Chlamydia trachomatis Seroepidemiology and Associated Factors in Fertility Treatment-Seeking Patients in the Abu Dhabi Emirate, United Arab Emirates.

PURPOSE: This study was designed to investigate the seroepidemiology of and identify factors associated with exposure to Chlamydia trachomatis ( C. trachomatis ) in fertility treatment-seeking patients in Abu Dhabi Emirate, United Arab Emirates. METHODS: A total of 308 fertility treatment-seeking patients were surveyed. Seroprevalence of past (IgG positive), current/acute (IgM positive), and active infection (IgA positive) with C. trachomatis was quantified. Factors associated with exposure to C. trachomatis were identified. RESULTS: Overall, 19.0%, 5.2%, and 1.6% found to have past, acute/recent, and ongoing active infection with C. trachomatis , respectively. Overall, 22.0% of the patients were seropositive to any of the 3 to C. trachomatis antibodies. Male compared with female patients (45.7% vs. 18.9%, P < 0.001) and current/ex-smokers compared with nonsmokers (44.4% vs. 17.8%) had higher seropositivity. Patients with a history of pregnancy loss had higher seropositivity compared with other patients (27.0% vs. 16.8%), particularly recurrent pregnancy losses (33.3%). Current smoking (adjusted odds ratio [aOR], 3.8; 95% confidence interval, 1.32-11.04) and history of pregnancy loss (adjusted odds ratio [aOR], 3.0; 95% confidence interval, 1.5-5.8) were significantly associated with higher odds of exposure to C. trachomatis . CONCLUSIONS: The observed high seroprevalence of C. trachomatis , particularly in patients with a history of pregnancy loss, possibly indicates the contribution of C. trachomatis to the growing burden of infertility in the United Arab Emirates.

Double-faced implication of CD4+ Foxp3+ regulatory T cells expanded by acute dengue infection via TLR2/MyD88 pathway.

Dengue infection causes dengue fever (DF) and dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). CD4+ Foxp3+ Tregs are expanded in patients during dengue infection, and appear to be associated with clinical severity. However, molecular pathways involved in Treg proliferation and the reason for their insufficient control of severe diseases are poorly understood. Here, dengue infection induced the proliferation of functional CD4+ Foxp3+ Tregs via TLR2/MyD88 pathway. Surface TLR2 on Tregs was responsible for their proliferation, and dengue-expanded Tregs subverted in vivo differentiation of effector CD8+ T cells. An additional interesting finding was that dengue-infected hosts displayed changed levels of susceptibility to other diseases in TLR2-dependent manner. This change included enhanced susceptibility to tumors and bacterial infection, but highly enhanced resistance to viral infection. Further, the transfer of dengue-proliferated Tregs protected the recipients from dengue-induced DHF/DSS and LPS-induced sepsis. In contrast, dengue-infected hosts were more susceptible to sepsis, an effect attributable to early TLR2-dependent production of proinflammatory cytokines. These facts may explain the reason why in some patients, dengue-proliferated Tregs is insufficient to control DF and DHF/DSS. Also, our observations lead to new insights into Treg responses activated by dengue infection in a TLR2-dependent manner, which could differentially act on subsequent exposure to other disease-producing situations.

Etiology of diarrhea by multiplex polymerase chain reaction among young children in the United Arab Emirates: a case-control study.

