Optimizing SARS-CoV-2 vaccine responses in kidney transplant recipients: an urgent need.

Kidney transplant recipients (KTRs) have been identified as a population at increased risk for severe SARS-CoV-2 infection outcomes. This study focused on understanding the immune response of KTRs post-vaccination, specifically examining both serological and cellular responses to the SARS-CoV-2 vaccine. Thirteen individuals, including seven KTRs and six healthy donors, were evaluated for antibody levels and T cell responses post-vaccination. The study revealed that KTRs had significantly lower serological responses, including reduced anti-receptor binding domain (RBD) binding antibodies and neutralizing antibodies against the Wuhan, Delta, and Omicron BA.2 strains. Additionally, KTRs demonstrated weaker CD8 T cell cytotoxic responses and lower Th1 cytokine secretion, particularly IFN-γ, after stimulation with variant spike peptide pools. These findings highlight the compromised immunity in KTRs post-vaccination and underscore the need for tailored strategies to bolster immune responses in this vulnerable group. Further investigations are warranted into the mechanisms underlying reduced vaccine efficacy in KTRs and potential therapeutic interventions. IMPORTANCE: Some studies have revealed that KTRs had lower serological response against SARS-CoV-2 than healthy people. Nevertheless, limited studies investigate the cellular response against SARS-CoV-2 in KTRs receiving SARS-CoV-2 vaccines. Here, we found that KTRs have lower serological and cellular responses. Moreover, we found that KTRs had a significantly lower IFN-γ secretion than healthy individuals when their PBMCs were stimulated with SARS-CoV-2 spike peptide pools. Thus, our findings suggested that additional strategies are needed to enhance KTR immunity triggered by the vaccine.

Humoral responses to multiple SARS-CoV-2 variants after two doses of vaccine in kidney transplant patients.

Background: The COVID-19 pandemic has led to millions of fatalities globally. Kidney transplant (KT) patients, given their comorbidities and under immunosuppressant drugs, are identified as a high-risk group. Though vaccination remains pivotal for pandemic control, some studies indicate that KT exhibits diminished immune reactions to SARS-CoV-2 vaccines. Therefore, evaluating the vaccine responses in KT, especially the humoral responses against emergent variants is crucial.Methods: We developed a multiplexed SARS-CoV-2 variant protein microarray, incorporating the extracellular domain (ECD) and the receptor binding domain (RBD) of the spike proteins from the variants. This was employed to investigate the collective humoral responses after administering two doses of mRNA-1273 and AZD1222 vaccines in KT under immunosuppressive drugs and in healthy controls.Results: After two doses of either mRNA-1273 or AZD1222, the KT generally showed lower surrogate neutralizing and total antibodies against spike ECD in multiple variants compared to healthy controls. Although two doses of mRNA-1273 induced 1.5-2 fold more surrogate neutralizing and total antibodies than AZD1222 in healthy controls, the KT subjects with two doses of mRNA-1273 generally exhibited higher surrogate neutralizing but similar total antibodies against spike ECD in multiple variants. There were moderate to high correlations between the surrogate neutralizing and total antibodies against spike ECDs.Conclusion: This study offers pivotal insights into the relative vulnerability of KT concerning humoral immunity and the evolving mutations of SARS-CoV-2. Such findings are useful for evaluating vaccine responses and recommending vaccine episodes for KT.

Antibody Profiling of Dengue Severities Using Flavivirus Protein Microarrays.

Dengue is a viral disease transmitted by Aedes aegypti mosquitoes. According to the World Health Organization, about half of the world's population is at risk of dengue. There are four serotypes of the dengue virus. After infection with one serotype, it will be immune to such a serotype. However, subsequent infection with other serotypes will increase the risk of severe outcomes, e.g., dengue hemorrhagic fever, dengue shock syndrome, and even death. Since severe dengue is challenging to predict and lacks molecular markers, we aim to build a multiplexed Flavivirus protein microarray (Flaviarray) that includes all of the common Flaviviruses to profile the humoral immunity and cross-reactivity in the dengue patients with different outcomes. The Flaviarrays we fabricated contained 17 Flavivirus antigens with high reproducibility (R-square = 0.96) and low detection limits (172-214 pg). We collected serums from healthy subjects (n = 36) and dengue patients within 7 days after symptom onset (mild dengue (n = 21), hospitalized nonsevere dengue (n = 29), and severe dengue (n = 36)). After profiling the serum antibodies using Flaviarrays, we found that patients with severe dengue showed higher IgG levels against multiple Flavivirus antigens. With logistic regression, we found groups of markers with high performance in distinguishing dengue patients from healthy controls as well as hospitalized from mild cases (AUC > 0.9). We further reported some single markers that were suitable to separate dengue patients from healthy controls (AUC > 0.9) and hospitalized from mild outcomes (AUC > 0.8). Together, Flaviarray is a valuable tool to profile antibody specificities, uncover novel markers for decision-making, and shed some light on early preventions and treatments.

