Nickel (Ni) is the most frequent metal allergen and induces Th1-dependent type-IV allergies. In local skin, epidermal Langerhans cells (Lcs) and/or dermal dendritic cells (Dcs) uptake antigens and migrate to draining lymph nodes (LNs). However, the subsets of antigen-presenting cells that contribute to Ni presentation have not yet been identified. In this study, we analyzed the Ni-binding capabilities of murine DCs using fluorescent metal indicator Newport Green. Elicitation of Ni allergy was assessed after intradermal (i.d.) injection of Ni-treated DCs into ear pinnae of Ni-sensitized mice. The Ni-binding capabilities of MHC class II hi CD11c int migratory DCs were significantly stronger than those of MHC class ii int CD11c hi resident DCs and CD11c int PDCA1 + MHC class II int B220 + plasmacytoid DCs. Migratory DCs in skin-draining and mandibular LNs showed significantly stronger Ni-binding capabilities than those in mesenteric and medial iliac LNs. An i.d. injection of IL-1β induced the activation of Lcs and dermal Dcs with strong Ni-binding capabilities. Ni-binding LCs were detected in draining LNs after i.d. challenge with IL-1β and Ni. Moreover, an i.d. injection of Ni-treated DCs purified from skin-draining LNs elicited Ni-allergic inflammation. These results demonstrated that migratory DCs in skin-draining LNs have strong Ni-binding capabilities and elicit Ni allergy. Cutaneous MHC class II + professional APCs are classified into epidermal CD207 (langerin) + Langerhans cells (LCs) and dermal dendritic cells (DCs) 1,2. LCs were originally considered to be skin-resident DCs, but are now recognized as tissue-resident macrophages, the precursors of which originate from the yolk sac and fetal liver. DCs consist of conventional DCs (cDCs) and plasmacytoid DCs (pDCs). Dermal DCs have been classified into at least three subsets: XCR1 + cDC1, XCR1-CD11b + cDC2, and XCR1-CD11b − double negative (DN) cDCs 2. XCR1 + cDC1s express CD207 and CD103. These professional APCs capture and transport local self and non-self Ags to skin-draining lymph nodes (LNs). Two subsets of DCs are detected in skin-draining LNs: MHC class II hi CD11c int migratory DCs and MHC class II int CD11c hi resident DCs. Migratory DCs have been classified into four subsets: LCs, cDC1s, cDC2s, and DNcDCs, similar to local skin. Resident DCs comprise cDC1s and cDC2s. pDCs are detected in skin-draining LNs but not in steady-state local skin. Although there are high levels of redundancy, each APC contributes to specific immune responses. A previous study reported that LCs mainly induce Th17 responses, particularly against Candida albicans 3. cDC1s have been shown to contribute to Th1 responses and cross-presentation 3,4. cDC2s and DNcDCs contribute to Th2 responses 5,6. Regulatory T (Treg) cells are induced by various APC subsets including epidermal LCs 7 , cDC1s in the intestinal mucosa 8 , and cDC2s in the sublingual mucosa 9. These findings indicated that specific APCs are responsible for immune responses against specific Ags. Metal allergies have b...
Background: Tuberculosis (TB) is an infectious disease that persists as a health problem worldwide. Mycobacterium tuberculosis, as an etiological agent, is transmitted from infected to uninfected individuals via airborne droplet nuclei. Oral health care workers or dental practitioners may be at high risk of TB infection because of their close proximity to infected individuals during treatment procedures. Simple and rapid screening of mycobacterium tuberculosis in the oral cavity is necessary in order to prevent transmission of infection. Purpose: To investigate the presence of acid-fast bacilli in the buccal mucosa of pulmonary TB patients. Methods: Nineteen pulmonary TB patients of both sexes, ranging in age from 19 to 74 years old participated in this study. The diagnosis of tuberculosis was performed by clinical symptom assessment and supporting examination, including acid-fast bacilli on sputum examination. Two buccal mucosa swabs taken from pulmonary TB patients were collected for acid fast bacilli direct smear by Ziehl Neelsen staining. Results: With regard to mycobacterium tuberculosis, acid-fast bacilli presented in 10.5% of the oral buccal mucosa swabs of subjects, whereas in the sputum specimens, bacilli were found in 52.6% of subjects. Conclusion: Acid-fast bacilli can be found in the buccal epithelial mucosa of pulmonary tuberculosis patients, although its presence was very limited.
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