Type 1/Type 2 immunity in infectious diseases

Primary cutaneous cryptococcal infection due to fingolimod - Induced lymphopenia with literature review

Cryptococcus. Neoformans (C. neoformans) is an encapsulated heterobasidiomycetous fungus responsible for opportunistic infections worldwide in immunocompromised patients. Clinical presentation ranges from asymptomatic respiratory tract colonization to disseminated infection in any human body part. The central nervous system (CNS) and pulmonary diseases garner most of the clinical attention. Secondary cutaneous cryptococcosis is an uncommon manifestation seen as a sentinel sign commonly in disseminated cryptococcal infection. Primary cutaneous cryptococcosis (PCC) is a rare manifestation seen in both immunocompromised and immunocompetent patients. It is a discrete infection with different epidemiological trends. Immunosuppressive therapy (corticosteroids, tacrolimus) predisposes a patient to acquire this clinical entity. We present a case of an elderly Caucasian male on fingolimod for relapsing-remitting multiple sclerosis with nonhealing scalp lesions for four years. He was a referral to our healthcare center for the presence of fungal elements seen on a scalp biopsy fungal stains. Final cultures returned positive for C. neoformans susceptible to fluconazole (MIC = 8 μg/mL). The CD4 count was 13 cells/uL, and workup for CNS and disseminated cryptococcal infection were negative. Fingolimod is an immunomodulator that acts on sphingosine 1-phosphate receptors, affecting the lymphocytes. Pubmed literature review revealed few case reports (< 5) with PCC in patients on fingolimod. To our knowledge, ours is the first case with scalp cryptococcosis, with the lowest CD4 count while being on fingolimod. No randomized controlled trial data exist for the treatment of PCC. Therapy initiated with oral luconazole for six months with significant improvement at three months.

Expression of IL-33 Receptor Is Significantly Up-Regulated in B Cells During Pregnancy and in the Acute Phase of Preterm Birth in Mice

Interleukin-33 (IL-33) is a mucosal alarmin belonging to the IL-1 cytokine family and is now recognized to have a key role in innate and adaptive immunity, contributing to tissue homeostasis and response to environmental stresses. In addition, IL-33 has also been shown to work as a positive regulator that initiates and maintains a Th2 immune response. In the context of pregnancy, it has been recently demonstrated that upon certain stress conditions, such as an infection induced inflammation, IL-33 is released from the uterine mucosa and triggers decidual B cells to produce anti-inflammatory molecules, which in turn restore immune homeostasis and prevents the development of preterm birth. In this study we therefore performed a detailed characterization of IL-33 receptor (Il1rl1 or ST2) expression in B cells during normal pregnancy, as well as in a mouse model of preterm birth. We observed that splenic B cells significantly up-regulate the expression of Il1rl1 during pregnancy and identified the B1 B cell population as the main ST2-expressing B cell subset. A further kinetic analysis showed that percentages of ST2-expressing B1 B cells are significantly augmented on days 12 and 14 of pregnancy, both in the spleen and peritoneal cavity of pregnant mice, and then drop toward the end of pregnancy to the levels observed in non-pregnant animals. Furthermore, using a mouse model of LPS-induced preterm birth, we demonstrated that not only are the percentages of ST2-expressing B1 B cells significantly enlarged in the spleen during the acute phase of preterm birth, but decidual B cells also significantly up-regulate ST2 expression as compared to term-pregnant mice. Overall, our results suggest a functional role of ST2 expression in B cells during pregnancy and reinforce the importance of the IL-33/ST2 axis in B cells as a critical mechanism to control inflammation-induced preterm birth.

The Epidemiology and Control of Liver Flukes in Cattle and Sheep

Fasciola hepatica, Fasciola gigantica, and Fascioloides magna are liver flukes causing disease in cattle and sheep. Damage to the liver due to F hepatica and F gigantica results in clinical disease and/or production losses. F magna seems to have little effect in cattle but causes high mortality in sheep. The fluke life cycle involves an aquatic or amphibious snail intermediate host and thus requires suitable moisture and temperature conditions. F magna requires the presence of deer. Drug treatment is the mainstay of control and needs to be applied considering the life cycle and epidemiology of the parasite.

Cytokines/Chemokines: Novel Biomarkers Associated with Severe Cutaneous Adverse Reactions

Although the incidence of severe cutaneous adverse reactions (SCARs) is very low, if it is not diagnosed and treated in time, it can not only cause skin and mucous membrane involvement, but can also cause multiple organ failure and even death. The diagnostic criteria and treatment guidelines for severe drug eruptions have not been unified. Many medical centers have used human leukocyte antigen alleles to diagnose SCARs. Some prospective studies have shown that susceptibility gene testing can prevent SCARs as early as possible, but the widespread implementation of its technology is limited by being ethnically specific. With the unique advantages of cytokine detection technology, cytokines are increasingly important for the diagnosis and treatment of SCARs. Related cytokines/chemokines involved in the pathogenesis, adjuvant diagnosis, and treatment of SCARs are discussed.

Evaluating the immunomodulatory responses of LdODC-derived MHC Class-II restricted peptides against VL

In a bid to develop a novel immunoprophylactic measure against visceral leishmaniasis (VL), MHC class-II-restricted epitopes of LdODC were identified by reverse vaccinology approach. Five consensus HLA-DRB1*0101-restricted epitopes were screened. The analysis revealed that the set of epitopes was presented by at least 54 diverse MHC class-II alleles. Based on in silico screening, followed by molecular dynamics simulation, population coverage analysis, and HLA cross-presentation ability, five best epitopes were evaluated. PBMCs isolated from treated VL subjects, when stimulated with synthetic peptide alone or as a cocktail of peptides, triggered a secretory IFN-γ, but not the IL-10 level. Support in this notion came from intracellular cytokine level with a considerable up-regulated IFN-γ produced by CD4⁺ T cells. Also, the enhanced IFN-γ seemed to be augmented with the activation of macrophages with prominent IL-12 production. Therefore, it can be concluded that the screened MHC class-II-restricted epitope hotspots derived from Leishmania ODC can trigger CD4⁺ T cells, which can skew macrophage functions towards protection. However, a detailed analysis can explore its potentiality as a vaccine candidate.

PAG1 limits allergen-induced type 2 inflammation in the murine lung

BACKGROUND

Phosphoprotein associated with glycosphingolipid-enriched microdomains 1 (PAG1) is a transmembrane adaptor protein that affects immune receptor signaling in T and B cells. Evidence from genome-wide association studies of asthma suggests that genetic variants that regulate the expression of PAG1 are associated with asthma risk. However, it is not known whether PAG1 expression is causally related to asthma pathophysiology. Here, we investigated the role of PAG1 in a preclinical mouse model of house dust mite (HDM)-induced allergic sensitization and allergic airway inflammation.

METHODS

Pag1-deficient (Pag1^-/- ) and wild-type (WT) mice were sensitized or sensitized/challenged to HDM, and hallmark features of allergic inflammation were assessed. The contribution of T cells was assessed through depletion (anti-CD4 antibody) and adoptive transfer studies.

RESULTS

Type 2 inflammation (eosinophilia, eotaxin-2 expression, IL-4/IL-5/IL-13 production, mucus production) in the airways and lungs was significantly increased in HDM sensitized/challenged Pag1^-/- mice compared to WT mice. The predisposition to allergic sensitization was associated with increased airway epithelial high-mobility group box 1 (HMGB1) translocation and release, increased type 2 innate lymphoid cells (ILC2s) and monocyte-derived dendritic cell numbers in the mediastinal lymph nodes, and increased T-helper type 2 (T_H 2)-cell differentiation. CD4⁺ T-cell depletion studies or the adoptive transfer of WT OVA-specific CD4⁺ T cells to WT or Pag1^-/- recipients demonstrated that the heightened propensity for T_H 2-cell differentiation was both T cell intrinsic and extrinsic.

CONCLUSION

PAG1 deficiency increased airway epithelial activation, ILC2 expansion, and T_H 2 differentiation. As a consequence, PAG1 deficiency predisposed toward allergic sensitization and increased the severity of experimental asthma.