Developing magnetic barcode bead fluorescence assay for high throughput analyzing humoral responses against multiple SARS-CoV-2 variants.

The continuous mutation of SARS-CoV-2 highlights the need for rapid, cost-effective, and high-throughput detection methods. To better analyze the antibody levels against SARS-CoV-2 and its variants in vaccinated or infected subjects, we developed a multiplex detection named Barcode Bead Fluorescence (BBF) assay. These barcode beads were magnetic, characterized by 2-dimensional edges, highly multiplexed, and could be decrypted with visible light. We conjugated 12 magnetic barcode beads with corresponding nine spike proteins (wild-type, alpha, beta, gamma, delta, and current omicrons), two nucleocapsid proteins (wild-type and omicron), and one negative control. First, the conjugated beads underwent serial quality controls via fluorescence labeling, e.g., reproducibility (R square = 0.99) and detection limits (119 pg via anti-spike antibody). Next, we investigated serums from vaccinated subjects and COVID-19 patients for clinical applications. A significant reduction of antibody levels against all variant beads was observed in both vaccinated and COVID-19 studies. Subjects with two doses of mRNA-1273 exhibited the highest level of antibodies against all spike variants compared to two doses of AZD1222 and unvaccinated. We also found that COVID-19 patients showed higher antibody levels against spike beads from wild-type, alpha, beta, and delta. Finally, the nucleocapsid beads served as markers to distinguish infections from vaccinated subjects. Overall, this study developed the BBF assay for analyzing humoral immune responses, which has the advantages of robustness, automation, scalability, and cost-effectiveness.

Profiling humoral responses to COVID-19 immunization in Kawasaki disease using SARS-CoV-2 variant protein microarrays.

Kawasaki disease (KD) is a form of acute systemic vasculitis syndrome that predominantly occurs in children under the age of 5 years. Its etiology has been postulated due to not only genetic factors but also the presence of foreign antigens or infectious agents. To evaluate possible associations between Kawasaki disease (KD) and COVID-19, we investigated humoral responses of KD patients against S-protein variants with SARS-CoV-2 variant protein microarrays. In this study, plasma from a cohort of KD (N = 90) and non-KD control (non-KD) (N = 69) subjects in categories of unvaccinated-uninfected (pre-pandemic), SARS-CoV-2 infected (10-100 days after infection), and 1-dose, 2-dose, and 3-dose BNT162b2 vaccinated (10-100 days after vaccination) was collected. The principal outcomes were non-KD-KD differences for each category in terms of anti-human/anti-His for binding antibodies and neutralizing percentage for surrogate neutralizing antibodies. Binding antibodies against spikes were lower in the KD subjects with 1-dose of BNT162b2, and mean differences were significant for the P.1 S-protein (non-KD-KD, 3401; 95% CI, 289.0 to 6512; P = 0.0252), B.1.617.2 S-protein (non-KD-KD, 4652; 95% CI, 215.8 to 9087; P = 0.0351) and B.1.617.3 S-protein (non-KD-KD, 4874; 95% CI, 31.41 to 9716; P = 0.0477). Neutralizing antibodies against spikes were higher in the KD subjects with 1-dose of BNT162b2, and mean percentage differences were significant for the 1-dose BNT162b2 B.1.617.3 S-protein (non-KD-KD, -22.89%; 95% CI, -45.08 to -0.6965; P = 0.0399), B.1.1.529 S-protein (non-KD-KD, -25.96%; 95% CI, -50.53 to -1.376; P = 0.0333), BA.2.12.1 S-protein (non-KD-KD, -27.83%; 95% CI, -52.55 to -3.115; P = 0.0195), BA.4 S-protein (non-KD-KD, -28.47%; 95% CI, -53.59 to -3.342; P = 0.0184), and BA.5 S-protein (non-KD-KD, -30.42%; 95% CI, -54.98 to -5.869; P = 0.0077). In conclusion, we have found that KD patients have a comparable immunization response to healthy individuals to SARS-CoV-2 infection and COVID-19 immunization.

