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Chitin Protects Bronchial Epithelial Cells from Rhinovirus Infection
AB150 Abstracts
588
Effect Of Tobacco Smoke And Respiratory Virus Infection In Preschool-aged Children W. Kim; Inje University, Seoul, REPUBLIC OF KOREA. RATIONALE: Viral infections cause common colds and asthma exacerbations in children, but the relationships between rates of infection and the risk of clinical illness are not completely understood. The present study was performed to determine the relationship between environmental tobacco smoke (ETS) exposure and acute lower respiratory tract infection (LRI) caused by virus in children. METHODS: To determine rates of viral respiratory infection, 60 preschool-aged children performed routine weekly nasal swab for 4 weeks. Diary cards were used to record cold and asthma symptoms, and respiratory viruses were identified by multiplex PCR. At the same time, the level of urine cotinine by an enzyme immunoassay was used to evaluate ETS. RESULTS: Of 56 children completing the study, there were 43 episodes each of cold and asthma symptoms. Viruses were detected in 39.1% specimens. The type of viruses were rhinovirus, enterovirus, adenovirus, coronavirus, influenza, and parainfluenza. Cold and asthma scores were higher during virus-positive weeks than virus-negative weeks (P < 0.001, P < 0.002). During weeks when viral infections were detected, 21.2% were asymptomatic. The urinary cotinine concentrations were higher in children living with smoking parents (19.5 6 2.9 ng/mg) compared with children not exposed to parental smoke (6.7 6 3.8 ng/mg; p 5 0.02). There was no difference in urinary cotinine level between the virus types (median 0.5 vs 0.6 mcg/mg Cr; ns). CONCLUSIONS: These findings suggest that many kinds of virus were infected during the beginning of a term. However, tobacco smoke exposure was not associated with virus types.
589
MONDAY
Weekly Monitoring of Children with Asthma for Infections and Illness During Common Cold Seasons J. P. Olenec, W. K. Kim, L. Salazar, T. E. Pappas, W. M. Lee, J. E. Gern, R. F. Lemanske, Jr., M. D. Evans, F. Vang, K. A. Roberg, J. Bork; University of Wisconsin Hospitals and Clinics, Madison, WI. RATIONALE: Both viral infection and sensitization to allergens has been associated with wheezing episodes in childhood. The relative contribution of each to severity of illness is unclear. METHODS: A total of 58 children with asthma ages 6-8 years were enrolled. Five consecutive weekly samples of nasal lavage were collected during September and April in 2006, 2007, and 2008 and diary cards were recorded by the families. Information was obtained on the children regarding sensitization to multiple allergens at enrollment. Viruses were identified using multiplex PCR; rhinoviruses strains were identified using partial sequencing. RESULTS: Viruses were detected in 37-50% of all the weekly specimens, and of the viruses detected, 72-99% were rhinoviruses in each collection period. All but two of the children had a virus detected at some point during the evaluation. The duration of asthma symptoms was more than twice as long (7 vs. 3 days, p 5 0.0008) and more children had loss of control of their asthma (47% vs. 22%, p < 0.008) during virus-positive weeks compared to virus-negative weeks. While the number of infections was the same as those who were non-sensitized, the sensitized children had more viral associated illnesses per season (1.19 vs. 0.81, p 5 0.03). CONCLUSIONS: Rhinovirus infections are nearly universal in children with asthma during common cold seasons, likely due to a plethora of new strains appearing each season. While either viral infection or sensitization can cause respiratory symptoms, the combination is a major risk factor for increased illness severity and frequency.
