Nasal double DNA adjuvant induces salivary FimA-specific secretory IgA antibodies in young and aging mice and blocks Porphyromonas gingivalis binding to a salivary protein

Background: We previously showed that nasal administration of a combination of dendritic cell (DC) targeted DNA plasmid expressing Flt3 ligand and CpG oligodeoxynucleotides 1826 as a mucosal adjuvant (double adjuvant, DA) provoked protective immunity in the upper respiratory tract of young adult and aging mice. Here, we investigated whether the nasal DA system induces secretory (S)IgA antibodies (Abs) toward recombinant fimbrillin (rFimA) of Porphyromonas gingivalis (P. gingivalis) in the saliva of young adult and aging mice. Further, we examined the functional applicability of rFimA-specific salivary SIgA Abs. Methods: BALB/c mice (8- or 48-week-old) were nasally immunized with rFimA plus DA three times at weekly intervals. Control mice were nasally administered rFimA alone. Saliva samples were collected 1 week after the final immunization, and were subjected to rFimA-specific ELISA. To examine the functional applicability of rFimA-specific SIgA Abs, IgA-enriched saliva samples were subjected to an inhibition assay in order to assess the numbers of P. gingivalis cells bound to the salivary protein statherin. Results: The 8- and 48-week-old mice administered nasal rFimA plus DA showed significantly increased levels of rFimA-specific SIgA Abs in saliva and elevated numbers of CD11c+ DCs in sublingual glands (SLGs), periglandular lymph nodes (PGLNs) and submandibular glands (SMGs) as well as nasopharyngeal-associated lymphoid tissues (NALT) compared to mice administered rFimA alone. Further, rFimA-specific SIgA Abs-containing saliva, in which IgG Abs of 8- and 48-week-old mice administered nasal rFimA plus DA were removed, significantly inhibited binding of P. gingivalis to the salivary protein. Conclusions: These findings show that this DA system could be an effective nasal vaccine strategy for the enhancement of P. gingivalis-specific protective immunity in the oral cavity of adolescents and older individuals

Acetyl-L-carnitine suppresses thyroid hormone-induced and spontaneous anuran tadpole tail shortening

Mitochondrial membrane permeability transition (MPT) plays a crucial role in apoptotic tail shortening during anuran metamor phosis. L-carnitine is known to shuttle free fatty acids (FFAs) from the cytosol into mitochondria matrix for -oxidation and energy production, and in a previous study we found that treatment with L-carnitine suppresses 3, 3', 5-triiodothyronine (T3) and FFA-induced MPT by reducing the level of FFAs. In the present study we focus on acetyl-L-carnitine, which is also involved in fatty acid oxidation, to determine its effect on T3-induced tail regression in Rana rugosa tadpoles and spontaneous tail regression in Xenopus laevis tadpoles. The ladder-like DNA profile and increases in caspase-3 and caspase-9 indicative of apoptosis in the tails of T3-treated tadpoles were found to be suppressed by the addition of acetyl-L-carnitine. Likewise, acetyl-L-carnitine was found to inhibit thyroid hormone regulated spontaneous metamorphosis in X. laevis tadpoles, accompanied by decreases in caspase and phospholipase A2 activity, as well as non-ladder-like DNA profiles. These findings support our previous conclusion that elevated levels of FFAs initiate MPT and activate the signaling pathway controlling apoptotic cell death in tadpole tails during anuran metamorphosis