Helminth infections and immunosenescence: The friend of my enemy

Age-associated alterations of the immune system, which known as "immunosenescence", is characterized by a decline in innate and adaptive immunity, which leading to increased susceptibility to age-associated diseases, such as infectious diseases, rheumatic disease and malignancies. On the other hand, helminth infections are among the most prevalent infections in older individuals, especially in the nursing homes. Most of helminth infections have minor clinical symptoms and usually causing chronic infections without treatment. Nevertheless, chronic helminthiasis alters immune responses somewhat similar to the immunosenescence. Some similarities also exist between helminth infections and immunosenescence: 1) both of them led to declining the immune responses; 2) undernutrition is a consequence of immunosenescence and helminthiasis; 3) vaccine efficacy declines in aging and individuals with helminth infections; 4) increase incidence and prevalence of infectious diseases in the elder individuals and patients with helminth infections; and 5) both of them promote tumorigenesis. Hence, it is probable that helminth infections in the elderly population can intensify the immunosenescence outcomes due to the synergistic immunoregulatory effects of each of them. It would be suggested that, diagnosis, treatment and prevention of helminth infections should be more considered in older individuals. Also, it would be suggested that helminths or their antigens can be used for investigation of immunosenescence because both of them possess some similarities in immune alterations. Taken together, this review offers new insights into the immunology of aging and helminth infections.

A self-aggregating peptide: implications for the development of thermostable vaccine candidates

BACKGROUND

The use of biomaterials has been expanded to improve the characteristics of vaccines. Recently we have identified that the peptide PH_(1-110) from polyhedrin self-aggregates and incorporates foreign proteins to form particles. We have proposed that this peptide can be used as an antigen carrying system for vaccines. However, the immune response generated by the antigen fused to the peptide has not been fully characterized. In addition, the adjuvant effect and thermostability of the particles has not been evaluated.

RESULTS

In the present study we demonstrate the use of a system developed to generate nano and microparticles carrying as a fusion protein peptides or proteins of interest to be used as vaccines. These particles are purified easily by centrifugation. Immunization of animals with the particles in the absence of adjuvant result in a robust and long-lasting immune response. Proteins contained inside the particles are maintained for over 1 year at ambient temperature, preserving their immunological properties.

CONCLUSION

The rapid and efficient production of the particles in addition to the robust immune response they generate position this system as an excellent method for the rapid response against emerging diseases. The thermostability conferred by the particle system facilitates the distribution of the vaccines in developing countries or areas with no electricity.

6-Gingerol ameliorates sepsis-induced liver injury through the Nrf2 pathway

Sepsis-induced liver injury is very common in intensive care units. Here, we investigated the effects of 6-gingerol on sepsis-induced liver injury and the role of the Nrf2 pathway in this process. 6-Gingerol is the principal ingredient of ginger that exerts anti-inflammatory and antioxidant effects. Using cecal ligation and puncture (CLP) to induce polymicrobial sepsis and related liver injury, we found that mice pre-treated with 6-Gingerol showed less incidences of severe liver inflammation and death than untreated CLP groups. 6-Gingerol administration also inhibited the expression of pyroptosis-related proteins, including NOD-like receptor protein 3 (NLRP3), IL-1β, and caspase-1. Consistent with these findings, 6-gingerol reduced the effects of pyroptosis induced by lipopolysaccharide (LPS) and adenosine 5'-triphosphate (ATP) in RAW 264.7 cells, as evidenced by IL-1β and caspase-1 protein levels in the supernatant and propidium iodide (PI) staining. 6-Gingerol was shown to activate the Nrf2 pathway in vivo and in vitro. Notably, Nrf2 siRNA transfection nullified the inhibitory effects of 6-gingerol on pyroptosis in vitro. In summary, these findings suggested that 6-gingerol alleviated sepsis-induced liver injury by inhibiting pyroptosis through the Nrf2 pathway.

Identification of the Regulatory Role of lncRNA SNHG16 in Myasthenia Gravis by Constructing a Competing Endogenous RNA Network

Myasthenia gravis (MG) is an autoimmune disorder resulting from antibodies against the proteins at the neuromuscular junction. Emerging evidence indicates that long non-coding RNAs (lncRNAs), acting as competing endogenous RNAs (ceRNAs), are involved in various diseases. However, the regulatory mechanisms of ceRNAs underlying MG remain largely unknown. In this study, we constructed a lncRNA-mediated ceRNA network involved in MG using a multi-step computational strategy. Functional annotation analysis suggests that these lncRNAs may play crucial roles in the immunological mechanism underlying MG. Importantly, through manual literature mining, we found that lncRNA SNHG16 (small nucleolar RNA host gene 16), acting as a ceRNA, plays important roles in the immune processes. Further experiments showed that SNHG16 expression was upregulated in peripheral blood mononuclear cells (PBMCs) from MG patients compared to healthy controls. Luciferase reporter assays confirmed that SNHG16 is a target of the microRNA (miRNA) let-7c-5p. Subsequent experiments indicated that SNHG16 regulates the expression of the key MG gene interleukin (IL)-10 by sponging let-7c-5p in a ceRNA manner. Furthermore, functional assays showed that SNHG16 inhibits Jurkat cell apoptosis and promotes cell proliferation by sponging let-7c-5p. Our study will contribute to a deeper understanding of the regulatory mechanism of MG and will potentially provide new therapeutic targets for MG patients.

A rapid blood test to monitor immunity shift during pregnancy and potential application for animal health management

The immune health of a farm animal can have significant impact on its overall health, welfare and productivity. One of the most vulnerable physiological states for both humans and animals is pregnancy. Many systemic changes correlate with the gravid state, including shifts in the immune system that may impact the ability to respond optimally to pathogen challenge. Because of this, it would be beneficial to be able to monitor the immune health of the pregnant animals closely. Recently, we developed a new nanoparticle-enabled rapid blood test that can detect ongoing immune responses from both laboratory and farm animals. Here, we report that this novel test reveals highly repeatable and acute changes associated with pregnancy and peri-parturition period in laboratory mice and in cattle. We hypothesize that the test score change reflects changes in the immune status of the gravid females related to the humoral immune response. The test is easy to conduct, of low cost, with results obtained in less than 20 min. This rapid test could be potentially used as an onsite test in local farms and small clinics for animal health management.

A nanoparticle pseudo pathogen for rapid detection and diagnosis of virus infection

We herein report a new rapid blood test for virus infection detection and diagnosis. A citrate gold nanoparticle is first coated with a virus lysate to form a gold nanoparticle pseudo pathogen. The gold nanoparticle pseudo virus is then mixed with a blood plasma or serum samples. If the blood sample is from a positive patient, the activated immune molecules in the blood such as antibodies, complement proteins and others will react with the nanoparticle pseudo virus, leading to nanoparticle aggregate formation. The nanoparticle aggregate formation is detected and measured using a particle sizing technique called dynamic light scattering. In this study, we applied this test for Zika virus infection detection. We tested blood plasma samples from 85 Zika positive patients, 40 Dengue positive patients, 10 Chikungunya positive patients, and 78 non-patient control samples collected from both endemic and non-endemic locations. The study shows that the new test has a higher sensitivity compared to some existing commercial tests in the market, while maintaining a similar specificity. Within 7 days from the symptom onset, the new test can detect 43% of the infected patients while a commercial anti-Zika IgM test detects only 26% of the infected patients. Within 14 days from the symptom onset, our new test detects 73% of the infected patients while the same commercial anti-Zika IgM test detects 53% of the infected patients. The test is extremely simple, easy to develop, with test results obtained within minutes. This new test platform may be potentially adapted for the detection and diagnosis of a wide range of viral infectious diseases, for example, the currently ongoing COVID-19.

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A rapid blood test for point-of-care virus infectious disease detection and diagnosis.

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The test uses a gold nanoparticle pseudo virus particle to detect active immune response from patient’s blood.

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The test is a single-step process with results obtained within 20 min.

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The test shows significantly better sensitivity than a commercially available serology test.

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The test platform may be adapted to develop diagnostic tests for different virus infections.

[Clinical and economic analysis of Reslizumab use in the treatment of patients with severe allergic eosinophilic asthma]

Asthma is a heterogeneous chronic disease of airways. One of its endotypes is eosinophilic asthma, accompanied by both peripheral blood and airway eosinophilia, where severe eosinophilia is usually associated with more severe asthma. Anti - interleukin-5 (IL-5) monoclonal antibodies (MAb) can reduce eosinophil counts in peripheral blood and tissues in asthma patients. The first drug of this class registered in Russia was reslizumab.

AIM

Comparative clinical and economic analysis of reslizumab use in patients with allergic asthma and eosinophilia.

