported in 367/924 (39.7%) cases; many of them had no neurological symptoms despite also having abnormal brain imaging. Of 1,112 children with known outcomes, 341 (30.6%) died; mortality was higher in publications before 1995 (41.5%) and in children with CNS involvement (31.9%). TB microbiological confirmation (55.8%) and sensitivity of tuberculin skin test (46.9%) and QuantiFERON Gold (72.4%) were overall low.Evidence is lacking to support best practices for paediatric miliary TB. Whether lumbar puncture (LP) and brain imaging should both be routinely done in miliary TB children, or a step-by-step approach based on initial LP findings, remains unclear. This study should inform policymakers and funding agencies about current significant gaps that need to be addressed by future high-quality studies..

Diagnosis of tuberculosis infection in children with a novel skin test and the traditional tuberculin skin test: An observational study.

BACKGROUND: A novel skin test-called Diaskintest (DT)-containing specific M. tuberculosis antigens is in clinical use in the Russian Federation (RF). This test may improve diagnosis of tuberculosis (TB) infection. The use and performance of the DT was described and compared to the tuberculin skin test (TST). METHODS: Data on children <18 years referred to a TB reference centre (Jan/2018- Dec/2019) with ≥1 DT and TST result available were analysed. An immune correlate of TB infection was defined as a positive TST (≥10 mm induration) or a positive DT (any induration). RESULTS: Of 2710 included cases, the median age was 9.0 (IQR 5.7-13.1) years and 97.5% were BCG immunised. Overall, 1976 (79.9%) were TB uninfected, 724 (26.7%) had an immune correlate of TB infection and 10 (0.4%) TB disease. Reasons for referral were: positive or increasing skin test results in routine screening (992, 36.6%), screening before admission to a health care institution (501, 18.5%) and TB contact (457, 16.9%). DT was positive in 11.7% (308/2625) and TST in 63.1% (467/740) (Kappa 0.08, 95% CI:0.013-0.14). A positive DT was associated with older age (OR 1.16 (95% CI: 1.13-1.19) per year). Among TB contacts DT positivity was associated with contagiousness: highest proportion of positivity of 12.0% was observed when the index case was smear positive. CONCLUSION: In a setting with universal BCG vaccination and regular screening with TST, DT was used to rule out TB infection as TST was commonly positive. We found an association of DT positivity and contagiousness of the index case in children contacts. These observations may suggest improved specificity and sensitivity of DT compared to TST.

Description of BCG and Tuberculosis Disease in a Cohort of 79 Patients with Chronic Granulomatous Disease.

PURPOSE: Chronic granulomatous disease (CGD) is an inherited immunodeficiency caused by pathogenic variants of genes encoding the enzyme complex NADPH oxidase. In countries where tuberculosis (TB) is endemic and the Bacillus Calmette-Guérin (BCG) vaccine is routinely administered, mycobacteria are major disease-causing pathogens in CGD. However, information on the clinical evolution and treatment of mycobacterial diseases in patients with CGD is limited. The present study describes the adverse reactions to BCG and TB in Mexican patients with CGD. METHODS: Patients with CGD who were evaluated at the Immunodeficiency Laboratory of the National Institute of Pediatrics between 2013 and 2024 were included. Medical records were reviewed to determine the clinical course and treatment of adverse reactions to BCG and TB disease. RESULTS: A total of 79 patients with CGD were included in this study. Adverse reactions to BCG were reported in 55 (72%) of 76 patients who received the vaccine. Tuberculosis was diagnosed in 19 (24%) patients. Relapse was documented in three (10%) of 31 patients with BGC-osis and six (32%) of 19 patients with TB, despite antituberculosis treatment. There was no difference in the frequency of BCG and TB disease between patients with pathogenic variants of the X-linked CYBB gene versus recessive variants. CONCLUSIONS: This report highlights the importance of considering TB in endemic areas and BCG complications in children with CGD to enable appropriate diagnostic and therapeutic approaches to improve prognosis and reduce the risk of relapse.

Host and pathogen genetic diversity shape vaccine-mediated protection to Mycobacterium tuberculosis.

