Impact of IL-17-producing γδ T cells on chronic otitis media induced by nontypeable Haemophilus influenzae in a mouse model.

Nontypeable Haemophilus influenzae (NTHi) is considered a major pathogen underlying middle ear infection. This study aimed to investigate the impact of IL-17 on chronic otitis media (COM) induced by NTHi in mice. NTHi was inoculated into the tympanic bulla with eustachian tubal obstruction. Middle ear effusions (MEEs) and tissues were collected on days 3, 14, and at 1, 2, and 6 months after injection. The expression of interleukin-17A (IL-17A) in MEEs was significantly elevated compared to that in the control group at the translational and transcriptional levels during the experiments. The quantities of IL-17-producing γδ T cells were significantly increased compared to that in the control group during COM, but that of Th17 cells did not. Depletion of γδ T cells by anti-γδ T-cell receptor (TCR) monoclonal antibody (mAb) administration significantly decreased the bacteria counts and the concentrations of IL-1ß, IL-6, IL-17A, TNF-α, and IL-10 in MEEs. Our results suggest that IL-17 may play an important role in prolonging the inflammation in the middle ear in COM and that IL-17-producing γδ T cells may contribute to the exacerbated inflammatory response in the middle ear. In this study, anti-γδ TCR mAb administration was found to improve chronic middle ear inflammatory conditions.

Reconstruction using a free jejunal patch flap in salvage head and neck surgery after radiotherapy.

BACKGROUND: Chemoradiotherapy is a standard treatment for functional preservation in patients with advanced head and neck carcinoma. However, chemoradiotherapy increases the risk of postoperative complications. AIMS/OBJECTIVES: We report the usefulness of reconstruction using a free jejunal patch flap in treating recurrence or residual head and neck carcinoma after radiotherapy. Furthermore, we investigated the factors for the occurrence of postoperative complications in patients who underwent salvage surgery using a free flap transfer. MATERIAL AND METHODS: This study included 41 patients with head and neck carcinoma who underwent salvage surgery using a free flap transfer, including 11 patients who underwent reconstruction using a free jejunal patch flap. Prognostic analysis was performed for the development of complications. RESULTS: Ten jejunal patch flaps survived without microvascular problems. One patient underwent revision reconstructive surgery because of flap failure. However, no patient had a pharyngocutaneous fistula. Oral intake could be resumed in all patients at a median 14 days postoperatively. Multivariate logistic regression analysis indicated that the use of cutaneous flaps was significantly associated with the development of complications. CONCLUSIONS AND SIGNIFICANCE: Free jejunal patch flaps can be considered useful for head and neck reconstruction after radiotherapy for early intake resumption and complication prevention.

Interaction Between Regulatory T Cells and Antibody-Producing B Cells for Immune Responses at the Upper Respiratory Mucosa Against Nontypeable Haemophilus influenzae: In Vitro Assay Model.

OBJECTIVES: The aim of this study was to investigate the effect of regulatory T cells (Tregs) on B-cell immune responses against outer membrane protein (OMP) from nontypeable Haemophilus influenzae (NTHi) in vitro, to clarify its exact mechanism from an immunologic standpoint. METHODS: Mice were vaccinated intranasally with OMP to induce OMP-specific immune responses in the nasal mucosa. Mononuclear cells (MNCs) were collected from the nasal mucosa, and Tregs and helper T (Th) cells were isolated separately from the spleens of those mice. Three different cell culture groups were allocated: MNCs cocultured with Tregs, MNCs cocultured with Th cells, and MNCs cultured alone. At 24 and 72 hours after cell culture, the concentrations of various cytokines and antibodies in culture supernatants were measured to assess the effects of Tregs and Th cells on B-cell responses. Cytokine levels and specific anti-OMP antibody levels in culture media were determined using enzyme-linked immunosorbent assay. CD69 or CD80 expression on B220-positive cells was detected using flow cytometric analysis. RESULTS: Th1 and Th2 cytokine concentrations were significantly elevated in the 3 groups incubated with OMP from 24 to 72 hours. Additionally, interleukin-10 levels were significantly higher in the Treg and Th groups than in the control group. Levels of OMP-specific immunoglobulin A did not differ significantly among the groups. The ratios of CD69+B220+ B2 cells were nearly the same in the 3 groups; however, the ratio of CD80+B220+ B2 cells was higher in the control group than in the Treg and Th groups during incubation. CONCLUSIONS: Tregs and Th cells did not affect OMP-specific immunoglobulin A production in this study. However, these cells may partially inhibit B-cell functions, such as T-cell activation. These inhibitory effects may be related to interleukin-10.

Toll-like receptor 4 plays an important role to enhance bacterial clearance from the nose in synergy with triggering receptor expressed on myeloid cells (TREM)-1 expression on polymorphonuclear neutrophils.