MATERIALS AND METHODS

Omalizumab was chosen as a reference drug, because until now it was the only MAb for the treatment of severe asthma in Russia. The study population included patients with allergic asthma with both high levels of IgE and high eosinophil counts in peripheral blood, i.e. individuals eligible for both omalizumab and reslizumab treatment. A decrease in the number of exacerbations requiring prescription of systemic corticosteroids and an increase in QALY index was used as efficacy criteria. An indirect comparative study was used, because no direct comparison has been conducted to date. As a result, reslizumab demonstrated a statistically significant reduction in the frequency of clinically significant asthma exacerbations compared with omalizumab. The utility of the both asthma treatment strategies was compared using Markov models, taking into account the frequency of exacerbations, their severity, as well as decrease in QALYs due to exacerbations. The time horizon was 12 months.

RESULTS

Reslizumab treatment was 37.2% less expensive compared with omalizumab for the patients who are equally eligible for the both drugs. The calculated cost - effectiveness and cost - utility ratios were in favor of reslizumab. Budget impact analysis showed a significant effect of reslizumab on reducing budget costs. If reslizumab is used in 4250 patients (an estimated number of patients with severe allergic asthma and eosinophilia in Russia), this would reduce the costs for their treatment by up to 4896 million rubles per year.

CONCLUSIONS

For patients with severe allergic eosinophilic asthma who are equally eligible for the both drugs, reslizumab can be considered a more reasonable medical technology in terms of pharmacoeconomics when compared with omalizumab.

BLIMP-1 Plays Important Role in the Regulation of Macrophage Pyroptosis for the Growth and Multiplication of Leishmania donovani

Visceral leishmaniasis, one of the fatal forms of the disease, is caused by Leishmania donovani and presents morbid clinical manifestations. The parasite evades pro-inflammatory immune responses by several reported mechanisms and modulates the host immune system to cause fatal symptoms. A plethora of reports related to the role of BLIMP-1 and its involvement in suppressing the immune response in various infectious diseases have been documented. Higher parasitic burden due to increased BLIMP-1 production has been reported earlier for malaria and leishmaniasis with no detailed information. We report for the first time the role of BLIMP-1 in suppressing macrophage pyroptosis during L. donovani infection and thereby tweaking the tight regulation of the NFκβ-NLRP3 signaling pathway. Expression analyses of BLIMP-1 and NFκβ have been measured using real-time PCR and Western blotting. The importance of BLIMP-1 has been validated using a siRNA-mediated experiment along with caspase 1 activity, LDH release assay, and infectivity index analyses. An inverse relationship between BLIMP-1 and NFκβ expression has been highlighted during L. donovani infection, which is reversed in blimp-1 deficient cells infected with promastigotes. The above fact has been further validated with caspase 1 activity assay, and LDH release along with IFNγ and TNF-α release assay. Finally, resumption of pyroptosis has been concluded in infected blimp-1 deficient cells in contrast to wild type infected cells. We conjecture that parasites modulate the NFκβ-NLRP3 signaling pathway by taking advantage of BLIMP-1 dependent IL-10 production and finally disrupting an inflammation-mediated pyroptosis cell death pathway in infected cells.

Cytokine Profiles and Severity of Influenza Infection in Transplant Recipients

Influenza is responsible for significant morbidity after transplantation. We evaluated T-helper 1/T-helper 2 (Th2) cytokines and interleukin (IL) 10 levels during influenza infection in the posttransplant setting. Serum samples from 277 transplant recipients were analyzed at influenza diagnosis and 28 days later for interferon gamma (IFN-γ), IL-4, IL-13, and IL-10. IL-13 levels were associated with protection against pneumonia and intensive care unit (ICU) admission, whereas the IFN-γ/IL-13 ratio and IL-10 levels were associated with an increased risk of pneumonia and ICU admission. This association was independent of viral load. A skewing of immune responses toward Th2 in transplant patients appears to confer protection from severe influenza infection, independent of viral load.

Arginase Isoform Expression in Chronic Rhinosinusitis

Nitric oxide (NO) has emerged as an important regulator of upper airway inflammation, mainly as part of the local naso-sinusal defense mechanisms. Increased arginase activity can reduce NO levels by decreasing the availability of its precursor, L-arginine. Chronic rhinosinusitis (CRS) has been associated with low levels of nasal nitric oxide (nNO). Thus, the present study investigates the activity of arginase I (ARG1) and II (ARG2) in CRS and its possible involvement in the pathogenesis of this disease. Under endoscopic view, tissue samples of pathologic (n = 36) and normal (n = 29) rhinosinusal mucosa were collected. Arginase I and II mRNA levels were measured using real-time PCR. Our results showed low arginase I activity in all samples. The levels of ARG2 were significantly higher in patients with chronic rhinosinusitis compared to the control group (fold regulation (FR) 2.22 ± 0.42 vs. 1.31 ± 0.21, p = 0.016). Increased ARG2 expression was found in patients with CRS without nasal polyposis (FR 3.14 ± 1.16 vs. 1.31 ± 0.21, p = 0.0175), in non-allergic CRS (FR 2.55 ± 0.52 vs. 1.31 ± 0.21, p = 0.005), and non-asthmatic CRS (FR 2.42 ± 0.57 vs. 1.31 ± 0.21, p = 0.028). These findings suggest that the upregulation of ARG2 may play a role in the pathology of a distinctive phenotype of CRS.

Transcriptional Modulation of the Host Immunity Mediated by Cytokines and Transcriptional Factors in Plasmodium falciparum-Infected Patients of North-East India

Complications due to malaria are caused mostly by host immunological responses. Plasmodium falciparum subverts host immunity by various strategies, including modulation in the host immune responses by regulating cytokines. The transcriptional alterations of major cytokines and immunoregulators were analyzed in this study through gene expression profiling in clinically defined subgroups of P. falciparum patients. Malaria patients were included from Dhalai district hospital of Tripura with uncomplicated malaria (UC) and severe malaria (SM) and healthy controls from endemic and non-endemic areas of India. qPCR gene expression analysis was performed for all factors and they were grouped into three clusters based on their altered expressions. The first cluster was downregulated with an increased parasitic burden which included T-BET, GATA3, EOMES, TGF-β, STAT4, STAT6 and cytokines IFN-γ, IL-12, IL-4, IL-5, and IL-13. RANTES, IL-8, CCR8, and CXCR3 were decreased in the SM group. The second cluster was upregulated with severity and included TNF-α, IL-10, IL-1β and IL-7. PD-1 and BCL6 were increased in the SM group. The third cluster comprised of NF-κB and was not altered. The level of perforin was suppressed while GrB expression was elevated in SM. P. falciparum malaria burden is characterized by the modulation of host immunity via compromization of T cell-mediated responses and suppression of innate immune-regulators.

Diet-induced Generalized Periodontitis in Lewis Rats

Periodontitis is an important public health concern worldwide. Because rodents from the genus Rattus are resistant to spontaneous periodontitis, experimental periodontitis must be initiated by mechanical procedures and interventions. Due to their exacerbated Th1 response and imbalanced Th17 regulatory T-cell responses, Lewis rats are highly susceptible to inducible inflammatory and autoimmune diseases. We hypothesized that feeding Lewis rats a diet high in sucrose and casein (HSC) would alter the oral microenvironment and induce inflammation and the development of periodontitis lesions without mechanical intervention. A baseline group (BSL, n = 8) was euthanized at age 6 wk. Beginning at 6 wk of age, 2 groups of Lewis rats were fed standard (STD, n = 12) or HSC (n = 20) chow and euthanized at 29 wk of age. We evaluated the degree of periodontitis through histology and μCT of maxillae and mandibles. The HSC-induced inflammatory response of periodontal tissues was assessed by using immunohistochemistry. Gene expression analysis of inflammatory cytokines associated with Th1 and Th17 responses, innate immunity cytokines, and tissue damage in response to bacteria were assessed also. The potential systemic effects of HSC diet were evaluated by assessing body composition and bone densitometry endpoints; serum leptin and insulin concentrations; and gene expression of inflammatory cytokines in the liver. Placing Lewis rats on HSC diet for 24 wk induced a host Th1-immune response in periodontal tissues and mild to moderate, generalized periodontitis characterized by inflammatory cell infiltration (predominantly T cells and macrophages), osteoclast resorption of alveolar bone, and hyperplasia and migration of the gingival epithelium. HSC-fed Lewis rats developed periodontitis without mechanical intervention in the oral cavity and in the absence of any noteworthy metabolic abnormalities. Consequently, the rat model we described here may be a promising approach for modeling mild to moderate periodontitis that is similar in presentation to the human disease.

