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Tamar A Smith-Norowitz, Sarah Shidid, Yitzchok M Norowitz, Stephan Kohlhoff Department of Pediatrics, Division of Infectious Diseases, State University of New York Downstate Medical Center, Brooklyn, NY, 11203, USACorrespondence: Tamar A Smith-NorowitzSUNY Downstate Medical Center, Department of Pediatrics, Box 49, 450 Clarkson Ave., Brooklyn, NY, 11203, USATel +1 718 270-1295Fax +1 718 270-3289Email tamar.smith-norowitz@downstate.eduBackground: Chlamydia pneumoniae causes respiratory infection in adults and children. Previous studies in our laboratory identified significantly higher in vitro T lymphocyte responses to C. pneumoniae in children with asthma compared to healthy controls which may indicate the presence of T effector memory (TEM) lymphocytes.Aim: In the present study, healthy subjects were screened for the presence of TEM cells and their cytokines. CCR7 negative effector TEMs may indicate persistent infection with C. pneumoniae.Methods: Peripheral blood mononuclear cells (PBMC) (1× 106/mL) from adult non-asthmatic subjects were infected for 1h ± C. pneumoniae TW-183 at a multiplicity of infection (MOI) = 0.1 and cultured (48 hrs). Distributions of lymphocytes (CD4+, CD8+) and TEM cells (CD4+CCR7+CD45RA+CD154+, CD8+CCR7+CD45RA+CD154+) were determined. Levels of intracellular interleukin (IL)-2, IL-4, and interferon (IFN)-gamma were measured (flow microfluorimetry); IFN-gamma was measured in supernatants (ELISA).Results: C. pneumoniae infection led to a decrease in numbers of CD8+ TEM and CD8+CD154+ cells; CD4+TEM and CD4+CD154+ cells did not change. Numbers of TEM cells (CD4+IL-2+, CD8+ IL-2+) also decreased. However, number of TEM cells (CD4+IL4-+, CD8+ IL-4+) and (CD4+ IFN-gamma+, CD8+IFN-gamma+) did not change. When stratified according to IFN-gamma+ status, numbers of CD4+ IL-2+ and CD4+IL-4+ TEMs increased; CD8+IL-2+ and CD8+ IL-4+ TEMs decreased.Conclusion: C. pneumoniae-induced PBMC IFN-gamma+ responses increased numbers of CD4+ IL-2+ and CD4+IL-4+ TEM cells, while CD8+IL-2+ and CD8+IL-4+ TEMs decreased. Production of IFN-gamma by C. pneumoniae infected PBMC should be further studied as a biomarker of persistent infection in humans.Keywords: C. pneumoniae, T effector memory lymphocytes, interleukin-2

Objective: Chlamydia pneumoniae ( C. pneumoniae ) is a gram-negative intracellular bacterium that causes respiratory infections in humans. C. pneumoniae is responsible for cell activation and production of cytokines that may contribute to inflammatory responses in asthma. Cell-mediated immune responses are important for protective immunity; however, these responses may be impaired in asthma. In this study, we examined cytokine responses (IL-21, IL-12, IL-13) responsible for T helper (Th)1 versus Th2 responses in C. pneumoniae -stimulated PBMC from subjects with or without asthma. These cytokines could be potential biomarkers in the evaluation of past C. pneumoniae infection., Methods: Peripheral blood mononuclear cells (PBMC) (1×10 6 /mL) from stable adult asthmatic (N=6) and non-asthmatic subjects (N=6) were infected +/- C. pneumoniae TW-183 at a multiplicity of infection (MOI)=0.1, using dose responses (1:10, 1:100), and cultured 48 hrs. Cytokine responses (Interleukin (IL)-21, IL-12, IL-13) were measured in supernatants (ELISA)., Results: Cytokine responses (mean differences: unstimulated-stimulated cells) were significant for IL-12 (1:10, 1:100) ( P =0.0005, 0.0005) but not for IL-21 or IL-13 (Wilcoxon signed-rank test). Cytokine levels were higher in asthmatic subjects for IL-13 (mean differences: non-asthma-asthma) (unstimulated, 1:10, 1:100) (-210±167, -140±113, -89±59, respectively) ( P =0.05, 0.05, 0.05, respectively) compared with non-asthma. However, IL-21 and IL-12 responses were similar in both groups. When subjects were stratified according to C. pneumoniae IgG antibody status, no significant differences in cytokine responses were observed., Conclusion: Differential cytokine patterns in subjects with or without asthma may suggest a mechanism for the development of persistent infection with C. pneumoniae ., (© 2024 by the Association of Clinical Scientists, Inc.)