BACKGROUND: Little is known about the etiology of childhood diarrhea in the United Arab Emirates (UAE) especially after the introduction of rotavirus vaccines. This study aimed to identify gastrointestinal pathogens in children with diarrhea (cases) and the carriage rate of these pathogens in asymptomatic children (controls). METHODS: Stool samples were collected from 203 cases and 73 controls who presented to two major hospitals in Al Ain city, UAE. Samples were analyzed with Allplex™ Gastrointestinal Full Panel Assay for common entero-pathogens. The association between diarrhea and the isolated pathogens was calculated in a multivariate logistic regression model. The adjusted attributable fractions (aAFs) were calculated for all pathogens significantly associated with cases. RESULTS: At least one pathogen was identified in 87 samples (42.8%) from cases and 17 (23.3%) from controls (P < 0.001). Rotavirus, norovirus GII and adenovirus were significantly more prevalent in cases. Their aAFs with 95% ci are 0.95 (0.64, 1.00) for rotavirus, 0.86 (0.38, 0.97) for norovirus GII and 0.84 (0.29, 0.96) for adenovirus. None of the 13 bacteria tested for were more commonly found in the cases than in controls. Cryptosporidium spp. were more significantly detected in cases than in controls. Co-infections occurred in 27.9% of the children. Viruses and parasites were significantly more likely to occur together only in the cases. CONCLUSIONS: Multiplex PCR revealed high positivity rates in both cases and controls which demand a cautious interpretation. Rotavirus remains the main childhood diarrhea pathogen in UAE. Effective strategies are needed to better control rotavirus and other causative pathogens.

Sirolimus alters lung pathology and viral load following influenza A virus infection.

BACKGROUND: Inhibitors of mTOR, such as sirolimus, have been shown to induce thymus involution and inflammatory lung disease in mice. The latter effect supports the role of this serine/threonine kinase in ameliorating lung inflammation. Other studies have shown sirolimus reduces/delays lung disease associated with various strains of influenza A virus (IAV). Thus, the effects of mTOR inhibitors on influenza infection deserve further studies. METHODS: Here, we examined the changes in lung viral copies, pathology and pulmonary function associated with IAV (A/PR/8/34) infection in mice treated with sirolimus. RESULTS: Body weight loss peaked between days 6-11 post-infection and was more severe in IAV-infected mice that were administered sirolimus as compared to mice that received IAV alone (p = 0.030). Natural log viral gene copies, mean ± SD per mg lung tissue, in IAV-infected mice that were administered sirolimus were 17.31 ± 1.27 on day 4, 19.31 ± 7.46 on day 10, and 0 on day 25. The corresponding number of copies in mice that received IAV alone were 18.56 ± 0.95 on day 4 (p = 0.132), 1.52 ± 1.39 on day 10 (p = 0.008), and 0 on day 25. Lung pathology was evident on days 4, 10, and 25 post infection, with mean ± SD inflammatory score of 9.0 ± 4.5 in IAV-infected mice that were administered sirolimus, as compared to 11.5 ± 4.5 (p = 0.335) in mice received IAV alone (maximum score, 26.0). Impaired lung function was evident in IAV-infected mice on days 4 and 10, as demonstrated by increased airway resistance and decreased compliance. CONCLUSIONS: In this model, the effects of sirolimus on influenza infection included severe weight loss and modified viral replication, respiratory function and lung inflammation. The adverse events associated with sirolimus treatment are consistent with its potent immunosuppressive activity and, thus, preclude its use in IAV infection.

Seroepidemiology of Treponema pallidum, Mycoplasma hominis, and Ureaplasma urealyticum in fertility treatment-seeking patients in the Emirate of Abu Dhabi, United Arab Emirates.

