Expression of IL-10 and TNF-inhibitor genes in lacrimal gland epithelial cells suppresses their ability to activate lymphocytes

Lacrimal Gland as a Target Organ for Adenovirus Gene Therapy Encoding Erythropoietin for Dry Eye Induced by Benzalkonium Chloride

Purpose: The aims of this work were a) to describe the histology of the lacrimal gland (LG) and cornea induced by an adenovirus (Ad) vector encoding the human erythropoietin (Epo) gene delivered to the LG and b) to evaluate the therapeutic potential of this strategy to prevent benzalkonium chloride (BAK) corneal toxicity.Methods: Structure and function of male Wistar rats LG were compared in the groups: 1) naïve control and 2) Ad-hEpo in the right LG (RLG). The protective response against BAK eye drops was compared among the groups 1) naïve control, 2) BAK in the right eye, 3) Ad-hEpo RLG + BAK and 4) Ad-hEpo in the right salivary gland (RSG)+BAK. Ad-hEpo groups received an injection of AdLTR2EF1a-hEPO (25 ul, 10¹⁰ particles/ml) in the right LG or SG (positive control). The BAK groups received 0.2% BAK in the right cornea twice a day. The tests applied after 7 days, included tear secretion, hEPO mRNA detection by qRT-PCR, LG and cornea histology, LG ELISA for cytokines and hematocrit.Results: hEPO mRNA was present in the Ad-hEpo RLG and RSG, but not kidney or liver samples (negative controls). TNF-α and IL-1β increased in the LG exposed to Ad-hEpo compared to naïve control (p = .0115 and p = .0397, respectively). BAK reduced tear secretion, but this reduction was prevented by Ad-hEpo RLG+BAK and Ad-hEpo RSG+BAK (p = .017). The corneal epithelia were thinner in the BAK-treated groups independent of Ad-hEpo (p = .0009). Hematocrit increased only in the Ad-hEpo RSG group (p = .01).Conclusions: Ad-hEpo infection of rat LG and SG induces local, but only the SG infection induced systemic changes in rats. Importantly, Ad-hEpo attenuated the BAK-mediated toxic reduction in tear flow. Future studies must consider viral vector tissue tropism, biodistribution and effective therapeutic gene products for ocular surface diseases.

Prevention of Corneal Neovascularization by Adenovirus Encoding Human Vascular Endothelial Growth Factor Soluble Receptor (s-VEGFR1) in Lacrimal Gland

Purpose

The aims of this study were (1) to determine the efficacy of adenovirus vector serotype 5 (Ad) encoding human soluble VEGF receptor 1 (s-VEGFR1) gene transfer to the lacrimal gland (LG); (2) to investigate whether expression of s-VEGFR1 prevents corneal neovascularization (CNV) induced by alkali burns; and (3) to evaluate the safety of the procedure.

Methods

AdVEGFR1 vectors (25 μL, 1 × 1010 pfu/mL) were injected in the right LGs of rats and were compared with AdNull vector (25 μL, 1 × 1010 pfu/mL) or 25 μL of saline (Control) before cornea alkali burns with 1 M NaOH. After 7 days, CNV was documented at the slit lamp. Tear secretion was measured with phenol red threads. The animals were tested for s-VEGFR1 mRNA and protein in the LG by quantitative (q)PCR and immunohistochemistry staining, respectively. qPCR was used to compare the mRNA levels of IL-1β, IL-6, and TNF-α in the LG and ipsilateral trigeminal ganglion (TG).

Results

Ad-VEGFR1 transfected 83% (10/12) of the rats. VEGFR1 was present in LG acinar cells. CNV was prevented in 9 of 12 animals in the Ad-VEGFR1 group, compared with the Ad-Null (3:10) and Control groups (1:10) (P = 0.0317). The tear secretion and cytokine mRNA levels in the LG and TG were similar in all three groups (P > 0.05).

Conclusions

Adenoviral vector gene transfer was safe for LG structure and function. The LG as the target tissue showed local expression of human s-VEGFR1, and CNV was prevented in most of the eyes exposed to alkali burns.