Live Attenuated Pru:Δcdpk2 Strain of Toxoplasma gondii Protects Against Acute, Chronic, and Congenital Toxoplasmosis

Background

The threat of Toxoplasma gondii infection in immunocompromised individuals and pregnant women necessitates the development of a safe and effective vaccine. Here, we examined the immune protection conferred by a live attenuated strain of T. gondii.

Methods

We tested the efficacy of intraperitoneal vaccination using 500 Ca2+-dependent protein kinase 2 (cdpk2)-deficient tachyzoites of T. gondii Pru strain against acute, chronic, and congenital toxoplasmosis in mice. The kinetics of antibody response, cytokines, and other quantifiable correlates of protection against T. gondii infection were determined.

Results

Vaccination with Pru:Δcdpk2 induced a high level of anti-T. gondii immunoglobulin G titer, type 1 T-helper (Th1) response at 28 days postvaccination, and a mixed Th1/type 2 T-helper response at 70 days postvaccination. All vaccinated mice survived a heterologous challenge with 1000 tachyzoites of RH or ToxoDB#9 (PYS or TgC7) strains. Also, vaccination protected against homologous infection with 20 T. gondii Pru cysts, and improved pregnancy outcome by reducing parasite cyst load in the brain, maintaining litter size and body weight of pups born to vaccinated dams challenged with 10 Pru cysts compared to pups born to unvaccinated dams.

Conclusions

The use of T. gondii Pru:Δcdpk2 mutant strain represents a promising approach to protection against acute, chronic, and congenital toxoplasmosis in mice.

In vitro responses of multiple cytokines to purified protein derivative in healthy and naturally Mycobacterium tuberculosis-infected rhesus monkeys (Macaca mulatta)

BACKGROUND

As the widely used biomarker of whole-blood stimulation assays for tuberculosis diagnosis, the release of IFN-γ might be affected by multiple factors, such as immunosuppression and some infectious agents. Here, we evaluated additional cytokines as diagnostic biomarkers.

METHODS

Forty-three cytokines were measured by Luminex xMAP technologies in 30 healthy and 10 naturally Mycobacterium tuberculosis (MTB)-infected rhesus monkeys pre- and post-stimulation by purified protein derivative (PPD).

RESULTS

After stimulation, production of 23 and 38 cytokines was markedly increased in healthy and MTB-infected macaques, respectively. A comparison of the stimulation index (SI) between MTB infections and healthy macaques showed that the SIs of 32 cytokines in MTB-infected macaques were significantly higher than those in healthy macaques. Pooling the results, eight cytokines were suggested as ideal biomarkers for a whole-blood stimulation assay for MTB diagnosis.

CONCLUSION

PPD could induce multiple cytokine responses in either healthy or MTB-infected monkeys, and eight cytokines had reliable predictive capacity as diagnostic biomarkers of MTB infection.

Intranasal treatment with CpG-B oligodeoxynucleotides protects CBA mice from lethal equine herpesvirus 1 challenge by an innate immune response

Equine herpesvirus 1 (EHV-1) is the causative agent of a number of equine disease manifestations, including severe disease of the central nervous system, respiratory infections, and abortion storms. Our results showed that intranasal treatment with CpG-B oligodeoxynucleotides (ODN 1826) protected CBA mice from pathogenic EHV-1 RacL11 challenge. The IFN-γ gene and seven interferon-stimulated genes (ISGs) were upregulated 39.4- to 260.3-fold at 8 h postchallenge in the lungs of RacL11-challenged mice that had been treated with CpG-B ODN. Interestingly, IFN-γ gene expression was upregulated by 26-fold upon RacL11 challenge in CpG-B ODN-treated mice lungs as compared to that of CpG-A ODN (ODN 1585)-treated mice lungs; however, the seven ISGs were upregulated by 2.4-5.0-fold, suggesting that IFN-γ is a major factor in the protection of CBA mice from the lethal challenge. Pre-treatment with IFN-γ significantly reduced EHV-1 yield in murine alveolar macrophage MH-S cells, but not in mouse lung epithelial MLE12 cells. These results suggest that CpG-B ODN may be used as a prophylactic agent in horses and provide a basis for more effective treatment of EHV-1 infection.

Cooperation of Oligodeoxynucleotides and Synthetic Molecules as Enhanced Immune Modulators

Unmethylated cytosine–guanine dinucleotide (CpG) motifs are potent stimulators of the host immune response. Cellular recognition of CpG motifs occurs via Toll-like receptor 9 (TLR9), which normally activates immune responses to pathogen-associated molecular patterns (PAMPs) indicative of infection. Oligodeoxynucleotides (ODNs) containing unmethylated CpGs mimic the immunostimulatory activity of viral/microbial DNA. Synthetic ODNs harboring CpG motifs resembling those identified in viral/microbial DNA trigger an identical response, such that these immunomodulatory ODNs have therapeutic potential. CpG DNA has been investigated as an agent for the management of malignancy, asthma, allergy, and contagious diseases, and as an adjuvant in immunotherapy. In this review, we discuss the potential synergy between synthetic ODNs and other synthetic molecules and their immunomodulatory effects. We also summarize the different synthetic molecules that function as immune modulators and outline the phenomenon of TLR-mediated immune responses. We previously reported a novel synthetic ODN that acts synergistically with other synthetic molecules (including CpG ODNs, the synthetic triacylated lipopeptide Pam₃CSK₄, lipopolysaccharide, and zymosan) that could serve as an immune therapy. Additionally, several clinical trials have evaluated the use of CpG ODNs with other immune factors such as granulocyte-macrophage colony-stimulating factor, cytokines, and both endosomal and cell-surface TLR ligands as adjuvants for the augmentation of vaccine activity. Furthermore, we discuss the structural recognition of ODNs by TLRs and the mechanism of functional modulation of TLRs in the context of the potential application of ODNs as wide-spectrum therapeutic agents.

Neighborhood Social Conditions, Family Relationships, and Childhood Asthma

BACKGROUND AND OBJECTIVES

Poor neighborhood conditions have established associations with poorer child health, but little is known about protective factors that mitigate the effects of difficult neighborhood conditions. In this study, we tested if positive family relationships can buffer youth who live in dangerous and/or disorderly neighborhoods from poor asthma outcomes.

METHODS

A total of 308 youths (aged 9-17) who were physician-diagnosed with asthma and referred from community pediatricians and/or family practitioners participated in this cross-sectional study. Neighborhood conditions around families' home addresses were coded by using Google Street View images. Family relationship quality was determined via youth interviews. Clinical asthma outcomes (asthma symptoms, activity limitations, and forced expiratory volume in 1 second percentile), asthma management behaviors (family response to asthma symptoms and integration of asthma into daily life), and asthma-relevant immunologic processes (lymphocyte T helper 1 and T helper 2 cytokine production and sensitivity to glucocorticoid inhibition) were assessed via questionnaires, interviews, spirometry, and blood draws.

RESULTS

Significant interactions were found between neighborhood conditions and family relationship quality (β = |.11-.15|; P < .05). When neighborhood danger and/or disorder was low, family relationships were not associated with asthma. When neighborhood danger and/or disorder was high, better family relationship quality was associated with fewer asthma symptoms, fewer activity limitations, and higher forced expiratory volume in 1 second percentile. Similar patterns emerged for asthma management behaviors. With immunologic measures, greater neighborhood danger and/or disorder was associated with greater T helper 1 and T helper 2 cytokine production and reduced glucocorticoid sensitivity.

CONCLUSIONS

When youth live in dangerous and/or disorderly neighborhoods, high family relationship quality can buffer youth from poor asthma outcomes. Although families may not be able to change their neighborhoods, they may nonetheless be able to facilitate better asthma outcomes in their children through strong family relationships.