J ALLERGY CLIN IMMUNOL FEBRUARY 2010
590
Chitin Protects Bronchial Epithelial Cells from Rhinovirus Infection A. Greiman, S. Favoreto, Jr., M. Tang, J. Shen, J. Quraishi, P. Avila; Northwestern University Feinberg School of Medicine, Chicago, IL. RATIONALE: Chitin and its derivatives are non-allergenic and non-toxic compounds with adjuvant activity. Human rhinovirus (HRV) immunity relies on an effective Th1 response with production of interferons. Our goal was to determine whether soluble deacetylated chitin (Chitosan) alters epithelial response to HRV. METHODS: Primary human bronchial epithelial cells (HBEC) were treated with 1nM or 10nM of Chitosan before or after infection with HRV16 (MOI55). Real time RT-PCR analysis was used to evaluate viral binding, replication and epithelial inflammatory response at 48 hours. RESULTS: Chitosan treatment did not alter viral binding (p 5 0.26), but significantly reduced HRV16 replication by 2.7 fold (p < 0.01) when added 24h before infection and by 3.2 fold (p < 0.007) when added 6h after HRV16 infection. Chitosan treatment pre- and post-HRV16 infection resulted in 3.3 fold (p < 0.002) and 1.5 fold (p 5 0.179) increases in IFNb gene expression, respectively. Chitosan treatment inhibited, in a dose dependent manner, the up-regulation of inflammatory genes when added to the cultures before or after infection: IL-6 (8.9 and 5.3 fold reduction, p < 0.002 in both); TNF-a (2.2 and 1.8 fold reduction, p < 0.000 and p < 0.002); GM-CSF (3.4 and 2.8 fold reduction, p < 0.002 and p < 0.003) and IL-1b (2.2 and 1.6 fold reduction, respectively, p < 0.009 and p < 0.002). CONCLUSIONS: Low concentrations of chitosan upregulated IFNb production and enhanced antiviral activity in bronchial epithelial cells. Chitosan reduced viral load even when added 6h after viral infection; and it also reduced epithelial inflammatory response.
591
Fractalkine May Enhance Antiviral Th1 Response via Dendritic Cells M. Tang, S. Favoreto, Jr., A. Greiman, J. Shen, A. Koterba, J. Quraishi, P. Avila; Northwestern University Feinberg School of Medicine, Chicago, IL. RATIONALE: We have recently shown that nasal epithelial cells of asthmatic patients over-expressed fractalkine (CX3CL1) during rhinovirus (RV) infection. CX3CL1 plays an important role in chemoattraction of immune cells, including dendritic cells (DCs). CD1a+ DCs have recently been characterized as high producers of IL12 and IFNg and induce Th1 polarization of naı¨ve T cells. We determined whether CX3CL1 enhances Th1 response of CD1a+ DCs. METHODS: We FACS-sorted CD1a+ and CD1a- cells from monocyte-derived DC cultures. Sorted cells were stimulated with dsRNA for 14h and assayed for the expression of CX3CL1 receptor (CX3CR1), IL12 and IFNg by real time PCR. RESULTS: Flow cytometry analysis confirmed that CX3CR1 was expressed on monocytes, lymphocytes, and natural killer cells. On dendritic cells (DCs), we found that CX3CR1 was not homogeneously expressed on all monocyte-derived myeloid DCs. On days 4 and 6 of differentiation with IL-4 and GM-CSF, only 1-2% of DCs were CD1a+/CX3CR1hi cells. CD1a+ DCs expressed 5 times more CX3CR1 than CD1a- DC (p < 0.001) as measured by gene expression (real time PCR) and protein detection by flow cytometry. CD1a+/CX3CR1hi cells produced significantly greater amounts of IL12 (7-fold, p 5 0.046) and IFNg (3-fold, p 5 0.05) than CD1a-/ CX3CR1lo cells upon stimulation with 5mg/ml of poly I:C dsRNA. This indicates that upon RV infection, CD1a+/CX3CR1hi DCs may promote Th1 lymphocyte differentiation. CONCLUSIONS: Our data suggest that CX3CL1 may enhance Th1 type responses to RV infection in asthmatic subjects by preferentially recruiting CD1a+ CX3CR1hi IL12-producing myeloid DCs to the airway mucosa.