Chlamydia pneumoniae (C. pneumoniae) is a gram-negative intracellular bacterium that causes respiratory infection in humans, including subjects with or without asthma. C. pneumoniae activates cells (e.g., monocytes/macrophages) in vitro, and produces cytokines that may contribute to inflammatory responses observed in asthma. Immunological differences exist between subjects with or without asthma, with regard to host responses to C. pneumoniae. The heterogeneity and subsequent diverse pathophysiology of asthma can be better understood by analyzing the repertoire of T-cell subpopulations; the most common distinction between different asthma endotypes includes cytokines produced by CD4 +  cells (T helper (Th)2 high vs. Th2 low)., (© 2022 The Authors. Immunity, Inflammation and Disease published by John Wiley & Sons Ltd.)

Objective: Intercellular adhesion molecule-1 (ICAM-1), an endothelial cell adhesion molecule, contributes to inflammation and immune-mediated responses. Viral infection of endothelial cells caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause vascular changes and elevate the expression of ICAM-1 in coronavirus disease 2019 (COVID-19) patients and may be used as a biomarker to measure disease severity or recovery. This study sought to identify the ICAM-1 levels in convalescent COVID-19 serum 2 to 33 weeks after the initial diagnosis., Methods: ICAM-1 levels were measured 2-33 weeks after COVID-19 diagnosis (April 2020) in the serum from a subject in Brooklyn, New York who recovered from COVID-19 (ELISA). SARS-CoV-2 IgG antibody levels were also measured (ELISA)., Results: ICAM-1 levels were low 2 weeks after the initial COVID-19 diagnosis and increased 6-fold at 5 weeks. ICAM-1 levels decreased at 12 weeks (50%) and at 33 weeks (50%) after the initial COVID-19 diagnosis. SARS-CoV-2 IgG antibody levels were detected 4-5 weeks after the initial COVID-19 diagnosis., Conclusions: ICAM-1 levels in serum from a recovered COVID-19 patient were highest 5 weeks after the initial COVID-19 diagnosis. The presence of high levels of soluble markers such as ICAM-1, as measured by the anti-ICAM-1 antibody, may be due to their increased shedding from the cell surface. ICAM-1 may also be a prognostic indicator for late complications or sequelae due to COVD-19 infection., (© 2021 by the Association of Clinical Scientists, Inc.)

Objective: Mycoplasma pneumoniae ( M. pneumoniae ), an extracellular pathogen lacking a cell wall, causes respiratory infection in adults and children and has been implicated in asthma exacerbation; immunoglobulin (Ig) E may be involved in these exacerbations. Specific IgM and IgG immune response to M. pneumoniae has been reported, but less is known about IgE M. pneumoniae antibody (Ab) responses in asthma. Previous studies in our laboratory demonstrated that asthmatic children have increased IgM M. pneumoniae levels, but not IgE. Thus, we sought to investigate whether past M. pneumoniae infection triggers production of M. pneumoniae -specific IgE Abs in adult subjects with/without asthma., Methods: M. pneumoniae - IgE and -IgM Ab responses were studied in adult asthmatic (N=22) and non-asthmatic (N=22) subjects (ELISA). Data are reported as antibody index. Threshold detection levels: IgE, IgM: 0.2, 0.9, respectively., Results: M. pneumoniae -IgE Ab levels were low and below the threshold of detection in both asthmatic and non-asthmatics (0.002 ± 0.008 vs. 0.02 ± 0.03; P =0.021). However, specific-IgM levels were slightly higher in non-asthmatics compared with asthmatics (0.96 ± 0.37 vs. 0.79 ± 0.31; P =0.054). M. pneumoniae -IgM Ab positivity was similar in both groups ( P =1.0)., Conclusion: IgM M. pneumoniae Abs may play an important role in non-asthma and persist for months after acute infection. IgE M. pneumoniae Abs may play a less important role in both groups., (© 2021 by the Association of Clinical Scientists, Inc.)