The costs of high self-control in Black and Latino youth with asthma: Divergence of mental health and inflammatory profiles

Emerging evidence in psychology suggests a paradox whereby high levels of self-control when striving for academic success among minority youth can have physical health costs. This study tested the skin-deep resilience hypothesis in asthma- whether minority youth who are striving hard to succeed academically experience good psychological outcomes but poor asthma outcomes. Youth physician-diagnosed with asthma (N = 276, M age = 12.99; 155 = White, 121 = Black/Latino) completed interviews about school stress and a self-control questionnaire. Outcomes included mental health (anxiety/depression) and ex-vivo immunologic processes relevant to asthma (lymphocyte Th-1 and Th-2 cytokine production, and sensitivity to glucocorticoid inhibition). Physician contacts were tracked over a one-year follow-up. For minority youth experiencing high levels of school stress, greater self-control was associated with fewer mental health symptoms (beta = -0.20, p < .05), but worse asthma inflammatory profiles (larger Th-1 and Th-2 cytokine responses, lower sensitivity to glucocorticoid inhibition), and more frequent physician contacts during the one-year follow-up (beta's ranging from 0.22 to 0.43, p's < .05). These patterns were not evident in White youth. In minority youth struggling with school, high levels of self-control are detrimental to asthma inflammatory profiles and clinical outcomes. This suggests the need for health monitoring to be incorporated into academic programs to ensure that 'overcoming the odds' does not lead to heightened health risks in minority youth.

Conjugation of a Small-Molecule TLR7 Agonist to Silica Nanoshells Enhances Adjuvant Activity

Stimulation of Toll-like receptors (TLRs) and/or NOD-like receptors on immune cells initiates and directs immune responses that are essential for vaccine adjuvants. The small-molecule TLR7 agonist, imiquimod, has been approved by the FDA as an immune response modifier but is limited to topical application due to its poor pharmacokinetics that causes undesired adverse effects. Nanoparticles are increasingly used with innate immune stimulators to mitigate side effects and enhance adjuvant efficacy. In this study, a potent small-molecule TLR7 agonist, 2-methoxyethoxy-8-oxo-9-(4-carboxybenzyl)adenine (1V209), was conjugated to hollow silica nanoshells (NS). Proinflammatory cytokine (IL-6, IL-12) release by mouse bone-marrow-derived dendritic cells and human peripheral blood mononuclear cells revealed that the potency of silica nanoshells-TLR7 conjugates (NS-TLR) depends on nanoshell size and ligand coating density. Silica nanoshells of 100 nm diameter coated with a minimum of ∼6000 1V209 ligands/particle displayed 3-fold higher potency with no observed cytotoxicity when compared to an unconjugated TLR7 agonist. NS-TLR activated the TLR7-signaling pathway, triggered caspase activity, and stimulated IL-1β release, while neither unconjugated TLR7 ligands nor silica shells alone produced IL-1β. An in vivo murine immunization study, using the model antigen ovalbumin, demonstrated that NS-TLR increased antigen-specific IgG antibody induction by 1000× with a Th1-biased immune response, compared to unconjugated TLR7 agonists. The results show that the TLR7 ligand conjugated to silica nanoshells is capable of activating an inflammasome pathway to enhance both innate immune-stimulatory and adjuvant potencies of the TLR7 agonist, thereby broadening applications of innate immune stimulators.

Longitudinal multi-omics of host-microbe dynamics in prediabetes

Type 2 diabetes mellitus (T2D) is a growing health problem, but little is known about its early disease stages, its effects on biological processes or the transition to clinical T2D. To understand the earliest stages of T2D better, we obtained samples from 106 healthy individuals and individuals with prediabetes over approximately four years and performed deep profiling of transcriptomes, metabolomes, cytokines, and proteomes, as well as changes in the microbiome. This rich longitudinal data set revealed many insights: first, healthy profiles are distinct among individuals while displaying diverse patterns of intra- and/or inter-personal variability. Second, extensive host and microbial changes occur during respiratory viral infections and immunization, and immunization triggers potentially protective responses that are distinct from responses to respiratory viral infections. Moreover, during respiratory viral infections, insulin-resistant participants respond differently than insulin-sensitive participants. Third, global co-association analyses among the thousands of profiled molecules reveal specific host-microbe interactions that differ between insulin-resistant and insulin-sensitive individuals. Last, we identified early personal molecular signatures in one individual that preceded the onset of T2D, including the inflammation markers interleukin-1 receptor agonist (IL-1RA) and high-sensitivity C-reactive protein (CRP) paired with xenobiotic-induced immune signalling. Our study reveals insights into pathways and responses that differ between glucose-dysregulated and healthy individuals during health and disease and provides an open-access data resource to enable further research into healthy, prediabetic and T2D states.

Myalgia and chronic fatigue syndrome following immunization: macrophagic myofasciitis and animal studies support linkage to aluminum adjuvant persistency and diffusion in the immune system

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a multifactorial and poorly undersood disabling disease. We present epidemiological, clinical and experimental evidence that ME/CFS constitutes a major type of adverse effect of vaccines, especially those containing poorly degradable particulate aluminum adjuvants. Evidence has emerged very slowly due to the multiplicity, lack of specificity, delayed onset, and frequent medical underestimation of ME/CFS symptoms. It was supported by an epidemiological study comparing vaccinated vs unvaccinated militaries that remained undeployed during Gulf War II. Affected patients suffer from cognitive dysfunction affecting attention, memory and inter-hemispheric connexions, well correlated to brain perfusion defects and associated with a stereotyped and distinctive pattern of cerebral glucose hypometabolism. Deltoid muscle biopsy performed to investigate myalgia typically yields macrophagic myofasciitis (MMF), a histological biomarker assessing longstanding persistency of aluminum agglomerates within innate immune cells at site of previous immunization. MMF is seemingly linked to altered mineral particle detoxification by the xeno/autophagy machinery. Comparing toxicology of different forms of aluminum and different types of exposure is misleading and inadequate and small animal experiments have turned old dogma upside down. Instead of being rapidly solubilized in the extracellular space, injected aluminum particles are quickly captured by immune cells and transported to distant organs and the brain where they elicit an inflammatory response and exert selective low dose long-term neurotoxicity. Clinical observations and experiments in sheep, a large animal like humans, confirmed both systemic diffusion and neurotoxic effects of aluminum adjuvants. Post-immunization ME/CFS represents the core manifestation of "autoimmune/inflammatory syndrome induced by adjuvants" (ASIA).

The balance of type 1 and type 2 immune responses in the contexts of hepatitis B infection and hepatitis D infection

BACKGROUND AND AIM

Hepatitis delta virus (HDV) infection is the most rapidly progressive chronic viral hepatitis. Little is understood about the immune responses to HDV. This study aims to characterize the systemic immune environments of hepatitis B virus (HBV) and HDV patients at various disease stages.

METHODS

A total of 129 subjects were evaluated: 53 HBV, 43 HDV, and 33 healthy controls. HBV and HDV subjects were categorized by aspartate aminotransferase to platelet ratio index (APRI) into mild (APRI < 0.5), moderate, and severe (APRI > 1.0). Serum cytokines and immune markers were assessed at a single treatment-naïve time-point.

RESULTS

Type 1 cytokines are elevated in both HBV and HDV. Both groups show higher tumor necrosis factor-α (TNF-α), interleukin (IL)-12p40, and C-X-C motif chemokine ligand 9 when compared with controls (all P < 0.05). However, only HBV group displayed elevated γ-interferon compared with controls. Type 2 cytokines are elevated in HBV. HBV group shows higher IL-4, IL-13, and C-C motif chemokine ligand (CCL) 26 compared with healthy controls and HDV. Chemokines CCL2 and CCL13 are lower in HDV. When assessing ratios, HDV displays higher γ-interferon/IL-4, TNF-α/IL-4, and TNF-α/IL-13 ratios than HBV and controls.

CONCLUSION

Hepatitis B virus and HDV subjects show similarly elevated type 1 cytokines. HDV subjects display relatively lower type 2 cytokines. These differences in the systemic immune environments, particularly the predominance of type 1 responses, may contribute to the comparatively rapid progression of HDV disease. Characterization of the imbalance in type 1 and type 2 immunity unique HDV has the potential to provide immunological insights for designing therapeutic targets in HDV-associated disease progression.

Immunogenicity of high-dose trivalent inactivated influenza vaccine: a systematic review and meta-analysis

INTRODUCTION

High-dose trivalent, inactivated, split-virus influenza vaccine (IIV3-HD) has been available in the US since 2009 for adults aged ≥ 65 years. To better understand how IIV3-HD provides improved protection against influenza, we systematically reviewed clinical studies comparing immune responses to IIV3-HD and standard-dose trivalent vaccine (IIV3-SD).

