Contact Hypersensitivity as a Murine Model of Allergic Contact Dermatitis

Summary

Contact hypersensitivity (CHS) is a murine experimental model of allergic contact dermatitis (ACD). CHS is based on sensitization with reactive hapten by painting the shaved skin of the chest and abdomen, with a subsequent ear skin challenge with a diluted hapten, causing a swelling reaction that is assessed in various ways.

Abstract

Contact hypersensitivity (CHS) is an experimental model of allergic contact dermatitis (ACD) that can be studied in mice. This study aims to present an objective laboratory method that may help to study the CHS reaction in mice, which can be measured and quantified by various tests. To induce CHS, on day "0", mice were sensitized on a previously shaved spot by abdominal skin painting with the hapten 2,4,6-trinitrochlorobenzene (TNCB) in an acetone-ethanol mixture, whereas negative control mice were sham sensitized with vehicle alone-acetone-ethanol mixture. On day "4", the baseline ear thickness was measured with a micrometer prior to the elicitation of CHS (challenge) by painting both ears with diluted TNCB both in the test and control groups. After 24 h, the ear swelling was measured with a micrometer. CHS is an example of a T cell-mediated immune response that causes swelling in inflamed tissue, peaking 24 h after the skin challenge with the same hapten. An increase in ear edema correlated with augmented ear weight, myeloperoxidase (MPO) activity, pro-inflammatory cytokine concentration in the ear extracts, increased thickening of the edematous dermis in the histological examination, and ear vascular permeability. There was also an increase in the concentration of TNP-specific IgG1 antibodies in the sera of the test group when compared with the control mice. Additionally, CHS can be successfully transferred with the CHS-effector cells obtained from donors previously sensitized with TNCB. The CHS-effector cells were administered intravenously into naïve recipient mice, which were subsequently challenged with the same diluted hapten. Ear swelling was measured with a micrometer 24 h later.

Introduction

Allergic contact dermatitis (ACD) is a common skin inflammatory disease in industrialized countries caused by a type IV hypersensitivity reaction resulting from exposure to low molecular weight chemicals called haptens. The substances causing contact sensitization in humans include heavy metal ions (chromium, nickel, iron, cobalt), turpentine, fragrances, dyes, and preservatives present in cosmetics (e.g., p-phenylenediamine), some drugs (e.g., neomycin, benzocaine), β-lactam antibiotics (i.e., penicillin), chemicals produced by plants (pentadecacatechol, a substance present in poison ivy), as well as hydroquinone-used in the photographic industry

Protocol

All experiments presented in this article were conducted according to the guidelines of the 1st Local Ethical Committee on Animal Testing in Krakow. All the procedures described were performed according to the local recommendations, especially regarding using ketamine/xylazine as an anesthetic, using both sides of the ears to apply the substance/hapten, cutting off the ear, and collecting blood by eyeball removal. BALB/c (haplotype H-2^d), CBA/J (H-2^k), and C57BL/6 (H-2^b) male and female mice, 6-12 weeks old, were used for the present study (see Table of Materials). For statistical significance, it is best if each group....

Results

For CHS induction, the animals were sensitized via skin painting (abdominal) with 150 µL of 5% TNCB or sham sensitized with the vehicle alone. On day "4", the ear swelling responses of both ears were induced by contact painting (challenge) with 10 µL of 0.4% TNCB in both mice previously contact sensitized with TNCB (test group) and the control group mice (sham sensitized). The presented data depict that the mice sensitized with TNCB and challenged 4 days later developed significantly increased ear swelling compa.......