BACKGROUND: Several genital pathogens affect fertility. The study estimated the seroprevalence of Treponema pallidum, Ureaplasma urealyticum, and Mycoplasma hominis and identify specific factors associated with exposure to at least one of these pathogens in patients seeking fertility treatment in the Emirate of Abu Dhabi, United Arab Emirates. METHODS: A seroepidemiological survey was conducted in a major fertility clinic in the Emirate of Abu Dhabi. Serum samples were screened for eight immunoglobulins (IgG, IgM, and IgA) against T. pallidum, U. urealyticum, and M. hominis using enzyme-linked immunoassays. Factors associated with seropositivity to at least one of the pathogens were investigated. RESULTS: The study surveyed 308 patients seeking fertility treatment (mean age: 36.1 ± 6.8 years). Most patients were female (88.0%), 24.9% had at least one chronic comorbidity, 19.3% had a previous genital infection, and 68.1% had been diagnosed with infertility for ≥ 6 months. Ig seroprevalence of T. pallidum (IgG: 3.0%, IgM: 3.2%), U. urealyticum (IgG: 2.6%, IgM: 2.0%), and M. hominis (IgG: 33.9%) was 6.4%, 4.6%, and 49.0%, respectively. Nearly one quarter (23.0%) and one decile (9.2%) of the patients exhibited evidence of ongoing infection (IgM seropositivity) or recent infection (IgA seropositivity) with M. hominis, respectively. Overall, 53.0% of the patients were seropositive for at least one of the screened immunoglobulins. Patients with an education level of secondary schooling or below (66.2%) or those who were unemployed (61.1%) had a higher seroprevalence of IgG antibodies compared with patients with college or higher-level education (48.4%) or those who were employed (48.1%) (p < 0.05). CONCLUSION: Exposure to T. pallidum or U. urealyticum was relatively low, whereas that to M. hominis was common in the surveyed patients. Enhanced awareness and screening programmes for genital pathogens are crucial to prevent and control the transmission of infections and reduce the growing burden of infertility.

Multifront assault on antigen presentation by Japanese encephalitis virus subverts CD8+ T cell responses.

Japanese encephalitis virus (JEV) is a frequent cause of acute and epidemic viral encephalitis. However, there is little information describing the mechanisms by which JEV subverts immune responses that may predispose the host to secondary infections. In this study, we found that JEV induced the subversion of CD8(+) T cell responses in a transient manner that was closely correlated with viral multiplication. Subsequently, analysis using a TCR-transgenic system revealed that CD8(+) T cells purified from JEV-infected mice showed impaired responses, and that naive CD8(+) T cells adoptively transferred into JEV-infected recipients showed less expanded responses. Furthermore, JEV altered the splenic dendritic cell (DC) subpopulation via preferential depletion of CD8alpha(+)CD11c(+) DCs without changing the plasmacytoid DCs and induced a significant reduction in the surface expression of MHC class II and CD40, but not MHC class I, CD80, and CD86 molecules. Finally, JEV was shown to inhibit the presentation of MHC class I-restricted Ag in DCs, and this immune suppression was ameliorated via the activation of DCs by TLR agonists. Collectively, our data indicate that JEV precludes the functions of Ag-presenting machinery, such as depletion of CD8alpha(+)CD11c(+) DCs and downregulation of MHC class I-restricted Ag presentation, thereby leading to immune subversion of CD8(+) T cells.

Herpes simplex virus type 2 seroprevalence and associated factors in fertility-treatment-seeking population: A cross-sectional survey in the United Arab Emirates.

Background: Herpes simplex virus type 2 (HSV-2) is a common genitally-transmitted viral infection affecting more than 400 million individuals globally. In the United Arab Emirates (UAE), in specific at-risk population groups, the burden of HSV-2 has not been reported. This study investigated the prevalence of HSV-2 IgG antibodies in patients seeking fertility treatment and characterized patients with seropositivity to HSV-2 IgG antibodies. Methodology: A cross-sectional sample of patients seeking fertility treatment in a major fertility clinic in Abu Dhabi, UAE was surveyed from April to May 2021. Patients were consecutively invited to complete self-administered questionnaires and provide blood for HSV-2 testing. Information on sociodemographics, medical history, and infertility was collected. Serum specimens were screened using an enzyme-linked immunosorbent assay for HSV-2 IgG antibodies detection. Results: Two hundred and ninety-nine patients were surveyed and provided blood samples. The mean age of the patients was 35.9 ± 6.8 [mean ± standard deviation (SD)] years with 89.3% being women. Sixty-six percent were overweight or obese, 25.0% had at least one chronic comorbidity, and 19.6% reported ever-had genital infection. More than two-thirds (68.3%) of the patients were infertile for ≥ 6 months. Of the 42 infertile males, 69.0% had an abnormal semen analysis. HSV-2 IgG antibodies was detected in 12.4% of patients. The HSV-2 IgG seropositive patients had a higher mean age (39.5 vs. 35.4 years; p < 0.001) compared to seronegative patients. HSV-2 IgG antibodies seropositivity was more common in males (15.6%) than females (12.0%), in patients with secondary (14.1%) vs. primary (9.2%) infertility, or in males with abnormal (10.3%) vs. normal (7.7%) semen. Conclusion: Exposure to HSV-2 at any time in patients seeking fertility treatment in the UAE was found to be slightly common in more than one out of 10 patients. Tailored health campaigns on HSV-2 prevention are warranted.