AREAS COVERED

The primary objective was to determine the relative hemagglutination inhibition (HAI) antibody response of IIV3-HD vs. IIV3-SD in adults aged ≥ 65 years. Based on seven randomized studies including more than 18,500 adults aged ≥ 65 years, combined HAI geometric mean titer (GMT) ratios (95% confidence interval) approximately 1 month post-vaccination were 1.74 (1.65-1.83) for influenza A/H1N1, 1.84 (1.73-1.95) for influenza A/H3N2, and 1.47 (1.36-1.58) for influenza B. HAI GMT ratios in these studies were similar irrespective of sex, older age (≥ 75 years), frailty, and underlying conditions. Trends were similar for A/H3N2 neutralization and anti-neuraminidase antibody titers. In immunocompromised individuals, HAI GMT ratios were mostly > 1.

EXPERT OPINION

In agreement with its improved efficacy and effectiveness, IIV3-HD is consistently more immunogenic than IIV3-SD in adults aged ≥ 65 years. IIV3-HD also appears more immunogenic in immunocompromised individuals.

Immune characteristics correlating with HSV-1 immune control and effect of squaric acid dibutyl ester on immune characteristics of subjects with frequent herpes labialis episodes

INTRODUCTION

Differences in immune characteristics, including immune gene expression by peripheral blood mononuclear cells (PBMCs), correlating with herpes labialis and good or poor immune control of herpes simplex virus type 1 (HSV-1), and how these characteristics change after dosing with squaric acid dibutyl ester (SADBE), were investigated.

METHODS

PBMCs were collected from persons positive for IgG against HSV-1 and having frequent, infrequent, or no herpes labialis outbreaks. The PBMCs were tested for proliferation against HSV-1 and a fungal antigen (Candida) and immune gene expression in the presence of HSV-1 and Candida. On day 1 after blood collection the subjects with frequent outbreaks were dosed topically on the arm once with SADBE, and their PBMCs were collected and tested 8 weeks later.

RESULTS

Those with good immune control of their HSV-1 infection (fewer outbreaks) differ from those with poorer immune control in these ways: (1) Greater PBMC proliferation in vitro to HSV-1, HSV-1-infected cell extracts, and Candida considered together (P < 0.01). (2) Higher expression of IFNG and five other immune-related genes (P < 0.05 for each) and lower expression of IL5 and two other immune-related genes (P < 0.05 for each) in PBMCs in vitro stimulated with HSV-1 virus. The subjects with frequent outbreaks were treated once with SADBE, and 56 days later the PBMCs of these subjects differed from PBMCs from the same subjects taken on day 1 before treatment in exactly the same ways listed above as differences between those with good and poor immune control of HSV-1, and at the same levels of significance.

CONCLUSIONS

Higher IFNG and lower IL5 expression by PBMCs in the presence of HSV-1 correlate with fewer herpes labialis outbreaks, and a single topical dose of SADBE to the arm of subjects with frequent herpes labialis episodes improves immune response to HSV-1.

Early and dynamic alterations of Th2/Th1 in previously immunocompetent patients with community-acquired severe sepsis: a prospective observational study

BACKGROUND

T helper (Th) cells regulate sepsis processes, including primary pathogen clear and secondary pathogen defence. The objectives of this study were to determine the early and dynamic alterations of Th1 and Th2 populations to community-acquired severe sepsis upon onset among previously immunocompetent patients and whether it was related to clinical outcomes.

METHODS

This prospective observational cohort study was conducted at a general intensive care unit (ICU) of a tertiary teaching hospital in China. Immunocompetent patients with community-acquired severe sepsis within 24 h upon onset were included as septic group. Healthy volunteers and critically ill patients without severe sepsis were recruited as controls. Whole blood was collected on D0, 3rd day (D3) and 7th day (D7) for septic group and once upon enrollment for controls. Th1 and Th2 populations were measured by flow cytometry and assessed for associations with 28-day mortality using cox proportional hazard models. Associations of dynamic alterations of Th cell subpopulations with clinical outcomes were investigated.

RESULTS

This study demonstrated that community-acquired severe sepsis patients (n = 71) had increased Th2/Th1 and Th2 populations, compared to healthy controls (n = 7) and critically ill patients without severe sepsis (n = 7) at admission. Among the septic cohort, values of Th2/Th1 were significantly higher in non-survivors than survivors on D0 (p = 0.04), D3 (p < 0.001) and D7 (p < 0.001). Patients with persistently increasing Th2/Th1 demonstrated the highest mortality (47.1%) and incidence of ICU-acquired infections (64.7%).

CONCLUSIONS

Th2/Th1 was markedly up-regulated with Th2 dominance upon community-acquired severe sepsis onset among previously immunocompetent patients and its persistently dynamic increase was associated with ICU-acquired infections and 28-day death. Trial registration Institutional Ethics Committee of Zhongda Hospital, 2014ZDSYLL086, registered in June 2014-prospectively registered; ClinicalTrials.gov, NCT02883218, registered on 25 Aug 2016-retrospectively registered, https://www.clinicaltrials.gov/ct2/show/NCT02883218?cond=NCT02883218&rank=1.

Toxoplasma gondii IgG associations with sleep-wake problems, sleep duration and timing

Background:

Evidence links Toxoplasmagondii (T. gondii), a neurotropic parasite, with schizophrenia, mood disorders and suicidal behavior, all of which are associated and exacerbated by disrupted sleep. Moreover, low-grade immune activation and dopaminergic overstimulation, which are consequences of T. gondii infection, could alter sleep patterns and duration.

Methods:

Sleep data on 833 Amish participants [mean age (SD) = 44.28 (16.99) years; 59.06% women] were obtained via self-reported questionnaires that assessed sleep problems, duration and timing. T. gondii IgG was measured with ELISA. Data were analyzed using multivariable logistic regressions and linear mixed models, with adjustment for age, sex and family structure.

Results:

T. gondii seropositives reported less sleep problems (p < 0.005) and less daytime problems due to poor sleep (p < 0.005). Higher T. gondii titers were associated with longer sleep duration (p < 0.05), earlier bedtime (p< 0.005) earlier mid-sleep time (p < 0.05).

Conclusions:

It seems unlikely that sleep mediates the previously reported associations between T. gondii and mental illness. Future longitudinal studies with objective measures are necessary to replicate our findings.

Vitamin D in malaria: more hypotheses than clues

Vitamin D is a secosteroid hormone regulating calcium and phosphate metabolism, immune response and brain development. Low blood 25(OH)D levels have been reported in patients affected by infectious diseases caused by parasites, including malaria. Despite the high effectiveness of antimalarials, malaria is burdened with high morbidity and mortality, and the search for additional therapies is rapidly growing. Furthermore, available preventive measures have proved to be barely effective so far. Finding new prevention and therapy tools is a matter of urgency. Studies on animal models and humans have hypothesized some mechanisms by which the hormone can influence malaria pathogenesis, and the role of Vitamin D supplementation in preventing and treating this disease has been suggested. Few studies on the association between Vitamin D and malaria are available and disagreeing results have been reported. Studies in humans reporting an association between low 25(OH)D circulating levels and Malaria have a small sample size and observational study-set. Randomized controlled trials are needed in order to understand if Vitamin D administration might play a role in preventing and treating malaria.

Distribution of distinct subsets of circulating T follicular helper cells in Kawasaki disease

Background

Kawasaki disease (KD) is an acute febrile vasculitis that primarily affects children. Previous studies have shown that both innate and adapt immune systems are involved in the immunopathogenesis of KD. The following study analyzes the distribution of the subsets of Circulating T follicular helper cells (cTfh cells) in KD patients with and without coronary artery lesions (CALs).

Methods

Twenty KD patients and fifteen healthy sex- and age- matched children were enrolled. Patients were divided into two groups depending on CALs. Blood samples were collected respectively before and after intravenous immunoglobulin (IVIG) administration. Circulating Tfh cells were categorized into three subsets by flow cytometry including cTfh1 (CXCR3 + CCR6-), cTfh2 (CXCR3-CCX6-) and cTfh17 (CXCR3-CCR6+) cells in circulating CD3 + CD4 + CXCR5 + CD45RA- T cells. Cytometric bead arrays were used to analyze the level of IFN-γ, IL-4 and IL-17A.

