Occult hepatitis B virus infection and current perspectives on global WHO 2030 eradication

The current World Health Organization (WHO) Hepatitis Elimination Strategy suffers from lack of a target for diagnosing or expunging occult HBV infection. A sizable segment of the global population has an undetected HBV infection, particularly the high-risk populations and those residing in countries like India with intermediate endemicity. There is growing proof that people with hidden HBV infection can infect others, and that these infections are linked to serious chronic hepatic complications, especially hepatocellular carcinoma. Given the current diagnostic infrastructure in low-resource settings, the WHO 2030 objective of obliterating hepatitis B appears to be undeniably challenging to accomplish. Given the molecular basis of occult HBV infection strongly linked to intrahepatic persistence, patients may inexplicably harbour HBV genomes for a prolonged duration without displaying any pronounced clinical or biochemical signs of liver disease, and present histological signs of moderate degree necro-inflammation, diffuse fibrosis, and hence the international strategy to eradicate viral hepatitis warrants inclusion of occult HBV infection.

Chronic Viral Infection Compromises the Quality of Circulating Mucosal-Associated Invariant T Cells and Follicular T Helper Cells via Expression of Inhibitory Receptors

BACKGROUND

Chronic viral infection results in impaired immune responses rendering viral persistence. Here, we compared the quality of T-cell responses among chronic hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV)-infected individuals by examining the levels of expression of selected immune activation and exhaustion molecules on circulating MAIT cells and Tfh cells.

METHODS

Cytokines were measured using a commercial Bio-plex Pro Human Cytokine Grp I Panel 17-plex kit (BioRad, Hercules, CA, USA). Inflammation was assessed by measuring an array of plasma cytokines, and phenotypic alterations in CD4+ T cells including circulating Tfh cells, CD8+ T cells, and TCR iVα7.2+ MAIT cells in chronic HBV, HCV, and HIV-infected patients and healthy controls. The cells were characterized based on markers pertaining to immune activation (CD69, ICOS, and CD27) proliferation (Ki67), cytokine production (TNF-α, IFN-γ) and exhaustion (PD-1). The cytokine levels and T cell phenotypes together with cell markers were correlated with surrogate markers of disease progression.

RESULTS

The activation marker CD69 was significantly increased in CD4+hi T cells, while CD8+ MAIT cells producing IFN-γ were significantly increased in chronic HBV, HCV and HIV infections. Six cell phenotypes, viz., TNF-α+CD4+lo T cells, CD69+CD8+ T cells, CD69+CD4+ MAIT cells, PD-1+CD4+hi T cells, PD-1+CD8+ T cells, and Ki67+CD4+ MAIT cells, were independently associated with decelerating the plasma viral load (PVL). TNF-α levels showed a positive correlation with increase in cytokine levels and decrease in PVL.

CONCLUSION

Chronic viral infection negatively impacts the quality of peripheral MAIT cells and Tfh cells via differential expression of both activating and inhibitory receptors.

Genomic surveillance of omicron B.1.1.529 SARS-CoV-2 and its variants between December 2021 and March 2023 in Tamil Nadu, India-A state-wide prospective longitudinal study

A state-wide prospective longitudinal investigation of the genomic surveillance of the omicron B.1.1.529 SARS-CoV-2 variant and its sublineages in Tamil Nadu, India, was conducted between December 2021 and March 2023. The study aimed to elucidate their mutational patterns and their genetic interrelationship in the Indian population. The study identified several unique mutations at different time-points, which likely could attribute to the changing disease characteristics, transmission, and pathogenicity attributes of omicron variants. The study found that the omicron variant is highly competent in its mutating potentials, and that it continues to evolve in the general population, likely escaping from natural as well as vaccine-induced immune responses. Our findings suggest that continuous surveillance of viral variants at the global scenario is warranted to undertake intervention measures against potentially precarious SARS-CoV-2 variants and their evolution.

Clinical characteristics and novel mutations of omicron subvariant XBB in Tamil Nadu, India - a cohort study

BACKGROUND

Despite the continued vaccination efforts, there had been a surge in breakthrough infections, and the emergence of the B.1.1.529 omicron variant of SARS-CoV-2 in India. There is a paucity of information globally on the role of newer XBB variants in community transmission. Here, we investigated the mutational patterns among hospitalised patients infected with the XBB omicron sub-variant, and checked if there was any association between the rise in the number of COVID-19 cases and the observed novel mutations in Tamil Nadu, India.

METHODS

Nasopharyngeal and oropharyngeal swabs, collected from symptomatic and asymptomatic COVID-19 patients were subjected to real-time PCR followed by Next Generation Sequencing (NGS) to rule out the ambiguity of mutations in viruses isolated from the patients (n = 98). Using the phylogenetic association, the mutational patterns were used to corroborate clinico-demographic characteristics and disease severity among the patients.

FINDINGS

Overall, we identified 43 mutations in the S gene across 98 sequences, of which two were novel mutations (A27S and T747I) that have not been reported previously with XBB sub-variants in the available literature. Additionally, the XBB sequences from our cohort had more mutations than omicron B.1.1.529. The phylogenetic analysis comprising six major branches clearly showed convergent evolution of XBB. Our data suggests that age, and underlying conditions (e.g., diabetes, hypertension, and cardiovascular disease) or secondary complications confers increased susceptibility to infection rather than vaccination status or prior exposure. Many vaccinated individuals showed evidence of a breakthrough infection, with XBB.3 being the predominant variant identified in the study population.

INTERPRETATION

Our study indicates that the XBB variant is highly evasive from available vaccines and may be more transmissible, and potentially could emerge as the 'next' predominant variant, which likely could overwhelm the existing variants of SARS-CoV-2 omicron variants.

FUNDING

National Health Mission (India), SIDASARC, VINNMER (Sweden), ORIP/NIH (USA).

Plasma CXCL8 and MCP-1 as surrogate plasma biomarkers of latent tuberculosis infection among household contacts-A cross-sectional study

Early detection of latent tuberculosis infection (LTBI) is critical to TB elimination in the current WHO vision of End Tuberculosis Strategy. The study investigates whether detecting plasma cytokines could aid in diagnosing LTBI across household contacts (HHCs) positive for IGRA, HHCs negative for IGRA, and healthy controls. The plasma cytokines were measured using a commercial Bio-Plex Pro Human Cytokine 17-plex assay. Increased plasma CXCL8 and decreased MCP-1, TNF-α, and IFN-γ were associated with LTBI. Regression analysis showed that a combination of CXCL8 and MCP-1 increased the risk of LTBI among HHCs to 14-fold. Our study suggests that CXCL-8 and MCP-1 could serve as the surrogate biomarkers of LTBI, particularly in resource-limited settings. Further laboratory investigations are warranted before extrapolating CXCL8 and MCP-1 for their usefulness as surrogate biomarkers of LTBI in resource-limited settings.

