transforming-growth-factor-beta and Keratitis--Herpetic

This study aimed to investigate the dynamic expression of glial fibrillary acidic protein (GFAP), a common neural factor, in cornea and stromal cells during herpes simplex virus-1 (HSV-1) infection. For each anesthetized BALB/c mouse, the cornea in one eye was inoculated with 1 × 10(5) plaque forming unit (PFU) of HSV-1, while the contralateral cornea was mock-infected as the control. At different timepoints post-infection, corneal lesion examination by slit-lamp biomicroscopy, corneal histology and HSV-1 DNA detection by real-time PCR were performed to estimate the different stage of HSV-1 infection. The expression of GFAP was examined using real-time PCR, western blotting and immunofluorescence staining. After infected with HSV-1 for 15 days, the mouse corneas began to become clear, the corneal pathology recovered to normal, and HSV-1 DNA almost could not be detected, indicating that HSV-1 was entering a relative quiescent state from the acute infection. The expression of GFAP in HSV-1-infected corneas was comparatively low on day 3, increased slightly on day 7, and further increased thereafter, higher than that in mock-infected corneas on day 15. GFAP detection on the cellular level also indicated that the expression was downregulated in acute HSV-1 infection. GFAP was found to be downregulated in HSV-1 acute infection in cornea and upregulated in late stage, suggesting that GFAP might play some role during HSV-1 infection in cornea.

Topics: Animals; Cornea; Disease Models, Animal; DNA, Viral; Eye Proteins; Female; Gene Expression Regulation; Glial Fibrillary Acidic Protein; Herpesvirus 1, Human; Keratitis, Herpetic; Mice; Mice, Inbred BALB C; Real-Time Polymerase Chain Reaction; Stromal Cells; Transforming Growth Factor beta

Innate and adaptive immunity play important protective roles by combating herpes simplex virus 1 (HSV-1) infection. Transforming growth factor β (TGF-β) is a key negative cytokine regulator of both innate and adaptive immune responses. Yet, it is unknown whether TGF-β signaling in either immune compartment impacts HSV-1 replication and latency. We undertook genetic approaches to address these issues by infecting two different dominant negative TGF-β receptor type II transgenic mouse lines. These mice have specific TGF-β signaling blockades in either T cells or innate cells. Mice were ocularly infected with HSV-1 to evaluate the effects of restricted innate or adaptive TGF-β signaling during acute and latent infections. Limiting innate cell but not T cell TGF-β signaling reduced virus replication in the eyes of infected mice. On the other hand, blocking TGF-β signaling in either innate cells or T cells resulted in decreased latency in the trigeminal ganglia of infected mice. Furthermore, inhibiting TGF-β signaling in T cells reduced cell lysis and leukocyte infiltration in corneas and trigeminal ganglia during primary HSV-1 infection of mice. These findings strongly suggest that TGF-β signaling, which generally functions to dampen immune responses, results in increased HSV-1 latency.

Topics: Animals; Disease Models, Animal; Eye; Gene Expression Regulation, Viral; Herpesvirus 1, Human; Keratitis, Herpetic; Mice; Mice, Transgenic; Rodent Diseases; Signal Transduction; Transforming Growth Factor beta; Trigeminal Ganglion; Virus Activation; Virus Latency; Virus Replication

Generating and using regulatory T cells (Tregs) to modulate inflammatory disease represents a valuable approach to therapy but has not yet been applied as a means to control virus-induced immunopathological reactions. In this report, we developed a simplified technique that used unfractionated splenocytes as a precursor population and showed that stimulation under optimized conditions for 5 days with solid-phase anti-CD3 monoclonal antibody in the presence of transforming growth factor beta (TGF-beta) and interleukin-2 could induce up to 90% of CD4(+) T cells to become Foxp3(+) and able to mediate suppression in vitro. CD11c(+) dendritic cells were intricately involved in the conversion process and, once modified in the presence of TGF-beta, could convert Foxp3(-) CD4(+) cells into Foxp3(+) CD4(+)cells by producing TGF-beta. The converted cells had undergone cell division, and the majority of them expressed activation markers along with surface molecules that would facilitate their migration into tissue sites. The primary reason for our study was to determine if such in vitro-converted Tregs could be used in vivo to influence the outcome of a virus-induced immunoinflammatory lesion in the eye caused by herpes simplex virus infection. We could show in three separate models of herpetic stromal keratitis that adoptive transfers of in vitro-converted Tregs effectively diminished lesion severity, especially when given in the initial phases of infection. The suppression effect in vivo appeared to be polyspecific. The protocol we have developed could provide a useful additional approach to control virus-induced inflammatory disease.

Topics: Adoptive Transfer; Animals; CD11c Antigen; CD4-Positive T-Lymphocytes; Dendritic Cells; Flow Cytometry; Forkhead Transcription Factors; Herpes Simplex; Immunosuppression Therapy; Immunotherapy, Adoptive; Interleukin-2 Receptor alpha Subunit; Keratitis, Herpetic; Mice; Mice, Inbred BALB C; Mice, Knockout; Simplexvirus; T-Lymphocyte Subsets; T-Lymphocytes, Regulatory; Transforming Growth Factor beta

FTY720 has been used to control inflammatory lesions, but the mechanisms by which the drug acts in vivo are poorly understood. Such mechanisms may result primarily from effects on lymphocyte and dendritic cell homing to lymphoid and inflammatory sites. We demonstrate that FTY720 may also act by causing the conversion of TCR-stimulated nonregulatory CD4(+) T cells to Foxp3(+)CD4(+) regulatory T cells and by enhancing their suppressive activity. In a model in which mice were ocularly infected with HSV, daily treatment with FTY720 resulted in significantly diminished ocular lesions. The treated animals showed increased frequencies of Foxp3(+) T cells in lymphoid organs and at two inflammatory sites, namely cornea and trigeminal ganglia. In a second series of experiments, immunized DO11.10RAG2(-/-) animals, normally lacking endogenous Foxp3(+) T cells, that were given FTY720 treatment developed high frequencies of Foxp3(+) regulatory T cells in lymph nodes. Some converted cells persisted in treated animals for several weeks after drug administration was discontinued. Finally, FTY720 could effectively induce Foxp3-expressing cells from Foxp3(-) cells in vitro, an effect inhibited by anti-TGF-beta or the proinflammatory cytokine IL-6. Accordingly, the anti-inflammatory effects of FTY720 could be mediated at least in part by its ability to cause the conversion of Ag-stimulated conventional T cells to become Foxp3(+) regulators. The use of FTY720 along with Ag administration could represent a useful therapeutic means to selectively expand Ag-specific regulators, which could be valuable in many clinical situations such as allotransplants, some autoimmunities, as well as with some chronic infections.

Topics: Animals; CD4-Positive T-Lymphocytes; Female; Fingolimod Hydrochloride; Forkhead Transcription Factors; Herpesvirus 1, Human; Immunosuppressive Agents; Keratitis, Herpetic; Lymphocyte Count; Mice; Mice, Mutant Strains; Propylene Glycols; Sphingosine; T-Lymphocyte Subsets; T-Lymphocytes, Regulatory; Transforming Growth Factor beta