covid
Buscar en
Allergologia et Immunopathologia
Toda la web
Inicio Allergologia et Immunopathologia Under the superficial dichotomy pathogen and allergen are two manifestations of ...
Información de la revista
Vol. 45. Núm. 6.
Páginas 619-620 (noviembre - diciembre 2017)
Compartir
Compartir
Descargar PDF
Más opciones de artículo
Visitas
1820
Vol. 45. Núm. 6.
Páginas 619-620 (noviembre - diciembre 2017)
Point of View
Acceso a texto completo
Under the superficial dichotomy pathogen and allergen are two manifestations of same immune activation and pathogenesis mechanisms
Visitas
1820
S. Patel
Bioinformatics and Medical Informatics Research Center, San Diego State University, 5500 Campanile Dr, San Diego, CA 92182, United States
Este artículo ha recibido
Información del artículo
Resumen
Texto completo
Bibliografía
Descargar PDF
Estadísticas
Abstract

Pathogens and allergens are deemed as two contrasting facets of host immune status, deficiency and exuberant. In silico domain analysis of a diverse panel of pathogen and allergen proteins has revealed the shortcoming of this notion. Both the pathogen and allergen proteins elicit immune activation, with the outcome of immune agitation depending on the pathogen strain, allergen exposure duration, and host factors. Pathogens can replicate within the host and constantly irritate the immune system, leading to blood coagulation, respiratory collapse and death. Allergens, being non-viable, can only provoke the immune system transiently; however, depending on the allergen dose and extent exposed to, inflammation and fatality can occur. In silico analysis of pathogen and allergen proteins showed the conserved domains to be AAA, WR1, VKc, Kelch, Hr1, HAMP, HELICc, Dak2, CHAD, CHASE2, Galanin, PKS_TE, Robl_LC7, Excalibur, DISIN, etc. This exciting discovery can have far-reaching effects in drug target identification approaches.

Keywords:
Pathogen
Allergen
Protein domains
Pathogenesis
Immune activation
Texto completo

Pathogens and allergens are conventionally considered as two ends of the pathogenesis continuum, while the former is associated with immunodeficiency, the latter is with autoimmunity.1,2 This definition is only partially correct or even erroneous, in the wake of noble genomic discoveries.

Both the pathogenesis-inducing agents are tied to one mechanism of immune activation which leads to tissue or systemic inflammation.3,4 The biggest difference between a pathogen and allergen lies in their in vivo replication ability, which the former is capable of and the latter is not.5 Pathogen can invade the human body via different routes and proliferate, overwhelming the immune system. The outcome of the tussle between pathogen and immune system hinges on the strain vigour and host factors. Consequently the pathogen can undergo quiescence for a later favourable period; or get eliminated from the system; or manipulate the immune system to fatality.6 Allergen on the other hand is a non-living macromolecule like proteins, lipids or polysaccharides from animal or plant origin (though metals, chemicals, drugs are allergens too, but not of organic source).7,8 On exposure to it, allergen sensitises the immune system, and activates it, just like a pathogen does. As allergens are non-viable and not capable of self-propagation, the immune system is able to tackle it. However; a chronic encounter with the allergen agitates the immune system, leading to inflammation, endocrine perturbation, cancer, autoimmune diseases and neural pathologies.9–11

Unfortunately, very few experimental studies have drawn this parallel or shown the similarity between the pathogenesis-evoking mechanisms of pathogens and allergens. This author found the resemblance through in silico analysis of several virus (HIV, Hepatitis C, Ebola, dengue, zika), bacteria (Escherichia coli, Mycobacterium tuberculosis, Pasteurella multocida) and allergen (cockroach, pollen) proteins. The consensus protein domains in them were found to be AAA, WR1, VKc, Tryp_SPc, Kelch, Hr1, Knot1, HAMP, HELICc, DHDPS, Dak2, CHAD, CHASE2, BTAD, Galanin, GCK, PKS_TE, Robl_LC7, Excalibur, DISIN, Col_cuticle_N, DUF4208, etc. Most of these signature domains occur in enzymes, transcriptional factors and immune adhesion proteins. Occasional loss of the domains can be explained by genomic rearrangement due to stress faced, phylogenetic trajectories and resultant domain diversification. Further investigation in this aspect might set a new paradigm for drug discovery.

Conflict of interest statement

The author has no conflict of interest to declare.

References
[1]
S. Gupta, A.G. Louis.
Tolerance and autoimmunity in primary immunodeficiency disease: a comprehensive review.
Clin Rev Allergy Immunol, 45 (2013), pp. 162-169
[2]
R. Warrington, W. Watson, H.L. Kim, F.R. Antonetti.
An introduction to immunology and immunopathology.
Allergy Asthma Clin Immunol, 7 (2011), pp. S1
[3]
D.D. Chaplin.
Overview of the immune response.
J Allergy Clin Immunol, 125 (2010), pp. S3-S23
[4]
T.H. Mogensen.
Pathogen recognition and inflammatory signaling in innate immune defenses.
Clin Microbiol Rev, 22 (2009), pp. 240-273
[Table of Contents]
[5]
F.J. Baird, A.L. Lopata.
The dichotomy of pathogens and allergens in vaccination approaches.
Front Microbiol, 5 (2014), pp. 365
[6]
J. Charles, A. Janeway, P. Travers, M. Walport, M.J. Shlomchik.
Pathogens have evolved various means of evading or subverting normal host defenses.
(2001),
[7]
A.M. Russano, E. Agea, C. Casciari, F.M. de Benedictis, F. Spinozzi.
Complementary roles for lipid and protein allergens in triggering innate and adaptive immune systems.
[8]
S.P. Commins, T.A.E. Platts-Mills.
Allergenicity of carbohydrates and their role in anaphylactic events.
Curr Allergy Asthma Rep, 10 (2010), pp. 29-33
[9]
H. Sarlus, C.O. Höglund, B. Karshikoff, X. Wang, M. Lekander, M. Schultzberg, M. Oprica.
Allergy influences the inflammatory status of the brain and enhances tau-phosphorylation.
J Cell Mol Med, 16 (2012), pp. 2401-2412
[10]
J.R. Murdoch, C.M. Lloyd.
Chronic inflammation and asthma.
Mutat Res, 690 (2010), pp. 24-39
[11]
N. Khansari, Y. Shakiba, M. Mahmoudi.
Chronic inflammation and oxidative stress as a major cause of age-related diseases and cancer.
Recent Pat Inflamm Allergy Drug Discov, 3 (2009), pp. 73-80
Copyright © 2017. SEICAP
Descargar PDF
Opciones de artículo
es en pt

¿Es usted profesional sanitario apto para prescribir o dispensar medicamentos?

Are you a health professional able to prescribe or dispense drugs?

Você é um profissional de saúde habilitado a prescrever ou dispensar medicamentos