Plasma CXCL8 and MCP-1 as biomarkers of latent tuberculosis infection

Background

Early detection of latent tuberculosis infection (LTBI) is critical to TB elimination in the current WHO vision of End Tuberculosis Strategy.

Methods

We investigated whether detecting plasma cytokines could aid in diagnosing LTBI across household contacts (HHCs) positive for IGRA, HHCs negative for IGRA, and healthy controls. We also measured the plasma cytokines using a commercial Bio-Plex Pro Human Cytokine 17-plex assay.

Results

Increased plasma CXCL8 and decreased MCP-1, TNF-α, and IFN-γ were associated with LTBI. Regression analysis showed that a combination of CXCL8 and MCP-1 increased the risk of LTBI among HHCs to 14-fold.

Conclusions

We postulated that CXCL8 and MCP-1 could be the surrogate biomarkers of LTBI, especially in resource-limited settings.

The Implementation of HIV Self-Testing in Resource-Limited Settings Where the HIV Disease Burden is High

In resource-limited settings, there is growing evidence that HIV testing is lacking among high-risk key populations such as men having sex with men, injection drug users, and transgenders largely due to stigma, discrimination, and lack of confidentiality. Findings from recent studies among high-risk key populations and the general population from various regions including resource-limited settings support the need for wider accessibility of HIV self-testing (HIV-ST) to reach those who may not otherwise have access to testing. Therefore, HIV-ST has untapped potential as a strategy to improve access to HIV testing and to increase testing frequency among key high-risk populations and their partners. Though HIV-ST has emerged as a safe, acceptable, and effective way to reach people, there are several roadblocks to implementing the HIV-ST policy, and fast-track policy implementation needs to be necessitated with newer or modified strategic plans.

Chronic viral infection compromises the quality of circulating mucosal-invariant T cells and follicular T helper cells via expression of both activating and inhibitory receptors

Chronic viral infection results in impaired immune responses rendering viral persistence. Here, we investigated the role of immune activation and compared the quality of T-cell responses in chronic HBV, HCV, and HIV infections. Cytokines were measured using a commercial Bio-plex Pro Human Cytokine Grp I Panel 17-plex kit (BioRad, Hercules, CA, USA). Inflammation was assessed by measuring an array of plasma cytokines, and peripheral CD4+ T cells including circulating Tfh cells, CD8+ T cells, and TCR iVα7.2+ MAIT cells in chronic HBV, HCV, and HIV-infected patients and healthy controls. The cells were characterized based markers pertaining to immune activation (CD69, ICOS, and CD27) proliferation (Ki67), cytokine production (TNF-α, IFN-γ) and exhaustion (PD-1). The cytokine levels and T cell phenotypes together with cell markers were correlated with surrogate markers of disease progression. The activation marker CD69 was significantly increased in CD4+ hi T cells, while CD8+ MAIT cells expressing IFN-γ were significantly increased in chronic HBV, HCV and HIV infections. Six cell phenotypes, viz., TNF-α+CD4+ lo T cells, CD69+CD8+ T cells, CD69+CD4+ MAIT cells, PD-1+CD4+ hi T cells, PD-1+CD8+ T cells, Ki67+CD4+ MAIT cells were independently associated with decelerating the plasma viral load (PVL). TNF-α levels showed a positive correlation with increase in cytokine levels and decrease in PVL. Chronic viral infection negatively impacts the quality of peripheral MAIT cells and TFH cells via expression of both activating and inhibitory receptors.

Impact of COVID-19 Vaccination on Pregnant Women

In light of the COVID-19 pandemic, researchers across the world hastened to develop vaccines that would aid in bolstering herd immunity. Utilizing mRNA coding and viral vector technology, the currently approved vaccines were required to undergo extensive testing to confirm their safety for mass usage in the general population. However, clinical trials failed to test the safety and efficacy of the COVID-19 vaccines in groups with weakened immune systems, especially pregnant women. Lack of information on the effects of vaccinations in pregnancy and the safety of fetuses are among the topmost reasons preventing pregnant women from receiving immunization. Thus, the lack of data examining the effects of COVID-19 vaccinations on pregnant women must be addressed. This review focused on the safety and efficacy of the approved COVID-19 vaccinations in pregnancy and their impact on both maternal and fetal immune responses. For that, we took the approach of combined systematic review/meta-analysis and compiled the available data from the original literature from PubMed, Web of Science, EMBASE and Medline databases. All articles analyzed presented no adverse effects of vaccination in pregnancy, with varying conclusions on the degree of effectiveness. The majority of the findings described robust immune responses in vaccinated pregnant women, successful transplacental antibody transfer, and implications for neonatal immunity. Hence, findings from the cumulative data available can be helpful in achieving COVID-19 herd immunization, including pregnant women.

Host cell responses against the pseudomonal biofilm: A continued tale of host-pathogen interactions

In biofilm formation, pathogens within the bacterial community coordinate a cell-cell communication system called quorum sensing (QS). This is achieved through various signalling pathways that regulate bacterial virulence and host immune response. Here, we reviewed the host responses, key clinical implications, and novel therapeutic approaches against the biofilms of P. aeruginosa. Given the high degree of intrinsic antibiotic resistance and biofilm formation by the pathogen, the ensuing treatment complications could result in high morbidity and mortality rates worldwide. Notwithstanding the availability of intervention strategies, there remains a paucity of effective therapeutic options to control biofilmogenesis. This review discusses the basic understanding of QS-associated virulence factors and several key therapeutic interventions to foil the biofilm menace of P. aeruginosa.