Functional modulation of dendritic cells and macrophages by Japanese encephalitis virus through MyD88 adaptor molecule-dependent and -independent pathways.

Dendritic cells (DCs) are potent initiators of T cell-mediated immunity that undergo maturation during viral infections. However, few reports describing the interactions of DCs with Japanese encephalitis virus (JEV), which remains the most frequent cause of acute and epidemic viral encephalitis, are available. In this study, we investigated the interaction of JEV with DCs and macrophages. JEV replicated its viral RNA in both cells with different efficiency, and JEV infection of macrophages followed the classical activation pathway of up-regulation of tested costimulatory molecules and proinflammatory cytokine production (IL-6, TNF-alpha, and IL-12). On the contrary, JEV-infected DCs failed to up-regulate costimulatory molecules such as CD40 and MHC class II. Of more interest, along with production of proinflammatory cytokines, DCs infected by JEV released antiinflammatory cytokine IL-10, which was not detected in macrophages. Moreover, signaling through MyD88 molecule, a pan-adaptor molecule of TLRs, and p38 MAPK in JEV-infected DCs was found to play a role in the production of cytokines and subversion of primary CD4(+) and CD8(+) T cell responses. We also found that IL-10 released from JEV-infected DCs led to a reduction in the priming of CD8(+) T cells, but not CD4(+) T cells. Taken together, our data suggest that JEV induces functional impairment of DCs through MyD88-dependent and -independent pathways, which subsequently leads to poor CD4(+) and CD8(+) T cell responses, resulting in boosting viral survival and dissemination in the body.

Exacerbation of Influenza A Virus Disease Severity by Respiratory Syncytial Virus Co-Infection in a Mouse Model.

Influenza A virus (IAV) and respiratory syncytial virus (RSV) are leading causes of childhood infections. RSV and influenza are competitive in vitro. In this study, the in vivo effects of RSV and IAV co-infection were investigated. Mice were intranasally inoculated with RSV, with IAV, or with both viruses (RSV+IAV and IAV+RSV) administered sequentially, 24 h apart. On days 3 and 7 post-infection, lung tissues were processed for viral loads and immune cell populations. Lung functions were also evaluated. Mortality was observed only in the IAV+RSV group (50% of mice did not survive beyond 7 days). On day 3, the viral loads in single-infected and co-infected mice were not significantly different. However, on day 7, the IAV titer was much higher in the IAV+RSV group, and the RSV viral load was reduced. CD4 T cells were reduced in all groups on day 7 except in single-infected mice. CD8 T cells were higher in all experimental groups except the RSV-alone group. Increased airway resistance and reduced thoracic compliance were demonstrated in both co-infected groups. This model indicates that, among all the infection types we studied, infection with IAV followed by RSV is associated with the highest IAV viral loads and the most morbidity and mortality.

Admission levels of Soluble Urokinase Plasminogen Activator Receptor (suPAR) are Associated with the Development of Severe Complications in Hospitalised COVID-19 Patients: A Prospective Cohort Study.

