Pathogenic Function of Herpesvirus Entry Mediator in Experimental Autoimmune Uveitis by Induction of Th1- and Th17-Type T Cell Responses.

Herpesvirus entry mediator (HVEM), a member of the TNFR superfamily, serves as a unique molecular switch to mediate both stimulatory and inhibitory cosignals, depending on its functions as a receptor or ligand interacting with multiple binding partners. In this study, we explored the cosignaling functions of HVEM in experimental autoimmune uveitis (EAU), a mouse model resembling human autoimmune uveitis conditions such as ocular sarcoidosis and Behcet disease. Our studies revealed that EAU severity significantly decreased in HVEM-knockout mice compared with wild-type mice, suggesting that stimulatory cosignals from the HVEM receptor are predominant in EAU. Further studies elucidated that the HVEM cosignal plays an important role in the induction of both Th1- and Th17-type pathogenic T cells in EAU, including differentiation of IL-17-producing αß(+)γδ(-) conventional CD4(+) T cells. Mice lacking lymphotoxin-like, inducible expression, competes with herpes simplex virus glycoprotein D for HVEM, a receptor expressed by T lymphocytes : LIGHT), B- and T-lymphocyte attenuator (BTLA) or both LIGHT and BTLA are also less susceptible to EAU, indicating that LIGHT-HVEM and BTLA-HVEM interactions, two major molecular pathways mediating HVEM functions, are both important in determining EAU pathogenesis. Finally, blocking HVEM cosignals by antagonistic anti-HVEM Abs ameliorated EAU. Taken together, our studies revealed a novel function of the HVEM cosignaling molecule and its ligands in EAU pathogenesis through the induction of Th1- and Th17-type T cell responses and suggested that HVEM-related molecular pathways can be therapeutic targets in autoimmune uveitis.

Neuropeptides released from trigeminal neurons promote the stratification of human corneal epithelial cells.

PURPOSE: To examine the effects of neural cells on the stratification of and junctional protein expression by corneal epithelial cells with a coculture system. METHODS: PC12 cells induced to undergo neuronal differentiation or rat trigeminal nerve cells were cultured together with simian virus 40-transformed human corneal epithelial (HCE) cells on opposite sides of a collagen vitrigel membrane. Stratification of HCE cells was examined by immunofluorescence analysis with antibodies to zonula occludens-1. Expression of junctional proteins in HCE cells was assessed by RT-PCR and immunoblot analyses. RESULTS: The presence of neural cells (PC12 cells or trigeminal neurons) markedly promoted the stratification of HCE cells as well as increased the amounts of N-cadherin mRNA and protein in these cells. These effects of the neural cells were mimicked by conditioned medium prepared from differentiating PC12 cells or by the neuropeptides substance P and calcitonin gene-related peptide (CGRP). Furthermore, the stimulatory effects of trigeminal neurons on the stratification of and N-cadherin expression by HCE cells were inhibited by antagonists of substance P or of CGRP. CONCLUSIONS: These results suggest that trigeminal neurons play an important role in the differentiation of corneal epithelial cells. Neuropeptides released from these neurons may thus regulate adhesion between corneal epithelial cells and thereby contribute to the establishment and maintenance of corneal structure and function.

Differential expression of semaphorin 3A and its receptors during mouse retinal development.

Semaphorins not only function in axon guidance during development but also contribute to various other biological processes. We have now examined the expression of semaphorin 3A (Sema3A) and its receptor components neuropilin 1 (Npn1) and plexin A (PlxA) during development of the mouse retina. Immunohistofluorescence analysis revealed that the expression patterns of Sema3A and Npn1 were similar during embryonic and postnatal development. The expression pattern of PlxA was also similar to those of Sema3A and Npn1 during embryonic and early postnatal (before eye opening) developments. However, the pattern of PlxA expression changed markedly after eye opening, with the expression disappearing from the optic nerve and increasing in intensity in the retinal pigment epithelium. Immunoprecipitation analysis showed that Sema3A interacted with PlxA in the retinal pigment epithelial cell line ARPE19 but not in the retinal ganglion cell line RGC5, whereas the opposite pattern of association was apparent for Sema3A and Npn1. Given that atmospheric oxygen is thought to play a role in the differentiation and maintenance of various ocular cell types, our results suggest that Sema3A-PlxA signalling activated by an effect of ambient oxygen on PlxA expression may contribute to differentiation of the retinal pigment epithelium.