Low Expression of IL-10 in Circulating Bregs and Inverted IL-10/TNF-α Ratio in Tears of Patients with Perennial Allergic Conjunctivitis: A Preliminary Study

Allergic conjunctivitis (AC) is one of the most common ophthalmological disorders seen in clinical practice. Growing evidence from recent years suggests that a subset of IL-10-expressing B cells is involved in inflammatory allergic diseases. In this study, we aimed to evaluate the potential involvement of blood Bregs cells in perennial allergic conjunctivitis (PAC), and interleukins (IL)-1β, IL-6, IL-8, IL-10, and IL-12, and tumor necrosis factor (TNF)-α, were measured in tear samples and compared with healthy controls (HC) using flow cytometry. Non-significant differences in CD19⁺IL-10⁺ cell frequency between PAC patients and healthy controls (HC) were observed. Nevertheless, when we analyzed the mean fluorescence intensity (MFI) of IL-10 on CD19⁺CD38^Lo/Med/Hi-gated cells, we observed a significant decrease in MFI in all Bregs subsets in PAC patients. Additionally, tear cytokines showed 2.8 times lower levels of IL-10 than TNF-α in PAC patients when compared to HC. Our findings demonstrate an immunological dysregulation in patients with allergic conjunctivitis, characterized by the low expression of IL-10 in circulating CD19⁺CD38⁺ Bregs subsets and an inverted tear IL-10/TNF-α ratio, promoting a local pro-inflammatory microenvironment. These findings highlight the novel pathologic changes involved in ocular allergic diseases. Understanding systemic and local mechanisms will aid the design of immunomodulating therapeutics at different levels.

Proteomic analysis revealed the altered tear protein profile in a rabbit model of Sjögren's syndrome-associated dry eye

Sjögren's syndrome (SS) is an autoimmune disease that results in pathological dryness of mouth and eye. The diagnosis of SS depends on both clinical evaluation and specific antibodies. The goal of this study was to use quantitative proteomics to investigate changes in tear proteins in a rabbit model of SS-associated dry eye, induced autoimmune dacryoadenitis (IAD). Proteomic analysis was performed by iTRAQ and nano LC-MS/MS on tears collected from the ocular surface, and specific proteins were verified by high resolution MRM. It was found that in the tears of IAD rabbits at 2 and 4 weeks after induction, S100 A6, S100 A9, and serum albumin were upregulated, whereas serotransferrin (TF), prolactin-inducible protein (PIP), polymeric immunoglobulin receptor (pIgR), and Ig gamma chain C region were downregulated. High resolution MRM with mTRAQ labeling verified the changes in S100 A6, TF, PIP, and pIgR. Our results indicated significant changes of tear proteins in IAD rabbits, suggesting these proteins could potentially be used as biomarkers for the diagnosis and prognosis of dry eye. Several of these proteins were also found in the tears of non-SS dry eye patients indicating a common basis of ocular surface pathology, however, pIgR appears to be unique to SS.

A review on recent advances in dry eye: Pathogenesis and management

Keratoconjunctivitis sicca, more commonly known as dry eye, is an extremely common and often unrecognized disease. It is the condition in ophthalmology that in its mild grade of severity will affect most of the population at one time or other. Due to a wide variety of presentations and symptoms, it often frustrates the ophthalmologists as well as patients. Due to multifactorial and elusive etiology, it is often challenging to treat dry eye. Ocular surface disorders are also clinically important to treat especially in terms of visual acuity. Xero-dacryology is therefore becoming a very important branch of ophthalmology. Recent studies have given insight into the inflammatory etiology of dry eye. The conventional and main approach to the treatment of dry eye is providing lubricating eye drops or tear substitutes. However, the newer treatment approach is to target the underlying cause of dry eye instead of conventional symptomatic relief. In light of the above knowledge, the present article focuses on newer theories on pathogenesis of dry eye and their impact on dry eye management. METHOD OF LITERATURE SEARCH: A systematic literature review was performed using PubMed databases in two steps. The first step was oriented to articles published for dry eye. The second step was focused on the role of inflammation and anti-inflammatory therapy for dry eye. The search strategy was not limited by year of publication. A manual literature search was also undertaken from authentic reference books on ocular surface disease.

Distinct dacryoadenitides autoadoptively transferred to rabbits by different subpopulations of lymphocytes activated ex vivo

PURPOSE

To test whether CD4+ T cells proliferate in mixed cell reactions with autologous lacrimal gland (LG) acinar cells and whether these cells can autoadoptively transfer disease.

METHODS

Purified acinar cells were gamma irradiated and cocultured with peripheral blood lymphocytes. Activated CD4+ T cells were sorted by fluorescence-activated cell sorting (FACS). Unfractionated activated peripheral blood lymphocytes (UF), CD4+-enriched and CD4+-depleted T cells from an autologous mixed cell reaction were injected into the donor rabbit's remaining LG. After 4 weeks, ocular examinations were performed, and the rabbits were euthanized; LGs were removed for histopathology, immunohistochemistry, and real-time reverse transcription-polymerase chain reaction studies.

