Age‐related changes in ocular mucosal tolerance: Lessons learned from gut and respiratory tract immunity

Abstract

Summary The ocular surface is the part of the visual system directly exposed to the environment, and it comprises the cornea, the first refractive tissue layer and its surrounding structures. The ocular surface has evolved to keep the cornea smooth and wet, a prerequisite for proper sight, and also protected. To this aim, the ocular surface is a bona fide mucosal niche with an immune system capable of fighting against dangerous pathogens. However, due to the potential harmful effects of uncontrolled inflammation, the ocular surface has several mechanisms to keep the immune response in check. Specifically, the ocular surface is maintained inflammation‐free and functional by a particular form of peripheral tolerance known as mucosal tolerance, markedly different from the immune privilege of intraocular structures. Remarkably, conjunctival tolerance is akin to the oral and respiratory tolerance mechanisms found in the gut and airways, respectively. And also similarly, this form of immunoregulation in the eye is affected by ageing just as it is in the digestive and respiratory tracts. With ageing comes an increased prevalence of immune‐based ocular surface disorders, which could be related to an age‐related impairment of conjunctival tolerance. The purpose of this review was to summarize the present knowledge of ocular mucosal tolerance and how it is affected by the ageing process in the light of the current literature on mucosal immunoregulation of the gut and airways.

Characteristics of Chest HRCT and pulmonary function tests in elderly-onset primary Sjögren syndrome with interstitial lung disease

“…Therefore, elderly patients are prone to refractory dry mouth, dry eyes, irritant cough, and other symptoms. [24] In addition, we found that arthritis, Raynaud, and parotid enlargement were more common in the AopSS patients, which was consistent with other studies. [8,10] These clinical features are similar to lung characteristics (NSIP/OP), suggesting inflammation is prominent in AopSS patients.…”

“…[23] In addition, tolerance of trachea mucous membrane to external antigen stimulation weakens during aging. [24] Therefore, age might be an independent risk factor for ILD and more attention is needed for lung disorders in elderly pSS patients.…”

Dry Eye Disease: An Overview of Its Risk Factors, Diagnosis, and Prevalence by Age, Sex, and Race

“…When modern eye drugs with preservatives are used concurrently with chronic allergic reactions in the ocular surface in elderly patients, the condition may be misdiagnosed as dry eye [ 54 ]. Patients with dry eyes are more likely to be sensitive and experience symptoms similar to allergic rhinoconjunctivitis [ 55 ]. The strong correlation between the naturally occurring flora of the gut and the occurrence of respiratory diseases is comparable to conjunctival approval.…”

The Intestinal Barrier Dysfunction as Driving Factor of Inflammaging

“…Booth et al compared the T cell responsiveness of elderly people with younger individuals (>60 vs. <60 years of age) and reported that in tissue resident memory T cells (T RM ) in ileum tissue, cellular characteristics, function, and number are affected by aging [ 83 ]. Furthermore, as reviewed by Galletti et al [ 84 ], in aging mice, the induction of tolerance as well as the humoral response to the oral administration of ovalbumin are decreased. Our own data suggested that oral immunizations induced both allergen-specific IgG1 and IgG2a in aged animals, while adult animals preferentially developed IgG1.…”