Results

We found that frequency of cTfh2 cells was significantly elevated in KD patients before IVIG administration with low expression of cTfh1 cells, where the ratio of cTfh2 + cTfh17/cTfh1 significantly increased. Levels of IFN-γ, IL-4 and IL-17A in KD were significantly higher compared to controls. Further analysis showed that cTfh1 cells were negatively correlated with serum CRP, whereas cTfh2 cells were positively correlated with serum CRP and ESR. Comparison of different groups showed that frequency of cTfh1 cells in CALs+ group were significantly lower compared to CALs- group. In contrast, cTfh2 cells in CALs+ group significantly increased. After IVIG administration, frequency of cTfh2 cells and the ratio significantly decreased while the frequency of cTfh1 cells significantly increased. Meanwhile, all levels of cytokines decreased.

Conclusions

Our data demonstrated that cTfh1 and cTfh2 cells participate in the pathogenesis of KD, and that the two subsets might be associated with CALs.

Immunization with adult Schistosoma mansoni tegument, treated with sub-curative praziquantel, partially protects mice against the infection

The tegument of schistosomes is a source of many potential anti-Schistosoma vaccine molecules. This work aimed to assess the protective effects of the adult Schistosoma mansoni tegument treated (TT) with sub-curative praziquantel (PZQ), whether in vivo (in vivo TT) or in vitro (in vitro TT), in murine schistosomiasis. In vitro TT and in vivo TT showed great similarity, and they differed from untreated tegument antigen (Teg) in terms of quantity and quality of protein bands on SDS-PAGE. Two immunization trials were performed, each with 50 mice, divided randomly into five groups of 10 mice each: (1) uninfected control mice (UC), (2) infected mice given phosphate buffer saline + adjuvant (PBS + adjuvant), (3) infected, Teg vaccinated, (4) infected, in vivo TT vaccinated, and (5) infected, in vitro TT vaccinated. All the immunizations with antigens induced mixed Th1/Th2 immune responses, as indicated by significantly high (P < 0.001) specific IgG2a and IgG1 levels, with Th1 predominating, as shown by a diminished IgG1/IgG2a ratio, as well as a high serum concentration of IFN-γ, an absence of IL-4 and increased IL-10. In vitro TT gave the most pronounced response. With respect to reduction of total worm burden, relative to PBS + adjuvant mice, in vitro TT achieved the highest significant (P < 0.001) results, followed by in vivo TT and Teg (51.8-57.04%, 44.6-50.2% and 35.2-39.3%, respectively). In scanning electron microscopy studies, all the tested antigens caused tegumental changes in adult worms, with the worst occurring with in vitro TT, such as retracted ventral sucker, an effect on the gynaecophoric canal, and changes to tubercles. In conclusion, in vitro TT, which is cheap to prepare, could be a potential vaccine against S. mansoni.

Antigen delivery format variation and formulation stability through use of a hybrid vector

A hybrid biological-biomaterial antigen delivery vector comprised of a polymeric shell encapsulating an Escherichia coli core was previously developed for in situ antigen production and subsequent delivery. Due to the engineering capacity of the bacterial core, the hybrid vector provides unique opportunities for immunogenicity optimization through varying cellular localization (cytoplasm, periplasm, cellular surface) and type (protein or DNA) of antigen. In this work, three protein-based hybrid vector formats were compared in which the pneumococcal surface protein A (PspA) was localized to the cytoplasm, surface, and periplasmic space of the bacterial core for vaccination against pneumococcal disease. Furthermore, we tested the hybrid vector's capacity as a DNA vaccine against Streptococcus pneumoniae by introducing a plasmid into the bacterial core to facilitate PspA expression in antigen presenting cells (APCs). Through testing these various formulations, we determined that cytoplasmic accumulation of PspA elicited the strongest immune response (antibody production and protection against bacterial challenge) and enabled complete protection at substantially lower doses when compared to vaccination with PspA + adjuvant. We also improved the storage stability of the hybrid vector to retain complete activity after 1 month at 4 °C using an approach in which hybrid vectors suspended in a microbial freeze drying buffer were desiccated. These results demonstrate the flexibility and robustness of the hybrid vector formulation, which has the potential to be a potent vaccine against S. pneumoniae.

Evidence of reduced vertical transmission of Neospora caninum associated with higher IgG1 than IgG2 serum levels and presence of IFN-γ in non-aborting chronically infected cattle under natural condition

Neospora caninum infection of cattle can be vertically transmitted, resulting in abortion or birth of infected calves. Vertical transmission occurs both in acutely or chronically infected cattle. There is little information on the immune response needed to prevent endogenous transplacental transmission, particularly from chronically infected cattle to their offspring in a natural environment. In this study, N. caninum seropositive pregnant cattle from three different farms with high avidity antibodies and low IgM titers were selected and their newborn colostrum-deprived calves were tested for anti-N. caninum antibodies. Based on these results, dams were grouped according to their congenital transmission status. The analysis of the immune profile of the chronically-infected pregnant cattle revealed that higher ratio between IgG1 and IgG2 anti-N. caninum serum titers and higher levels of systemic IFN-γ were associated with diminished vertical transmission rates, compared to dams with the opposite profile. Our results evidenced an association between the immune profile and vertical transmission in non-aborting chronically infected dams, and confirm that vertical transmission, even when not leading to abortion, is related to a defined immune profile. This is important information to accomplish successful vaccine development efforts.

Probiotic Exopolysaccharide Protects against Systemic Staphylococcus aureus Infection, Inducing Dual-Functioning Macrophages That Restrict Bacterial Growth and Limit Inflammation

Staphylococcus aureus causes severe systemic infection with high mortality rates. We previously identified exopolysaccharide (EPS) from a probiotic, Bacillus subtilis, that induces anti-inflammatory macrophages with an M2 phenotype and protects mice from Citrobacter rodentium-induced colitis. We tested if EPS could protect from systemic infection induced by S. aureus and found that EPS-treated mice had enhanced survival as well as reduced weight loss, systemic inflammation, and bacterial burden. While macrophages from EPS-treated mice display an M2 phenotype, they also restrict growth of internalized S. aureus through reactive oxygen species (ROS), reminiscent of proinflammatory phagocytes. These EPS-induced macrophages also limit T cell activation by S. aureus superantigens, and EPS abrogates systemic induction of gamma interferon after infection. We conclude that B. subtilis EPS is an immunomodulatory agent that induces hybrid macrophages that bolster antibacterial immunity and simultaneously limit inflammation, reducing disease burden and promoting host survival.

Let's cross-link: diverse functions of the promiscuous cellular transglutaminase factor XIII-A

Essentials Plasma Factor XIII, a heterodimer of A and B subunits FXIIIA2 B2 , is a transglutaminase enzyme with a well-established role in haemostasis. Cells of bone marrow and mesenchymal lineage express the FXIII-A gene (F13A1) that encodes the cellular form of the transglutaminase, a homodimer of the A subunits, FXIII-A. FXIII-A was presumed to function intracellularly, however, several lines of evidence now indicate that FXIII-A is externalised by an as yet unknown mechanism This review describes the mounting evidence that FXIII-A is a diverse transglutaminase with many intracellular and extracellular substrates that can participate in an array of biological processes SUMMARY: Factor XIII is a tranglutaminase enzyme that catalyzes the formation of ε-(γ-glutamyl)lysyl isopeptide bonds in protein substrates. The plasma form, FXIII-A2 B2 , has an established function in hemostasis, where its primary substrate is fibrin. A deficiency in FXIII manifests as a severe bleeding diathesis, underscoring its importance in this pathway. The cellular form of the enzyme, a homodimer of the A-subunits, denoted FXIII-A, has not been studied in as extensive detail. FXIII-A was generally perceived to remain intracellular, owing to the lack of a classical signal peptide for its release. In the last decade, emerging evidence has revealed that this diverse transglutaminase can be externalized from cells, by an as yet unknown mechanism, and can cross-link extracellular substrates and participate in a number of diverse pathways. The FXIII-A gene (F13A1) is expressed in cells of bone marrow and mesenchymal lineage, notably megakaryocytes, monocytes/macrophages, dendritic cells, chrondrocytes, osteoblasts, and preadipocytes. The biological processes that FXIII-A is coupled with, such as wound healing, phagocytosis, and bone and matrix remodeling, reflect its expression in these cell types. This review describes the mounting evidence that this cellular transglutaminase can be externalized, usually in response to stimuli, and participate in extracellular cross-linking reactions. A corollary of being involved in these biological pathways is the participation of FXIII-A in pathological processes. In conclusion, the functions of this transglutaminase extend far beyond its role in hemostasis, and our understanding of this enzyme in terms of its secretion, regulation and substrates is in its infancy.