Pre-existing humoral immunity and CD4+ T cell response correlate with cross-reactivity against SARS-CoV-2 Omicron subvariants after heterologous prime-boost vaccination.

BACKGROUND: Information regarding the heterologous prime-boost COVID vaccination has been fully elucidated. The study aimed to evaluate both humoral, cellular immunity and cross-reactivity against variants after heterologous vaccination. METHODS: We recruited healthcare workers previously primed with Oxford/AstraZeneca ChAdOx1-S vaccines and boosted with Moderna mRNA-1273 vaccine boost to evaluate the immunological response. Assay used: anti-spike RBD antibody, surrogate virus neutralizing antibody and interferon-γ release assay. RESULTS: All participants exhibited higher humoral and cellular immune response after the booster regardless of prior antibody level, but those with higher antibody level demonstrated stronger booster response, especially against omicron BA.1 and BA.2 variants. The pre-booster IFN-γ release by CD4+ T cells correlates with post-booster neutralizing antibody against BA.1 and BA.2 variant after adjustment with age and gender. CONCLUSIONS: A heterologous mRNA boost is highly immunogenic. The pre-existing neutralizing antibody level and CD4+ T cells response correlates with post-booster neutralization reactivity against the Omicron variant.

Negative regulation of type I interferon signaling by integrin-linked kinase permits dengue virus replication.

Dengue virus (DENV) infection can induce life-threatening dengue hemorrhagic fever/dengue shock syndrome in infected patients. DENV is a threat to global health due to its growing numbers and incidence of infection in the last 50 years. During infection, DENV expresses ten structural and nonstructural proteins modulating cell responses to benefit viral replication. However, the lack of knowledge regarding the cellular proteins and their functions in enhancing DENV pathogenesis impedes the development of antiviral drugs and therapies against fatal DENV infection. Here, we identified that integrin-linked kinase (ILK) is a novel enhancing factor for DENV infection by suppressing type I interferon (IFN) responses. Mechanistically, ILK binds DENV NS1 and NS3, activates Akt and Erk, and induces NF-κB-driven suppressor of cytokine signaling 3 (SOCS3) expression. Elevated SOCS3 in DENV-infected cells inhibits phosphorylation of STAT1/2 and expression of interferon-stimulated genes (ISGs). Inhibiting ILK, Akt, or Erk activation abrogates SOCS3 expression. In DENV-infected mice, the treatment of an ILK inhibitor significantly reduces viral loads in the brains, disease severity, and mortality rate. Collectively, our results show that ILK is a potential therapeutic target against DENV infection.

Profiling Humoral Immunity After Mixing and Matching COVID-19 Vaccines Using SARS-CoV-2 Variant Protein Microarrays.

In November 2022, 68% of the population received at least one dose of COVID-19 vaccines. Owing to the ongoing mutations, especially for the variants of concern (VOCs), it is important to monitor the humoral immune responses after different vaccination strategies. In this study, we developed a SARS-CoV-2 variant protein microarray that contained the spike proteins from the VOCs, e.g., alpha, beta, gamma, delta, and omicron, to quantify the binding antibody and surrogate neutralizing antibody. Plasmas were collected after two doses of matching AZD1222 (AZx2), two doses of matching mRNA-1273 (Mx2), or mixing AZD1222 and mRNA-1273 (AZ+M). The results showed a significant decrease of surrogate neutralizing antibodies against the receptor-binding domain in all VOCs in AZx2 and Mx2 but not AZ+M. A similar but minor reduction pattern of surrogate neutralizing antibodies against the extracellular domain was observed. While Mx2 exhibited a higher surrogate neutralizing level against all VOCs compared with AZx2, AZ+M showed an even higher surrogate neutralizing level in gamma and omicron compared with Mx2. It is worth noting that the binding antibody displayed a low correlation to the surrogate neutralizing antibody (R-square 0.130-0.382). This study delivers insights into humoral immunities, SARS-CoV-2 mutations, and mixing and matching vaccine strategies, which may provide a more effective vaccine strategy especially in preventing omicron.

