J ALLERGY CLIN IMMUNOL

VOLUME 131, NUMBER 2

Abstracts AB191

MONDAY

681 Prostaglandin I2 Receptor (IP) Signaling Inhibits Lung Type IInterferon Expression by RSV Infection

Shinji Toki, PhD1, Sara Reiss1, Kasia Goleniewska, MS1, Martin L.

Moore, PhD2, Garret FitzGerald, MD3, R. Stokes Peebles, Jr, MD,

FAAAAI1; 1Vanderbilt University School of Medicine, Nashville, TN,2Emory University, Atlanta, GA, 3University of Pennsylvania, Philadel-

phia, PA.

RATIONALE: Our laboratory has previously shown that prostaglandin I2(PGI2) – IP signaling reduced RSV-induced illness and inflammation in a

mouse model. However, the mechanisms of this down-regulation are not

yet fully understood. In addition, the effect of PGI2 signaling on type I inter-

feron (IFN) expression has not been reported.We hypothesized that PGI2–IP

signaling decreases RSV-induced type I IFN (a andb) induction. To test this

hypothesis, we measured airway and lung IFN-a and b protein expression.

METHODS: BALB/c background WT and IPKO mice were challenged

intranasally with RSVA2001/2-20 strain. Bronchoalveolar lavage (BAL)

fluid and lung were harvested after 12 and 24 hours. Control mice were not

challenged with RSV. IFN-a and b protein expression in the BAL fluid and

lung homogenate were measured by ELISA.

RESULTS: IPKOmice had significantly greater BAL IFN-a andb protein

expression compared to WT mice (p<0.05) 12 hours after intranasal

challenge of RSV. Lung IFN-a protein expression was increased in IPKO

mice compared to WT mice (p<0.05), but IFN-b was not significantly

different. There was a trend for a difference of both BAL and lung IFN-a

and b protein expression 24 hours after RSV challenge.

CONCLUSIONS: IPKO mice had significantly increased IFN-a and b

protein expression in the airway and lung. This result suggests that

endogenous PGI2 signaling down-regulates RSV-induced illness through

suppression of type I IFN induction.

682 Rhinovirus Induces Differential Expression of Th2-PromotingEpithelial Cytokines From Asthmatics Ex Vivo

Joshua L. Kennedy, MD1, Larry Borish, MD, FAAAAI2, Peter W.

Heymann, MD1, John W. Steinke, PhD, FAAAAI2; 1University of Vir-

ginia, Charlottesville, VA, 2Asthma and Allergic Disease Center, Carter

Center for Immunology Research, University of Virginia, Charlottesville,

VA.

RATIONALE: The majority of childhood asthma exacerbations are

provoked by rhinovirus (RV) infections, and these most often occur

when allergies are also present. We propose this reflects the propensity of

RV infection of epithelium to induce expression of Th2-promoting

cytokines and that this occurs without altering the innate immune response

of these cells to RV.

METHODS: Epithelial cells derived from sinonasal epithelium of asth-

matics and non-asthmatics were cultured and infected with RV39. Cells

and supernatants were collected at various time intervals. Quantitative

PCR was used to measure gene expression for the Th2-inducing cytokines

IL-25, IL-33, and TSLP, and innate immune cytokines IL-15, IFN-ß, and

IL-18. Supernatants were assayed for cytokine protein secretion.

RESULTS: mRNA levels for IL-25, IL-33, and TSLP were increased in

asthmatics compared to non-asthmatics after infection with RV39 at 2 (IL-

25), 4 (TSLP), and 24 hours (IL-33). mRNA levels were increased for IL-

15, IFN-ß, and IL-18 though no differences were observed between

asthmatics and non-asthmatics. Protein expression of IL-15 was compa-

rably evident in both cohorts at 48 hours.

CONCLUSIONS: In contrast to non-asthmatics, RV-infected sinonasal

epithelium derived from asthmatics express mRNA for cytokines impor-

tant in the induction of Th2 immune deviation. Additionally, there was

little difference in the expression of innate cytokines, specifically IL-15

and IL-18, which suggests that there is no defect in innate immune

responses to RVamongst asthmatics. We propose instead that it is this RV-

induced barrage of Th2-inducing cytokines that is responsible for asthma

exacerbations.