To investigate how host and pathogen diversity govern immunity against Mycobacterium tuberculosis (Mtb), we performed a large-scale screen of vaccine-mediated protection against aerosol Mtb infection using three inbred mouse strains [C57BL/6 (B6), C3HeB/FeJ (C3H), Balb/c x 129/SvJ (C129F1)] and three Mtb strains (H37Rv, CDC1551, SA161) representing two lineages and distinct virulence properties. We compared three protective modalities, all of which involve inoculation with live mycobacteria: Bacillus Calmette-Guérin (BCG), the only approved TB vaccine, delivered either subcutaneously or intravenously, and concomitant Mtb infection (CoMtb), a model of pre-existing immunity in which a low-level Mtb infection is established in the cervical lymph node following intradermal inoculation. We examined lung bacterial burdens at early (Day 28) and late (Day 98) time points after aerosol Mtb challenge and histopathology at Day 98. We observed substantial heterogeneity in the reduction of bacterial load afforded by these modalities at Day 28 across the combinations and noted a strong positive correlation between bacterial burden in unvaccinated mice and the degree of protection afforded by vaccination. Although we observed variation in the degree of reduction in bacterial burdens across the nine mouse/bacterium strain combinations, virtually all protective modalities performed similarly for a given strain-strain combination. We also noted dramatic variation in histopathology changes driven by both host and bacterial genetic backgrounds. Vaccination improved pathology scores for all infections except CDC1551. However, the most dramatic impact of vaccination on lesion development occurred for the C3H-SA161 combination, where vaccination entirely abrogated the development of the large necrotic lesions that arise in unvaccinated mice. In conclusion, we find that substantial TB heterogeneity can be recapitulated by introducing variability in both host and bacterial genetics, resulting in changes in vaccine-mediated protection as measured both by bacterial burden as well as histopathology. These differences can be harnessed in future studies to identify immune correlates of vaccine efficacy.

Overexpression of LAG-3: a potential indicator of low immune function in tuberculosis.

Background: Tuberculosis (TB) persists as a global health challenge, with its treatment hampered by the side effects of long-term combination drug therapies and the growing issue of drug resistance. Therefore, the development of novel therapeutic strategies is critical. This study focuses on the role of immune checkpoint molecules (ICs) and functions of CD8+ T cells in the search for new potential targets against TB. Methods: We conducted differential expression genes analysis and CD8+ T cell functional gene analysis on 92 TB samples and 61 healthy individual (HI) samples from TB database GSE83456, which contains data on 34,603 genes. The GSE54992 dataset was used to validated the findings. Additionally, a cluster analysis on single-cell data from primates infected with mycobacterium tuberculosis and those vaccinated with BCG was performed. Results: The overexpression of LAG-3 gene was found as a potentially important characteristic of both pulmonary TB (PTB) and extrapulmonary TB (EPTB). Further correlation analysis showed that LAG-3 gene was correlated with GZMB, perforin, IL-2 and IL-12. A significant temporal and spatial variation in LAG-3 expression was observed in T cells and macrophages during TB infection and after BCG vaccination. Conclusion: LAG-3 was overexpressed in TB samples. Targeting LAG-3 may represent a potential therapeutic target for tuberculosis.

The ΔfbpAΔsapM candidate vaccine derived from Mycobacterium tuberculosis H37Rv is markedly immunogenic in macrophages and induces robust immunity to tuberculosis in mice.

Tuberculosis (TB) remains a significant global health challenge, with approximately 1.5 million deaths per year. The Bacillus Calmette-Guérin (BCG) vaccine against TB is used in infants but shows variable protection. Here, we introduce a novel approach using a double gene knockout mutant (DKO) from wild-type Mycobacterium tuberculosis (Mtb) targeting fbpA and sapM genes. DKO exhibited enhanced anti-TB gene expression in mouse antigen-presenting cells, activating autophagy and inflammasomes. This heightened immune response improved ex vivo antigen presentation to T cells. Subcutaneous vaccination with DKO led to increased protection against TB in wild-type C57Bl/6 mice, surpassing the protection observed in caspase 1/11-deficient C57Bl/6 mice and highlighting the critical role of inflammasomes in TB protection. The DKO vaccine also generated stronger and longer-lasting protection than the BCG vaccine in C57Bl/6 mice, expanding both CD62L-CCR7-CD44+/-CD127+ effector T cells and CD62L+CCR7+/-CD44+CD127+ central memory T cells. These immune responses correlated with a substantial ≥ 1.7-log10 reduction in Mtb lung burden. The DKO vaccine represents a promising new approach for TB immunization that mediates protection through autophagy and inflammasome pathways.

