Structure-based design of antibodies targeting the EBNA1 DNA-binding domain to block Epstein-Barr virus latent infection and tumor growth.

The Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is critically involved in maintaining episomes during latent infection and promoting tumorigenesis. The development of an epitope-specific monoclonal antibody (mAb) for EBNA1 holds great promise due to its high affinity and specificity, offering a new and innovative approach for the treatment of EBV-related diseases. In this proof-of-concept study, we employed a structure-based design strategy to create three unique immunogens specifically targeting the DNA binding state of the EBNA1 DBD. By immunizing mice, we successfully generated a mAb, named 5E2-12, which selectively targets the DNA binding interface of EBNA1. The 5E2-12 mAb effectively disrupts the interaction between EBNA1 and DNA binding, resulting in reduced proliferation of EBV-positive cells and inhibition of xenograft tumor growth in both cellular assays and mouse tumor models. These findings open up new avenues for the development of innovative biological macromolecular drugs that specifically target EBNA1 and provide potential for clinical therapy options for early-stage EBV-positive tumors. The epitope-specific mAb approach demonstrates novelty and innovation in tackling EBV-related diseases and may have broad implications for precision medicine strategies in the field of viral-associated cancers.

Identification of Rv1133c (MetE) as a marker of Mycobacterium tuberculosis replication and as a highly immunogenic antigen with potential immunodiagnostic power.

The immunization of mice with the sterile culture medium supernatants of Mycobacterium tuberculosis (Mtb) H37Rv permitted the production of several monoclonal antibodies (mAbs) specific for secreted and/or released antigens. Two mAbs bound and immunoprecipitated an 80-kDa protein that was identified by mass spectrometry as Rv1133c, the methionine synthase MetE. The protein MetE is ubiquitous among prokaryota and shows a significant sequence homology in many bacteria. We produced both the full-length recombinant MetE and its N-terminal fragment, whose sequence is more conserved among mycobacteria, to select mAbs recognizing an Mtb-specific region of MetE. Finally, we produced and selected eight mAbs that specifically detect the MetE protein in the supernatant and cell lysate of Mtb and BCG, but not other bacteria such as non-tuberculous mycobacteria (NTM), Streptococcus pneumoniae, Staphylococcus aureus, Acinetobacter baumanii, or Escherichia coli. Taking advantage of our mAbs, we studied (i) the vitamin B12 dependence for the synthesis of MetE in Mtb and NTM and (ii) the kinetics of MetE production and secretion in supernatants during the in vitro reproduced replicative, dormant, and resuscitation cycle of Mtb. Our data demonstrate that dormant Mtb, which are assumed to be prevalent in latent infections, as well as NTM do not produce and secrete MetE. Results indicate an unexpected specificity for Mtb of our anti-MetE mAbs and encourage the use of rMetE and our mAbs as tools for the immunodiagnosis of TB and its stages.

Applications of Biological Therapy for Latent Infections: Benefits and Risks.

Biological therapies have revolutionized medical treatment by targeting the key mediators or receptors involved in inflammatory responses, thereby effectively suppressing inflammation and achieving beneficial outcomes. They are more advanced than conventional therapies using corticosteroids and immunosuppressants, offering effective solutions for autoimmune diseases, cancer, transplant rejection, and various infectious diseases, including coronavirus disease 2019. Although they exert low immunosuppressive effects, biological therapies can reactivate specific biological targets associated with infections. This review summarizes the currently available biological therapies and discusses their immunosuppressive mechanisms and clinical applications, highlighting the variations in the types and frequencies of infection recurrence induced by different biological agents. Additionally, this review describes the risk factors associated with various biological agents, thus aiding clinicians in selecting the most appropriate biological therapy.

Breaking Latent Infection: How ORF37/38-Deletion Mutants Offer New Hope against EHV-1 Neuropathogenicity.