Effect of Hinokitiol on Salivary Secretory-IgA Antibody Production System

ヒノキチオール（HNK）は，古くから細菌や真菌に対する抗菌作用を有し，生体に対してはストレス緩和作用という生理機能改善効果が知られ，現在，歯磨剤や整髪料，アロマ，食品に広く応用されている．だが，生体防御機構である免疫システムへのHNKが与える影響についてはほとんど知られていない．本研究では，HNKが粘膜免疫学的影響の一端を明らかにすることを目的に，マウス鼻腔からHNKを投与し，投与前・後の唾液中の分泌型IgA抗体（SIgA Ab）量の測定と，顎下唾液腺（SMG）における免疫細胞学的解析を行った． BALB/cマウス（8週齢，メス）に，HNK 50 μgを毎週1回計4回経鼻投与し，各投与日の投与前および投与0.5時間後，1.5時間後，3時間後，6時間後の唾液採取を行い，唾液SIgA Abの定量を行った．さらに最終投与日（初回投与から21日目；Day 21）のHNK投与前・後のマウスSMGにおけるIgA Ab産生細胞（IgA AFCs）数を計測し，さらにIgA AFCsの生存・増殖能の測定を行った. HNK各投与日におけるSIgA Ab分泌量は，投与1.5時間後が最大であり，投与6時間後で投与前と同レベルになることが認められた．興味深いことに，投与回数とSIgA Ab分泌量は正の相関傾向が認められた．Day 21のHNK投与前・後においては，SMGのIgA AFCs数に有意な差は認められなかったが，IgA AFCsの生存・増殖能はHNK投与0.5時間後と1.5時間後に有意な上昇が認められた．以上から，HNKの経鼻投与は，投与後1.5時間までのSMG IgA AFCsを活性化し，唾液SIgA Abの分泌を促進している可能性が示唆された.Hinokitiol (HNK) is a well-known antimicrobial and antifungal agent, and is widely used in various formulations including tooth pastes, mouth rinses, aromatics, cosmetics, and food. There is limited information on the immunobiological activity of HNK. In the present study, we investigated the effects of interanasally administered HNK on salivary secretory-IgA antibody (SIgA Ab) secretion in mice. BALB/c (8 weeks old) mice were given 50 μg of HNK four times at weekly intervals (Days 0, 7, 14, and 21) via the nasal route. Saliva samples were collected prior to (−0 hour) and after (0.5, 1.5, 3, and 6 hours) the nasal administration of HNK on respective days, and the levels of salivary SIgA Ab were determined by ELISA. Furthermore, the numbers of SIgA Ab-producing cells (SIgA AFCs) in submandibular glands (SMG) were examined by ELISPOT, and proliferation responses of IgA+ B cells were measured by MTT assays based on the same schedule on Day 21. On Days 0, 7, 14, and 21, the maximum level of SIgA Ab secretion in saliva occurred at 1.5 hours after the nasal administration of HNK. Interestingly, the number of doses of HNK and quantities of SIgA secretion showed a positive correlation. On Day 21, there were no significant differences between the number of SMG IgA AFCs prior to and after (0.5, 1.5, 3, and 6 hours) the nasal administration of HNK. However, significantly increased levels of IgA AFCs due to promotion of their proliferative activity were noted 0.5 and 1.5 hours after the nasal administration of HNK. Our results suggest that HNK has an impact on salivary SIgA Ab secretion immediately after nasal administration via elevating the proliferative activity of SMG IgA AFCs

High-Intensity Red Light-Emitting Diode Irradiation Suppresses the Inflammatory Response of Human Periodontal Ligament Stem Cells by Promoting Intracellular ATP Synthesis

Periodontitis is an inflammatory lesion in the periodontal tissue. The behavior of human periodontal ligament stem cells (hPDLSCs), which play an important role in periodontal tissue regeneration, is restricted by the influence of inflammatory mediators. Photobiomodulation therapy exerts anti-inflammatory effects. The purpose of this study was to investigate the effects of light-emitting diode (LED) irradiation on the inflammatory responses of hPDLSCs. The light source was a red LED (peak wavelength: 650 nm), and the total absolute irradiance was 400 mW/cm2. The inflammatory response in hPDLSCs is induced by tumor necrosis factor (TNF)-α. Adenosine triphosphate (ATP) levels and pro-inflammatory cytokine (interleukin [IL]-6 and IL-8) production were measured 24 h after LED irradiation, and the effects of potassium cyanide (KCN) were investigated. LED irradiation at 6 J/cm2 significantly increased the ATP levels and reduced TNF-α-induced IL-6 and IL-8 production. Furthermore, the inhibitory effect of LED irradiation on the production of pro-inflammatory cytokines was inhibited by KCN treatment. The results of this study showed that high-intensity red LED irradiation suppressed the TNF-α-stimulated pro-inflammatory cytokine production in hPDLSCs by promoting ATP synthesis. These results suggest that high-intensity red LED is a useful tool for periodontal tissue regeneration in chronically inflamed tissues