Caiado, Joana

Castells, Mariana

Giavina-Bianchi, Pedro

Mezzano, Veronica

Picard, Matthieu

Clinical and Translational Allergy

Harvard University - DASH 

 Desensitization induces hyporesponsiveness and cell-surfacephenotype changes on mouse mast cells  (Article begins on next page)The Harvard community has made this article openly available.Please share how this access benefits you. Your story matters.Citation Giavina-Bianchi, Pedro, Matthieu Picard, Joana Caiado,Veronica Mezzano, and Mariana Castells. 2014.“Desensitization induces hyporesponsiveness and cell-surfacephenotype changes on mouse mast cells.” Clinical andTranslational Allergy 4 (Suppl 3): P36. doi:10.1186/2045-7022-4-S3-P36. http://dx.doi.org/10.1186/2045-7022-4-S3-P36.Published Version doi:10.1186/2045-7022-4-S3-P36Accessed February 16, 2015 8:36:13 PM ESTCitable Link http://nrs.harvard.edu/urn-3:HUL.InstRepos:12785873Terms of Use This article was downloaded from Harvard University's DASHrepository, and is made available under the terms and conditionsapplicable to Other Posted Material, as set forth athttp://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAAPOSTER PRESENTATION Open AccessDesensitization induces hyporesponsiveness andcell-surface phenotype changes on mouse mastcellsPedro Giavina-Bianchi, Matthieu Picard, Joana Caiado, Veronica Mezzano, Mariana Castells*From 6th Drug Hypersensitivity Meeting (DHM 6)Bern, Switzerland. 9-12 April 2014BackgroundRapid drug desensitization (DST) protocols have beendeveloped based on clinical evidence, but in vitro studiesare lacking. Understanding the mechanisms involved inthe early stages of DST will allow improvements inpatients’ treatment, overcome unwanted adverse reactions,and identify markers for therapeutic efficacy. The aim ofthis study is to demonstrate and characterize the inductionof hyporesponsiveness in murine mast cells by desensitiza-tion and activation, phenotyping the cell surface.MethodMouse bone marrow derived mast cells (BMMCs) sensi-tized with DNP (2,4-dinitrophenol)-IgE were activated ordesensitzed to DNP (1 ng). Desensitization was acheivedby sequential doubling doses of DNP every 10 min startingat 1pg. After activation or desensitization, BMMCs wererechallenged by an activating dose of DNP to assesshyporesponsiveness. LAMP1 surface expression and©¬-hexosaminidase (¥â-Hex) release were used as mainoutcomes.ResultsDST inhibited the IgE-mediated degranulation of BMMCsas desensitized cells released 43.3% less ¥â-Hex andshowed 73.2% lower LAMP1 surface expression comparedto activated BMMCs. A group of desensitized and acti-vated BMMCs were challenged again with an extra doseof 1 ng DNP-HAS and additional release of ¥â-Hex andLAMP1 expresssion were not different from the negativecontrol, regardless whether BMMCs had been previouslydesensitized or activated. The hyporesponsiveness state ofBMMCs induced by DST and activation was not due tomediator depletion as calcium ionophore induced markedrelease of ¥â-Hex in these cells. Expression of Fc¥åRI,PDL1 and GP49 was assessed next. Activated and desensi-tized BMMCs, respectively, expressed 40.3% and 15.7%less Fc¥åRI, 45.9% and 13.1% less PDL1, and 23.5% and11.3% less GP49 than negative controls. We observed thatwhile the expression of PDL1 on the cell membranedecreased, its intracellular amount increased.ConclusionRapid desensitization and activation induced hyporespon-siveness in murine mast cells, which can be assessed byLAMP1 expression and ¥â-Hex secretion. Hyporespon-siveness is not due to depletion of mediators or mediatedby a soluble factors, and is associated with cell-surfacephenotype changes.Published: 18 July 2014doi:10.1186/2045-7022-4-S3-P36Cite this article as: Giavina-Bianchi et al.: Desensitization induceshyporesponsiveness and cell-surface phenotype changes on mousemast cells. Clinical and Translational Allergy 2014 4(Suppl 3):P36.Harvard Medical School, Division of Rheumatology, Allergy and Immunology,Department of Medicine, BWH, USAGiavina-Bianchi et al. Clinical and Translational Allergy 2014, 4(Suppl 3):P36http://www.ctajournal.com/content/4/S3/P36© 2014 Giavina-Bianchi et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the CreativeCommons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, andreproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Desensitization induces hyporesponsiveness and cell-surface phenotype changes on mouse mast cells