Surrogate Biomarkers of Disease Progression in Human Pegivirus Seropositive Human Immunodeficiency Virus-Infected Individuals

Scientific observations indicate that an actively prevailing systemic condition could alleviate the pathology of another disease. Human pegivirus (HPgV), a highly ubiquitous flavivirus is believed to be associated with slow human immunodeficiency virus (HIV) disease progression, and has seldom been linked to hepatic pathology. In this study, we investigated whether HPgV seropositivity had any impact on surrogate markers of HIV disease progression in a cohort of HIV-infected HPgV seropositive (n = 28) and seronegative (n = 12) individuals who were prospectively evaluated for absolute CD4+ T cell counts, plasma viral load (PVL), liver enzymes, and plasma cytokine levels. The HIV PVL was relatively lower in HPgV seropositive than in HPgV seronegative HIV-infected subjects. Clinical markers of hepatic injury were significantly low among HPgV seropositive HIV-infected participants. HPgV seropositive individuals showed significantly higher levels of interleukin-7 (IL-7), and although not significant, the levels of IL-6 were lower among HPgV seropositive subjects. Spearman correlation analysis showed that the absolute CD4+T cell count was inversely correlated with HIV PVL. Exposure to HPgV appears to have a positive prognostic impact on the levels of surrogate biomarkers of HIV disease progression.

Plasma interleukin-7 correlation with human immunodeficiency virus RNA and CD4+ T cell counts, and interleukin-5 with circulating hepatitis B virus DNA may have implications in viral control

Chronic viral infections represent a leading cause of global morbidity and mortality. Chronic HBV, HCV, and HIV infections result in cytokine perturbations that may hold key implications in understanding the complex disease mechanisms driving virus persistence and/or resolution. Here, we determined the levels of various plasma cytokines using a commercial Bio-Plex Luminex cytokine array in chronic HBV (n = 30), HCV (n = 15), and HIV (n = 40) infections and correlated with corresponding plasma viral loads (PVLs) and liver parameters. We observed differential perturbations in cytokine profiles among the study groups. The cytokines levels positively correlated with PVL and liver transaminases. The monocyte-derived cytokines viz., MIP-1β, IL-8, and TNF-α, and Th2 cytokines like IL-4, IL-5, and IL-13 showed a better correlation with liver enzymes as compared to their corresponding PVLs. Our investigation also identified two cytokines viz., IL-5 and IL-7 that inversely correlated with HBV DNA and HIV PVLs, respectively. Regression analysis adjusted for age showed that every increase of IL-5 by one unit was associated with a reduction in HBV PVL by log10 0.4, whereas, every elevation by a unit of IL-7 was associated with decreased HIV PVL by log10 2.5. We also found that IL-7 levels correlated positively with absolute CD4+ T cell counts in HIV-infected patients. We concluded that plasma IL-5 and IL-7 may likely have a key role on viral control in HBV and HIV infections, respectively. A noteworthy increase in cytokines appears to bear protective and pathological significance, and indeed is reflective of the host's versatile immune armory against viral persistence.

Low SARS-CoV-2 viral load among vaccinated individuals infected with Delta B.1.617.2 and Omicron BA.1.1.529 but not with Omicron BA.1.1 and BA.2 variants

The rapid spread of SARS-CoV-2 variants in the global population is indicative of the development of selective advantages in emerging virus strains. Here, we performed a case-control investigation of the clinical and demographic characteristics, clinical history, and virological markers to predict disease progression in hospitalized adults for COVID-19 between December 2021 and January 2022 in Chennai, India. COVID-19 diagnosis was made by a commercial TaqPath COVID-19 RT-PCR, and WGS was performed with the Ion Torrent Next Generation Sequencing System. High-quality (<5% of N) complete sequences of 73 Omicron B.1.1.529 variants were randomly selected for phylogenetic analysis. SARS-CoV-2 viral load, number of comorbidities, and severe disease presentation were independently associated with a shorter time-to-death. Strikingly, this was observed among individuals infected with Omicron BA.2 but not among those with the BA.1.1.529, BA.1.1, or the Delta B.1.617.2 variants. Phylogenetic analysis revealed severe cases predominantly clustering under the BA.2 lineage. Sequence analyses showed 30 mutation sites in BA.1.1.529 and 33 in BA.1.1. The mutations unique to BA.2 were T19I, L24S, P25del, P26del, A27S, V213G, T376A, D405N and R408S. Low SARS-CoV-2 viral load among vaccinated individuals infected with Delta B.1.617.2 and the Omicron BA.1.1.529 variant but not with Omicron BA.1.1 or BA.2 suggests that the newer strains are largely immune escape variants. The number of vaccine doses received was independently associated with increased odds of developing asymptomatic disease or recovery. We propose that the novel mutations reported herein could likely bear a significant impact on the clinical characteristics, disease progression, and epidemiological aspects of COVID-19. Surging rates of mutations and the emergence of eclectic variants of SARS-CoV-2 appear to impact disease dynamics.

HIV-1 induction of tolerogenic dendritic cells is mediated by cellular interaction with suppressive T cells

HIV-1 infection gives rise to a multi-layered immune impairment in most infected individuals. The chronic presence of HIV-1 during the priming and activation of T cells by dendritic cells (DCs) promotes the expansion of suppressive T cells in a contact-dependent manner. The mechanism behind the T cell side of this HIV-induced impairment is well studied, whereas little is known about the reverse effects exerted on the DCs. Herein we assessed the phenotype and transcriptome profile of mature DCs that have been in contact with suppressive T cells. The HIV exposed DCs from cocultures between DCs and T cells resulted in a more tolerogenic phenotype with increased expression of e.g., PDL1, Gal-9, HVEM, and B7H3, mediated by interaction with T cells. Transcriptomic analysis of the DCs separated from the DC-T cell coculture revealed a type I IFN response profile as well as an activation of pathways involved in T cell exhaustion. Taken together, our data indicate that the prolonged and strong type I IFN signaling in DCs, induced by the presence of HIV during DC-T cell cross talk, could play an important role in the induction of tolerogenic DCs and suppressed immune responses seen in HIV-1 infected individuals.

T cell perturbations persist for at least 6 months following hospitalization for COVID-19

COVID-19 is being extensively studied, and much remains unknown regarding the long-term consequences of the disease on immune cells. The different arms of the immune system are interlinked, with humoral responses and the production of high-affinity antibodies being largely dependent on T cell immunity. Here, we longitudinally explored the effect COVID-19 has on T cell populations and the virus-specific T cells, as well as neutralizing antibody responses, for 6-7 months following hospitalization. The CD8⁺ TEMRA and exhausted CD57⁺ CD8⁺ T cells were markedly affected with elevated levels that lasted long into convalescence. Further, markers associated with T cell activation were upregulated at inclusion, and in the case of CD69⁺ CD4⁺ T cells this lasted all through the study duration. The levels of T cells expressing negative immune checkpoint molecules were increased in COVID-19 patients and sustained for a prolonged duration following recovery. Within 2-3 weeks after symptom onset, all COVID-19 patients developed anti-nucleocapsid IgG and spike-neutralizing IgG as well as SARS-CoV-2-specific T cell responses. In addition, we found alterations in follicular T helper (TFH) cell populations, such as enhanced TFH-TH2 following recovery from COVID-19. Our study revealed significant and long-term alterations in T cell populations and key events associated with COVID-19 pathogenesis.