Recommendations and guidelines for the diagnosis and management of Coronavirus Disease-19 (COVID-19) associated bacterial and fungal infections in Taiwan.

Coronavirus disease-19 (COVID-19) is an emerging infectious disease caused by SARS-CoV-2 that has rapidly evolved into a pandemic to cause over 600 million infections and more than 6.6 million deaths up to Nov 25, 2022. COVID-19 carries a high mortality rate in severe cases. Co-infections and secondary infections with other micro-organisms, such as bacterial and fungus, further increases the mortality and complicates the diagnosis and management of COVID-19. The current guideline provides guidance to physicians for the management and treatment of patients with COVID-19 associated bacterial and fungal infections, including COVID-19 associated bacterial infections (CABI), pulmonary aspergillosis (CAPA), candidiasis (CAC) and mucormycosis (CAM). Recommendations were drafted by the 7th Guidelines Recommendations for Evidence-based Antimicrobial agents use Taiwan (GREAT) working group after review of the current evidence, using the grading of recommendations assessment, development, and evaluation (GRADE) methodology. A nationwide expert panel reviewed the recommendations in March 2022, and the guideline was endorsed by the Infectious Diseases Society of Taiwan (IDST). This guideline includes the epidemiology, diagnostic methods and treatment recommendations for COVID-19 associated infections. The aim of this guideline is to provide guidance to physicians who are involved in the medical care for patients with COVID-19 during the ongoing COVID-19 pandemic.

COVID-19 associated mold infections: Review of COVID-19 associated pulmonary aspergillosis and mucormycosis.

COVID-19-associated mold infection (CAMI) is defined as development of mold infections in COVID-19 patients. Co-pathogenesis of viral and fungal infections include the disruption of tissue barrier following SARS CoV-2 infection with the damage in the alveolar space, respiratory epithelium and endothelium injury and overwhelming inflammation and immune dysregulation during severe COVID-19. Other predisposing risk factors permissive to fungal infections during COVID-19 include the administration of immune modulators such as corticosteroids and IL-6 antagonist. COVID-19-associated pulmonary aspergillosis (CAPA) and COVID-19-associated mucormycosis (CAM) is increasingly reported during the COVID-19 pandemic. CAPA usually developed within the first month of COVID infection, and CAM frequently arose 10-15 days post diagnosis of COVID-19. Diagnosis is challenging and often indistinguishable during the cytokine storm in COVID-19, and several diagnostic criteria have been proposed. Development of CAPA and CAM is associated with a high mortality despiteappropriate anti-mold therapy. Both isavuconazole and amphotericin B can be used for treatment of CAPA and CAM; voriconazole is the primary agent for CAPA and posaconazole is an alternative for CAM. Aggressive surgery is recommended for CAM to improve patient survival. A high index of suspicion and timely and appropriate treatment is crucial to improve patient outcome.

Therapeutic efficacy of humanized monoclonal antibodies targeting dengue virus nonstructural protein 1 in the mouse model.

Dengue virus (DENV) which infects about 390 million people per year in tropical and subtropical areas manifests various disease symptoms, ranging from fever to life-threatening hemorrhage and even shock. To date, there is still no effective treatment for DENV disease, but only supportive care. DENV nonstructural protein 1 (NS1) has been shown to play a key role in disease pathogenesis. Recent studies have shown that anti-DENV NS1 antibody can provide disease protection by blocking the DENV-induced disruption of endothelial integrity. We previously demonstrated that anti-NS1 monoclonal antibody (mAb) protected mice from all four serotypes of DENV challenge. Here, we generated humanized anti-NS1 mAbs and transferred them to mice after DENV infection. The results showed that DENV-induced prolonged bleeding time and skin hemorrhage were reduced, even several days after DENV challenge. Mechanistic studies showed the ability of humanized anti-NS1 mAbs to inhibit NS1-induced vascular hyperpermeability and to elicit Fcγ-dependent complement-mediated cytolysis as well as antibody-dependent cellular cytotoxicity of cells infected with four serotypes of DENV. These results highlight humanized anti-NS1 mAb as a potential therapeutic agent in DENV infection.