Pedro Giavina-Bianchi

Matthieu Picard

Joana Caiado

Veronica Mezzano

Mariana Castells

Springer - Publisher Connector

POSTER PRESENTATION Open Access
Desensitization induces hyporesponsiveness and
cell-surface phenotype changes on mouse mast
cells
Pedro Giavina-Bianchi, Matthieu Picard, Joana Caiado, Veronica Mezzano, Mariana Castells*
From 6th Drug Hypersensitivity Meeting (DHM 6)
Bern, Switzerland. 9-12 April 2014
Background
Rapid drug desensitization (DST) protocols have been
developed based on clinical evidence, but in vitro studies
are lacking. Understanding the mechanisms involved in
the early stages of DST will allow improvements in
patients’ treatment, overcome unwanted adverse reactions,
and identify markers for therapeutic efficacy. The aim of
this study is to demonstrate and characterize the induction
of hyporesponsiveness in murine mast cells by desensitiza-
tion and activation, phenotyping the cell surface.
Method
Mouse bone marrow derived mast cells (BMMCs) sensi-
tized with DNP (2,4-dinitrophenol)-IgE were activated or
desensitzed to DNP (1 ng). Desensitization was acheived
by sequential doubling doses of DNP every 10 min starting
at 1pg. After activation or desensitization, BMMCs were
rechallenged by an activating dose of DNP to assess
hyporesponsiveness. LAMP1 surface expression and
©¬-hexosaminidase (¥â-Hex) release were used as main
outcomes.
Results
DST inhibited the IgE-mediated degranulation of BMMCs
as desensitized cells released 43.3% less ¥â-Hex and
showed 73.2% lower LAMP1 surface expression compared
to activated BMMCs. A group of desensitized and acti-
vated BMMCs were challenged again with an extra dose
of 1 ng DNP-HAS and additional release of ¥â-Hex and
LAMP1 expresssion were not different from the negative
control, regardless whether BMMCs had been previously
desensitized or activated. The hyporesponsiveness state of
BMMCs induced by DST and activation was not due to
mediator depletion as calcium ionophore induced marked
release of ¥â-Hex in these cells. Expression of Fc¥åRI,
PDL1 and GP49 was assessed next. Activated and desensi-
tized BMMCs, respectively, expressed 40.3% and 15.7%
less Fc¥åRI, 45.9% and 13.1% less PDL1, and 23.5% and
11.3% less GP49 than negative controls. We observed that
while the expression of PDL1 on the cell membrane
decreased, its intracellular amount increased.
Conclusion
Rapid desensitization and activation induced hyporespon-
siveness in murine mast cells, which can be assessed by
LAMP1 expression and ¥â-Hex secretion. Hyporespon-
siveness is not due to depletion of mediators or mediated
by a soluble factors, and is associated with cell-surface
phenotype changes.
Published: 18 July 2014
doi:10.1186/2045-7022-4-S3-P36
Cite this article as: Giavina-Bianchi et al.: Desensitization induces
hyporesponsiveness and cell-surface phenotype changes on mouse
mast cells. Clinical and Translational Allergy 2014 4(Suppl 3):P36.
Harvard Medical School, Division of Rheumatology, Allergy and Immunology,
Department of Medicine, BWH, USA
Giavina-Bianchi et al. Clinical and Translational Allergy 2014, 4(Suppl 3):P36
http://www.ctajournal.com/content/4/S3/P36
© 2014 Giavina-Bianchi et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver
(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.


file:///data/core-remote/dit/data/Springer-OA/pdf/0bd/aHR0cDovL2xpbmsuc3ByaW5nZXIuY29tLzEwLjExODYvMjA0NS03MDIyLTQtUzMtUDM2LnBkZg==.pdf

Desensitization induces hyporesponsiveness and cell-surface phenotype changes on mouse mast cells

Abstract

Similar works

Full text

Available Versions

Harvard University - DASH

Springer - Publisher Connector