Dengue Infection - Recent Advances in Disease Pathogenesis in the Era of COVID-19

The dynamics of host-virus interactions, and impairment of the host’s immune surveillance by dengue virus (DENV) serotypes largely remain ambiguous. Several experimental and preclinical studies have demonstrated how the virus brings about severe disease by activating immune cells and other key elements of the inflammatory cascade. Plasmablasts are activated during primary and secondary infections, and play a determinative role in severe dengue. The cross-reactivity of DENV immune responses with other flaviviruses can have implications both for cross-protection and severity of disease. The consequences of a cross-reactivity between DENV and anti-SARS-CoV-2 responses are highly relevant in endemic areas. Here, we review the latest progress in the understanding of dengue immunopathogenesis and provide suggestions to the development of target strategies against dengue.

Factors Associated With the Decay of Anti-SARS-CoV-2 S1 IgG Antibodies Among Recipients of an Adenoviral Vector-Based AZD1222 and a Whole-Virion Inactivated BBV152 Vaccine

Background

The magnitude of protection conferred following recovery from COVID-19 or by vaccine administration, and the duration of protective immunity developed, remains ambiguous.

Methods

We investigated the factors associated with anti-SARS-CoV-2 S1 IgG decay in 519 individuals who recovered from COVID-19 illness or received COVID-19 vaccination with two commercial vaccines, viz., an adenoviral vector-based (AZD1222) and a whole-virion-based inactivated (BBV152) vaccine in Chennai, India from March to December 2021. Blood samples collected during regular follow-up post-infection/-vaccination were examined for anti-SARS-CoV-2 S1 IgG by a commercial automated chemiluminescent immunoassay (CLIA).

Results

Age and underlying comorbidities were the two variables that were independently associated with the development of a breakthrough infection. Individuals who were >60 years of age with underlying comorbid conditions (viz., hypertension, diabetes mellitus and cardiovascular disease) had a ~15 times and ~10 times greater odds for developing a breakthrough infection and hospitalization, respectively. The time elapsed since the first booster dose was associated with attrition in anti-SARS-CoV-2 IgG, where each month passed was associated with an ebb in the anti-SARS-CoV-2 IgG antibody levels by a coefficient of -6 units.

Conclusions

Our findings advocate that the elderly with underlying comorbidities be administered with appropriate number of booster doses with AZD1222 and BBV152 against COVID-19.

Comparative expression of pro-inflammatory and apoptotic biosignatures in chronic HBV-infected patients with and without liver cirrhosis

The interplay of immune mediators is paramount to optimal host anti-viral immune responses, especially against chronic hepatitis B virus (HBV) infection. Here, we investigated the dynamic changes in host immune responses in chronic HBV-infected individuals with and without liver cirrhosis by examining the signatures of apoptosis and plasma levels of pro-inflammatory cytokines, chemokines, and cytotoxic proteins. A total of 40 chronic HBV patients with and without liver cirrhosis were studied for plasma levels of immune mediators, and signatures of apoptosis in peripheral blood mononuclear cells (PBMCs). The intracellular concentrations of reactive oxygen species (ROS) in patients with chronic HBV with liver cirrhosis was relatively higher as compared to chronic HBV patients. The onset of apoptosis was sustained due to ongoing liver inflammation in concert with plasma TNF-α and IL-6 levels. Plasma VEGF was upregulated among chronic HBV patients with liver cirrhosis, whereas CCL2, CCL5 and granzyme B levels were down-regulated. High levels of ROS, IL-6 and TNF-α correlated with ongoing inflammation among chronic HBV patients with liver cirrhosis, which likely attributed to the expression of biosignatures of apoptosis and activation in immune cells.

Hijacking of the Host's Immune Surveillance Radars by Burkholderia pseudomallei

Burkholderia pseudomallei (B. pseudomallei) causes melioidosis, a potentially fatal disease for which no licensed vaccine is available thus far. The host-pathogen interactions in B. pseudomallei infection largely remain the tip of the iceberg. The pathological manifestations are protean ranging from acute to chronic involving one or more visceral organs leading to septic shock, especially in individuals with underlying conditions similar to COVID-19. Pathogenesis is attributed to the intracellular ability of the bacterium to ‘step into’ the host cell’s cytoplasm from the endocytotic vacuole, where it appears to polymerize actin filaments to spread across cells in the closer vicinity. B. pseudomallei effectively evades the host’s surveillance armory to remain latent for prolonged duration also causing relapses despite antimicrobial therapy. Therefore, eradication of intracellular B. pseudomallei is highly dependent on robust cellular immune responses. However, it remains ambiguous why certain individuals in endemic areas experience asymptomatic seroconversion, whereas others succumb to sepsis-associated sequelae. Here, we propose key insights on how the host’s surveillance radars get commandeered by B. pseudomallei.

Role of Aquaporins in Inflammation-a Scientific Curation

Inflammation is a universal response mechanism existing as inter-communicator of biological systems. Uncontrolled or dysregulated inflammation addresses chronic low-grade effects eventually resulting in multimorbidity. Active solute transport across the membrane establishes varying osmotic gradients. Aquaporins (AQPs) are a class of critical ubiquitously expressed transmembrane proteins that aid in fluid and small solute transport via facilitated diffusion over established osmotic gradients. Numerous significant data features the biological functions of AQPs rendering them as an appropriate biomarker of health and diseases. Besides their physiological role in well-balanced inflammatory responses, it is worth noting the dysregulation of AQPs during any undesirable inflammatory event. Most literature to date clearly sets out AQPs as potential drug targets instigating AQP-based therapies. In light of this conception, the current review provides a compendious overview on the propitious and portentous out-turns of AQPs under inflammation.

