Assuntos
Alérgenos/imunologia , Antígenos de Plantas/imunologia , Endossomos/imunologia , Lisossomos/imunologia , Polissacarídeo-Liases/imunologia , Animais , Linhagem Celular Tumoral , Feminino , Humanos , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Peptídeo Hidrolases/imunologia , Pólen/imunologia , RatosRESUMO
Pollen is one of the most common causes of allergy worldwide, making the study of their molecular composition crucial for the advancement of allergy research. Despite substantial efforts in this field, it is not yet clear why some plant pollens strongly provoke allergies while others do not. However, proteases and protease inhibitors from allergen sources are known to play an important role in the development of pollen allergies. In this study, we aim to uncover differences in the transcriptional pattern of proteases and protease inhibitors in Betula verrucosa and Pinus sylvestris pollen as models for high and low allergenic potential, respectively. We applied RNA sequencing to Betula verrucosa and Pinus sylvestris pollen. After de-novo assembly we derived general functional profiles of the protein coding transcripts. By utilization of domain based functional annotation we identified potential proteases and protease inhibitors and compared their expression in the two types of pollen. Functional profiles are highly similar between Betula verrucosa and Pinus sylvestris pollen. Both pollen contain proteases and inhibitors from 53 and 7 Pfam families, respectively. Some of the members comprised within those families are implicated in facilitating allergen entry, while others are known allergens themselves. Our work revealed several candidate proteins which, with further investigation, represent exciting new leads in elucidating the process behind allergic sensitization.
Assuntos
Peptídeo Hidrolases/genética , Proteínas de Plantas/genética , Pólen/genética , Inibidores de Proteases , Alérgenos/genética , Alérgenos/imunologia , Antígenos de Plantas/genética , Antígenos de Plantas/imunologia , Biologia Computacional/métodos , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Anotação de Sequência Molecular , Peptídeo Hidrolases/imunologia , Proteínas de Plantas/imunologia , Pólen/imunologia , Rinite Alérgica Sazonal , Transcriptoma , Fluxo de TrabalhoRESUMO
BACKGROUND: Patients with pollen allergies are frequently polysensitized. Pollens contain epitopes that are conserved across multiple species. OBJECTIVE: We sought to demonstrate that cross-reactive T cells that recognize conserved epitopes show higher levels of expansion than T cells recognizing monospecific epitopes because of more frequent stimulation. METHOD: RNA was sequenced from 9 pollens, and the reads were assembled de novo into more than 50,000 transcripts. T-cell epitopes from timothy grass (Phleum pratense) were examined for conservation in these transcripts, and this was correlated to their ability to induce T-cell responses. T cells were expanded in vitro with P pratense-derived peptides and tested for cross-reactivity to pollen extracts in ELISpot assays. RESULTS: We found that antigenic proteins are more conserved than nonimmunogenic proteins in P pratense pollen. Additionally, P pratense epitopes that were highly conserved across pollens elicited more T-cell responses in donors with grass allergy than less conserved epitopes. Moreover, conservation of a P pratense peptide at the transcriptomic level correlated with the ability of that peptide to trigger T cells that were cross-reactive with other non-P pratense pollen extracts. CONCLUSION: We found a correlation between conservation of peptides in plant pollens and their T-cell immunogenicity within P pratense, as well as their ability to induce cross-reactive T-cell responses. T cells recognizing conserved epitopes might be more prominent because they can be stimulated by a broader range of pollens and thereby drive polysensitization in allergic donors. We propose that conserved peptides could potentially be used in diagnostic or immunomodulatory approaches that address the issue of polysensitization and target multiple pollen allergies.