Equid alphaherpesvirus 1 (EHV-1) has been linked to the emergence of neurological disorders, with the horse racing industry experiencing significant impacts from outbreaks of equine herpesvirus myeloencephalopathy (EHM). Building robust immune memory before pathogen exposure enables rapid recognition and elimination, preventing infection. This is crucial for effectively managing EHV-1. Removing neuropathogenic factors and immune evasion genes to develop live attenuated vaccines appears to be a successful strategy for EHV-1 vaccines. We created mutant viruses without ORF38 and ORF37/38 and validated their neuropathogenicity and immunogenicity in hamsters. The ∆ORF38 strain caused brain tissue damage at high doses, whereas the ∆ORF37/38 strain did not. Dexamethasone was used to confirm latent herpesvirus infection and reactivation. Dexamethasone injection increased viral DNA load in the brains of hamsters infected with the parental and ∆ORF38 strains, but not in those infected with the ∆ORF37/38 strain. Immunizing hamsters intranasally with the ∆ORF37/38 strain as a live vaccine produced a stronger immune response compared to the ∆ORF38 strain at the same dose. The hamsters demonstrated effective protection against a lethal challenge with the parental strain. This suggests that the deletion of ORF37/38 may effectively inhibit latent viral infection, reduce the neuropathogenicity of EHV-1, and induce a protective immune response.

Proliferative arrest induces neuron differentiation and innate immune responses in control and Creutzfeldt-Jakob Disease agent infected rat septal neurons.

Rat post-mitotic septal (SEP) neurons, engineered to conditionally proliferate at 33°C, differentiate when arrested at 37.5°C and can be maintained for weeks without cytotoxic effects. Nine independent cDNA libraries were made to follow arrest-induced neural differentiation and innate immune responses in normal (Nl) uninfected and CJ agent infected SEP cells. Proliferating Nl versus latently infected (CJ-) cells showed few RNA-seq differences. However arrest induced major changes. Normal cells displayed a plethora of anti-proliferative transcripts. Additionally, known neuron differentiation transcripts, e.g., Agtr2, Neuregulin-1, GDF6, SFRP4 and Prnp were upregulated. These Nl neurons also displayed many activated IFN innate immune genes, e.g., OAS1, RTP4, ISG20, GTB4, CD80 and cytokines, complement, and clusterin (CLU) that binds to misfolded proteins. In contrast, arrested highly infectious CJ+ cells (10 logs/gm) downregulated many replication controls. Furthermore, arrested CJ+ cells suppressed neuronal differentiation transcripts, including Prnp which is essential for CJ agent infection. CJ+ cells also enhanced IFN stimulated pathways, and analysis of the 342 CJ+ unique transcripts revealed additional innate immune and anti-viral-linked transcripts, e.g., Il17, ISG15, and RSAD2 (viperin). These data show: 1) innate immune transcripts are produced by normal neurons during differentiation; 2) CJ infection can enhance and expand anti-viral responses; 3) latent CJ infection epigenetically imprints many proliferative pathways to thwart complete arrest. CJ+ brain microglia, white blood cells and intestinal myeloid cells with shared transcripts may be stimulated to educe latent CJD infections that can be clinically silent for >30 years.

Potential Development Ability of Residual Zoites, a Second-Generation Meront, Inducing Long-Term Infection by the Mouse Eimerian Parasite, Eimeria krijgsmanni.

PURPOSE: Coccidiosis caused by eimerian parasites results in lethal watery or bloody diarrhea in hosts, and markedly impairs the growth of and feed utilization by host animals. We previously investigated detailed the life cycle of Eimeria krijgsmanni as a mouse eimerian parasite. Only second-generation meronts, as an asexual stage, were morphologically detected in the epithelium of the host cecum for at least 8 weeks after infection, even though oocyst shedding finished approximately 3 weeks after infection. The presence of zoites was of interest because infection by eimerian parasites is considered to be self-limited after their patent period. METHODS: To clarify the significance of residual second-generation meronts in E. krijgsmanni infection, we performed infection experiments using immunocompetent mice under artificial immunosuppression and congenital immunodeficient mice. RESULTS: The number of oocysts discharged and the duration of oocyst discharge both increased in immunosuppressed mice. In immunodeficient mice, numerous oocysts were shed over a markedly longer period, and oocyst discharge did not finish until 56 days after inoculation. CONCLUSIONS: The present results suggest that the second-generation meronts survived in the epithelial cells of the cecum after the patent period, thereby contributing to extended infection as an asexual stage. The results obtained on E. krijgsmanni indicate that infections by Eimeria spp. are not self-limited and potentially continue for a long period of time.

Identification of immune-associated genes involved in latent Mycobacterium marinum infection.

