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A Non-invasive Way to Isolate and Phenotype Cells from the Conjunctiva
Published on: July 5, 2017
Expression of CD23/CD21 and CD40/CD40 ligand in vernal keratoconjunctivitis
A M Abu El-Asrar1, R A Fatani, L Missotten
1Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia. abuasrar@KSU.edu.sa
Insights
Vernal keratoconjunctivitis (VKC) involves immunoglobulin E (IgE) overproduction. Activated B lymphocytes in the conjunctiva express CD23, CD21, and CD40, suggesting the conjunctiva contributes to IgE synthesis in VKC.
Area of Science:
- Ophthalmology
- Immunology
Background:
- Immunoglobulin E (IgE) overproduction is linked to vernal keratoconjunctivitis (VKC).
- CD23/CD21 and CD40/CD40 ligand (CD40L) interactions are implicated in regulating IgE synthesis.
Purpose of the Study:
- To investigate the presence and distribution of CD23, CD21, CD40, and CD40L in conjunctival tissues of patients with active VKC.
Main Methods:
- Conjunctival biopsy specimens from 8 active VKC patients and 6 controls were analyzed.
- Immunohistochemical techniques using monoclonal antibodies against CD23, CD21, CD40, and CD40L were employed.
- Inflammatory infiltrate composition was characterized using additional monoclonal antibodies.
Main Results:
- Normal conjunctiva showed weak CD40 immunoreactivity in basal epithelial and vascular endothelial cells; CD23, CD21, and CD40L were absent.
- VKC specimens exhibited diffuse stromal infiltrates and lymphoid follicles containing CD20+ B lymphocytes, CD3+ T lymphocytes, and CD68+ monocytes/macrophages.
- Lymphocytes within lymphoid follicles displayed CD23 and CD21 immunoreactivity. CD40 immunoreactivity was enhanced in epithelial and vascular cells, and present on most mononuclear cells in VKC. CD40L was not detected.
Conclusions:
- B lymphocytes within lymphoid follicles expressing CD23, CD21, and CD40 are activated.
- These activated B lymphocytes may be precursors to IgE-producing B cells.
- The conjunctiva may play a role in IgE synthesis in VKC.
Purpose:
The overproduction of immunoglobulin E (IgE) antibodies is associated with vernal keratoconjunctivitis (VKC). CD23/CD21 and CD40/CD40 ligand (CD40L) interactions have been proposed to be involved in the regulation of IgE synthesis. The purpose of the present study was to investigate the presence and distribution of CD23, CD21, CD40 and CD40L in the conjunctiva from patients with active VKC.
Methods:
Conjunctival biopsy specimens from 8 subjects with active VKC and 6 control subjects were studied. We used immunohistochemical techniques and a panel of monoclonal antibodies (mAbs) directed against CD23, CD21, CD40 and CD40L. In addition, a panel of mAbs were used to characterise the composition of the inflammatory infiltrate.
Results:
In the normal conjunctiva, basal epithelial cells and vascular endothelial cells in the upper substantia propria showed a constitutive very weak immunoreactivity for CD40. The immunoreactivity for CD23, CD21 and CD40L was absent. In VKC specimens, the stromal inflammatory infiltrate was orgnanised as a diffuse infiltrate and as small lymphoid follicles consisting of CD20+ B lymphocytes intermingled with smaller numbers of CD3+ T lymphocytes, and CD68+ monocytes/macrophages. Lymphocytes in the centre of the lymphoid follicles showed CD23 and CD21 immunoreactivity. CD40 immunoreactivity in epithelial cells and vascular endothelial cells was stronger in VKC specimens than in control eyes. Furthermore, the majority of mononuclear cells, including T and B lymphocytes, showed immunoreactivity for CD40. CD40L immunoreactivity was not detected.
Conclusion:
B lymphocytes in the lymphoid follicles expressing CD23, CD21 and CD40 are activated and might be precursors of IgE-producing B cells. These results suggest that the conjunctiva might contribute to IgE synthesis.
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