Background: Chlamydia pneumoniae is an obligate intracellular bacterium that causes respiratory infection. There may exist an association between C. pneumoniae, asthma, and production of immunoglobulin (Ig) E responses in vitro. Interleukin (IL-4) is required for IgE production., Objective: We previously demonstrated that doxycycline suppresses C. pneumoniae-induced production of IgE and IL-4 responses in peripheral blood mononuclear cells (PBMC) from asthmatic subjects. Whereas macrolides have anti-chlamydial activity, their effect on in vitro anti-inflammatory (IgE) and IL-4 responses to C. pneumoniae have not been studied., Methods: PBMC from IgE- adult atopic subjects (N = 5) were infected +/- C. pneumoniae BAL69, +/- azithromycin (0.1, 1.0 ug/mL) for 10 days. IL-4 and IgE levels were determined in supernatants by ELISA. IL-4 and IgE were detected in supernatants of PBMC (day 10)., Results: When azithromycin (0.1, 1.0 ug/ml) was added, IL-4 levels decreased. At low dose, IgE levels increased and at high dose, IgE levels decreased. When PBMC were infected with C. pneumoniae, both IL-4 and IgE levels decreased. Addition of azithromycin (0.1, 1.0 ug/mL) decreased IL-4 levels and had no effect on IgE levels., Conclusions: These findings indicate that azithromycin decreases IL-4 responses but has a bimodal effect on IgE responses in PBMC from atopic patients in vitro., Competing Interests: The authors have declared that no competing interests exist.

Chlamydia pneumoniae is an obligate intracellular bacterium that causes respiratory infection in adults and children. There is evidence for an association between atypical bacterial pathogens and asthma pathogenesis. We sought to determine whether past C. pneumoniae infection triggers C. pneumoniae - IgE antibodies (Abs) in asthmatics and non-asthmatics, who had detectable IgG titers. C. pneumoniae IgE Abs were quantified using enzyme immunoassay (EIA). C. pneumoniae IgE Ab levels were higher in asthmatics compared with non-asthmatics. There was no correlation found between total serum IgE levels and specific C. pneumoniae IgE Ab levels. C. pneumoniae infection may trigger IgE-specific responses in asthmatics., (© 2020 Published by Elsevier Ltd.)