Tuberculosis (TB) is a high mortality infectious disease caused by Mycobacterium tuberculosis (Mtb), and often develops into latent infection. About 5～10% of latent infections turn into active tuberculosis when the host immune system becomes deficient. Therefore, exploring the latent infection mechanism of Mtb is pivotal for the prevention and treatment of tuberculosis. We first established the zebrafish latent infection model and the chronic infection model utilizing Mycobacterium marinum, which has the highly similar gene background to Mtb. Using the latent infection model, we characterized the gene expression profiles and found 462 genes expressed differentially in the latent period and chronic tuberculosis infection. These differentially expressed genes are involved in various biological processes including transcription, transcriptional regulation, organism development, and immune responses. Among them, nineteen immune-related genes were found to express differentially in the latent period. By analyzing immune related protein network, the genes in the center of the network, including Nos2b, TNFα, IL1, TNFß, TLR1, TLR2, and TLR4b, displayed significant deferential expression in latent infection and chronic infection period of zebrafish, suggesting that these genes might play an important role in controlling latent infection of Mtb. Identifying immune biomarker related to the status of tuberculosis latent infection might lead to novel strategy for diagnosis and treatment.

Transcriptomic analysis reveals bovine herpesvirus 1 infection regulates innate immune response resulted in restricted viral replication in neuronal cells.

BACKGROUND: Bovine herpesvirus 1 (BoHV-1) is a major pathogen that affects the global bovine population, primarily inducing respiratory and reproductive disorders. Its ability to establish latent infections in neuronal cells and to reactivate under certain conditions poses a continual threat to uninfected hosts. In this study, we aimed to analyze the replication characteristics of BoHV-1 in neuronal cells, as well as the effects of viral replication on host cell immunity and physiology. METHODS: Using the Neuro-2a neuronal-origin cell line as a model, we explored the dynamics of BoHV-1 replication and analyzed differential gene expression profiles post-BoHV-1 infection using high-throughput RNA sequencing. RESULTS: BoHV-1 demonstrated restricted replication in Neuro-2a cells. BoHV-1 induced apoptotic pathways and enhanced the transcription of interferon-stimulated genes and interferon regulatory factors while suppressing the complement cascade in Neuro-2a cells. CONCLUSIONS: Different from BoHV-1 infection in other non-highly differentiated somatic cells result in viral dominance, BoHV-1 regulated the innate immune response in neuronal cells formed a "virus-nerve cell" relative equilibrium state, which may account for the restricted replication of BoHV-1 in neuronal cells, leading to a latent infection. These findings provide a foundation for further research into the mechanism underlying BoHV-1-induced latent infection in nerve cells.

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.

Effect of tuberculosis-specific antigen stimulation on the diagnostic accuracy of interferon-γ inducible protein-10 in distinguishing active and latent tuberculosis infection: a meta-analysis.

BACKGROUND: Identifying active tuberculosis (ATB) from latent tuberculosis infection (LTBI) persists as a challenge, and interferon-γ inducible protein-10 (IP-10) has been employed as the solution. To further improve its diagnostic performance, the sample can be stimulated with TB specific antigen (TBAg). AIM: To perform meta-analysis on diagnostic accuracy of unstimulated and TBAg-stimulated IP-10 in differentiating ATB from LTBI. METHODS: Systematic search was performed on five major scientific databases as of 29 November 2023. Observational studies reporting diagnostic values of unstimulated or TBAg-stimulated IP-10 in identifying ATB from LTBI were included. Meta-analysis was carried out using two-level mixed-effect logistic regression model. RESULTS: Twenty-five studies recruiting 2301 patients (1137 ATB versus 1164 LTBI) were included in the quantitative analysis. The pooled sensitivity and specifity of IP-10 were 72% (95%CI: 0.59-0.82) and 78% (95%CI: 0.63-0.88), respectively. As for TBAg-stimulated IP-10, the sensitivity and specifity were 82% (95%CI: 0.76-0.87) and 85% (95%CI: 0.73-0.92), respectively. The senstivity was reduced signiticantly (p < 0.01) when the patients with human immunodeficiency virus infection were included, except after the TBAg stimulation. CONCLUSION: Stimulating IP-10 with TBAg could improve the diagnostic accuracy in differentiating ATB from LTBI.

Experimental infection of goats with pVAPN-harboring Rhodococcus equi causes latent infection in the lymph nodes.

