Induction of shrimp tropomyosin-specific hypersensitivity in mice.
BACKGROUND
Shellfish hypersensitivity is amongst the most common food allergies. The major shellfish allergen was identified as tropomyosin. Here, we investigated the immediate hypersensitivity responses, IgE and cell-mediated immune response in mice sensitized with recombinant shrimp tropomyosin.


METHODS
Shrimp tropomyosin was cloned and expressed as a His-tagged fusion recombinant protein in Escherichia coli. Three- to 4-week-old BALB/c mice were sensitized by intragastric administration of recombinant tropomyosin (0.1 mg) plus cholera toxin (10 mug) on days 0, 12, 19 and 26 and challenged on day 33. Mice fed with phosphate-buffered saline plus cholera toxin were included as controls. Animals were monitored for immediate hypersensitive responses and tropomyosin-specific IgE over time. In addition, shrimp tropomyosin-specific CD4+ T cells, interleukin-4 and interferon-gamma levels were determined from in vitro splenocyte cultures. A passive cutaneous anaphylaxis assay was also conducted.


RESULTS
Mice fed with shrimp tropomyosin developed swelling of the snout, increased scratching behavior and shrimp tropomyosin-specific IgE. Sera from tropomyosin-sensitized mice elicited vascular leakage in naïve mice in the passive cutaneous anaphylaxis assay. Shrimp tropomyosin-specific CD4+ T cell proliferations and elevated interleukin-4 over interferon-gamma levels were evident in splenocyte cultures of tropomyosin-fed mice upon tropomyosin stimulation. In contrast, shrimp tropomyosin-specific IgE, CD4+ T cells and hypersensitive responses were absent in the control mice.


CONCLUSIONS
We have generated a BALB/c model of shrimp allergy. This model provides a useful tool for evaluating the immunopathogenic mechanisms involved in shellfish hypersensitivity.
Leung
Patrick S C
PS
Division of Rheumatology/Allergy and Clinical Immunology, School of Medicine, University of California, Davis, Calif., USA.
Lee
Yuen Shan
YS
Tang
Chi Yan
CY
Kung
Wing Yee
WY
Chuang
Ya-Hui
YH
Chiang
Bor-Luen
BL
Fung
Ming Chiu
MC
Chu
Ka Hou
KH
D000707:Anaphylaxis / Q000209:etiology; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D033364:Decapoda / Q000276:immunology*; D005260:Female; D005512:Food Hypersensitivity / Q000209:etiology*; D007073:Immunoglobulin E / Q000096:biosynthesis; D007371:Interferon-gamma / Q000096:biosynthesis; D020381:Interleukin-17 / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D010323:Passive Cutaneous Anaphylaxis / Q000276:immunology; D011506:Proteins / Q000276:immunology*; D014335:Tropomyosin / Q000276:immunology*
D020381:Interleukin-17; C102464:Met e 1 allergen; D011506:Proteins; D014335:Tropomyosin; D015847:Interleukin-4; D007073:Immunoglobulin E; D007371:Interferon-gamma