588
Effect Of Tobacco Smoke And Respiratory Virus Infection In Preschool-aged Children W. Kim; Inje University, Seoul, REPUBLIC OF KOREA. RATIONALE: Viral infections cause common colds and asthma exacerbations in children, but the relationships between rates of infection and the risk of clinical illness are not completely understood. The present study was performed to determine the relationship between environmental tobacco smoke (ETS) exposure and acute lower respiratory tract infection (LRI) caused by virus in children. METHODS: To determine rates of viral respiratory infection, 60 preschool-aged children performed routine weekly nasal swab for 4 weeks. Diary cards were used to record cold and asthma symptoms, and respiratory viruses were identified by multiplex PCR. At the same time, the level of urine cotinine by an enzyme immunoassay was used to evaluate ETS. RESULTS: Of 56 children completing the study, there were 43 episodes each of cold and asthma symptoms. Viruses were detected in 39.1% specimens. The type of viruses were rhinovirus, enterovirus, adenovirus, coronavirus, influenza, and parainfluenza. Cold and asthma scores were higher during virus-positive weeks than virus-negative weeks (P < 0.001, P < 0.002). During weeks when viral infections were detected, 21.2% were asymptomatic. The urinary cotinine concentrations were higher in children living with smoking parents (19.5 6 2.9 ng/mg) compared with children not exposed to parental smoke (6.7 6 3.8 ng/mg; p 5 0.02). There was no difference in urinary cotinine level between the virus types (median 0.5 vs 0.6 mcg/mg Cr; ns). CONCLUSIONS: These findings suggest that many kinds of virus were infected during the beginning of a term. However, tobacco smoke exposure was not associated with virus types.
589
MONDAY
Weekly Monitoring of Children with Asthma for Infections and Illness During Common Cold Seasons J. P. Olenec, W. K. Kim, L. Salazar, T. E. Pappas, W. M. Lee, J. E. Gern, R. F. Lemanske, Jr., M. D. Evans, F. Vang, K. A. Roberg, J. Bork; University of Wisconsin Hospitals and Clinics, Madison, WI. RATIONALE: Both viral infection and sensitization to allergens has been associated with wheezing episodes in childhood. The relative contribution of each to severity of illness is unclear. METHODS: A total of 58 children with asthma ages 6-8 years were enrolled. Five consecutive weekly samples of nasal lavage were collected during September and April in 2006, 2007, and 2008 and diary cards were recorded by the families. Information was obtained on the children regarding sensitization to multiple allergens at enrollment. Viruses were identified using multiplex PCR; rhinoviruses strains were identified using partial sequencing. RESULTS: Viruses were detected in 37-50% of all the weekly specimens, and of the viruses detected, 72-99% were rhinoviruses in each collection period. All but two of the children had a virus detected at some point during the evaluation. The duration of asthma symptoms was more than twice as long (7 vs. 3 days, p 5 0.0008) and more children had loss of control of their asthma (47% vs. 22%, p < 0.008) during virus-positive weeks compared to virus-negative weeks. While the number of infections was the same as those who were non-sensitized, the sensitized children had more viral associated illnesses per season (1.19 vs. 0.81, p 5 0.03). CONCLUSIONS: Rhinovirus infections are nearly universal in children with asthma during common cold seasons, likely due to a plethora of new strains appearing each season. While either viral infection or sensitization can cause respiratory symptoms, the combination is a major risk factor for increased illness severity and frequency.