Complement-Opsonized HIV Modulates Pathways Involved in Infection of Cervical Mucosal Tissues: A Transcriptomic and Proteomic Study

Genital mucosal transmission is the most common route of HIV spread. The initial responses triggered at the site of viral entry are reportedly affected by host factors, especially complement components present at the site, and this will have profound consequences on the outcome and pathogenesis of HIV infection. We studied the initial events associated with host-pathogen interactions by exposing cervical biopsies to free or complement-opsonized HIV. Opsonization resulted in higher rates of HIV acquisition/infection in mucosal tissues and emigrating dendritic cells. Transcriptomic and proteomic data showed a significantly more pathways and higher expression of genes and proteins associated with viral replication and pathways involved in different aspects of viral infection including interferon signaling, cytokine profile and dendritic cell maturation for the opsonized HIV. Moreover, the proteomics data indicate a general suppression by the HIV exposure. This clearly suggests that HIV opsonization alters the initial signaling pathways in the cervical mucosa in a manner that promotes viral establishment and infection. Our findings provide a foundation for further studies of the role these early HIV induced events play in HIV pathogenesis.

Activated peripheral TFH cells and MAIT cells together with increased plasma TNF-α levels mark the pathogenesis of acute dengue virus infection

Dengue virus (DENV) infection has become an increasingly common public health concern in tropical and subtropical regions. Dengue infection appears to cause immune activation in a wide array of immune cells. Here, we estimated Th1 and Th2 cytokines and correlated their levels with primary and secondary dengue. We also investigated the signatures of immune activation of circulating Tfh cells and mucosal-associated invariant T (MAIT) cells in adults with confirmed acute clinical dengue virus infection. We found that IL-2, TNF-α, IL-4, and IL-10 levels were significantly elevated in patients with secondary DENV infection, whereas the level of IL-13 remained unaltered during both primary and secondary infections. No statistically significant difference was noticed with IL-12p70, IL-5, IFN-γ, and GM-CSF between the healthy controls and the primary and secondary dengue. Increase of 1 unit of TNF-α was associated with a decrease of 160 units of blood platelets. We found a higher frequency of activated Tfh cells and pTfh cells in clinical DENV infection. We also found similar activated and expanding phenotypes of MAIT cells. Our study suggests that TNF-α could play a key role in the pathogenesis of dengue along with activated pTfh cells and circulating MAIT cells in acute DENV infection.

SARS-CoV-2-Indigenous Microbiota Nexus: Does Gut Microbiota Contribute to Inflammation and Disease Severity in COVID-19?

Gut microbiome alterations may play a paramount role in determining the clinical outcome of clinical COVID-19 with underlying comorbid conditions like T2D, cardiovascular disorders, obesity, etc. Research is warranted to manipulate the profile of gut microbiota in COVID-19 by employing combinatorial approaches such as the use of prebiotics, probiotics and symbiotics. Prediction of gut microbiome alterations in SARS-CoV-2 infection may likely permit the development of effective therapeutic strategies. Novel and targeted interventions by manipulating gut microbiota indeed represent a promising therapeutic approach against COVID-19 immunopathogenesis and associated co-morbidities. The impact of SARS-CoV-2 on host innate immune responses associated with gut microbiome profiling is likely to contribute to the development of key strategies for application and has seldom been attempted, especially in the context of symptomatic as well as asymptomatic COVID-19 disease.

Chronic inflammation involves CCL11 and IL-13 to facilitate the development of liver cirrhosis and fibrosis in chronic hepatitis B virus infection

The pathogenesis involving non-alcoholic fatty liver disease (NAFLD) in the context of chronic HBV (CHB) virus infection requires to be understood for developing improved modalities of diagnosis and treatment. We retrospectively investigated the association between NAFLD and CHB virus infection in the context of liver fibrosis. Among the 522 consecutive CHB patients who underwent transient elastography between years 2013 and 2016, we studied 455 subjects in the current investigation. Controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) scores were generally higher in patients with steatosis and fibrosis or cirrhosis. Antiviral treatment had significantly reduced the hepatitis B virus (HBV) viral load. Other liver function markers showed a significant positive correlation with both CAP and LSM scores. Plasma IL-13 was independently associated with increased CAP score where every increase of 1 unit of IL-13 was associated with an increase in CAP score by 0.98 unit. CCL11 was independently associated with LSM with every increase of CCL11 by a unit that, in turn, was associated with an increase of LSM score. We found that there was a high concurrence of NAFLD among patients with CHB virus infection. The presence of metabolic syndrome and chronic inflammation in CHB virus-infected patients were two independent factors that led to the progression of liver cirrhosis, with IL-13 playing the key role in linking the metabolic with the inflammatory components.

The Functional Significance of Endocrine-immune Interactions in Health and Disease

Hormones are known to influence various body systems that include skeletal, cardiac, digestive, excretory, and immune systems. Emerging investigations suggest the key role played by secretions of endocrine glands in immune cell differentiation, proliferation, activation, and memory attributes of the immune system. The link between steroid hormones such as glucocorticoids and inflammation is widely known. However, the role of peptide hormones and amino acid derivatives such as growth and thyroid hormones, prolactin, dopamine, and thymopoietin in regulating the functioning of the immune system remains unclear. Here, we reviewed the findings pertinent to the functional role of hormone-immune interactions in health and disease and proposed perspective directions for translational research in the field.

Asymptomatic SARS-CoV-2 infection: is it all about being refractile to innate immune sensing of viral spare-parts?-Clues from exotic animal reservoirs

A vast proportion of coronavirus disease 2019 (COVID-19) individuals remain asymptomatic and can shed severe acute respiratory syndrome (SARS-CoV) type 2 virus to transmit the infection, which also explains the exponential increase in the number of COVID-19 cases globally. Furthermore, the rate of recovery from clinical COVID-19 in certain pockets of the globe is surprisingly high. Based on published reports and available literature, here, we speculated a few immunovirological mechanisms as to why a vast majority of individuals remain asymptomatic similar to exotic animal (bats and pangolins) reservoirs that remain refractile to disease development despite carrying a huge load of diverse insidious viral species, and whether such evolutionary advantage would unveil therapeutic strategies against COVID-19 infection in humans. Understanding the unique mechanisms that exotic animal species employ to achieve viral control, as well as inflammatory regulation, appears to hold key clues to the development of therapeutic versatility against COVID-19.