Persistent respiratory infections caused by Chlamydia pneumoniae have been implicated in the pathogenesis of chronic diseases (e.g. asthma). Antibiotics are used to treat C. pneumoniae respiratory infections; however, the use of antibiotics as anti-inflammatory agents in treatment of asthma remains controversial. The current study investigated whether ciprofloxacin, azithromycin, or doxycycline can suppress C. pneumoniae-induced production of immunoglobulin (Ig) E or cytokines in peripheral blood mononuclear cells (PBMC) obtained from asthmatic children. Apart from blood, nasopharyngeal swab specimens were also collected to test for the presence of C. pneumoniae and/or M. pneumoniae (qPCR). PBMC (1.5 x 10 6 ) from asthmatic pediatric patients (N = 18) were infected or mock infected for 1 h ± C. pneumoniae AR-39 at a multiplicity of infection (MOI) = 0.1, and cultured ± ciprofloxacin, azithromycin, or doxycycline (0.1 or 1.0 μg/mLmL) for either 48 h (cytokines) or 10 days (IgE). Interleukin (IL)-4, interferon (IFN)-γ and IgE levels in supernatants were measured (ELISA). When PBMC were infected with C. pneumoniae, IL-4 and IFNγ production increased (p = 0.06 and 0.03, respectively); IgE levels were low. The now-elevated levels of IL-4 didn't decrease significantly after addition of ciprofloxacin, azithromycin, or doxycycline. However, infected PBMC IFNγ formation decreased significantly when 0.1 μg/mL doxycycline was employed (p = 0.04); no dose of ciprofloxacin or azithromycin had any impact. This inhibitory outcome with doxycycline lends support to the use of tetracyclines as immune modulators and anti-inflammatory medications in treatment of C. pneumoniae-infected asthma patients., (Copyright © 2018 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Introduction: Chlamydia pneumoniae respiratory tract infection has been implicated in the pathogenesis of reactive airway disease and asthma. Innate cytokine responses that are protective of infection with intracellular pathogens may be impaired in patients with asthma. Tumour necrosis factor alpha (TNF-α) is a cytokine related to functions of monocytes and may inhibit C. pneumoniae infection. We investigated TNF-α responses in C. pneumoniae -infected peripheral blood mononuclear cells (PBMCs) in patients with asthma and non-asthma, and whether ciprofloxacin, azithromycin or doxycycline affects TNF-α responses., Methods: PBMC (1.5×10 6 ) from paediatric patients with asthma (n=19) and non-asthmatic controls (n=6) were infected or mock infected for 1 hour with or without C. pneumoniae AR-39 at a multiplicity of infection=0.1, and cultured+ciprofloxacin, azithromycin or doxycycline (0.1 ug/mL) for 48 hours. TNF-α levels were measured in supernatants by ELISA., Results: When PBMC from patients with asthma were infected with C. pneumoniae , levels of TNF-α were significantly lower than in subjects without asthma (48 hours) (5.5±5.6, 38.4±53.7; p=0.0113). However, baseline responses (no infection with C. pneumoniae ) were similar in asthma and non-asthma (1.0±1.7, 1.1±1.2; p=0.89). When PBMC frompatiens with asthma were infected with C. pneumoniae +ciprofloxacin, azithromycin or doxycycline, TNF-α levels increased (25%-45%); this affect was not observed in PBMC from patients without asthma., Conclusions: We identified differences in the quantity of TNF-α produced by C. pneumoniae- infected PBMC in asthma compared with non-asthma., Competing Interests: Competing interests: None declared.

Background: Haemophilus influenzae type b (Hib) bacterium causes severe illness in infants and children, but has largely been eliminated by introducing a universal Hib conjugate vaccine. While effects of certain vaccinations on atopic disease have been studied, little is known about the relationship between Hib vaccination and diseases of altered immunoglobulin E (IgE) regulation (asthma or atopy). As such, it is necessary to provide more evidence concerning Hib vaccination as a possible risk factor for atopic disease., Methods: Total serum IgE and IgE-and IgG-anti-Hib antibody responses were studied in Hib vaccinated asthmatic (N.=14) and non-asthmatic children (N=26) (VaccZyme™ Human Anti Hib Enzyme Immunoassay Kit). Data are reported as mean optical density (OD) values., Results: We found that: 1) total serum IgE levels were higher in asthmatic compared with non-asthmatic subjects (389±125 vs. 125±129, P<0.001); 2) IgE and IgG anti-Hib antibody responses were similar in both asthmatic and non-asthmatic subjects (0.722±0.279 and 0.681±0.280, respectively; P=0.65; 0.450±0.505 and 0.573±0.779, respectively; P=0.580)., Conclusions: The universal Hib vaccine antigen did not result in either increased IgE, or IgG anti-Hib antibody responses in asthmatic or non-asthmatics subjects. Thus, in this cohort, no association between Hib vaccination and asthma status was identified.

Respiratory infections caused by Chlamydia pneumoniae have been associated with exacerbations of asthma. Cell-mediated immunity (CMI) is critical for maintaining immunity. We compared interferon (IFN)-γ responses in C. pneumoniae-infected peripheral blood mononuclear cells (PBMC) in paediatric patients ± asthma. Presence of C. pneumoniae was tested from asthma patients (N = 17) and non-asthmatic controls (N = 16) (PCR). PBMC were infected for 1 h ± C. pneumoniae AR-39 (MOI = 0.1) and cultured for 48 h. IFN-γ levels were measured in supernatants (ELISA). C. pneumoniae-IgG antibodies in serum were determined (MIF). All subjects tested negative for C. pneumoniae (PCR). C. pneumoniae-induced IFN-γ production in vitro was more prevalent in asthma compared with non-asthma; levels of IFN-γ were higher in asthma compared with non-asthma (P = 0.003). There was no association between recent respiratory infection and positive IFN-γ responses. These data show that C. pneumoniae modulates IFN-γ responses in patients with asthma, even in absence of active infection., (© 2017 The Foundation for the Scandinavian Journal of Immunology.)