RESULTS

CD4 T cells increased in the autologous mixed cell reaction from 20% to 80%. Tear production decreased in the induced disease/UF (ID/UF) group and declined even more in the ID/CD4+-enriched group. Tear breakup times decreased and rose bengal staining increased in all groups. All LGs exhibited significant histopathology and increased messenger RNAs for tumor necrosis factor α. The ID/UF group exhibited the largest increases of CD4+ and rabbit T-lymphocyte antigen-positive cells. The ID/CD4+-enriched group contained fewer infiltrating CD4 cells but more eosinophils, severely altered acinar morphology, and increased fibrosis. LG of the ID/CD4+-depleted group exhibited large increases of CD18, major histocompatibility complex II, and CD4+ cells. Messenger RNAs for interleukin 2, interleukin 4, and CD4+ increased in the ID/CD4+-enriched group compared with the CD4+-depleted group.

CONCLUSIONS

Autoreactive CD4+ effector cells activated ex vivo and autoadoptively transferred, caused what seems to be a distinct dacryoadenitis. The CD4+-depleted cell fraction also contained pathogenic effector cells capable of inducing disease.

Long-term topical cyclosporine treatment improves tear production and reduces keratoconjunctivitis in rabbits with induced autoimmune dacryoadenitis

PURPOSE

To use a rabbit model of induced autoimmune dacryoadenitis to evaluate the efficacy of topical ophthalmic cyclosporine A (CsA).

METHODS

Autoimmune dacryoadenitis was induced by injecting autologous peripheral blood lymphocytes, which had been activated in a mixed cell reaction with acinar cells isolated from one inferior lacrimal gland (LG), back into the donor animal's remaining inferior LG. Schirmer's test, tear breakup time, and rose Bengal staining were assessed. Animals with established disease were treated topically with either CsA or Endura twice daily for 5 months.

RESULTS

Without treatment tear production and tear stability were abnormal for 6 months, and clear signs of ocular surface defects were evident. Severe immune cell infiltration was observed in the LG. Long-term CsA treatment increased tear production only slightly, but the severity of LG histopathology decreased noticeably. CD4(+) T-cell infiltration of the LG was decreased and infiltration by MHC class II-expressing cells was also decreased. For the Endura-treated group tear production did not improve, rose Bengal scores remained high, and histopathology showed infiltration comparable to the untreated group, but by the end of the study the tear breakup time did improve.

CONCLUSIONS

The rabbit model of autoimmune dacryoadenitis had signs of chronic dry eye disease 6 months after induction of disease. Tear production improved slightly with CsA treatment and CD4(+) T-cell infiltration decreased significantly in the LG. This suggests that some Sjögren's patients may benefit from long-term CsA treatment.

Transduced viral IL-10 is exocytosed from lacrimal acinar secretory vesicles in a myosin-dependent manner in response to carbachol

The purpose of this study was to determine the intracellular trafficking and release pathways for the therapeutic protein, viral IL-10 (vIL-10), from transduced acinar epithelial cells from rabbit lacrimal gland. Primary cultured rabbit lacrimal gland acinar cells (LGACs) were transduced with adenovirus serotype 5 containing viral interleukin-10 (AdvIL-10). The distribution of vIL-10 was assessed by confocal fluorescence microscopy. Carbachol (CCH)-stimulated release of vIL-10 was quantified by ELISA. vIL-10 localization and exocytosis was probed in response to treatments with agents modulating actin- and myosin-based transport. vIL-10 immunoreactivity was detected in large intracellular vesicles in transduced LGAC. vIL-10 was partially co-localized with biosynthetic but not endosomal compartment markers. vIL-10 release was sensitive to CCH, and the kinetics of release showed an initial burst phase that was similar but not identical to that of the secretory protein, beta-hexosaminidase. Disassembly of actin filaments with latrunculin B significantly increased CCH-stimulated vIL-10 secretion, suggesting that vIL-10 was released from stores sequestered beneath the subapical actin barrier. That release required the activity of actin-dependent myosin motors previously implicated in secretory vesicle exocytosis was confirmed by findings that CCH-stimulated vIL-10 release was reduced by inhibition of non-muscle myosin 2 and myosin 5c function, using ML-7 and overexpression of dominant negative myosin 5c, respectively. These results suggest that the majority of vIL-10 transgene product is packaged into a subpopulation of secretory vesicles that utilize actin-dependent myosin motors for aspects of actin coat assembly, compound fusion and exocytosis at the apical plasma membrane in response to CCH stimulation.