Peripheral Follicular T Helper Cells and Mucosal-Associated Invariant T Cells Represent Activated Phenotypes During the Febrile Phase of Acute Dengue Virus Infection

Peripheral follicular helper T (pTfh) cells represent specialized CD4⁺ T cells that help B cells to secrete antibodies. Dengue infection appears to cause immune activation in a wide array of immune cells. Herein, we investigated the signatures of immune activation of circulating Tfh cells and mucosal-associated invariant T (MAIT) cells in adult subjects with confirmed acute clinical dengue virus (DENV) infection by multiparametric flow cytometry. The acute DENV infection induced a significant expansion of highly activated pTfh cells and circulating MAIT cells during acute febrile infection. We found a higher frequency of activated PD-1⁺ Tfh cells and CD38⁺ pTfh cells in clinical DENV infection. We also found similar activated and expanding phenotypes of MAIT cells in the patients tested. The total counts of activated pTfh cells and circulating MAIT cells were higher in dengue patients relative to healthy controls. We concluded that pTfh cells and circulating MAIT cells represent activated phenotypes in acute DENV infection.

Complement opsonization of HIV affects primary infection of human colorectal mucosa and subsequent activation of T cells

HIV transmission via genital and colorectal mucosa are the most common routes of dissemination. Here, we explored the effects of free and complement-opsonized HIV on colorectal tissue. Initially, there was higher antiviral responses in the free HIV compared to complement-opsonized virus. The mucosal transcriptional response at 24 hr revealed the involvement of activated T cells, which was mirrored in cellular responses observed at 96 hr in isolated mucosal T cells. Further, HIV exposure led to skewing of T cell phenotypes predominantly to inflammatory CD4+ T cells, that is Th17 and Th1Th17 subsets. Of note, HIV exposure created an environment that altered the CD8+ T cell phenotype, for example expression of regulatory factors, especially when the virions were opsonized with complement factors. Our findings suggest that HIV-opsonization alters the activation and signaling pathways in the colorectal mucosa, which promotes viral establishment by creating an environment that stimulates mucosal T cell activation and inflammatory Th cells.

Molecular diversity of dengue virus serotypes 1-4 during an outbreak of acute dengue virus infection in Theni, India

Background

Dengue fever (DF) is caused by an arthropod-borne dengue virus (DENV), has four serotypes and several genotypes. Although having clinical and epidemiological significance, the information on the circulating serotypes/genotypes is scarce in India.

Materials and Methods

Blood specimens were collected from the patients suspected of DF and they are tested for DENV NS1 antigen and DENV IgM by ELISA. Antigen-positive samples were further serotyped by reverse transcriptase polymerase chain reaction. Representative samples from each serotype were sequenced to identify the genotypes.

Results

All the four DENV serotypes were detected with the pre-dominance of DENV-1 (n = 49; 41.9%). Cases with multiple DENV serotype infections were also identified. Genotyping showed that DENV-1 belonging to genotype I, DENV-2 cosmopolitan (IV), DENV-3 genotype III and DENV-4 genotype I were active in the circulation during the outbreak in 2017.

Conclusion

Our study documents the molecular characteristics of DENV circulating in our geographical locality. The detection of heterologous DENV serotypes highlights the importance of regular molecular monitoring for the early recognition of any switch in pre-dominant serotype.

Intracellular survival and innate immune evasion of Burkholderia cepacia: Improved understanding of quorum sensing-controlled virulence factors, biofilm, and inhibitors

Burkholderia cepacia complex (Bcc) are opportunistic pathogens implicated with nosocomial infections, and high rates of morbidity and mortality, especially in individuals with cystic fibrosis (CF). B. cepacia are naturally resistant to different classes of antibiotics, and can subvert the host innate immune responses by producing quorum sensing (QS) controlled virulence factors and biofilms. It still remains a conundrum as to how exactly the bacterium survives the intracellular environment within the host cells of CF patients and immunocompromised individuals although the bacterium can invade human lung epithelial cells, neutrophils, and murine macrophages. The mechanisms associated with intracellular survival in the airway epithelial cells and the role of QS and virulence factors in B. cepacia infections in cystic fibrosis remain largely unclear. The current review focuses on understanding the role of QS-controlled virulence factors and biofilms, and provides additional impetus to understanding the potentials of QS-inhibitory strategies against B. cepacia.

Immune Biomarkers for Diagnosis and Treatment Monitoring of Tuberculosis: Current Developments and Future Prospects

Tuberculosis (TB) treatment monitoring is paramount to clinical decision-making and the host biomarkers appears to play a significant role. The currently available diagnostic technology for TB detection is inadequate. Although GeneXpert detects total DNA present in the sample regardless live or dead bacilli present in clinical samples, all the commercial tests available thus far have low sensitivity. Humoral responses against Mycobacterium tuberculosis (Mtb) antigens are generally low, which precludes the use of serological tests for TB diagnosis, prognosis, and treatment monitoring. Mtb-specific CD4⁺ T cells correlate with Mtb antigen/bacilli burden and hence might serve as good biomarkers for monitoring treatment progress. Omics-based techniques are capable of providing a more holistic picture for disease mechanisms and are more accurate in predicting TB disease outcomes. The current review aims to discuss some of the recent advances on TB biomarkers, particularly host biomarkers that have the potential to diagnose and differentiate active TB and LTBI as well as their use in disease prognosis and treatment monitoring.

HSV-2 Cellular Programming Enables Productive HIV Infection in Dendritic Cells

Genital herpes is a common sexually transmitted infection caused by herpes simplex virus type 2 (HSV-2). Genital herpes significantly enhances the acquisition and transmission of HIV-1 by creating a microenvironment that supports HIV infection in the host. Dendritic cells (DCs) represent one of the first innate cell types that encounter HIV-1 and HSV-2 in the genital mucosa. HSV-2 infection has been shown to modulate DCs, rendering them more receptive to HIV infection. Here, we investigated the potential mechanisms underlying HSV-2-mediated augmentation of HIV-1 infection. We demonstrated that the presence of HSV-2 enhanced productive HIV-1 infection of DCs and boosted inflammatory and antiviral responses. The HSV-2 augmented HIV-1 infection required intact HSV-2 DNA, but not active HSV-2 DNA replication. Furthermore, the augmented HIV infection of DCs involved the cGAS-STING pathway. Interestingly, we could not see any involvement of TLR2 or TLR3 nor suppression of infection by IFN-β production. The conditioning by HSV-2 in dual exposed DCs decreased protein expression of IFI16, cGAS, STING, and TBK1, which is associated with signaling through the STING pathway. Dual exposure to HSV-2 and HIV-1 gave decreased levels of several HIV-1 restriction factors, especially SAMHD1, TREX1, and APOBEC3G. Activation of the STING pathway in DCs by exposure to both HSV-2 and HIV-1 most likely led to the proteolytic degradation of the HIV-1 restriction factors SAMHD1, TREX1, and APOBEC3G, which should release their normal restriction of HIV infection in DCs. This released their normal restriction of HIV infection in DCs. We showed that HSV-2 reprogramming of cellular signaling pathways and protein expression levels in the DCs provided a setting where HIV-1 can establish a higher productive infection in the DCs. In conclusion, HSV-2 reprogramming opens up DCs for HIV-1 infection and creates a microenvironment favoring HIV-1 transmission.