Background: Chlamydia pneumoniae causes respiratory infection in adults and children, and has been associated with asthma exacerbations and induction of Immunoglobulin (Ig) E responses. We previously reported that C. pneumoniae enhances T helper (Th) 2 responses of peripheral blood mononuclear cells (PBMC) from asthmatic patients. It is likely that toll like receptor (TLR)-2 and TLR-4 mediate cytokine responses and host defense against C. pneumoniae. Thus, we sought to determine whether engagement of TLR-2 or TLR-4 may induce IL-12 production in our C. pneumoniae model., Methods: PBMC (1.5 × 10 6 ) from asthmatic patients (N = 10) and non-asthmatic controls (N = 5) were infected or mock-infected for 1 h ± C. pneumoniae TW183 at a multiplicity of infection (MOI) = 1 and MOI = 0.1, and cultured for 48 h ± anti- TLR-2 and TLR-4 antibodies (Abs) (1 mg/mL). Interleukin (IL)-12 (48 h p.i.) and total IgE levels (day 10) were measured in supernatants (ELISA)., Results: High IgE levels were detected in supernatants of C. pneumoniae- infected PBMC from asthmatics on day 10, compared with mock-infected PBMC (p < 0.03). In contrast, IgE was not detected (<0.3 ng/mL) in either C. pneumoniae infected or mock-infected PBMC from non-asthmatics. IL-12 production by C. pneumoniae-infected asthmatic and non-asthmatic PBMC were similar. When anti-TLR4, but not anti-TLR2, was included in culture, IL-12 production by C. pneumoniae- infected asthmatic PBMC decreased., Conclusions: C. pneumoniae infection induces IgE production and modulates IL-12 responses in patients with asthma, which may be caused, in part, by differences in TLR-2 and TLR-4 stimulation.

Background: Chlamydia pneumoniae (C. pneumoniae) causes respiratory infection in children and adults and is associated with asthma and induction of immunoglobulin E (IgE) responses. Previous studies in our laboratory reported that green tea extract (GTE) and its catechin, epigallocatechin gallate (EGCG) have immunoregulatory effects on IgE responses. Whereas tea polyphenols have in vitro inhibitory effects on the proliferation of C. pneumoniae, the in vitro effects of EGCG on C. pneumoniae- mediated IgE responses haven't been studied. We sought to clarify the in vitro effect of EGCG on C. pneumoniae mediated IgE responses by peripheral blood mononuclear cells (PBMC) in asthma., Methods: PBMC from subjects with asthma and non-asthmatic controls were incubated with C. pneumoniae and cultured for 10 days ±EGCG (0.5, 5.0, 50 ng/mL). IgE levels in supernatants were determined (ELISA)., Results: Elevated IgE levels were detected in supernatants of PBMC from an asthma patient (2.6 ng/mL), whereas IgE levels of PBMC from non-asthmatics were low (<2.0 ng/mL) at baseline. When EGCG (0.5-50 ng/mL) was added to PBMC from the asthma patient, IgE production was suppressed in a dose-dependent manner (10-30%), compared with no EGCG. When PBMC from the asthma patient were incubated with C. pneumoniae, IgE production was suppressed (70%); when PBMC from non-asthmatics were incubated with C. pneumoniae, IgE levels remained undetectable (<2.0 ng/mL). When EGCG (0.5-50 ng/mL) was added to PBMC from the asthma patient, C. pneumoniae-induced IgE production was suppressed moderately (35-48%)., Conclusions: EGCG suppressed C. pneumoniae- mediated IgE responses in PBMC from a patient with asthma.