OBJECTIVE: Acute rhinosinusitis (ARS) is among the most common infectious diseases. Neutrophils play a major role in innate host defenses against pathogenic microorganisms such as fungi and bacteria. Recently, in neutrophils, ligation of the triggering receptor expressed on myeloid cells (TREM)-1 was found to activate the full spectrum of neutrophil effector mechanisms, including the release of inflammatory mediators, degranulation, phagocytosis, and oxidative burst in synergy with Toll-like receptors (TLRs). In this study, we investigated the effect of TREM-1 on the functions of neutrophils in relation to TLR4 in a nasal and nasopharyngeal inflammation mouse model via nontypeable Haemophilus influenzae (NTHi) intranasal inoculation. METHODS: We used C3H/HeJ (TLR4-deficient) mice, which arose spontaneously and have non-functional TLR4 protein, and normal wild-type (WT) C3H/HeN mice. Mice were inoculated intranasally with NTHi (107 cfu/mouse) to investigate the effects of TLR4 on the function of Neutrophils. We examined the kinetics of bacterial clearance and inflammatory cell infiltration in nasal washes at 6, 12, 24, and 72 h after inoculation. The expression of TREM-1 on neutrophils, and TREM-1 mRNA expression in neutrophils in the nasal washes were examined by flow cytometric analysis and RT-PCR. RESULTS: Bacterial counts of NTHi from nasal washes were significantly lower in WT mice than in TLR4-mutant mice after inoculation. The numbers of inflammatory cells in nasal washes were significantly higher in WT mice at 6 h, 12 h, and 24 h after inoculation than in TLR4-deficient mice. The expression of TREM-1 protein on neutrophils and the mRNA levels were greater in WT mice than in TLR4-mutant mice. The concentrations of soluble TREM-1 in WT nasal washes were also significantly higher than in those of TLR4-deficient mice. CONCLUSION: TREM-1 may play an important role together with TLR4 in the nasopharyngeal clearance of NTHi by neutrophils. Further studies will need to clarify the innate immune responses of neutrophils via TLR4 to prevent NTHi infection.

The Relationship between Werner Syndrome and Sinonasal Malignant Melanoma: Two Sibling Cases of Werner Syndrome with Malignant Melanoma.

Werner syndrome (WS) is an autosomal recessive disease characterized by premature aging. Malignant tumors such as thyroid carcinoma and malignant melanoma occur frequently in WS patients. We describe 2 siblings with WS who suffered from sinonasal malignant melanoma (MM). Both patients initially experienced nasal obstruction and recurrent nasal bleeding and died within 2 years of the diagnosis of MM. Otolaryngologists should recognize that WS patients have a high risk for head and neck malignant disease, particularly sinonasal MM, even if they are aged below the expected age range and undergo periodic examinations. Furthermore, it is important that WS patients are aware that a prompt nasal examination is indicated if they experience continuous nasal obstruction or recurrent nasal bleeding.

Endoscopic-modified medial maxillectomy and its limitation for a solitary fibrous tumor of the lacrimal sac and nasolacrimal duct.

Solitary fibrous tumor (SFT) is an uncommon neoplasm that usually arises from the pleura. Recently, SFTs have been reported in the head and neck region located in subsites such as the orbit. SFTs of the lacrimal sac are extremely rare, with only six cases reported in the English literature. We describe a SFT arising from the right lacrimal sac and extending along the nasolacrimal duct into the nasal cavity. Although, the tumor could not be removed by endoscopic-modified medial maxillectomy (EMMM) alone, combined approach with EMMM and a small external incision achieved the complete removal of the tumor. The patient has remained disease-free 24 months after surgery.

Monophosphoryl lipid A enhances nontypeable Haemophilus influenzae-specific mucosal and systemic immune responses by intranasal immunization.

OBJECTIVE: Acute otitis media (AOM) is one of the most common infectious diseases in children. Nontypeable Haemophilus influenzae (NTHi) is Gram-negative bacteria that are considered major pathogens of AOM and respiratory tract infections. In this study, we used monophosphoryl lipid A (MPL), a toll-like receptor (TLR) 4 agonist, as an adjuvant to induce mucosal immune responses against NTHi to enhance bacterial clearance from the nasopharynx. METHODS: Mice were administered 10 µg outer membrane protein (OMP) from NTHi and 0, 10, or 20 µg MPL intranasally once a week for 3 weeks. Control mice were administered phosphate-buffered saline alone. After immunization, these mice were challenged with NTHi. At 6 and 12 h after bacterial challenge, the mice were killed and nasal washes and sera were collected. The numbers of NTHi- and OMP-specific antibodies were quantified by enzyme-linked immunosorbent assay. RESULTS: The MPL 10 and 20 µg group produced a significant reduction in the number of bacteria recovered from the nasopharynx at 12 h after bacterial challenge compared to the control group. OMP-specific IgA titers were also augmented in the MPL groups compared to the control and OMP groups. CONCLUSION: MPL is suitable for eliciting effective mucosal immune responses against NTHi in the nasopharynx. These results demonstrate the possibility of an adjuvant that involves stimulation of the innate immune system by TLR4 agonists such as MPL for mucosal vaccination.

The role of Toll-like receptor 4 in eliciting acquired immune responses against nontypeable Haemophilus influenzae following intranasal immunization with outer membrane protein.

OBJECTIVE: Acute otitis media (AOM) is one of the most common infectious diseases in children. Nontypeable Haemophilus influenzae (NTHi) is considered a major pathogen in AOM. Current treatment options depend mainly on the use of antibiotics, thus developing vaccines to prevent this disease is an urgent goal for public health. Outer membrane proteins (OMPs) are promising candidate targets for vaccination against NTHi. METHODS: We used C3H/HeJ (Toll-like receptor 4 [TLR4]-mutant) mice, which arose spontaneously and have a non-functional TLR4 protein, and normal wild-type (WT) C3H/HeN mice. These mice were immunized intranasally with OMP from NTHi to investigate the mechanism of acquired immunity via TLR4. We examined the kinetics of mucosal and systemic antibody secretion and the migration of antibody producing lymphocytes to the mucosa in both strains during the course of intranasal immunization. RESULTS: The mucosal and systemic immune responses against OMP from NTHi were elicited in both TLR4-mutant and WT mice. However, the mucosal IgA, and systemic IgG, and Th1 immune responses in WT mice were stronger than those in TLR4-mutant mice. CONCLUSIONS: TLR4 plays an important role in relation to Th1 function for optimal development of the acquired immune responses to OMP administered intranasally. The variety of immune responses via TLR4 expression needs to be taken into consideration of individual vaccinations to prevent AOM.