A multistage protein subunit vaccine as BCG-booster confers protection against Mycobacterium tuberculosis infection in murine models.

The eradication of tuberculosis remains a global challenge. Despite being the only licensed vaccine, Bacillus Calmette-Guérin (BCG) confers limited protective efficacy in adults and individuals with latent tuberculosis infections (LTBI). There is an urgent need to develop novel vaccines that can enhance the protective effect of BCG. Protein subunit vaccines have garnered significant research interest due to their safety and plasticity. Based on previous studies, we selected three antigens associated with LTBI (Rv2028c, Rv2029c, Rv3126c) and fused them with an immunodominant antigen Ag85A, resulting in the construction of a multistage protein subunit vaccine named A986. We evaluated the protective effect of recombinant protein A986 adjuvanted with MPL/QS21 as a booster vaccine for BCG against Mycobacterium tuberculosis (Mtb) infection in mice. The A986 + MPL/QS21 induced the secretion of antigen-specific Th1 (IL-2+, IFN-γ+ and TNF-α+) and Th17 (IL-17A+) cytokines in CD4+ and CD8+ T cells within the lung and spleen of mice, while also increased the frequency of central memory and effector memory T cells. Additionally, it also induced the enhanced production of IgG antibodies. Compared to BCG alone, A986 + MPL/QS21 boosting significantly augmented the proliferation of antigen-specific multifunctional T cells and effectively reduced bacterial load in infected mice. Taken together, A986 + MPL/QS21 formulation induced robust antigen-specific immune responses and provided enhanced protection against Mtb infection as a booster of BCG vaccine.

Immunogenicity and vaccine potential of clinical isolate Mycobacterium kansasii strain against Mycobacterium tuberculosis infection.

Mycobacterium kansasii is a bacterium included in non-tuberculous mycobacteria (NTM) that can cause lung disease. It shares a significant number of antigens with Mycobacterium tuberculosis (Mtb), suggesting that it has the potential to be used as a tuberculosis (TB) vaccine. Therefore, we subcutaneously vaccinated mice with reference strain, M. kansasii-ATCC12478 [M. kansasii-American Type Culture Collection (ATCC)], and clinically isolated strain, M. kansasii-SM-1 to evaluate potential as a TB vaccine by comparing with bacille Calmette-Guerin (BCG) vaccine. Ten weeks after vaccination, we evaluated immunogenicity of M. kansasii-ATCC and M. kansasii-SM-1, and M. kansasii-SM-1 immunization induces potent Mtb antigen-specific IFN-γ-producing CD4+ T cells than M. kansasii-ATCC. Upon Mtb infection, M. kansasii-SM-1 provided better protection than M. kansasii-ATCC, which was comparable to the efficacy of BCG. These results showed that the clinical strain M. kansasii-SM-1, which exhibits an enhanced Mtb antigen-specific Th1 response, shows greater vaccine efficacy compared to M. kansasii-ATCC. In this study, we demonstrated that vaccine efficacy can vary depending on the strain of M. kansasii and that its efficacy can be comparable to BCG. This suggests that M. kansasii has the potential to be a live TB vaccine candidate.IMPORTANCEMycobacterium kansasii, a non-tuberculous mycobacteria (NTM) species causing lung disease, shares key antigens with Mycobacterium tuberculosis (Mtb), indicating its potential for TB vaccine development. Subcutaneous vaccination of mice with M. kansasii strains reference strain M. kansasii-ATCC12478 [(M. kansasii-American Type Culture Collection (ATCC)] and clinically isolated strain M. kansasii-SM-1 revealed differences in immunogenicity. M. kansasii-SM-1 induced a robust Mtb antigen-specific IFN-γ-producing CD4+ T cell response compared to M. kansasii-ATCC. Additionally, M. kansasii-SM-1 conferred better protection against Mtb infection than M. kansasii-ATCC, which is comparable to bacille Calmette-Guerin (BCG). These findings underscore the variable vaccine efficacy among M. kansasii strains, with M. kansasii-SM-1 exhibiting promising potential as a live TB vaccine candidate, suggesting its comparative effectiveness to BCG.