Recent advances on T-cell exhaustion in malaria infection

T-cell exhaustion reportedly leads to dysfunctional immune responses of antigen-specific T cells. Investigations have revealed that T cells expand into functionally defective phenotypes with poor recall/memory abilities to parasitic antigens. The exploitation of co-inhibitory pathways represent a highly viable area of translational research that has very well been utilized against certain cancerous conditions. Malaria, at times, evolve into a sustained chronic state where T cells express several co-inhibitory molecules (negative immune checkpoints) facilitating parasite escape and sub-optimal protective responses. Experimental evidence suggests that blockade of co-inhibitory molecules on T cells in malaria could result in the sustenance of protective responses together with dramatic parasite clearance. The role of several co-inhibitory molecules in malaria infection largely remain unclear, and here we discussed the potential applicability of co-inhibitory molecules in the management of malaria with a view to harness protective host responses against chronic disease and associated consequences.

Complement-Opsonized HIV-1 Alters Cross Talk Between Dendritic Cells and Natural Killer (NK) Cells to Inhibit NK Killing and to Upregulate PD-1, CXCR3, and CCR4 on T Cells

Dendritic cells (DCs), natural killer (NK) cells, and T cells play critical roles during primary HIV-1 exposure at the mucosa, where the viral particles become coated with complement fragments and mucosa-associated antibodies. The microenvironment together with subsequent interactions between these cells and HIV at the mucosal site of infection will determine the quality of immune response that ensues adaptive activation. Here, we investigated how complement and immunoglobulin opsonization influences the responses triggered in DCs and NK cells, how this affects their cross talk, and what T cell phenotypes are induced to expand following the interaction. Our results showed that DCs exposed to complement-opsonized HIV (C-HIV) were less mature and had a poor ability to trigger IFN-driven NK cell activation. In addition, when the DCs were exposed to C-HIV, the cytotolytic potentials of both NK cells and CD8 T cells were markedly suppressed. The expression of PD-1 as well as co-expression of negative immune checkpoints TIM-3 and LAG-3 on PD-1 positive cells were increased on both CD4 as well as CD8 T cells upon interaction with and priming by NK–DC cross talk cultures exposed to C-HIV. In addition, stimulation by NK–DC cross talk cultures exposed to C-HIV led to the upregulation of CD38, CXCR3, and CCR4 on T cells. Together, the immune modulation induced during the presence of complement on viral surfaces is likely to favor HIV establishment, dissemination, and viral pathogenesis.

Adhesion and invasion attributes of Burkholderia pseudomallei are dependent on airway surface liquid and glucose concentrations in lung epithelial cells

Physiological constituents in airway surface liquids (ASL) appear to impact the adherence and invasion potentials of Burkholderia pseudomallei contributing to recrudescent melioidosis. Here, we investigated the factors present in ASL that is likely to influence bacterial adhesion and invasion leading to improved understanding of bacterial pathogenesis. Six B. pseudomallei clinical isolates from different origins were used to investigate the ability of the bacteria to adhere and invade A549 human lung epithelial cells using a system that mimics the physiological ASL with different pH, NaCl, KCl, CaCl₂ and glucose concentrations. These parameters resulted in markedly differential adherence and invasion abilities of B. pseudomallei to the lung epithelial cells. The concentration of 20 mM glucose dramatically increased adherence and invasion by increasing the rate of pili formation in depiliated bacteria. Glucose significantly increased adherence and invasion of B. pseudomallei to A549 cells, and presence of NaCl, KCl and CaCl₂ markedly ablated the effect despite the presence of glucose. Our data established a link between glucose, enhanced adhesion and invasion potentials of B. pseudomallei, hinting increased susceptibility of individuals with diabetes mellitus to clinical melioidosis.

Hyper-Expression of PD-1 Is Associated with the Levels of Exhausted and Dysfunctional Phenotypes of Circulating CD161++TCR iVα7.2+ Mucosal-Associated Invariant T Cells in Chronic Hepatitis B Virus Infection

Mucosal-associated invariant T (MAIT) cells, defined as CD161⁺⁺TCR iVα7.2⁺ T cells, play an important role in the innate defense against bacterial infections, and their functionality is impaired in chronic viral infections. Here, we investigated the frequency and functional role of MAIT cells in chronic hepatitis B virus (HBV) infection. The peripheral CD3⁺CD161⁺⁺TCR iVα7.2⁺ MAIT cells in chronic HBV-infected patients and healthy controls were phenotypically characterized based on CD57, PD-1, TIM-3, and CTLA-4, as well as HLA-DR and CD38 expression. The frequency of MAIT cells was significantly decreased among chronic HBV-infected individuals as compared to controls. Expression of CD57, PD-1, CTLA-4, as well as HLA-DR and CD38 on MAIT cells was significantly elevated in chronic HBV-infected individuals relative to controls. The percentage of T cell receptor (TCR) iVα7.2⁺ CD161⁺ MAIT cells did not correlate with HBV viral load but inversely with HLA-DR on CD4⁺ T cells and MAIT cells and with CD57 on CD8⁺ T cells suggesting that decrease of MAIT cells may not be attributed to direct infection by HBV but driven by HBV-induced chronic immune activation. The percentage and expression levels of PD-1 as well as CTLA-4 on MAIT cells inversely correlated with plasma HBV-DNA levels, which may suggest either a role for MAIT cells in the control of HBV infection or the effect of HBV replication in the liver on MAIT cell phenotype. We report that decrease of TCR iVα7.2⁺ MAIT cells in the peripheral blood and their functions were seemingly impaired in chronic HBV-infected patients likely because of the increased expression of PD-1.