Sjogrens syndrome as failed local immunohomeostasis: prospects for cell-based therapy

Sjogrens syndrome has been estimated to affect between 0.2% and 2% or more of the population. It is an autoimmune disease with the hallmark histopathology of focal, periductal, and perivascular CD4(+) cell infiltration of the lacrimal and salivary glands. The immunohistopathology is typically associated with severe lacrimal and salivary dysfunctions, which contribute to debilitating ocular surface and oral symptoms. The quality of life of patients with Sjogrens syndrome often is degraded further by serious, multisystemic manifestations, and they are subject to a forty-fold increased risk of developing B cell lymphomas. In normal lacrimal glands, secretory epithelial cells, autoimmune effector lymphocytes, and regulatory lymphocytes can be seen as collaborating to maintain a local immunohomeostasis. The epithelium contributes by secreting immunomodulatory paracrine factors and also by continuously exposing autoantigens, which thereby become available for uptake by professional antigen presenting cells (APCs). Local or systemic perturbations may initiate autoimmune pathophysiology by impairing the replacement of normally-turning-over regulatory cells, by altering epithelial production of immunomodulatory paracrine factors, by inducing intact epithelial cells to begin secreting previously cryptic epitopes (epitopes that previously were not available to bind to major histocompatibility complex (MHC) molecules and so could not be recognized by T cell antigen receptors), and by inducing epithelial cells to begin expressing MHC Class II molecules and presenting formerly cryptic epitopes directly to CD4(+) cells. This process has been modeled ex vivo with mixed cell reactions comprised of isolated epithelial cells and autologous lymphocytes. This development has occurred as studies of anterior chamber-associated immune deviation (ACAID) and other immunoregulatory phenomena have elucidated the origins and functions of several different kinds of regulatory lymphocytes and shown that regulatory lymphocytes can be generated ex vivo. It now is possible to envision strategies for exploiting each possible mode of epithelial autoantigen exposure to produce therapeutic regulatory cells that might be capable of re-establishing normal immunohomeostasis. Consideration of the hypothetical therapies identifies a number of basic questions that warrant investigation.

Viral interleukin-10 gene transfer prevents liver ischemia-reperfusion injury: Toll-like receptor-4 and heme oxygenase-1 signaling in innate and adaptive immunity

Ischemia-reperfusion injury (IRI) contributes to early and late dysfunction of liver transplants. We have shown that sentinel Toll-like receptor-4 (TLR4) plays a key role in the activation of T cell immune responses during hepatic IRI. We have also documented that overexpression of heme oxygenase-1 (HO-1) exerts potent cytoprotective effects. This study analyzes how adenovirus (Ad)-based viral interleukin-10 (vIL-10) gene transfer affects TLR4 and HO-1 signaling in host innate and adaptive immunity during liver IRI. Using a partial lobar warm IRI model, groups of wild-type and HO-1(+/-) knockout (KO) mice were assessed for severity of hepatocellular damage after 90 min of warm ischemia followed by 6 hr of reperfusion. Both wild-type and HO-1 (+/-) KO mice treated with Ad-vIL-10 have shown improved hepatic function (serum glutamic-oxaloacetic transaminase levels), ameliorated histological signs of IRI (Suzuki's score), decreased neutrophil accumulation (myeloperoxidase activity), and depressed tumor necrosis factor-alpha/IL-1beta, IL-2/interferon-gamma, E-selectin, and macrophage inflammatory protein-2 expression. These effects were IL-10 dependent as treatment with neutralizing antibody re-created liver IRI. In contrast, untreated wild-type and HO-1 (+/-) KO mice, as well as wild-type and HO-1 (+/-) KO mice treated with Ad-beta-Gal, showed severe hepatocellular damage due to IRI. Unlike in controls, wild-type and HO-1 (+/-) KO mice treated with Ad-vIL-10 revealed markedly depressed TLR4 and NF-kappaB expression, along with increased HO-1 and Bcl-2/Bcl-x(L) expression, as compared with respective controls. Thus, vIL-10 gene transfer prevents hepatic IRI in association with depressed expression of innate TLR4, and adaptive Th1 cytokine/chemokine programs. The induction of antioxidant HO-1 and anti-apoptotic Bcl-2/Bcl-x(L) by vIL-10 exerts synergistic cytoprotective function against antigen-independent hepatic inflammatory response triggered by IRI.