Rhodococcus equi has recently been identified in various animals, including ruminants. Several studies have highlighted the emergence of pVAPN-harboring strains, isolated from multiple abscesses, in the liver and lungs of ruminants. Epidemiological evidence strongly suggests that pVAPN-harboring strains are pathogenic in ruminants. This study aims to replicate the disease in goats through experimental infection. Intravenous administration of the pVAPN-harboring strain (Yokkaichi), pVAPA-harboring strain (ATCC33701), and pVAPN-cured strain (Yokkaichi_P-), each at 1.0 × 107 CFU/head, was conducted in 24-month-old goats (n = 1 per group). During the observation period, goats treated with Yokkaichi or ATCC33701 exhibited transient increases in body temperature and white blood cell count, alongside a decrease in body weight from the administration day. Conversely, goats treated with Yokkaichi_P- displayed no significant changes in these values. The Yokkaichi-treated goat demonstrated a >10-fold increase in anti-VapN antibody titers from 11 to 14 days postadministration, whereas the other two goats exhibited no variation in anti-VapA and VapN antibody titers. Pathological autopsy analysis of organs harvested 28 days postadministration revealed no characteristic lesions on gross examination. However, the inoculated strain (vapN-positive R. equi) was exclusively recovered from the tracheobronchial lymph node in the Yokkaichi-treated goat. Immunohistochemistry detected a VapN-positive reaction in the tracheobronchial lymph node, confirming latent infection despite the absence of dramatic suppurative lesions seen in ruminants. Overall, this study highlights the latent infection in lymph nodes induced by the pVAPN-harboring strain, despite the absence of overt pathological manifestations.

A Decade-Long Cohort Analysis of Human Cytomegalovirus (HCMV)-Induced Early and Late Renal Rejection in Post-Transplant Patients in the Eastern Indian Population.

Background: HCMV causes severe clinical complications in transplant recipients and may lead to graft rejection. Successful renal transplantation heavily relies on the early prevention and diagnosis of CMV infections, followed by prompt prophylactic treatment before transplantation. Despite the majority of renal rejection cases with acute HCMV infections being asymptomatic and occurring one to two years later, the objective of this research was to comprehend the effect of late HCMV infection on renal rejection by examining specific clinical parameters in the Eastern Indian cohort. Method: In this study, 240 patients were studied for five years following transplantation, and their data were collected from the local metropolitan hospital in Eastern India. Both HCMV-positive and -negative post-transplant patients were investigated using the clinical parameters and viral loads for latent infection. Results: Within the studied population, 79 post-transplant patients were found to be HCMV positive. Among them, 13 (16.45%) patients suffered from renal rejection within less than 2 yrs. of transplantation (early rejection) and 22 (27.84%) patients suffered from renal rejection after 2 yrs. from the operation date (late rejection). Assessment of clinical parameters with respect to HCMV infection revealed that in early rejection cases, fever (p-0.035) and urinary tract infection (p-0.017) were prominent, but in late rejection, hematuria (p-0.032), diabetes (p-0.005), and creatinine level changes (p < 0.001) were significant along with urinary tract infection (p-0.047). Conclusions: This study provides valuable insights into monitoring latent CMV infections and highlights the understanding of reducing renal rejection rates and the need for further research in this field.

Partial Alleviation of Homologous Superinfection Exclusion of SeMNPV Latently Infected Cells by G1 Phase Infection and G2/M Phase Arrest.

