[THE IMMUNOLOGIC INDICATORS IN PATIENTS WITH CARIES OF CONTACT SURFACES OF LATERAL TEETH].

The samplings of patients aged 18-45 years with caries of contact surfaces of lateral teeth (n=18) and healthy adults aged 18-20 years with intact teeth (n=18) were examined The saliva taken in rotary vial on empty stomach in amount of 3-4 mi served as assay for analysis. To identify secretory immunoglobulin A, interleukin lß, interleukin-4 and interferon y saliva was centrifuged during 15 min under 1500 rpm. The supernatant fluid was analyzed using enzymoimmunoassay (test-systems "Vector-Best", Novosibirsk). The registration of reaction was implemented using multiscan Labsystem under wavelength 450 nm. The content of secretory immunoglobulin A was expressed in mg/l, cytokines - in pg/ml. It is demonstrated that in patients with caries average level of interleukin lß was almost two times higher (p<0.05) than analogous indicator in healthy examined patients. In healthy patients average level of interferon γ significantly (more than in 10 times) exceeded upper limit of allowable standard and was higher (p<0.05) in comparison with such in patients with caries of contact surfaces. The analysis of content of secretory immunoglobulin A in saliva established that in healthy patients average values of the given indicator were higher (p<0.05) than in patients with caries of contact surfaces of lateral teeth. The lower content of secretory immunoglobulin A and interferon y against the background of increased level of interleukin lß was detected in saliva of patients with caries of contact surfaces of lateral teeth. This occurrence can be considered as factor predisposing to development of caries process.

Mechanisms that lead to the regulation of NLRP3 inflammasome expression and activation in human dental pulp fibroblasts.

BACKGROUND: The NLRP3 inflammasome plays an important role in the cellular defense against invading pathogens and is reported to be expressed in human dental pulp fibroblasts (HDPFs). However, the role of the NLRP3 inflammasome in HDPFs during pulpal infection and inflammation remains unclear. OBJECTIVES: To elucidate the function of the NLRP3 inflammasome and the mechanisms that lead to its expression and activation in HDPFs. METHODS: The test model used lipopolysaccharide (LPS) and adenosine triphosphate (ATP) to simulate an inflammatory environment. Lentiviral vectors encoding short hairpin RNAs were used to knock down NLRP3 and caspase-1 in HDPFs. Specific inhibitors were used to determine whether the toll-like receptor 4 (TLR4), myeloid differentiating factor 88 (MyD88), or nuclear factor-kappa B (NF-κB) pathways were involved in the regulation of NLRP3 expression. Reactive oxygen species (ROS) production was measured by fluorescent microscopy and flow cytometry using the total ROS/superoxide detection kit. Gene and protein expression were quantified by real-time polymerase chain reaction and Western blot, while cytokine release was measured by an enzyme-linked immunosorbent assay. RESULTS: LPS up-regulated NLRP3 and IL-1ß expression while ATP induced the activation of caspase-1 and the release of IL-1ß in LPS-primed HDPFs. The knockdown of NLRP3 or caspase-1 expression significantly inhibited IL-1ß secretion. Pretreatment with a TLR4 inhibitor, a MyD88 inhibitory peptide, or an I Kappa B alpha (IκBα) phosphorylation inhibitor significantly inhibited LPS-induced NLRP3 and IL-1ß expression. ATP potently promoted ROS generation in HDPFs; N-acetyl cysteine inhibited ROS production, caspase-1 activation and IL-1ß secretion induced by ATP. CONCLUSIONS: Our results demonstrated that the NLRP3 inflammasome in HDPFs is crucial for IL-1ß secretion in response to LPS plus ATP. LPS engaged the TLR4/MyD88/NF-κB pathway to enhance NLRP3 and pro-IL-1ß expression in HDPFs. ATP promoted the generation of ROS and activated the NLRP3 inflammasome in a ROS-dependent manner.

Premolar child-to-parent grafting within the framework of orthodontic serial extraction.

While allografting of human teeth holds all the risks and problems of immunological reactions or host-versus-graft reactions encountered in any organ transplantation, root resorption and thus the loss of the grafted tooth may be delayed by several decades if the transfer is between close relatives and minimum histocompatibility is 50%. In 2 cases premolars with incomplete root growth, which had to be extracted because of considerable crowding, were transplanted from child to mother and child to father, respectively. The grafts healed without complications and after a retention time of several weeks the teeth were attached. Three years after transplantation the teeth show only minor signs of root resorption and are fully functional.

Immunohistochemical localization of HLA-DR-positive cells in unerupted and erupted normal and carious human teeth.

Class II major histocompatibility complex (MHC) antigen-expressing cells are generally associated with the early phase of the immune response. We have studied the distribution of class II-expressing cells in developing, normal, and carious human teeth to clarify when human pulp acquires an immunologic defense potential and how this reacts to dental caries. Antigen-expressing cells were identified immunohistochemically by means of HLA-DR monoclonal antibody. In the pulp of unerupted developing teeth, numerous HLA-DR-positive cells were distributed mainly in and around the odontoblast layer. In erupted teeth, HLA-DR-positive cells were located, for the most part, just beneath the odontoblast layer, with slender cytoplasmic processes extending into the layer. Superficial caries lesions caused an aggregation of HLA-DR-positive cells in dental pulp corresponding to the lesion. In teeth with deeper caries lesions, this aggregation of cells expanded to include the odontoblast layer. Also noted were HLA-DR-positive cells lying along the pulp-dentin border, with cytoplasmic processes projecting deep into the dentinal tubules, where they co-localized with odontoblast processes. These findings suggest that: (1) human dental pulp is equipped with immunologic defense potential prior to eruption; (2) in the initial stage of caries infection, an immunoresponse mediated by class-II-expressing cells is initiated in human dental pulp; and (3) HLA-DR-positive cells trespass deep into dentinal tubules as the caries lesion advances.

Selection of allogenic tooth graft using HLA-A, -B, -C and DR typing and the MLC test.

An allotransplantation of a partly developed premolar from a 12-year-old daughter to her mother is reported. The tooth graft was selected by the use of HLA-A, -B, -C and DR typing and the MLC tests. Follow-up over a 3-year period included periodic identically taken radiographs, electric and galvanic pulp tests and tests for cytotoxic antibodies. Almost complete closure of the apex of the tooth has occurred with no sign of root resorption. The transplant has remained vital, and no production of antibodies against the graft has occurred.