Antibody Profiling in COVID-19 Patients with Different Severities by Using Spike Variant Protein Microarrays.

The disease progression of COVID-19 varies from mild to severe, even death. However, the link between COVID-19 severities and humoral immune specificities is not clear. Here, we developed a multiplexed spike variant protein microarray (SVPM) and utilized it for quantifying neutralizing activity, drug screening, and profiling humoral immunity. First, we demonstrated the competition between antispike antibody and ACE2 on SVPM for measuring the neutralizing activity against multiple spike variants. Next, we collected the serums from healthy subjects and COVID-19 patients with different severities and profile the neutralizing activity as well as antibody isotypes. We identified the inhibition of ACE2 binding was stronger against multiple variants in severe compared to mild/moderate or critical patients. Moreover, the serum IgG against nonstructural protein 3 was elevated in severe but not in mild/moderate and critical cases. Finally, we evaluated two ACE2 inhibitors, Ramipril and Perindopril, and found the dose-dependent inhibition of ACE2 binding to all the spike variants except for B.1.617.3. Together, the SVPM and the assay procedures provide a tool for profiling neutralizing antibodies, antibody isotypes, and reagent specificities.

A novel chimeric dengue vaccine candidate composed of consensus envelope protein domain III fused to C-terminal-modified NS1 protein.

There is an urgent need for a safe and effective vaccine against dengue virus (DENV) which infects about 390 million humans per year. In the present study we combined modifications of two DENV proteins, the nonstructural protein 1 (NS1) and the envelope (E) protein, to produce a DENV vaccine candidate with enhanced features. One of these modified proteins was a C-terminal-deleted fragment of NS1 called ΔC NS1 which we have shown previously to be protective without the potentially harmful effects of cross-reactive epitopes common to surface antigens on platelets and endothelial cells. The other modified protein was an envelope protein domain III (cEDIII) containing a consensus amino acid sequence among the four serotypes of DENV, which induces neutralizing antibody against all four DENV serotypes. The cEDIII and ΔC NS1 were expressed as a fusion protein cEDIII-ΔC NS1 and its protective effects against DENV were evaluated in a mouse model. C3H/HeN mice were immunized three times with cEDIII-ΔC NS1 fusion protein mixed with alum as adjuvant. Sera collected from cEDIII-ΔC NS1-immunized mice neutralized four serotypes of DENV and also caused complement-mediated cytolysis of HMEC-1 cells infected with each of the four different DENV serotypes. Mice immunized with cEDIII-ΔC NS1 and challenged with DENV showed reduced serum virus titer, soluble NS1 and bleeding time, compared with mice infected with DENV alone. The results reveal that antibodies induced by cEDIII-ΔC NS1 not only show anti-viral efficacy by in vitro assays but also provide protective effects against DENV infection in a mouse model. The cEDIII-ΔC NS1 thus represents a novel, effective DENV vaccine candidate.

Development of SARS-CoV-2 variant protein microarray for profiling humoral immunity in vaccinated subjects.

SARS-CoV-2 is quickly evolving from wild-type to many variants and spreading around the globe. Since many people have been vaccinated with various types of vaccines, it is crucial to develop a high throughput platform for measuring the antibody responses and surrogate neutralizing activities against multiple SARS-CoV-2 variants. To meet this need, the present study developed a SARS-CoV-2 variant (CoVariant) array which consists of the extracellular domain of spike variants, e.g., wild-type, D614G, B.1.1.7, B.1.351, P.1, B.1.617, B.1.617.1, B.1.617.2, and B.1.617.3. A surrogate virus neutralization on the CoVariant array was established to quantify the bindings of antibody and host receptor ACE2 simultaneously to spike variants. By using a chimeric anti-spike antibody, we demonstrated a broad binding spectrum of antibodies while inhibiting the bindings of ACE2 to spike variants. To monitor the humoral immunities after vaccination, we collected serums from unvaccinated, partial, or fully vaccinated individuals with either mRNA-1273 or AZD1222 (ChAdOx1). The results showed partial vaccination increased the surrogate neutralization against all the mutants while full vaccination boosted the most. Although IgG, IgA, and IgM isotypes correlated with surrogate neutralizing activities, they behave differently throughout the vaccination processes. Overall, this study developed CoVariant arrays and assays for profiling the humoral responses which are useful for immune assessment, vaccine research, and drug development.