Persistent infection due to a small-colony variant of Burkholderia pseudomallei leads to PD-1 upregulation on circulating immune cells and mononuclear infiltration in viscera of experimental BALB/c mice

Background

Melioidosis is a neglected tropical disease endemic across South East Asia and Northern Australia. The etiological agent, Burkholderia pseudomallei (B.pseudomallei), is a Gram-negative, rod-shaped, motile bacterium residing in the soil and muddy water across endemic regions of the tropical world. The bacterium is known to cause persistent infections by remaining latent within host cells for prolonged duration. Reactivation of the recrudescent disease often occurs in elders whose immunity wanes. Moreover, recurrence rates in melioidosis patients can be up to ~13% despite appropriate antibiotic therapy, suggestive of bacterial persistence and inefficacy of antibiotic regimens. The mechanisms behind bacterial persistence in the host remain unclear, and hence understanding host immunity during persistent B. pseudomallei infections may help designing potential immunotherapy.

Methodology/Principal findings

A persistent infection was generated using a small-colony variant (SCV) and a wild-type (WT) B. pseudomallei in BALB/c mice via intranasal administration. Infected mice that survived for >60 days were sacrificed. Lungs, livers, spleens, and peripheral blood mononuclear cells were harvested for experimental investigations. Histopathological changes of organs were observed in the infected mice, suggestive of successful establishment of persistent infections. Moreover, natural killer (NK) cell frequency was increased in SCV- and WT-infected mice. We observed programmed death-1 (PD-1) upregulation on B cells of SCV- and WT-infected mice. Interestingly, PD-1 upregulation was only observed on NK cells and monocytes of SCV-infected mice. In contrast, cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) downregulation was seen on NK cells of WT-infected mice, and on monocytes of SCV- and WT-infected mice.

Conclusions/Significance

The SCV and the WT of B. pseudomallei distinctly upregulated PD-1 expression on B cells, NK cells, and monocytes to dampen host immunity, which likely facilitates bacterial persistence. PD-1/PD-L1 pathway appears to play an important role in the persistence of B. pseudomallei in the host.

B. pseudomallei is a bacterium that causes melioidosis, a disease endemic in Southeastern Asia and Northern Australia. It is estimated that melioidosis leads to 89,000 deaths worldwide each year. Nevertheless, melioidosis continues to remain a neglected tropical disease that is not even on the list of neglected tropical diseases of the World Health Organization. Furthermore, the disease has a high mortality and recurrence rate, which can be up to 40% and 13%, respectively. It has also been well documented that B. pseudomallei causes latent/persistent infections for a prolonged period without showing apparent symptoms in the infected individual. The mechanisms that are responsible for bacterial persistence in the host remain unclear. Our results demonstrated that B. pseudomallei were able to upregulate PD-1 expression on B cells, NK cells, and/or monocytes during persistent diseases, which likely diminish optimal host immunity. The weakened host immunity in turns facilitates persistence of the bacterium. Interestingly, the SCV had a higher PD-1 expression on distinct immune cells compared to the WT, which might explain its frequent association with persistent infections. Immunotherapies by targeting PD-1/PD-L1 pathway could serve as a better treatment than the conventional antibiotic regimens, which cause a high rate of recurrence in melioidosis patients.

Decrease of CD69 levels on TCR Vα7.2+CD4+ innate-like lymphocytes is associated with impaired cytotoxic functions in chronic hepatitis B virus-infected patients

Hepatitis B virus (HBV) infection is a major cause of chronic liver disease that may progress to liver cirrhosis and hepatocellular carcinoma. Host immune responses represent the key determinants of HBV clearance or persistence. Here, we investigated the role of the early activation marker, CD69 and effector cytokines, granzyme B (GrB) and IFN-γ in the exhaustion of innate-like TCR Vα7.2⁺CD4⁺T cells, in 15 individuals with chronic HBV (CHB) infection where six were HBV DNA⁺ and nine were HBV DNA^-. The percentage of cytokine-producing T cells and MAIT cells were significantly perturbed in HBV patients relative to healthy controls (HCs). The intracellular expression of GrB and IFN-γ was significantly reduced in MAIT cells derived from HBV-infected patients as compared to HCs, and the levels correlated with the percentage and levels [mean fluorescence intensity (MFI)] of CD69 expression. The total expression of CD69 (iMFI) was lower in CHB patients as compared to HCs. The frequency of CD69⁺ cells correlated with the levels of cytokine expression (MFI), particularly in CHB patients as compared to HCs. In summary, the polyfunctionality of peripheral T cells was significantly reduced among CHB patients, especially in the TCR Vα7.2⁺CD4⁺T cells, and the levels of cytokine expression correlated with functional cytokine levels.

Aberrant monocyte responses predict and characterize dengue virus infection in individuals with severe disease

BACKGROUND

Currently, several assays can diagnose acute dengue infection. However, none of these assays can predict the severity of the disease. Biomarkers that predicts the likelihood that a dengue patient will develop a severe form of the disease could permit more efficient patient triage and allows better supportive care for the individual in need, especially during dengue outbreaks.

METHODS

We measured 20 plasma markers i.e. IFN-γ, IL-10, granzyme-B, CX3CL1, IP-10, RANTES, CXCL8, CXCL6, VCAM, ICAM, VEGF, HGF, sCD25, IL-18, LBP, sCD14, sCD163, MIF, MCP-1 and MIP-1β in 141 dengue patients in over 230 specimens and correlate the levels of these plasma markers with the development of dengue without warning signs (DWS-), dengue with warning signs (DWS+) and severe dengue (SD).

RESULTS

Our results show that the elevation of plasma levels of IL-18 at both febrile and defervescence phase was significantly associated with DWS+ and SD; whilst increase of sCD14 and LBP at febrile phase were associated with severity of dengue disease. By using receiver operating characteristic (ROC) analysis, the IL-18, LBP and sCD14 were significantly predicted the development of more severe form of dengue disease (DWS+/SD) (AUC = 0.768, P < 0.0001; AUC = 0.819, P < 0.0001 and AUC = 0.647, P = 0.014 respectively). Furthermore, we also found that the levels of VEGF were directly correlated and sCD14 was inversely correlated with platelet count, suggesting that the endothelial activation and microbial translocation may played a role in pathogenesis of dengue disease.

CONCLUSIONS

Given that the elevation IL-18, LBP and sCD14 among patients with severe form of dengue disease, our findings suggest a pathogenic role for an aberrant inflammasome and monocyte activation in the development of severe form of dengue disease.