Resveratrol Attenuates Allergic Asthma and Associated Inflammation in the Lungs Through Regulation of miRNA-34a That Targets FoxP3 in Mice

Asthma is a chronic inflammatory disease of airways mediated by T-helper 2 (Th2) cells involving complex signaling pathways. Although resveratrol has previously been shown to attenuate allergic asthma, the role of miRNA in this process has not been studied. We investigated the effect of resveratrol on ovalbumin-induced experimental allergic asthma in mice. To that end, BALB/c mice were immunized with ovalbumin (OVA) intraperitoneally followed by oral gavage of vehicle (OVA-veh) or resveratrol (100 mg/kg body) (OVA-res). On day 7, the experimental groups received intranasal challenge of OVA followed by 7 days of additional oral gavage of vehicle or resveratrol. At day 15, all mice were euthanized and bronchioalveolar fluid (BALF), serum and lung infiltrating cells were collected and analyzed. The data showed that resveratrol significantly reduced IL-5, IL-13, and TGF-β in the serum and BALF in mice with OVA-induced asthma. Also, we saw a decrease in CD3+CD4+, CD3+CD8+, and CD4+IL-4+ cells with increase in CD4+CD25+FOXP3+ cells in pulmonary inflammatory cell infiltrate in OVA-res group when compared to OVA-veh. miRNA expression arrays using lung infiltrating cells showed that resveratrol caused significant alterations in miRNA expression, specifically downregulating the expression of miR-34a. Additionally, miR-34a was found to target FOXP3, as evidenced by enhanced expression of FOXP3 in the lung tissue. Also, transfection studies showed that miR-34a inhibitor upregulated FOXP3 expression while miR-34a-mimic downregulated FOXP3 expression. The current study suggests that resveratrol attenuates allergic asthma by downregulating miR-34a that induces increased expression of FOXP3, a master regulator of Treg development and functions.

Immune cell counts and signaling in body fluids of cows vaccinated against Clostridium difficile

BACKGROUND

New treatment options are needed to prevent relapses following failed antibiotic therapies of Clostridium difficile infections (CDI) in humans. The concomitant therapy with an anti-C. difficile IgA containing whey protein concentrate can support the sustainable recovery of CDI patients. For 31 weeks, nine dairy cows were continuously vaccinated with several anti-C. difficile vaccines by certain routes of administration to produce anti-C. difficile IgA enriched milk. The study aimed at finding decisive differences between low responder (LR) and high responder (HR) cows (> 8.0 µg ml-1 total milk C. difficile specific IgA) concerning their immune response to vaccination on cellular and molecular biological levels.

RESULTS

The results of total and differential cell counting (DCC) in blood and milk and the outcomes of the gene expression analysis of selected immune factors were assessed relating to the usage of two vaccine batches for injection (MucoCD-I batch A and B), marking two immunization (IM) periods, and compared to a control group (Ctr). The MucoCD-I batch A caused short-term leukopenia followed by leukocytosis in the blood of LR and HR. The total somatic cell counts in milk were not altered by the treatment. The DCC revealed that the leukocytes of the treated groups were partly impaired by the treatment. The gene expression analysis exposed cumulative and sustainable differences (p < 0.05) between LR and HR for the genes encoding for lactoferrin, CXCL8, IL1β, IL2, IL6, IL12β, IFNγ, CD4 and CD163. The regulation of the epithelial IgA cell receptor PIGR was not impaired by the IM. In contrast to the vaccination with MucoCD-I batch A, the second IM period with MucoCD-I batch B resulted in mitigation and synchronization of the treated groups' immune responses.

CONCLUSIONS

The inversely regulated cytokines in the blood and milk cells of the treated groups led to a variously directed, local T cell response resulting in their different production intensities of C. difficile specific IgA in milk.

Moderation of the relationship between Toxoplasma gondii seropositivity and trait impulsivity in younger men by the phenylalanine-tyrosine ratio

Previously, we reported that Toxoplasma gondii (T. gondii)-seropositivity is associated with higher impulsive sensation seeking in younger men. As dopaminergic and serotonergic signaling regulate impulsivity, and as T. gondii directly and indirectly affects dopaminergic signaling and induces activation of the kynurenine pathway leading to the diversion of tryptophan from serotonin production, we investigated if dopamine and serotonin precursors or the tryptophan metabolite kynurenine interact with the T. gondii-impulsivity association. In 950 psychiatrically healthy participants, trait impulsivity scores were related to T. gondii IgG seropositivity. Interactions were also identified between categorized levels of phenylalanine (Phe), tyrosine (Tyr), Phe:Tyr ratio, kynurenine (Kyn), tryptophan (Trp) and Kyn:Trp ratio, and age and gender. Only younger T. gondii-positive men with a high Phe:Tyr ratio, were found to have significantly higher impulsivity scores. There were no significant associations in other demographic groups, including women and older men. No significant effects or interactions were identified for Phe, Tyr, Kyn, Trp, or Kyn:Trp ratio. Phe:Tyr ratio, therefore, may play a moderating role in the association between T. gondii seropositivity and impulsivity in younger men. These results could potentially lead to individualized approaches to reduce impulsivity, based on combined demographic, biochemical and serological factors.

Fasudil exerts a cardio-protective effect on mice with coxsackievirus B3-induced acute viral myocarditis

AIMS

To investigate whether there exists a cardio-protective effect of Fasudil, a selective Rho kinase (ROCK) inhibitor, in an experimental murine model of acute viral myocarditis.

METHODS

Male BALB/c mice were randomly assigned to three groups: control, myocarditis treated with placebo and myocarditis treated with Fasudil (n = 40 animals per group). Myocarditis was established by intraperitoneal injection with coxsackievirus B3 (CVB3). Twenty-four hours after infection, Fasudil was intraperitoneally administered for 14 consecutive days. Twenty mice were randomly selected from each group to monitor a 14-day survival rate. On day 7 and day 14, eight surviving mice from each group were sacrificed and their hearts and blood were obtained to perform serological and histological examinations. Expression of ROCKs, IL-17, IL-1b, TNFα, RORgt, and Foxp3 were quantified with RT-PCR. Plasma levels of TNF alpha, IL-1 beta, and IL-17 were measured by ELISA. In addition, protein levels of IL-17 and ROCK2 in cardiac tissues were analyzed with Western blot.

RESULTS

Fasudil treatment significantly increased survival, attenuated myocardial necrotic lesions, reduced CVB3 replication and expression of ROCK2 and IL-17 in the infected hearts. This treatment also imposed a T-cell subpopulation shift, from Th17 to Treg, in cardiac tissues.

CONCLUSIONS

ROCK pathway inhibition was cardio-protective in viral myocarditis with increased survival, decreased viral replication, and inflammatory response. These findings suggest that Fasudil might be a potential therapeutic agent for patients with viral myocarditis.

Influence of swine leukocyte antigen haplotype on serum antibody titers against swine erysipelas vaccine and reproductive and meat production traits of SLA-defined selectively bred Duroc pigs

We investigated possible associations of SLA class II haplotypes with serum antibody titers against a swine erysipelas vaccine, reproductive and meat production traits using a population of selective breeding Duroc pigs. In the selective breeding Duroc pigs, four SLA class II-DRB1 and -DQB1 alleles were assigned by using PCR-sequence specific primer technique. Low-resolution haplotype (Lr)-0.30 and/or Lr-0.13 were deduced from the SLA class II alleles in the population of SLA-defined Duroc pigs. SLA-homozygous piglets with the Lr-0.30 haplotype had relatively lower serum antibody titers against the vaccine compared to those with Lr-0.13. In contrast, there were no statistically significant differences in reproductive performance between the SLA-defined pigs with two SLA class II haplotypes. Weaning and rearing rates until the body weight of 105 kg was reached in homozygous piglets with Lr-0.30 were significantly lower than those in homozygous piglets with Lr-0.13. The SLA-defined pigs had lower birth and weaning weights, body weights at 60 days of age, and daily weight gains than non-selective breeding Duroc pigs. Furthermore, the SLA-defined pigs had slightly lower back fat thickness compared to the non-selective breeding pigs. The rib eye areas of homozygous or heterozygous pigs with Lr-0.13 were larger than those of homozygous pigs with Lr-0.30 and non-selective breeding pigs. These data suggested that SLA haplotypes had the potential as useful genetic markers for selective breeding in the population of SLA-defined Duroc pigs.