The epidemiology, clinical characteristics, and macrolide susceptibility of Mycoplasma pneumoniae pneumonia in children in Southern Taiwan, 2019-2020.

BACKGROUND: Since the global use of the pneumococcal conjugate vaccine, Mycoplasma pneumoniae (MP) has become the most common bacterial cause of lower respiratory tract infections among children. Monitoring the changing epidemiology and antimicrobial resistance rates of this organism is important for MP clinical management. METHODS: This study characterizes key features of MP during the 2019-2020 epidemic in children in Taiwan. The cohort included all hospitalized children under 18 years of age with polymerase chain reaction (PCR)-confirmed community-acquired mycoplasma pneumonia (CAMP) in southern Taiwan. Macrolide resistance was identified by mutations in domain V of MP 23S rRNA. Severe disease referred to symptoms warranting oxygen therapy, septic shock, or intensive care unit admission. RESULTS: Among 495 LRTI patients, 195 (39.4%) had CAMP, of which 106 (54.4%) had concurrent serological evidence of MP infection. The diagnostic sensitivity of IgM in the acute phase was 65.6%. CAMP case numbers were highest from July 2019 to January 2020. The most common clinical presentations of CAMP were fever (99.0%), cough (99.0%), and coryza (31.8%). Despite a high rate of macrolide resistance (88.1%), macrolide-resistant MP (MRMP) did not differ from macrolide-sensitive MP (MSMP) in clinical course or severity. Delayed administration of effective antimicrobial treatment was also associated with severe disease (p < 0.05). CONCLUSION: Early diagnosis and determination of MRMP are needed for effective management of MP infection.

Regulation of innate immune signaling pathways by autophagy in dengue virus infection.

Autophagy is not only an intracellular recycling degradation system that maintains cellular homeostasis but is also a component of innate immunity that contributes to host defense against viral infection. The viral components as well as viral particles trapped in autophagosomes can be delivered to lysosomes for degradation. Abundant evidence indicates that dengue virus (DENV) has evolved the potent ability to hijack or subvert autophagy process for escaping host immunity and promoting viral replication. Moreover, autophagy is often required to deliver viral components to pattern recognition receptors signaling for interferon (IFN)-mediated viral elimination. Hence, this review summarizes DENV-induced autophagy, which exhibits dual effects on proviral activity of promoting replication and antiviral activity to eliminating viral particles.

Serum IL-18 Is a Potential Biomarker for Predicting Severe Dengue Disease Progression.

Background. Dengue virus (DENV) infection is the most common arboviral disease that affects tropical and subtropical regions. Based on the clinical hallmarks, the different severities of patients range from mild dengue fever (MDF) to severe dengue diseases (SDDs) and include dengue hemorrhagic fever or dengue shock syndrome. These are commonly associated with cytokine release syndrome (CRS). The types and levels of cytokines/chemokines, which are suppressed or enhanced, are varied, indicating CRS's pathogenic and host defensive effects. Principal Finding. In this study, we created an integrated and precise multiplex panel of cytokine/chemokine assays based on our literature analysis to monitor dengue CRS. A 24-plex panel of cytokines/chemokines was evaluated to measure the plasma levels of targeting factors in dengue patients with an MDF and SDD diagnosis without or with comorbidities. As identified in sixteen kinds of cytokines/chemokines, ten were significantly (P < 0.05) (10/16) increased, one was significantly (P < 0.01) (1/16) decreased, and five were potentially (5/16) altered in all dengue patients (n = 30) in the acute phase of disease onset. Compared to MDF, the levels of IL-8 (CXCL-8) and IL-18 in SDD were markedly (P < 0.05) increased, accompanied by positively increased IL-6 and TNF-α and decreased IFN-γ and RANTES. With comorbidities, SDD significantly (P < 0.01) portrayed elevated IL-18 accompanied by increased IL-6 and decreased IFN-α2 and IL-12. In addition, decreased platelets were significantly (P < 0.05) associated with increased IL-18. Significance. These results demonstrate an efficient panel of dengue cytokine/chemokine assays used to explore the possible level of CRS during the acute phase of disease onset; also, we are the first to report the increase of IL-18 in severe dengue with comorbidity compared to severe dengue without comorbidity and mild dengue.