Models for predicting the risk of illness in leprosy contacts in Brazil: Leprosy prediction models in Brazilian contacts.

OBJECTIVE: This study aims to develop and validate predictive models that assess the risk of leprosy development among contacts, contributing to an enhanced understanding of disease occurrence in this population. METHODS: A cohort of 600 contacts of people with leprosy treated at the National Reference Center for Leprosy and Health Dermatology at the Federal University of Uberlândia (CREDESH/HC-UFU) was followed up between 2002 and 2022. The database was divided into two parts: two-third to construct the disease risk score and one-third to validate this score. Multivariate logistic regression models were used to construct the disease score. RESULTS: Of the four models constructed, model 3, which included the variables anti-phenolic glycolipid I immunoglobulin M positive, absence of Bacillus Calmette-Guérin vaccine scar and age ≥60 years, was considered the best for identifying a higher risk of illness, with a specificity of 89.2%, a positive predictive value of 60% and an accuracy of 78%. CONCLUSIONS: Risk prediction models can contribute to the management of leprosy contacts and the systematisation of contact surveillance protocols.

Immune cell population dynamics following neonatal BCG vaccination and aerosol BCG revaccination in rhesus macaques.

The BCG vaccine is given to millions of children globally but efficacy wanes over time and differences in the immune systems between infants and adults can influence vaccine efficacy. To this end, 34 rhesus macaques were vaccinated with BCG within seven days of birth and blood samples were collected over 88 weeks for quantification of blood cell populations. Overall, the composition of cell populations did not change significantly between BCG vaccinated and unvaccinated groups, and that BCG vaccination did not perturb normal development. In comparison to adult macaques, higher numbers of CD4+ T-cells, Tregs and NK cells were measured in the infant age group, suggesting a potential bias towards immunosuppressive and innate immune populations. Antigen-specific IFNγ secreting cell frequencies in infant BCG vaccinated animals were detectable in peripheral blood samples for 36 weeks after vaccination but declined following this. To evaluate the long-term impact of infant BCG vaccination on subsequent revaccination with BCG, a pilot study of three adult macaques received an aerosol BCG revaccination approximately 3 years after their initial BCG vaccination as infants. This induced an increase in PPD-specific IFNγ secreting cells, and increased secretion of the cytokines IFNγ and IL-1ß, following stimulation with other microorganisms, which are signals associated with trained innate immunity.

A viral vaccine design harnessing prior BCG immunization confers protection against Ebola virus.

Previous studies have demonstrated the efficacy and feasibility of an anti-viral vaccine strategy that takes advantage of pre-existing CD4+ helper T (Th) cells induced by Mycobacterium bovis bacille Calmette-Guérin (BCG) vaccination. This strategy uses immunization with recombinant fusion proteins comprised of a cell surface expressed viral antigen, such as a viral envelope glycoprotein, engineered to contain well-defined BCG Th cell epitopes, thus rapidly recruiting Th cells induced by prior BCG vaccination to provide intrastructural help to virus-specific B cells. In the current study, we show that Th cells induced by BCG were localized predominantly outside of germinal centers and promoted antibody class switching to isotypes characterized by strong Fc receptor interactions and effector functions. Furthermore, BCG vaccination also upregulated FcγR expression to potentially maximize antibody-dependent effector activities. Using a mouse model of Ebola virus (EBOV) infection, this vaccine strategy provided sustained antibody levels with strong IgG2c bias and protection against lethal challenge. This general approach can be easily adapted to other viruses, and may be a rapid and effective method of immunization against emerging pandemics in populations that routinely receive BCG vaccination.