Viral infection can regulate the cell cycle, thereby promoting viral replication. Hijacking and altering the cell cycle are important for the virus to establish and maintain a latent infection. Previously, Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV)-latently infected P8-Se301-C1 cells, which grew more slowly than Se301 cells and interfered with homologous SeMNNPV superinfection, were established. However, the effects of latent and superinfection with baculoviruses on cell cycle progression remain unknown. In this study, the cell cycle profiles of P8-Se301-C1 cells and SeMNPV or Autographa californica multiple nucleopolyhedrovirus (AcMNPV)-infected P8-Se301-C1 cells were characterized by flow cytometry. The results showed that replication-related genes MCM4, PCNA, and BAF were down-regulated (p < 0.05) in P8-Se301-C1 cells, and the S phase of P8-Se301-C1 cells was longer than that of Se301 cells. P8-Se301-C1 cells infected with SeMNPV did not arrest in the G2/M phase or affect the expression of Cyclin B and cyclin-dependent kinase 1 (CDK1). Furthermore, when P8-Se301-C1 cells were infected with SeMNPV after synchronized treatment with hydroxyurea and nocodazole, light microscopy and qRT-PCR analysis showed that, compared with unsynchronized cells and S and G2/M phase cells, SeMNPV-infected P8-Se301-C1 cells in G1 phase induced G2/M phase arrest, and the amount of virus adsorption and intracellular viral DNA replication were significantly increased (p < 0.05). In addition, budded virus (BV) production and occlusion body (OB)-containing cells were both increased at 120 h post-infection (p < 0.05). The expression of Cyclin B and CDK1 was significantly down-regulated at 48 h post-infection (p < 0.05). Finally, the arrest of SeMNPV-infected G1 phase cells in the G2/M phase increased BV production (p < 0.05) and the number of OB-containing cells. In conclusion, G1 phase infection and G2/M arrest are favorable to SeMNPV proliferation in P8-Se301-C1 cells, thereby alleviating the homologous superinfection exclusion. The results contribute to a better understanding of the relationship between baculoviruses and insect cell cycle progression and regulation.

Encephalitozoon cuniculi Microsporidia in Cerebrospinal Fluid from Immunocompetent Patients, Czech Republic.

We retrospectively analyzed of 211 frozen cerebrospinal fluid samples from immunocompetent persons in the Czech Republic and detected 6 Encephalitozoon cuniculi-positive samples. Microsporidiosis is generally underestimated and patients are not usually tested for microsporidia, but latent infection in immunodeficient and immunocompetent patients can cause serious complications if not detected and treated.

Mycobacterium tuberculosis is less likely to acquire pathogenic mutations during latent infection than during active disease.

Most people infected with Mycobacterium tuberculosis (Mtb) are believed to be in a state of latent tuberculosis (TB) infection (LTBI). Although LTBI is asymptomatic and not infectious, there is a risk of developing active disease even decades after infection. Here, to characterize mutations acquired during LTBI, we collected and analyzed Mtb genomes from seven Japanese patient pairs, each pair consisting of two active TB patients whose starting dates of developing active disease were >3 years apart; one had a high suspicion of LTBI before developing active disease, whereas the other did not. Thereafter, we compared these genomes with those of longitudinal sample pairs within a host of chronic active TB infections combined with public data. The bacterial populations in patients with LTBI were genetically more homogeneous and accumulated single nucleotide polymorphisms (SNPs) slower than those from active disease. Moreover, the lower proportion of nonsynonymous SNPs indicated weaker selective pressures during LTBI than active disease. Finally, the different mutation spectrums indicated different mutators between LTBI and active disease. These results suggest that the likelihood of the acquisition of mutations responsible for antibiotic resistance and increased virulence was lower in the Mtb population from LTBI than active disease.IMPORTANCEControlling latent tuberculosis (TB) infection (LTBI) activation is an effective strategy for TB elimination, where understanding Mycobacterium tuberculosis (Mtb) dynamics within the host plays an important role. Previous studies on chronic active disease reported that Mtb accumulated genomic mutations within the host, possibly resulting in acquired drug resistance and increased virulence. However, several reports suggest that fewer mutations accumulate during LTBI than during the active disease, but the associated risk is largely unknown. Here, we analyzed the genomic dynamics of Mtb within the host during LTBI. Our results statistically suggest that Mtb accumulates mutations during LTBI, but most mutations are under low selective pressures, which induce mutations responsible for drug resistance and virulence. Thus, we propose that LTBI acts as a source for new TB disease rather than as a period for in-host genome evolution.

Origins of the problematic E in SEIR epidemic models.

During the COVID-19 pandemic, over one thousand papers were published on "Susceptible-Exposed-Infectious-Removed" (SEIR) epidemic computational models. The English word "exposed" in its vernacular and public health usage means a state of having been in contact with an infectious individual, but not necessarily infected. In contrast, the term "exposed" in SEIR modeling usage typically stands for a state of already being infected but not yet being infectious to others, a state more properly termed "latently infected." In public health language, "exposed" means possibly infected, yet in SEIR modeling language, "exposed" means already infected. This paper retraces the conceptual and mathematical origins of this terminological disconnect and concludes that epidemic modelers should consider using the "SLIR" notational short-hand (L for Latent) instead of SEIR.