Discussion

CHS is induced via haptens, which bind to self-protein antigens in the skin, creating neoantigens. CHS is mediated by local extravascular recruitment of circulating antigen-specific CHS-effector T cells, which results in swelling in the challenged tissue, peaking 24 h after exposure of the secondary skin to the same hapten⁶. The swelling of the tissue is mainly caused by the infiltration of leukocytes and leukocyte-dependent fibrin deposition²⁴. These changes can b.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
70% ethanol	Merck KGaA, Darmstadt, Germany	65350-M	for surface disinfection
96-well flat-bottom plates, polypropylene	Greiner Bio-One GmbH, Kremsmunster, Austria	655101	for MPO and Evans blue measurement - plates should be made of polypropylene, that has a lower binding capacity so proteins or DNA will not bind
Acetone (ACS reagent, ≥99.5%)	Merck KGaA, Darmstadt, Germany	179124
Aluminum foil	Merck KGaA, Darmstadt, Germany	Z185140
Analytical balance	Sartorius Weighing Technology GmbH, Goettingen, Germany	PRACTUM224-1s, 29105177
Automated tissue processor	MediMeas Instruments, Sarsehri, Haryana, India	MTP-E-212	automatically prepare tissue samples by fixing, dehydrating, clearing, and infiltrating them with paraffin
BD Vacutainer SST II Advance (tube with gel for obtaining serum)	Becton Dickinson (BD), Franklin Lakes, NJ, USA	BD 366882
Bicinchoninic acid kit for protein determination	Merck KGaA, Darmstadt, Germany	BCA1-1KT
Biotin Rat Anti-Mouse IgG1	Becton Dickinson (BD Biosciences), Franklin Lakes, NJ, USA	553441
BSA (bovine serum albumine)	Merck KGaA, Darmstadt, Germany	A9418	protein assays & analysis, 2 mg/mL
Cell strainer, pore size 70 μm	BIOLOGIX, China	15-1070	suitable for 50 mL tubes
Coverslip	VWR, Radnor, Pennsylvania, United States	631-1583	24 mm, but it possible to use different size
Disposable pipettes capacity: 5 mL, 10 mL, 25 mL	Merck KGaA, Darmstadt, Germany	Z740301, Z740302, Z740303
DPBS (Dulbecco′s phosphate buffered saline)	ThermoFisher Scientific,  Waltham, Massachusetts, USA	14190144	no calcium, no magnesium, mammalian cell culture
DPX Mountant for histology	Merck KGaA, Darmstadt, Germany	6522	mounting media for H-E, might be used some other e.g, Canada balsam
Dumont 5 tweezers - straight	Animalab, Poznan, Poland	11251-10FST	surgical instruments for procedures on mice (should be steriled)
Dumont 7 tweezers - bent	Animalab, Poznan, Poland	11272-50FST	surgical instruments for procedures on mice (should be steriled)
Eosin Y solution, alcoholic	Merck KGaA, Darmstadt, Germany	HT110116
Eppendorf Safe-Lock Tubes 1.5 mL	Eppenforf, Germany	3,01,20,086	polypropylene
Eppendorf Safe-Lock Tubes, 2.0 mL	Eppenforf, Germany	3,01,20,094	polypropylene, round bottom (the homogenization beads can easily move)
Ethanol 100% (absolute alkohol)	Merck KGaA, Darmstadt, Germany	1.07017
Ethanol 96%	Merck KGaA, Darmstadt, Germany	1.59010
Evans blue	Merck KGaA, Darmstadt, Germany	E2129
FBS (fetal bovine serum)	ThermoFisher Scientific, Waltham, Massachusetts, USA	A3160802
Formalin solution, neutral buffered, 10%	Merck KGaA, Darmstadt, Germany	HT501128
Formamide 99.5% (GC)	Merck KGaA, Darmstadt, Germany	F7503
Freezer -20 °C	Bosch, Germany	GSN54AW30
Fridge +4 °C / freezer -20 °C	Bosch, Germany	KGV36V10	mammalian Cell Culture, qualified, Brazil, 10 x 50 mL
Glass microskope slides, SuperFrost Plus	VWR, Radnor, Pennsylvania, United States	631-0108, 631-0446, 631-0447, 631-0448, 631-0449	Slides that eliminates the need to apply adhesive materials or protein coatings, to preventing any tissue sections loss during staining.
Graph Pad Prism	GraphPad Software Inc.	v. 9.4.0
Grey soap	Pollena Ostrzeszów, Producent Chemii Gospodarczej Sp. Z.o.o. , Sp. K., Poland	Bialy jelen soap bar	grey Soap Bar Natural Hypoallergenic. Generally available product
H2SO4 (sulfuric acid) 1 mol/l (1 M)	Merck KGaA, Darmstadt, Germany	1.60313
Harris hematoxylin solution	Merck KGaA, Darmstadt, Germany	HHS16
Hemocytometer	VWR, Avantor, U.S.A	612-5719	manual counting chamber is recommend, which is more accurate
Hexadecyltrimethylammonium bromide	Merck KGaA, Darmstadt, Germany	H5882
Homogenizer	QIAGEN Hilden, Germany	Tissue Lyser LT, SN 23.1001/05234	homogenizer with stainless steel beads (diameter 5 mm) for 2 mL centrifuge tubes
Horseradish peroxidase streptavidin (HRP streptavidin)	Vector Laboratories, Inc., Burlingame, CA, USA	SA-5004-1
Hydrogen peroxide solution (H202)	Merck KGaA, Darmstadt, Germany	H1009