OBJECTIVE: To examine the association between plasma levels of the soluble urokinase plasminogen activator receptor (suPAR) and the incidence of severe complications of COVID-19. METHODS: 403 RT-PCR-confirmed COVID-19 patients were recruited and prospectively followed-up at a major hospital in the United Arab Emirates. The primary endpoint was time from admission until the development of a composite outcome, including acute respiratory distress syndrome (ARDS), intensive care unit (ICU) admission, or death from any cause. Patients discharged alive were considered as competing events to the primary outcome. Competing risk regression was used to quantify the association between suPAR and the incidence of the primary outcome. RESULTS: 6.2% of patients experienced ARDS or ICU admission, but none died. Taking into account competing risk, the incidence of the primary outcome was 11.5% (95% confidence interval [CI], 6.7-16.3) in patients with suPAR levels >3.91 ng/mL compared to 2.9% (95% CI, 0.4-5.5) in those with suPAR ≤3.91 ng/mL. Also, an increase by 1 ng/mL in baseline suPAR resulted in a 58% rise in the hazard of developing the primary outcome (hazard ratio 1.6, 95% CI, 1.2-2.1, p = 0.003). CONCLUSION: suPAR has an excellent prognostic utility in predicting severe complications in hospitalised COVID-19 patients.

Serum biomarkers differentiating Kawasaki disease from febrile infections: A pilot case-control study.

Although some serum biomarkers are elevated in both Kawasaki disease (KD) and infections, these conditions have not been compared by individual or combined biomarkers. The aim of this study, undertaken between January 2016 and May 2018 in a large teaching hospital, was to compare the serum concentration of cytokines, metalloproteinases (MMP) and heat shock protein (HSP) between cases defined as children with Kawasaki disease (KD) and those with febrile infections (controls). Serum concentrations of tumour necrosis factor-alpha (TNF-alpha), interleukins (IL 1beta, 6, and 8), heat shock proteins (HSP 60 and 70) and matrix metalloproteinase (MMP 9) were measured on admission in 17 children under six years of age with a temperature >38.5 °C for ≥five days, and compared between the two groups. The median age was 25 months and the median duration of fever eight days. Seven children were diagnosed with KD and ten had a febrile infection. Only the serum concentrations of IL-6 and TNF-alpha were significantly higher in the former than in the latter group (P = 0.01 and 0.04 respectively). To differentiate between the two groups with the best sensitivity and specificity, the optimal cut-off value for IL-6 was 12.6 pg/mL, and for TNF-alpha 47.9 pg/mL. Their combined increase, however, outperformed their individual concentrations. The characteristic diagnostic "signature" of the combined elevation of IL-6 and TNF-alpha serum levels has the potential, in febrile children, to differentiate early KD from febrile infections, allowing the institution of appropriate therapy.

Idelalisib induces apoptosis in the lymphoid tissues and impairs lung function in mice.

Idelalisib, an inhibitor of the phosphatidylinositol-3-kinase p110δ subunit (PI3Kδ), is approved for treating lymphoid malignancy. The drug is associated with hematopoietic and pulmonary toxicities, which limit its clinical use. However, the toxicity mechanisms are not completely elucidated. In this study, mice were intraperitoneally injected with idelalisib (40 or 80 µg/g) or dimethyl sulfoxide for five days every week for up to four weeks to evaluate the changes in the thymus, spleen, and pulmonary functions. Idelalisib treatment induced thymic involution, decreased CD4+/CD8+ T-cell population, and increased CD4-/CD8- T-cell population. In the spleen, idelalisib dose dependently decreased the lymphocyte viability and cell count. Idelalisib-treated mice exhibited enhanced cleaved caspase-3 expression in the thymus, spleen, and lung tissues. Idelalisib augmented thoracic and airway resistance and decreased thoracic compliance. Thus, PI3Kδ has physiological roles in T-cell development and airway function. Monitoring drug toxicity is important for developing follow-up compounds that target PI3Kδ signalling.

