Manila grass (Zoysia matrella) Zoy m 1 allergen may contribute to allergic sensitization in tropical/subtropical regions due to extensive cross-reactivity with other group-1 grass pollen allergens

Koravit Somkid,^1,7 Sirirat Aud-in,^2,3 Bannapuch Pinkaew,⁴ Pongsakorn Tantilipikorn,⁴ Surapon Piboonpocanun,⁵ Wisuwat Songnuan^2,6,7

¹ Toxicology graduate programme, Faculty of Science, Mahidol University, Bangkok, Thailand
² Department of Plant Science, Faculty of Science, Mahidol University, Bangkok, Thailand
³ Department of Pharmaceutical Botany, Faculty of Pharmacy, Bangkok, Thailand
⁴ Rhinology & Allergy Division, Department of Otorhinolaryngology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
⁵ Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Nakhon Pathom, Thailand
⁶ Systems Biology of Diseases Research Unit, Faculty of Science, Mahidol University, Bangkok, Thailand
⁷ Center of Excellence on Environmental Health and Toxicology, Bangkok, Thailand (EHT)

Abstract

Background: Pollen of grasses in Chloridoideae and Panicoideae subfamilies is a major source of grass group-1 allergens in tropical/subtropical areas. Previously, most studies of subtropical grass pollen allergens have focused on Cynodon dactylon (Bermuda grass-Chloridoideae) and Sorghum halepense (Johnson grass-Panicoideae). However, little information is available about allergenicity of pollen from Zoysia matrella (Manila grass or Zoysia grass-Chloridoideae), which is among the most popular turfgrasses in tropical/subtropical areas.
Objective: This study aimed to investigate the IgE reactivity and cross-reactivity of grass group-1 allergen from Z. matrella. In addition, the clinical relevance of Z. matrella in comparison with other species was assessed.
Methods: IgE reactivity and cross-reactivity between recombinant proteins of group-1 allergen from Z. matrella (Zoy m 1) and C. dactylon (Cyn d 1) were determined by ELISA and immunoblot assays. Clinical relevance of Z. matrella pollen in Thai atopic patients was assessed using its pollen crude extract for skin-prick test, in comparison with extracts from four other pollen species.
Results: The Zoy m 1 had high IgE binding and could interfere with binding to C. dactylon crude extract. In addition, Z. matrella pollen extract elicited positive skin-prick test results comparable to previously reported allergenic species. Group-1 grass pollen allergen was confirmed to be a major allergen from Z. matrella among Thai atopic patients and was officially designated Zoy m 1.0101.
Conclusion: Zoy m 1 allergen is a major allergen from Z. matrella that cross-reacts with other group-1 grass pollen allergens in the tropical/subtropical region.
Key words: Zoysia grass, Chloridoideae, subtropical grass, allergic rhinitis, cross-reactivity, Zoy m 1