Elevated prolactin redirects secretory vesicle traffic in rabbit lacrimal acinar cells

During pregnancy, lymphocytes infiltrating the rabbit lacrimal gland disperse to the interacinar space from their normal focal concentrations, basal fluid secretion decreases, pilocarpine-induced fluid secretion increases, and stimulated fluid protein concentration decreases. Ductal epithelial cell prolactin (PRL) content increases and redistributes from the apical to the basal-lateral cytoplasm. A replication-incompetent adenovirus vector for rabbit PRL (AdPRL) was used to test the hypothesis that increased intracrine/autocrine PRL signaling alters secretory protein traffic in an ex vivo lacrimal acinar cell model. AdPRL had no discernable influence on microtubules or actin microfilaments or their responses to carbachol (CCh). Endogenous and transduced PRLs exhibited similar, nonpolarized, punctate distributions. Cells secreted PRL consititutively and at increased rates in response to CCh. In contrast, constitutive secretion of beta-hexosaminidase was negligible, suggesting that the constitutive pathway for PRL is relatively inaccessible to typical secretory proteins. AdPRL had no significant effect on total secretion of beta-hexosaminidase or syncollin-green fluorescent protein (GFP), a chimeric secretory protein construct. However, it reversed the polarized distributions of vesicles containing rab3D and syncollin-GFP. Live-cell imaging indicated that AdPRL redirected CCh-dependent syncollin-GFP exocytosis from the apical plasma membrane to the basal-lateral membrane. Elevated concentrations of exogenous rabbit PRL in the ambient medium elicited similar changes. These observations suggest that elevated PRL, as occurs in the physiological hyperprolactinemia of pregnancy, induces lacrimal epithelial cells to express a mixed exocrine/endocrine phenotype that secretes fluid to the acinus-duct lumen but secretes proteins to the underlying tissue space. This phenotype may contribute to the pregnancy-associated immunoarchitecture.

Current status of gene delivery and gene therapy in lacrimal gland using viral vectors

Gene delivery is one of the biggest challenges in the field of gene therapy. It involves the efficient transfer of transgenes into somatic cells for therapeutic purposes. A few major drawbacks in gene delivery include inefficient gene transfer and lack of sustained transgene expression. However, the classical method of using viral vectors for gene transfer has circumvented some of these issues. Several kinds of viruses, including retrovirus, adenovirus, adeno-associated virus, and herpes simplex virus, have been manipulated for use in gene transfer and gene therapy applications. The transfer of genetic material into lacrimal epithelial cells and tissues, both in vitro and in vivo, has been critical for the study of tear secretory mechanisms and autoimmunity of the lacrimal gland. These studies will help in the development of therapeutic interventions for autoimmune disorders such as Sjögren's syndrome and dry eye syndromes which are associated with lacrimal dysfunction. These studies are also critical for future endeavors which utilize the lacrimal gland as a reservoir for the production of therapeutic factors which can be released in tears, providing treatment for diseases of the cornea and posterior segment. This review will discuss the developments related to gene delivery and gene therapy in the lacrimal gland using several viral vector systems.

Effects of local and systemic viral interleukin-10 gene transfer on corneal allograft survival

In this study, we explored the immunomodulatory effects of viral interleukin (IL) IL-10 after ex vivo and in vivo gene transfer in experimental corneal transplantation. Wistar-Furth rats were used as donors and major histocompatibility complex class I/II-disparate Lewis rats served as recipients. For ex vivo gene therapy donor corneas were either transfected with liposome/vIL-10 plasmid DNA mixtures or transduced with a vIL-10 expressing adenovirus vector (AdvIL-10). For in vivo studies, recipients were treated with AdvIL-10 intraperitoneally 1 day before transplantation. Graft survival was analysed using the Kaplan-Meier survival method. To monitor the efficacy of the therapy messenger RNA (mRNA) cytokine expression profiles in grafts and draining lymph nodes were analysed by quantitative real-time reverse transcription-polymerase chain reaction. Moreover, anti-adenovirus immunity was also investigated. Neither ex vivo liposome-mediated vIL-10 gene transfer nor ex vivo AdvIL-10 gene transfer led to prolonged corneal allograft survival. In contrast, corneal allograft survival was significantly prolonged in animals receiving systemic AdvIL-10 gene transfer. Moreover, only systemic vIL-10 gene therapy modulated the cytokine mRNA expression profile in draining lymph nodes. Interestingly, systemic AdvIL-10 gene transfer could not inhibit the generation of anti-adenovirus antibodies. Our data indicate systemic expression of the vIL-10 gene is required to modulate the cytokine expression profile in the draining lymph nodes, which might be a pre-requisite for the success of cytokine gene therapy.