Nasopharyngeal Isolates from a Cohort of Medical Students with or without Pharyngitis.

OBJECTIVES: Few studies have investigated pharyngeal colonisation in the United Arab Emirates (UAE). This study aims to identify the pharyngeal organisms present in a cohort of medical students with and without symptomatic pharyngitis. METHODS: This study was conducted between September 2016 and June 2018 at the College of Medicine and Health Sciences, UAE University, Al-Ain. Nasopharyngeal swabs were collected from preclinical and clinical medical students attending the college during the study period. The specimens were tested for 16 viral and nine bacterial pathogens using a real-time polymerase chain reaction assay. RESULTS: A total of 352 nasopharyngeal swabs were collected from 287 students; of these, 22 (7.7%) had pharyngitis symptoms. Overall, the most common isolates were human rhinovirus, Streptococcus pneumoniae and Haemophilus influenzae, with no significant differences in terms of gender, year of study or stage of study. The prevalence of S. pyogenes in asymptomatic and symptomatic students was 1.1% and 0%, respectively. A Centor score of ≥2 was not associated with S. pyogenes-positive samples. Six pathogens were isolated from symptomatic students including H. influenzae. Fusobacterium necrophorum was not detected in any of the samples. CONCLUSION: The diagnosis and management of pharyngitis should be tailored to common pathogens in the region. This study found that S. pyogenes and F. necrophorum were not detected among students with symptoms of pharyngitis; moreover, Centor scores of ≥2 were not associated with the presence of S. pyogenes. This cut-off score therefore should not be employed as an empirical measure to initiate penicillin therapy in this population.

Pertussis seronegativity in pregnant women in the city of Al Ain, United Arab Emirates.

OBJECTIVE: As the current recommendation of administering Tdap (tetanus-diphtheria-acellular pertussis) to all pregnant women has not been widely implemented in the United Arab Emirates (UAE), we aimed to ascertain the prevalence of pertussis seronegativity during pregnancy. METHODS: IgG antibodies against Bordetella pertussis toxin (PT) were measured in 213 women attending the antenatal clinic at Oasis hospital, Al Ain, UAE. Results were compared by maternal age, nationality and gestational age with the Kruskal-Wallis test for IgG-PT levels and the Chi-squared test for serology status. RESULTS: The mean age±SD of the participants was 30.4±5.6 years, mean gestational age±SD of 25.5±3.3 weeks. Serum concentration of IgG-PT <10IU/ml were found in 160 out of 213 women (75%; 95% confidence interval 69%, 81%). There was no significant difference in the geometric mean of serum IgG-PT concentration across maternal age (P=0.80) or nationality (P=0.90). There were no differences in the prevalence of seronegativity with maternal age (P=0.65) or nationality (P=0.90). CONCLUSION: With a high prevalence of pertussis seronegativity in pregnant women, there is a potential benefit of introducing pertussis vaccination during pregnancy into our national immunization program.

Involvement of Acetylcholine Receptors in Cholinergic Pathway-Mediated Protection Against Autoimmune Diabetes.

Type I diabetes (T1D) is a T cell-driven autoimmune disease that results in the killing of pancreatic ß-cells and, consequently, loss of insulin production. Using the multiple low-dose streptozotocin (MLD-STZ) model of experimental autoimmune diabetes, we previously reported that pretreatment with a specific acetylcholinesterase inhibitor (AChEI), paraoxon, prevented the development of hyperglycemia in C57BL/6 mice. This correlated with an inhibition of T cell infiltration into the pancreatic islets and a reduction in pro-inflammatory cytokines. The cholinergic anti-inflammatory pathway utilizes nicotinic and muscarinic acetylcholine receptors (nAChRs and mAChRs, respectively) expressed on a variety of cell types. In this study, we carried out a comparative analysis of the effect of specific antagonists of nAChRs or mAChRs on the development of autoimmune diabetes. Co-administration of mecamylamine, a non-selective antagonist of nAChRs maintained the protective effect of AChEI on the development of hyperglycemia. In contrast, co-administration of atropine, a non-selective antagonist of mAChRs, mitigated AChEI-mediated protection. Mice pretreated with mecamylamine had an improved response in glucose tolerance test (GTT) than mice pretreated with atropine. These differential effects of nAChR and mAChR antagonists correlated with the extent of islet cell infiltration and with the structure and functionality of the ß-cells. Taken together, our data suggest that mAChRs are essential for the protective effect of cholinergic stimulation in autoimmune diabetes.