Latent tuberculosis prevalence, diagnosis and treatment in Multiple Sclerosis as a strategy for reducing infection reactivation during immunosuppressant therapy.

BACKGROUND: Tuberculosis is an infectious disease with a risk of reactivation in Multiple Sclerosis patients on immunosuppressant therapy. Diagnosis and treatment of Latent Tuberculosis Infection (LTBI) prevents the infection. OBJECTIVE: To diagnose and treat LTBI in Multiple Sclerosis (MS). METHODS: Cross-sectional study of the prevalence and treatment of LTBI in MS, between February 2021 and June 2023. LTBI was defined as an absence of symptoms, positive PPD or IGRA and normal chest X-ray. RESULTS: Of the 58 patients with MS, 17 (29.3 %) were diagnosed with LTBI, 15 with PPD > 5 mm and 2 with positive IGRA, 10 (58.8 %) female and 7 (41.1 %) male, mean age of 41.3 (SD ±13.4) years. All patients with LTBI were treated with immunomodulators or immunosuppressants: Fingolimod 5 (29.4 %), Natalizumab 5 (29.4 %), Cladribine 2 (11.8 %), Glatiramer 2 (11.8 %), Ocrelizumab 2 (11.8 %), and Interferon beta 1 (5.9 %). Steroids therapy for relapses, were used in 5/17 (93.8 %) with LTBI and 30/37 (81.1 %) without LTBI. To treat LTBI, 11 (64.7 %) received Isoniazid and 6 (35.3 %) Isoniazid plus Rifapentine. Hepatotoxicity occurred in 3 (17.6 %) with INH. There were no interruptions of ILTB treatment during the study. CONCLUSION: The prevalence of LTBI was found to be high and treatment proved safe.

Fechar o cerco: estratégias na busca ativa de comunicantes de tuberculose / Closing the siege: strategies in the active search for tuberculosis contacts

A tuberculose é uma das doenças mais antigas do mundo. Os fatores de vulnerabilidade social, individual, programática, permitem que a tuberculose fique em latência por vários anos no indivíduo. Objetivo: Analisar, por meio de dados secundários, incidência e protocolo de infecção latente de tuberculose no município de São Paulo. Método: Trata-se de revisão sistemática da literatura. Em 29 de agosto de 2023, com a busca no Descritores em ciências da saúde: Tuberculose AND Infecção Latente, foram encontrados 4.527 artigos, após aplicação dos filtros: Base de dados LILACS e MEDLINE, texto completo, em Português, 2018 a 2023, restaram 38 documentos que foram submetidos ao checklist PRISMA. Resultados: Restaram 16 artigos que embasaram os resultados e a discussão. Conclusão: Iniciativas, como a busca ativa de comunicantes de tuberculose, devem ser construídas a partir de estratégias propostas em conjunto com pesquisadores e gestores alinhados ao Ministério da Saúde.(AU)

Tuberculosis is one of the oldest diseases in the world. Social, individual and programmatic vulnerability factors allow tuberculosis to remain latent for several years in the individual. Objective: To analyze, using secondary data, the incidence and protocol of latent tuberculosis infection in the city of São Paulo. Method: This is a systematic literature review. On August 29, 2023, 4,527 articles were found after applying the filters in the Health Sciences Descriptors: Tuberculosis AND Latent Infection: LILACS and MEDLINE database, full text, in Portuguese, 2018 to 2023, 38 documents remained that were submitted to the PRISMA checklist. Results: 16 articles were found to support the results and discussion. Conclusion: Initiatives, such as the active search for tuberculosis communicants, should be built on strategies proposed jointly with researchers and managers in line with the Ministry of Health.(AU)

La tuberculosis es una de las enfermedades más antiguas del mundo. Factores sociales, individuales y programáticos de vulnerabilidad permiten que la tuberculosis permanezca latente por varios años en el individuo. Objetivo: Analizar, a partir de datos secundarios, la incidencia y el protocolo de infección tuberculosa latente en el municipio de São Paulo. Método: Se trata de una revisión sistemática de la literatura. El 29 de agosto de 2023, fueron encontrados 4.527 artículos después de la aplicación de los filtros en los Descriptores de Ciencias de la Salud: Tuberculosis E Infección Latente: Base de datos LILACS y MEDLINE, texto completo, en portugués, 2018 a 2023, permanecieron 38 documentos que fueron sometidos a la lista de verificación PRISMA. Resultados: Quedaron 16 artículos, que constituyeron la base de los resultados y la discusión. Conclusión: Iniciativas como la búsqueda activa de comunicantes de tuberculosis deben construirse a partir de estrategias propuestas conjuntamente por investigadores y gestores en consonancia con el Ministerio de Salud.(AU)

Modulation of cytomegalovirus immune evasion identifies direct antigen presentation as the predominant mode of CD8 T-cell priming during immune reconstitution after hematopoietic cell transplantation.

