Biomedical subjects

Cecil P Moore

Publications and source records attributed to Cecil P Moore.

5 recordsLinked to original sources

PubMed2005

Conjunctival M cells selectively bind and translocate Maackia amurensis leukoagglutinin.

Antigen-sampling M cells are found in the follicle-associated epithelium above organized lymphoid tissue in many mucosae. They play a key role in initiating the mucosal immune response and act as a site of entry for opportunistic pathogens. This study investigates the presence of M cells in the Guinea pig conjunctiva. Maackia amurensis leukoagglutinin I and II (MAL-I and MAL-II) were identified as potential conjunctival M cell markers based on a screening of 12 lectins and 5 carbohydrate epitope antibodies on aldehyde-fixed follicles. Biotinylated or fluorescein-conjugated MAL-I was then instilled into conjunctival sacs in vivo for 15-60 min. Specimens were assessed by epi-fluorescence stereomicroscopy, confocal scanning laser microscopy and transmission and scanning electron microscopy (TEM and SEM). Selective labelling of a subset of epithelial cells overlying lymphoid follicles was observed following in vivo exposure to MAL-I. MAL-I labelling was restricted to cells with sparse, irregular microvilli. Cells preferentially labelled with MAL-I were found to internalize the lectin during a 60 min in vivo exposure. MAL-I was transcytosed to basolateral membranes of cells filled with intracellular vesicles during a 45 min in vivo incubation. This study demonstrates that the Guinea pig conjunctiva contains a cell with morphological and functional characteristics of antigen-sampling M cells.

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PubMed2005

M cells in the follicle-associated epithelium of the rabbit conjunctiva preferentially bind and translocate latex beads.

PURPOSE: This study investigates the presence of M cells in the rabbit conjunctiva. Resolving whether the conjunctiva contains M cells is important, because at other mucosal sites, these antigen sampling cells are known to initiate the mucosal immune response and to act as a site of entry for opportunistic pathogens. METHODS: Fluorescent 0.2-microm polystyrene latex beads were either instilled into the conjunctival sac for 20 to 120 minutes in vivo or applied to flat mounts in vitro. Specimens were assessed by epi-fluorescence stereomicroscopy, widefield fluorescence microscopy, confocal scanning laser microscopy, and transmission and scanning electron microscopy. RESULTS: Latex beads preferentially bound to a subpopulation of cells in the epithelium overlying mucosal lymphoid follicles in the fornix region. At 4 degrees C, the beads were associated with the apical surface of cells that had longer, more irregular microvilli than the surrounding epithelial cells. Within 20 minutes of an in vivo exposure, latex beads were internalized by the follicle-associated epithelial cells and with time moved into the underlying follicle region. After 120 minutes of in vivo exposure, latex beads could be found in cervical lymph nodes. CONCLUSIONS: This study demonstrates that the follicle-associated epithelium of the rabbit conjunctiva contains a cell with morphologic characteristics and the ability to bind and translocate latex beads, which make it indistinguishable from antigen sampling M cells in the rabbit cecum and tonsils. Consistent with its hypothesized antigen sampling role, beads that have been translocated by this cell are rapidly transferred to cervical lymph nodes.

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PubMed2004

Ocular therapeutics.

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Administration, Topical↗

PubMed2004

Immunomodulating agents.

Inflammation involves a universally recognized, although incompletely understood, cascade of molecular events orchestrated by lymphokines and other innate biochemicals of immunity. Repeated or extended contact with immunogenic agents results in adaptive immunity involving antigen-induced events that stimulate down-stream immune cells and result in expansion of the inflammatory cascade. When immunogenic stimulation persists or autoregulatory immune mechanisms go awry, however, adaptive immunologic events can result in immune-mediated processes detrimental to systemic or organ-specific homeostasis. Because of the complexities of immunologic events, the potential side effects of long-term corticosteroid therapy, and the focused spectrum of most conventional nonsteroidal anti-inflammatory agents (centered on arachidonic acid-related mechanisms), a variety of other chemotherapeutic immunosuppressive agents have assumed an increasingly prominent therapeutic role in veterinary ophthalmology in the management of chronic ocular inflammatory diseases. In addition, nonimmunosuppressive immunomodulating agents (ie, immuno-stimulants or immunorestoratives) may be used as adjunctive therapies in the management of ocular or visual system diseases.

Adjuvants, Immunologic↗

PubMed2002

Morphological evidence of M cells in healthy canine conjunctiva-associated lymphoid tissue.

PURPOSE: To characterize the follicle-associated epithelium (FAE) and organized lymphoid nodules from dog nictitating membranes to determine if canine conjunctiva-associated lymphoid tissue (CALT) contains M cells analogous to those described in other regions of mucosa-associated lymphoid tissue (MALT). METHODS: Nictitan lymphoid follicles from 15 healthy dogs (30 eyes) were harvested immediately post-mortem. Twelve follicles from each nictitating membrane were isolated. Four follicles from each eye of 10 dogs were examined by light microscopy, transmission electron microscopy and scanning electron microscopy. Five of the 10 dogs were treated with a heat-killed staphylococcal topical suspension immediately prior to euthanasia. Nictitan follicles from five other dogs were processed for immunohistochemistry to characterize follicle lymphocyte populations. RESULTS: The FAE overlying CALT demonstrated morphology characteristic of M cells, including attenuated apical cell surface with blunted microvilli and microfolds, invaginated basolateral membrane forming a cytoplasmic pocket containing lymphocytes and macrophages, and diminished distance between the apical and pocket membrane. Heat-killed bacteria were bound to the surface and transcytosed to the cytoplasmic pocket of CALT M cells. Immunohistochemistry of organized lymphoid tissue subtending the FAE demonstrated B-cell germinal centers with T-cell predominant apical caps. CONCLUSIONS: In canine CALT, the FAE overlying lymphoid follicles, as well as the distribution of T and B lymphocytes subtending this region, contain morphologic and functional features analogous to MALT described in other regions. Documentation of canine conjunctival M cells is of clinical relevance in the study of primary ocular diseases, as well as a potential means of vaccination or drug delivery.

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