Background: Influenza virus is a major health care burden and is associated with significant morbidity and mortality. Data on morbidity and complications (pneumonia, otitis media) related to influenza virus infection in primary care settings are limited with reports mainly obtained from hospital settings. We assessed the prevalence of complications from viral/bacterial infections in influenza- positive compared with influenza- negative children presenting with influenza-like illness (ILI) in a primary care setting., Methods: This retrospective, practice-based chart review studied complications from viral/bacterial infections in 255 children and adolescents (females/males, 1-21 years) who presented with ILI. We also compared the prevalence of complications by influenza vaccination status between influenza positive (N = 32/121) and influenza negative (N = 50/134) cases (2013-2015). Comparisons for categorical variables were made using chi-squared tests., Results: The prevalence of complications was similar in influenza positive (18/121) and influenza negative (22/134) patients (P = NS). Patients presenting with ILI, who were vaccinated, were less likely to test positive for influenza compared with patients who were not vaccinated (P = 0.064). However, prevalence of infections was similar in both groups based on vaccination status. We did not find any effect of type of health insurance on influenza status (P > 0.05) CONCLUSION: Common respiratory complications of seasonal influenza did not differ in influenza positive compared with influenza negative patients. Vaccination with influenza vaccine may result in decreased duration or severity of symptoms, and remains an important public health intervention. In primary care settings, determination of influenza status may be an important tool for clinicians to predict the likelihood of complications.

Chlamydia pneumoniae is a cause of respiratory infection in adults and children. There is evidence for an association between atypical bacterial respiratory pathogens and the pathogenesis of asthma. We compared T helper (Th) responses in C. pneumoniae - infected peripheral blood mononuclear cells (PBMC) in patients with or without asthma. PBMC (1×10(6)/mL) from asthmatic patients (N=11) and non-asthmatic controls (N=12) were infected or mock-infected for 1h +/- C. pneumoniae TW-183 at a multiplicity of infection (MOI)=1 and MOI=0.1, or cultured for 24h +/- Lactobacillus rhamnosus GG (LGG). Interleukin (IL)-4, IL-10, IL-12, Interferon (IFN)-gamma and total IgE levels were measured in supernatants (ELISA). C. pneumoniae infection led to an increase (>50%) of IgE levels in PBMC from asthmatics, compared with mock-infected on day 10; IgE wasn't detected in non-asthmatics. C. pneumoniae - infected PBMC from asthmatics increased levels of IL-4 and IFN-gamma after 24h, compared with PBMC alone; levels of IL-10 and IL-12 were low. When uninfected-PBMC from asthmatics were LGG-stimulated, after 24h, IL-4 was undetectable, but IL-10, IL-12, and IFN-gamma increased, compared with PBMC alone. Thus, C. pneumoniae infection has the ability to induce allergic responses in PBMC of asthmatics, as evidenced by production of Th2 responses and IgE., (Copyright © 2016 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.)

The production of IgE specific to different viruses (HIV-1, Parvovirus B19, RSV), and the ability for IgE anti-HIV-1 to suppress HIV-1 production in vitro, strongly suggest an important role for IgE and/or anti viral specific IgE in viral pathogenesis. Previous studies in our laboratory were the first to report the presence of IgE anti-varicella zoster virus (VZV) in an adolescent patient with shingles. However, the presence and long term persistence of IgE anti VZV antibodies has not been studied in adults. The presence of serum IgE in addition to IgE and IgG anti-VZV antibody in sera were studied in children (N=12) (0-16 y/o) and adults (N=9) (32-76 y/o) with either a past history of (wild type) chicken pox (N=7 children, 9 adults) or 5 years after vaccination with varicella zoster (N=2 children) (Varicella virus vaccine live, Oka/Merck), as well as in non-infected subjects (N=3 children). Of the patients who had a positive history of chicken pox 13 of 16 (81%) contained IgE anti-VZV antibodies; they were both serum IgEHi (>100 IU/ml) and IgELo (<100 IU/ml). Of the patients who were vaccinated, IgE anti-VZV antibodies were undetected. In contrast, serum from the patients without a history of chicken pox or vaccination did not make either IgE or IgG anti-VZV antibodies. This is the first demonstration of the existence of IgE anti-VZV antibodies, and its long-term persistence in serum of previously infected subjects. Future studies regarding the functional role of anti-viral IgE and its relationship to VZV are warranted.