Incubator Heracell 150i	Thermo Electron LED Gmbh, Germany	41071068	37 oC in the atmosphere of 5 % CO2, and 65 0C for deparaffinization the sections for histology
Ketamine 100 mg/mL, solution for injection	Biowet Pulawy Sp. z o.o., Pulawy, Poland	cat.# not avaliable
KH2PO4 (potassium dihydrogen phosphate) 99.995% anhydrous basis	Merck KGaA, Darmstadt, Germany	1.05108
Laboratory Centrifuge	Heraeus Megafuge 1.0R, Thermo Scientific, Germany	B00013899	speed to 300 x g, with cooling to 4 0C
Laboratory Centrifuge	Heraeus Fresco 21, Thermo Scientific, Germany	75002425	speed to 3,000 x g, with cooling to 4 0C
Mask (FFP2)	VWR, Radnor, Pennsylvania, United States	111-0917	for working with ortho-dianisine dihydrochloride
Mice	Breeding unit of the Chair of Biomedical Sciences, Faculty of Health Sciences, Jagiellonian University Medical College, Krakow, Poland	CBA/J, C57BL/6
Micrometer	Mitutoyo, Tokyo, Japan	193-111	digit Outside Micrometer, Ratchet Stop, 0-25mm Range, 0.001mm Graduation, +/-0.002mm Accuracy, https://shop.mitutoyo.pl/web/mitutoyo/pl_PL/all/all/Mikrometr%20analogowy%20/PR/193-111/index.xhtml
microplate, 96 well, microlon, high binding (for ELISA test)	Greiner Bio-One GmbH, Kremsmunster, Austria	655061	with maxi-sorp binding surfaces for reliable and reproducible results in colormetric assays
Microscope with objectives	Leica Microsystems CMS GmbH, Germany	DM1000, 294011-082007	histology presented in the paper was performed under ThermoFisher Scientific EVOS M5000 Imaging System, with objectives: FL 20X LWDPH, 0.40NA/3.1WD and FL 40X LWDPH 0.65NA/1.79WD
Myeloperoxidase from human leukocytes (MPO standard)	Merck KGaA, Darmstadt, Germany	M6908
Na2HPO4 x 7 H2O (sodium phosphate dibasic heptahydrate)	Merck KGaA, Darmstadt, Germany	S9390
Olive-oil	Merck KGaA, Darmstadt, Germany	75343	pure, natural
OptEIA Mouse IFN-γ ELISA Set	Becton Dickinson (BD Biosciences), Franklin Lakes, NJ, USA	555138
Ortho-dianisine dihydrochloride	Merck KGaA, Darmstadt, Germany	D3252
Paraffin wax	Merck KGaA, Darmstadt, Germany	76242	beads, waxy solid
PBS (phosphate buffered saline)	ThermoFisher Scientific,  Waltham, Massachusetts, USA	20012027	pH 7.2, mammalian cell culture
ph meter	Elmetron, Poland	CP-401
Pipettes, variable volume with tips	Merck KGaA, Darmstadt, Germany	EP3123000900-1EA	3-pack, Option 1, 0.5-10 uL/10-100 uL/100-1000 uL, includes epT.I.P.S.
Razor blade	VWR, Radnor, Pennsylvania, United States	PERS94-0462	scraper and cutter blades, single edge, aluminium spine, 100 blades per box, individually wrapped
Rotary microtome	MRC Laboratory-Instruments, Essex, CM20 2HU UK	HIS-202A
Scissors - straight, sharp / sharp	Animalab, Poznan, Poland	14060-10FST	Surgical instruments for procedures on mice (should be steriled)
Screw cap (open top)	Merck KGaA, Darmstadt, Germany	27056	black polypropylene hole cap, for use with 22 mL vial with 20-400 thread
Spectrophotometer	BioTek Instruments, U.S.A	201446	universal microplate spectrophotometer: λ range: 200 - 999 nm, absorbance measurement range: 0.000 - 4.000 Abs
Staining dish 20 slides with rack	Merck KGaA, Darmstadt, Germany	S6141	e.g. 20 slide staining dishes complete with covers, slide rack and handle
Sterile Disposable Biopsy Punch 6mm	Integra LifeSciences, Princeton, NJ, USA	33-36
Surgical scissors	Animalab, Poznan, Poland	52138-46	surgical instruments for procedures on mice (should be steriled)
Tissue processing cassettes	Merck KGaA, Darmstadt, Germany	Z672122	tissue processing/ embedding cassettes with lid
TMB Substrate Reagent Set	Becton Dickinson (BD Biosciences), Franklin Lakes, NJ, USA	555214
TNCB (2,4,6-trinitrochlorobenzene)	Tokyo Chemical Industry CO., LTD, Japan	C0307
TNP-BSA (bovine serum albumin conjugated with 2,4,6-trinitrophenyl)	Biosearch Technologies LGC, Petaluma, CA, USA	T-5050
T-PER (tissue protein extration reagent)	ThermoFisher Scientific, Waltham, Massachusetts, USA	78510
Tubes 15 mL sterile	Merck KGaA, Darmstadt, Germany	CLS430055 (Corning)	polypropylene, conical bottom
Tubes 50 mL, sterile	Merck KGaA, Darmstadt, Germany	CLS430290 (Corning)	polypropylene, conical bottom
Tween 20	Merck KGaA, Darmstadt, Germany	P1379
Vials, screw top, clear glass (vial only) 22 mL	Merck KGaA, Darmstadt, Germany	27173	for the preparation of hapten, screwed on so that it does not evaporate
Water bath	AJL Electronic, Poland	LW102
Wax (paraffin) dispenser	VWR, Radnor, Pennsylvania, United States	114-8737
Xylazine (xylapan 20 mg/mL) solution for injection	Vetoquinol Biowet Sp. z o.o., Gorzow Wielkopolski, Poland	cat.# not avaliable
Xylene (histological grade)	Merck KGaA, Darmstadt, Germany	534056