IL-18: The Forgotten Cytokine in Dengue Immunopathogenesis.

Dengue fever is an infection by the dengue virus (DENV) transmitted by vector mosquitoes. It causes many infections in tropical and subtropical countries every year, thus posing a severe disease threat. Cytokine storms, one condition where many proinflammatory cytokines are mass-produced, might lead to cellular dysfunction in tissue/organ failures and often facilitate severe dengue disease in patients. Interleukin- (IL-) 18, similar to IL-1ß, is a proinflammatory cytokine produced during inflammation following inflammasome activation. Inflammatory stimuli, including microbial infections, damage signals, and cytokines, all induce the production of IL-18. High serum IL-18 is remarkably correlated with severely ill dengue patients; however, its possible roles have been less explored. Based on the clinical and basic findings, this review discusses the potential immunopathogenic role of IL-18 when it participates in DENV infection and dengue disease progression based on existing findings and related past studies.

Development and Application of Human Coronavirus Protein Microarray for Specificity Analysis.

Coronavirus is an enveloped RNA virus that causes mild to severe respiratory diseases in humans, including HKU1-CoV, 229E-CoV, NL63-CoV, OC43-CoV, SARS-CoV, MERS-CoV, and SARS-CoV-2. Due to the outbreak of SARS-CoV-2, it is important to identify the patients and investigate their immune responses. Protein microarray is one of the best platforms to profile the antibodies in the blood because of its fast, multiplexed, and sensitive nature. To fully understand the immune responses and biological specificities, this study developed a human coronavirus (HCoV) protein microarray and included all seven human coronaviruses and three influenza viruses. Each protein was printed in triplicate and formed 14 identical blocks per array. The HCoV protein microarray showed high reproducibility and sensitivity to the monoclonal antibodies against spike and nucleocapsid protein with detection limits of 10-200 pg. The HCoV proteins that were immobilized on the array were properly folded and functional by showing interactions with a known human receptor, e.g., ACE2. By profiling the serum IgG and IgA from 32 COVID-19 patients and 36 healthy patients, the HCoV protein microarray demonstrated 97% sensitivity and 97% specificity with two biomarkers. The results also showed the cross-reactivity of IgG and IgA in COVID-19 patients to spike proteins from various coronaviruses, including that from SARS-CoV, HKU1-CoV, and OC43-CoV. Finally, an innate immune protein named surfactant protein D showed broad affinities to spike proteins in all human coronaviruses. Overall, the HCoV protein microarray is multiplexed, sensitive, and specific, which is useful in diagnosis, immune assessment, biological development, and drug screening.

Use of seroprevalence to guide dengue vaccination plans for older adults in a dengue non-endemic country.

A shift in dengue cases toward the adult population, accompanied by an increased risk of severe cases of dengue in the elderly, has created an important emerging issue in the past decade. To understand the level of past DENV infection among older adults after a large dengue outbreak occurred in southern Taiwan in 2015, we screened 1498 and 2603 serum samples from healthy residents aged ≥ 40 years in Kaohsiung City and Tainan City, respectively, to assess the seroprevalence of anti-DENV IgG in 2016. Seropositive samples were verified to exclude cross-reaction from Japanese encephalitis virus (JEV), using DENV/JEV-NS1 indirect IgG ELISA. We further identified viral serotypes and secondary DENV infections among positive samples in the two cities. The overall age-standardized seroprevalence of DENV-IgG among participants was 25.77% in Kaohsiung and 11.40% in Tainan, and the seroprevalence was significantly higher in older age groups of both cities. Although the percentages of secondary DENV infection in Kaohsiung and Tainan were very similar (43.09% and 44.76%, respectively), DENV-1 and DENV-2 spanned a wider age range in Kaohsiung, whereas DENV-2 was dominant in Tainan. As very few studies have obtained the serostatus of DENV infection in older adults and the elderly, this study highlights the need for further investigation into antibody status, as well as the safety and efficacy of dengue vaccination in these older populations.