T-cell receptor gene therapy targeting melanoma-associated antigen-A4 inhibits human tumor growth in non-obese diabetic/SCID/γcnull mice.

Adoptive cell therapy with lymphocytes that have been genetically engineered to express tumor-reactive T-cell receptors (TCR) is a promising approach for cancer immunotherapy. We have been exploring the development of TCR gene therapy targeting cancer/testis antigens, including melanoma-associated antigen (MAGE) family antigens, that are ideal targets for adoptive T-cell therapy. The efficacy of TCR gene therapy targeting MAGE family antigens, however, has not yet been evaluated in vivo. Here, we demonstrate the in vivo antitumor activity in immunodeficient non-obese diabetic/SCID/γc(null) (NOG) mice of human lymphocytes genetically engineered to express TCR specific for the MAGE-A4 antigen. Polyclonal T cells derived from human peripheral blood mononuclear cells were transduced with the αß TCR genes specific for MAGE-A4, then adoptively transferred into NOG mice inoculated with MAGE-A4 expressing human tumor cell lines. The transferred T cells maintained their effector function in vivo, infiltrated into tumors, and inhibited tumor growth in an antigen-specific manner. The combination of adoptive cell therapy with antigen peptide vaccination enhanced antitumor activity, with improved multifunctionality of the transferred cells. These data suggest that TCR gene therapy with MAGE-A4-specific TCR is a promising strategy to treat patients with MAGE-A4-expressing tumors; in addition, the acquisition of multifunctionality in vivo is an important factor to predict the quality of the T-cell response during adoptive therapy with human lymphocytes.

Non-extractable procyanidins and lignin are important factors in the bile acid binding and radical scavenging properties of cell wall material in some fruits.

The cell wall components and the food functions of alcohol-insoluble solids (AIS) of Chinese quince, quince, hawthorn, apple, pear and blueberry fruits were analyzed. Chinese quince contained characteristically high contents of cellulose, lignin, and non-extractable procyanidins (NEPCs). On the other hand, the quince AIS contained the highest proportion of NEPCs, the highest mean degree of polymerization (mDP), the strongest radical scavenging activity, and strong bile acid binding activity. In fruit AIS, the lignin and NEPC contents both showed positive correlations with the bile acid binding and radical scavenging activities. The value for mDP × NEPC content was a good index for the radical scavenging activity. The results suggest that highly polymerized NEPCs and lignin are important factors of cell wall components of fruits to having a high functionality, and Chinese quince and quince are interesting fruits from this view point.

Expression of semaphorin 3A and its receptors during mouse corneal development.

Semaphorin 3A (Sema3A) functions to guide the growth of neurons during development, with its effects being mediated by receptor complexes composed of neuropilin (Npn) and plexin (Plx) proteins. We have now examined the expression of Sema3A and its receptor components Npn1 and PlxA during development of the mouse cornea. Sema3A and Npn1 showed similar patterns of expression by immunohistofluorescence analysis, with such expression being prominent in the corneal epithelium during both embryonic and postnatal development. In contrast, PlxA was not expressed in the corneal epithelium until after eye opening between postnatal days 12 and 14. Laser capture microdissection followed by reverse transcription and polymerase chain reaction analysis also showed that the abundance of PlxA mRNA in corneal epithelial cells increased significantly during postnatal development, again in association with eye opening. Given that atmospheric oxygen is thought to play a role in corneal epithelial differentiation and maintenance, our results suggest that the up-regulation of PlxA expression in the corneal epithelium during postnatal development is triggered by exposure of the cornea to the atmosphere. Furthermore, the newly expressed PlxA may contribute to the differentiation of corneal epithelial cells by mediating Sema3A signaling.