Low-dose antigen-experienced CD4+ T cells display reduced clonal expansion but facilitate an effective memory pool in response to secondary exposure.

The strength and duration of an antigenic signal at the time of initial stimulation were assumed to affect the development and response of effectors and memory cells to secondary stimulation with the same antigen. To test this assumption, we used T-cell receptor (TCR)-transgenic CD4+ T cells that were stimulated in vitro with various antigen doses. The primary effector CD4+ T cells generated in response to low-dose antigen in vitro exhibited reduced clonal expansion upon secondary antigenic exposure after adoptive transfer to hosts. However, the magnitude of their contraction was much smaller than both those generated by high-dose antigen stimulation and by naïve CD4+ T cells, resulting in higher numbers of antigen-specific CD4+ T cells remaining until the memory stage. Moreover, secondary effectors and memory cells developed by secondary antigen exposure were not functionally impaired. In hosts given the low-dose antigen-experienced CD4+ T cells, we also observed accelerated recall responses upon injection of antigen-bearing antigen-presenting cells. These results suggest that primary TCR stimulation is important for developing optimal effectors during initial antigen exposure to confer long-lasting memory CD4+ T cells in response to secondary exposure.

Polarization of protective immunity induced by replication-incompetent adenovirus expressing glycoproteins of pseudorabies virus.

Replication-incompetent adenoviruses expressing three major glycoproteins (gB, gC, and gD) of pseudorabies virus (PrV) were constructed and used to examine the ability of these glycoproteins to induce protective immunity against a lethal challenge. Among three constructs, recombinant adenovirus expressing gB (rAd-gB) was found to induce the most potent immunity biased to Th1-type, as determined by the IgG isotype ratio and the profile of the Th1/Th2 cytokine production. Conversely, the gC-expressing adenovirus (rAd-gC) revealed Th2-type immunity and the gD-expressing adenovirus (rAd-gD) induced lower levels of IFN-? and IL-4 production than other constructs, except IL-2 production. Mucosal delivery of rAd-gB induced mucosal IgA and serum IgG responses and biased toward Th2-type immune responses. However, these effects were not observed in response to systemic delivery of rAd-gB. In addition, rAd-gB appeared to induce effective protective immunity against a virulent viral infection, regardless of whether it was administered via the muscular or systemic route. These results suggest that administration of replication-incompetent adenoviruses can induce different types of immunity depending on the expressed antigen and that recombinant adenoviruses expressing gB induced the most potent Th1-biased humoral and cellular immunity and provided effective protection against PrV infection.

Protective immunity induced by systemic and mucosal delivery of DNA vaccine expressing glycoprotein B of pseudorabies virus.

A murine model immunized by systemic and mucosal delivery of plasmid DNA vaccine expressing glycoprotein B (pCIgB) of pseudorabies virus (PrV) was used to evaluate both the nature of the induced immunity and protection against a virulent virus. With regard to systemic delivery, the intramuscular (i.m.) immunization with pCIgB induced strong PrV-specific IgG responses in serum but was inefficient in generating a mucosal IgA response. Mucosal delivery through intranasal (i.n.) immunization of pCIgB induced both systemic and mucosal immunity at the distal mucosal site. However, the levels of systemic immunity induced by i.n. immunization were less than those induced by i.m. immunization. Moreover, i.n. genetic transfer of pCIgB appeared to induce Th2-biased immunity compared with systemic delivery, as judged by the ratio of PrV-specific IgG isotypes and Th1- and Th2-type cytokines produced by stimulated T cells. Moreover, the immunity induced by i.n. immunization did not provide effective protection against i.n. challenge of a virulent PrV strain, whereas i.m. immunization produced resistance to viral infection. Therefore, although i.n. immunization was a useful route for inducing mucosal immunity at the virus entry site, i.n. immunization did not provide effective protection against the lethal infection of PrV.