Impact of in-utero exposure to HIV and latent TB on infant humoral responses.

Introduction: Latent tuberculosis infection (LTBI) is a common coinfection in people living with HIV (PWH). How LTBI and HIV exposure in utero influence the development of infant humoral immunity is not well characterized. To address this question, we assessed the relationship between maternal humoral responses in pregnant women with HIV or with HIV/LTBI on humoral responses in infants to BCG vaccination and TB acquisition. Methods: Plasma samples were obtained from mother infant pairs during pregnancy (14-34 wks gestation) and in infants at 12 and 44 wks of age from the IMPAACT P1078 clinical trial. LTBI was established by Interferon gamma release assay (IGRA). Progression to active TB (ATB) disease was observed in 5 women at various times after giving birth. All infants were BCG vaccinated at birth and tested for IGRA at 44 weeks. Mtb (PPD, ESAT6/CFP10, Ag85A, LAM), HIV (GP120), and Influenza (HA) specific IgG, IgM, and IgA were measured in plasma samples using a bead based Luminex assay with Flexmap 3D. Results: In maternal plasma there were no differences in Mtb-specific antibodies or viral antibodies in relation to maternal IGRA status. ATB progressors showed increases in Mtb-specific antibodies at diagnosis compared to study entry. However, when compared to the non-progressors at entry, progressors had higher levels of Ag85A IgG and reduced ESAT6/CFP10 IgG and LAM IgG, IgM, and IgA1. All infants showed a decrease in IgG to viral antigens (HIV GP120 and HA) from 12 to 44 weeks attributed to waning of maternally transferred antibody titers. However, Mtb-specific (PPD, ESAT6/CFP10, Ag85A, and LAM) IgG and IgM increased from 12 to 44 weeks. HIV and HA IgG levels in maternal and 12-week infant plasma were highly correlated, and ESAT6/CFP10 IgG and LAM IgG showed a relationship between maternal and infant Abs. Finally, in the subset of infants that tested IGRA positive at 44 weeks, we observed a trend for lower LAM IgM compared to IGRA- infants at 44 weeks. Discussion: The results from our study raise the possibility that antibodies to LAM are associated with protection from progression to ATB and support further research into the development of humoral immunity against TB through infection or vaccination.

Association between Bacillus Calmette-Guérin (BCG) vaccination and inflammatory bowel disease: A two-stage sampling design within the Quebec Birth Cohort on Immunity and Health (CO·MMUNITY).

BACKGROUND: Bacillus Calmette-Guérin (BCG) vaccination, primarily administered to prevent tuberculosis, exhibits nonspecific immune effects and could play a role in inflammatory bowel disease prevention. We investigated the associations of BCG with Crohn's disease and ulcerative colitis, and assessed sex-differences. METHODS: This two-stage study included 365,206 Canadians from the Quebec Birth Cohort on Immunity and Health (1970-2014; stage 1). Vaccination status was registry-based and inflammatory bowel disease cases were identified from health services with validated algorithms. We documented additional factors among 2644 participants in a nested case-control study in 2021 (stage 2). A two-stage logistic regression analysis was applied to estimate the odds ratios (OR), corrected for sampling fractions and adjusted for confounding factors. We used interaction terms to assess sex-differences on the multiplicative scale. RESULTS: In the stage 1 sample, 2419 cases of Crohn's disease and 1079 of ulcerative colitis were included. Forty-six percent of non-cases received the BCG vaccine as compared to 47% for Crohn's disease and 49% for ulcerative colitis. Associations differed by sex. BCG vaccination was not associated with Crohn's disease among men (OR = 0.91; 95% CI: 0.79-1.04) but was related to an increased risk among women (OR = 1.13; 95% CI: 1.00-1.28, P interaction: 0.001). For ulcerative colitis, there was a tendency toward a slightly elevated risk among men (OR = 1.09; 95%CI: 0.90-1.32), whereas the risk was more substantial for women (OR = 1.17; 95% CI:0.99-1.39, P interaction: <0.001). CONCLUSION: BCG vaccination does not play a preventive role in inflammatory bowel disease. Our results point to distinct associations between men and women.