Expression of TNF inhibitor gene in the lacrimal gland promotes recovery of tear production and tear stability and reduced immunopathology in rabbits with induced autoimmune dacryoadenitis

BACKGROUND

The most common cause of ocular morbidity in developed countries is dry eye, many cases of which are due to lacrimal insufficiency. Dry eye affects approximately 10 million in the United States, most of whom are women. In the U.S. alone, an estimated 2 million Sjögren's syndrome patients have dysfunctional lacrimal glands and severe dry eye, and there is no satisfactory treatment. These patients would benefit if their lacrimal tissue function could be restored.

METHODS

The effect of adenovirus-mediated transfer of tumor necrosis factor (TNF)-alpha inhibitor gene on induced autoimmune dacryoadenitis was evaluated in a rabbit model. Soluble transgene protein was detected in tears by ELISA for 7 days following transduction.

RESULTS

Two weeks after induction of disease with activated lymphocytes, tear production, as determined by Schirmer testing, was reduced by about 40%, while tear film stability, as measured by tear breakup time (BUT), declined by 43%. Adenovirus-mediated gene therapy using AdTNFRp55-Ig given 2 weeks after disease induction, resulted in the return of tear production to normal levels by week 4. In the treated disease group, tear BUT improved significantly by week 4. Rose bengal scores, an indicator of corneal surface defects, increased after disease induction and declined after gene therapy. In the lacrimal gland, the CD4 to CD8 T cell ratio was 4:1 in the disease group compared to 1:2 in the treated group. Infiltration of T cells and CD18+ cells was reduced approximately 50% after gene therapy.

CONCLUSION

We concluded that therapeutic levels of soluble TNF inhibitor were achieved in the lacrimal gland and on the corneal surface. Anti-inflammatory cytokine gene expression might offer a potential therapeutic modality for the treatment of autoimmune dacryoadenitis, once suitable vectors become available.

Tumor necrosis factor inhibitor gene expression suppresses lacrimal gland immunopathology in a rabbit model of autoimmune dacryoadenitis

PURPOSE

To evaluate the effect of tumor necrosis factor (TNF) inhibitor protein on lacrimal gland immunopathology and ocular surface disease resulting from induced dacryoadenitis.

METHODS

Autoimmune dacryoadenitis was induced in rabbits by injecting the lacrimal glands with peripheral blood lymphocytes (PBLs) activated by 5 days of coculture with autologous acinar cells in a mixed cell reaction. In the treated group, an adenoviral vector carrying the TNF inhibitor gene (AdTNFRp55-Ig) was concurrently injected with AMCR-PBL. Tear production was monitored by Schirmer test, and tears were collected for detection of TNF-inhibitor protein. Frozen sections of the glands were immunostained for expression of CD4, CD8, rabbit thymic lymphocyte antigen (RTLA), and CD18. Histological sections of lacrimal glands were examined using the TUNEL technique to monitor apoptosis.

RESULTS

Soluble TNF-inhibitor protein was detected by ELISA in tears, with titers at a maximum on day 3, declining by day 7, and undetectable by day 14. Tear production declined in the induced dacryoadenitis group but did not change when glands had been treated with AdTNFRp55-Ig simultaneously with disease induction. Tear break-up time and rose bengal staining properties were not altered by treatment. Fourteen days after the glands were injected with activated PBLs, focal mononuclear cell infiltrates were observed around ducts and venules, some of which assumed the high endothelial phenotype, and between acini. Immune cells in the infiltrates stained positive for CD4, RTLA, and CD18. Glands that received AdTNFRp55-Ig concurrently with activated PBLs had decreased numbers of CD4 cells, CD18 cells, RTLA, and apoptotic cells.

CONCLUSIONS

In vivo transduction of the lacrimal gland with AdTNFRIp55-Ig resulted in transient expression in the gland and the appearance of TNF-inhibitor protein in tears. The presence of soluble TNF-inhibitor protein partially suppressed the appearance of Sjögren's syndrome-like features of reduced tear production and the immunohistopathology associated with induced autoimmune dacryoadenitis but not tear break-up time and ocular surface disease. This may reflect immunoregulation in the lacrimal gland but not in the conjunctiva.