J ALLERGY CLIN IMMUNOL FEBRUARY 2010
590
Chitin Protects Bronchial Epithelial Cells from Rhinovirus Infection A. Greiman, S. Favoreto, Jr., M. Tang, J. Shen, J. Quraishi, P. Avila; Northwestern University Feinberg School of Medicine, Chicago, IL. RATIONALE: Chitin and its derivatives are non-allergenic and non-toxic compounds with adjuvant activity. Human rhinovirus (HRV) immunity relies on an effective Th1 response with production of interferons. Our goal was to determine whether soluble deacetylated chitin (Chitosan) alters epithelial response to HRV. METHODS: Primary human bronchial epithelial cells (HBEC) were treated with 1nM or 10nM of Chitosan before or after infection with HRV16 (MOI55). Real time RT-PCR analysis was used to evaluate viral binding, replication and epithelial inflammatory response at 48 hours. RESULTS: Chitosan treatment did not alter viral binding (p 5 0.26), but significantly reduced HRV16 replication by 2.7 fold (p < 0.01) when added 24h before infection and by 3.2 fold (p < 0.007) when added 6h after HRV16 infection. Chitosan treatment pre- and post-HRV16 infection resulted in 3.3 fold (p < 0.002) and 1.5 fold (p 5 0.179) increases in IFNb gene expression, respectively. Chitosan treatment inhibited, in a dose dependent manner, the up-regulation of inflammatory genes when added to the cultures before or after infection: IL-6 (8.9 and 5.3 fold reduction, p < 0.002 in both); TNF-a (2.2 and 1.8 fold reduction, p < 0.000 and p < 0.002); GM-CSF (3.4 and 2.8 fold reduction, p < 0.002 and p < 0.003) and IL-1b (2.2 and 1.6 fold reduction, respectively, p < 0.009 and p < 0.002). CONCLUSIONS: Low concentrations of chitosan upregulated IFNb production and enhanced antiviral activity in bronchial epithelial cells. Chitosan reduced viral load even when added 6h after viral infection; and it also reduced epithelial inflammatory response.
591
Fractalkine May Enhance Antiviral Th1 Response via Dendritic Cells M. Tang, S. Favoreto, Jr., A. Greiman, J. Shen, A. Koterba, J. Quraishi, P. Avila; Northwestern University Feinberg School of Medicine, Chicago, IL. RATIONALE: We have recently shown that nasal epithelial cells of asthmatic patients over-expressed fractalkine (CX3CL1) during rhinovirus (RV) infection. CX3CL1 plays an important role in chemoattraction of immune cells, including dendritic cells (DCs). CD1a+ DCs have recently been characterized as high producers of IL12 and IFNg and induce Th1 polarization of naı¨ve T cells. We determined whether CX3CL1 enhances Th1 response of CD1a+ DCs. METHODS: We FACS-sorted CD1a+ and CD1a- cells from monocyte-derived DC cultures. Sorted cells were stimulated with dsRNA for 14h and assayed for the expression of CX3CL1 receptor (CX3CR1), IL12 and IFNg by real time PCR. RESULTS: Flow cytometry analysis confirmed that CX3CR1 was expressed on monocytes, lymphocytes, and natural killer cells. On dendritic cells (DCs), we found that CX3CR1 was not homogeneously expressed on all monocyte-derived myeloid DCs. On days 4 and 6 of differentiation with IL-4 and GM-CSF, only 1-2% of DCs were CD1a+/CX3CR1hi cells. CD1a+ DCs expressed 5 times more CX3CR1 than CD1a- DC (p < 0.001) as measured by gene expression (real time PCR) and protein detection by flow cytometry. CD1a+/CX3CR1hi cells produced significantly greater amounts of IL12 (7-fold, p 5 0.046) and IFNg (3-fold, p 5 0.05) than CD1a-/ CX3CR1lo cells upon stimulation with 5mg/ml of poly I:C dsRNA. This indicates that upon RV infection, CD1a+/CX3CR1hi DCs may promote Th1 lymphocyte differentiation. CONCLUSIONS: Our data suggest that CX3CL1 may enhance Th1 type responses to RV infection in asthmatic subjects by preferentially recruiting CD1a+ CX3CR1hi IL12-producing myeloid DCs to the airway mucosa.