Multiple alternating immunizations with DNA vaccine and replication incompetent adenovirus expressing gB of pseudorabies virus protect animals against lethal virus challenge.

The prime-boost vaccination with DNA vaccine and recombinant viral vector has emerged as an effective prophylactic strategy to control infectious diseases. Here, we compared the protective immunities induced by multiple alternating immunizations with DNA vaccine (pCIgB) and replication-incompetent adenovirus (Ad-gB) expressing glycoprotein gB of pseudorabies virus (PrV). The platform of pCIgB-prime and Ad-gB-boost induced the most effective immune responses and provided protection against virulent PrV infection. However, priming with pCIgB prior to vaccinating animals by the DNA vaccine-prime and Ad-boost protocol provided neither effective immune responses nor protection against PrV. Similarly, boosting with Ad-gB following immunization with DNA vaccine-prime and Ad-boost showed no significant responses. Moreover, whereas the administration of Ad-gB for primary immunization induced Th2-type-biased immunity, priming with pCIgB induced Th1-type-biased immunity, as judged by the production of PrV-specific IgG isotypes and cytokine IFN-gamma. These results indicate that the order and injection frequency of vaccine vehicles used for heterologous prime-boost vaccination affect the magnitude and nature of the immunity. Therefore, our demonstration implies that the prime-boost protocol should be carefully considered and selected to induce the desired immune responses.

Nasopharyngeal isolates and their clinical impact on young children with asthma: a pilot study.

INTRODUCTION: Respiratory infections have significant effects on childhood asthma. Viral respiratory infections, such as rhinovirus and respiratory syncytial virus are likely to be important in the development and exacerbation of asthma. In this study, we investigated the nasopharyngeal colonization in children with asthma to determine the prevalence of pathogens and their contribution to respiratory symptoms and airway resistance during winter. METHODS: From December 2016 to March 2017, 50 nasopharyngeal specimens were collected from 18 patients (age, 5.0±1.1 years) with asthma and 9 specimens from 9 control children (age, 4.9±1.0 years). Samples were tested for 19 viruses and 7 bacteria, using multiplex real-time PCR. Respiratory disease markers included the Global Asthma Network Questionnaire, the Common-Cold Questionnaire, the Global Initiative for Asthma assessment of asthma control, and the airway resistance at 5 Hz by forced-oscillation technique. RESULTS: The most commonly isolated organisms in both groups (patients and controls) were Streptococcus pneumoniae, Haemophilus influenzae, and rhinovirus. Most patients had multiple isolates (median, 3.5; range, 1-5), which changed during the study period. Types of isolates were 4 bacteria (S. pneumoniae, H. influenzae, Bordetella pertussis, and Bordetella parapertussis) and 6 viruses (rhinovirus, enterovirus, metapneumovirus, adenovirus, coronaviruses, and parainfluenza viruses). Similar isolates, including influenza A-H3 virus and bocavirus, were detected in the controls. Of the 9 patients with "wheezing disturbing sleep ≥1 per week", 6 had rhinovirus, 2 coronaviruses, and 1 no detectable viruses. Patients with mild common cold symptoms had significantly higher airway resistance at 5 Hz z-score (P=0.025). CONCLUSION: Multiple respiratory pathogens were isolated from many patients with asthma, which appeared to contribute to disease symptoms and airway resistance. Minimizing children's exposure to respiratory pathogens might be beneficial, especially during winter.