683 Genetic Variants in Thymic Stromal Lymphopoietin (TSLP) andReceptor (TSLPR) and Their Influence On the HumoralImmune Response

Luis Fang, Cesar Mu~noz, Luz Hernandez, Beatriz Martinez, Javier Mar-

rugo; University of Cartagena, Cartagena, Colombia.

RATIONALE: TSLP/TSLPR participates in the initiation of the Th2-

immune response. Recently, genetic variants of these genes have been

associated with atopic diseases. However, it’s unknown whether these

polymorphisms influence humoral immune response. This study evaluated

the influence of polymorphisms in TSLP and TSLPR on the antibody re-

sponse against dietary antigens, Blomia tropicalis and Ascaris

lumbricoides.METHODS: By RT-qPCR and TaqMan� probes, we genotyped the SNPs:

rs1837253 [C/T], rs17551370 [A/G], rs2289276 [C/T] in TSLP and

rs36139698 [A/G], rs36177645 [C/T], and rs36133495 [A/G] in TSLPR in

80 African-descent individuals. The serum levels of specific IgE, IgA and

IgG4againstBlomia tropicalis, egg,milk, andpeanut extracts and IgEagainst

Ascaris lumbricoides extract, were measured by ELISA. Data analysis was

performed using principal component analysis (PCA) by R Project software.

RESULTS: The minor allele frequencies were as following: rs1837253

[T:0.41.9%], rs7551370 [A:14.4%], rs2289276 [T:22.5%], rs36139698

[A:37%], rs36177645 [C:24%] and rs36133495 [G:45%]. The PCA

showed that specific IgE-IgG4 responses to dietary antigens were different

fromB. tropicalis response, while specific IgA responsewas similar in both

groups of antigens, furthermore IgE response against B. tropicalis and A.

lumbricoides were positively correlated. The genotype CT/TT in

rs1837253 influenced IgE-IgG4 responses independent of antigenic group,

while GG in rs17551370, CT/TT in rs2289276, AG/GG in rs36139698 and

CT/TT in rs36177645 strongly favor IgE-IgG4 responses to egg and pea-

nuts extracts. Only AG/GG in rs36133495 influenced IgA response against

dietary and B. tropicalis antigens.CONCLUSIONS: TSLP/TSLPR variants influence the IgE-IgG4-IgA im-

mune responses against dietary and environment antigens in African-de-

scent individuals from Colombia.

684 Immune Modulatory Effects of IL-22 On Allergen-InducedPulmonary Inflammation

Ping Fang; Asthma & allergy center, Johns Hopkins University School of

Medicine.

RATIONALE: Allergen-induced pulmonary inflammation in asthma is

mainly TH2 dominated. A recently discovered TH17/TH22 cell-derived cy-

tokine, IL-22, has been found to be increased in asthma. However, several

studies showed controversial findings in the immune modulatory effects of

IL-22 in animal models of allergic asthma. Our objective was to determine

the regulatory role of IL-22 in OVA-induced allergic inflammation using a

novel lung-specific IL-22 transgenic overexpression system.

METHODS: Inducible IL-22 transgenic (CC10-rtTA- and SPC-rtTA-TRE-

tight-IL-22) mice on C57BL/6 genetic background were generated. IHC of

lung tissue and ELISA of bronchoalveolar lavage (BAL) fluid for IL-22were

performed to confirm the location and quantity of IL-22 expression. OVA-

induced pulmonary inflammatory responses were compared between IL-22

transgenic andwild type control mice. BAL total and differential cell counts,

lung histology, mucous metaplasia, IHC of major basic protein for eosino-

phils, and serum OVA-specific IgE were determined.

RESULTS: IL-22 transgene was successfully activated in the large (CC10

promoter) and small (SPC promoter) airway epithelium cells by doxycy-

cline in the drinking water. OVA sensitization and challenge did not induce

endogenous IL-22 expression. Compared to wild type mice, IL-22

transgenic mice showed decreased percentage of eosinophils in the BAL

and slight reduction in eosinophilic inflammation and mucus metaplasia in

the airways. Interestingly, inflammatory cell infiltration in lung paren-

chyma appeared slightly accentuated. In addition, there was no statistic

difference in serum OVA-specific IgE.

CONCLUSIONS: These findings indicate that IL-22 may have immune

modulatory effects on pulmonary inflammatory responses in the develop-

ment of allergen-induced asthma.