Cytomegalovirus (CMV) infection is the most critical infectious complication in recipients of hematopoietic cell transplantation (HCT) in the period between a therapeutic hematoablative treatment and the hematopoietic reconstitution of the immune system. Clinical investigation as well as the mouse model of experimental HCT have consistently shown that timely reconstitution of antiviral CD8 T cells is critical for preventing CMV disease in HCT recipients. Reconstitution of cells of the T-cell lineage generates naïve CD8 T cells with random specificities among which CMV-specific cells need to be primed by presentation of viral antigen for antigen-specific clonal expansion and generation of protective antiviral effector CD8 T cells. For CD8 T-cell priming two pathways are discussed: "direct antigen presentation" by infected professional antigen-presenting cells (pAPCs) and "antigen cross-presentation" by uninfected pAPCs that take up antigenic material derived from infected tissue cells. Current view in CMV immunology favors the cross-priming hypothesis with the argument that viral immune evasion proteins, known to interfere with the MHC class-I pathway of direct antigen presentation by infected cells, would inhibit the CD8 T-cell response. While the mode of antigen presentation in the mouse model of CMV infection has been studied in the immunocompetent host under genetic or experimental conditions excluding either pathway of antigen presentation, we are not aware of any study addressing the medically relevant question of how newly generated naïve CD8 T cells become primed in the phase of lympho-hematopoietic reconstitution after HCT. Here we used the well-established mouse model of experimental HCT and infection with murine CMV (mCMV) and pursued the recently described approach of up- or down-modulating direct antigen presentation by using recombinant viruses lacking or overexpressing the central immune evasion protein m152 of mCMV, respectively. Our data reveal that the magnitude of the CD8 T-cell response directly reflects the level of direct antigen presentation.

[Study on risk factors of mycobacterium tuberculosis infection among health workers in medical institutions].

Objective: To understand the infection status of mycobacterium tuberculosis among health workers in tuberculosis designated medical institutions and explore the risk factors of infection. Methods: From September 2021 to June 2022, a questionnaire survey was conducted among health workers in relevant departments of 4 tuberculosis designated medical institutions by cluster stratified sampling, including the implementation of hospital infection control measures in medical institutions and occupational exposure of medical staff to mycobacterium tuberculosis. Peripheral blood interferon gamma release assays (IGRAs) and lung imaging examination were performed to determine the mycobacterium tuberculosis infection. Factors with statistical significance in univariate analysis were included in multivariate logistic regression to analyze the risk factors of mycobacterium tuberculosis infection. Results: A total of 657 people completed the lung imaging examination and questionnaire, of which 654 people had peripheral blood IGRAs detection, and the latent infection rate of tuberculosis was 39.45% (258/654) . Univariate analysis showed that age, sex, marital status, economic income, occupational category, professional title, length of service, and other variables had statistical significances in tuberculosis latent infection (P<0.05) . In terms of personal health status, there were statistically significant differences in the distribution of health workers in terms of their tuberculosis history, tuberculosis history of their immediate family members, previous tuberculin skin test (TST) (P<0.05) . Multivariate analysis showed that there were four risk factors related to tuberculosis, including professional title (X(1)) , years of tuberculosis related works (X(2)) , tuberculosis history (X(3)) and previous TST (X(4)) . The regression equation of the probability of tuberculosis among health workers was y=-1.920+0.246X(1)+0.046X(2)+1.231X(3)+0.478X(4). Conclusion: The latent infection rate of tuberculosis among health workers in tuberculosis designated medical institutions is high. It is necessary to strengthen the management of infection control, carry out regular screening, enhance the self-protection awareness of health workers, and reduce their exposure to mycobacterium tuberculosis and infection risk.