Inflammation, Aging and Cancer by Mahin Khatami

Author:Mahin Khatami
Language: eng
Format: epub
Publisher: Springer International Publishing, Cham

5 Ocular Tissues: Ideal Targets for Studying Inflammatory Diseases or Tumorigenesis and Angiogenesis . Comparison of Composition and Function of Immune and Non-immune Cells in Conjunctiva and Lung Airways

Among body’s organ systems, conjunctiva and lung airways represent ideal systems for demonstration of a wide range of human inflammatory diseases. A major immune function of the conjunctival epithelium and lid architecture is to prevent entry of microorganisms or foreign elements (e.g., infective agents, toxins, allergen , environmental and chemical hazards) into the globe and to clear the eye and prevent damage to the oxidative-sensitive immune-privileged ocular tissues such as the avascular cornea, retina and neuroretina. Major ocular inflammatory conditions include vernal conjunctivitis, keratoconjunctivities, punctuate keratitis, giant papillary conjunctivitis, bechet’s disease, Sjogren’s syndrome, retinitis or squamous cell carcinoma of conjunctiva [18–23, 40–44, 62–76, 89, 90]. Similarly, an immune function of the epithelial structure of the lung airway is to prevent entry and clearance of inhaled toxins or unwanted particles from the lung tissues [77–81, 83–85].

To perform their functions , both tissues, being accessible to external chemical or environmental hazards (stimuli), have similar diverse cell types, including epithelium, mucus secreting goblet cells (GCs), mast cells (MCs) or dendritic cells (DCs ) and depending on the types of immune disruptors (stimuli), they provide somewhat similar cellular and molecular responses. Clinical and histopathological manifestations and immune response mechanisms that are involved in lung allergies or infectious diseases (e.g., asthma , emphysema , COPD , pneumonia) or lung cancers are, to some extent, comparable to those occurring in conjunctival allergic reactions (e.g., vernal and giant papillary conjunctivitis, keratoconjunctivitis, hay fever, atopic eczema, punctuate keratitis) or Behcet’s diseases, Sjogren’s syndrome and squamous cell carcinomas of the conjunctiva. Stimuli-induced mast cells-IgE activation and degranulation and release of histamine, heparin and other preformed or newly synthesized inflammatory mediators , eosinophil infiltration into epithelium and goblet cells and hyperproduction of thick mucus secretion from GCs have been identified as principal responses during inflammatory conditions in both conjunctiva and lung tissues. Furthermore, abnormalities and diversities in B-cell memory expression of immunoglobulin subclasses have been reported in patients with atopic eczema and Sjogren’s syndrome, autoimmune disorders associated with lymphoid follicles and progression to lymphoma are comparable to the mechanisms occurring in asthmatic patients [21, 44, 66, 67, 76–81]. In lung diseases of the respiratory airway, activated epithelial cells, which are coated with a layer of mucus causing a thick barrier has been reported as major contributors in the development of cystic fibrosis, asthma and emphysema that also prevent access to therapeutic drugs [7, 40–44, 62–87, 108–110]. Participation of mast cells (MCs) sensitization and activation (effector function) and release of preformed or newly synthesized mediators, followed by infiltration of eosinophils has been reported in acute and chronic ocular allergies or asthma . Furthermore, activation of mucus secreting goblet cells (GCs) and infiltration of eosinophils into GCs during ocular inflammatory conditions or asthma and the progression of diseases may be considered comparable events. It is also noteworthy that individuals suffering from asthma often manifest ocular allergic reactions and vice versa.

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