Thematic Special Issue: Modern Drug Discovery – Current Challenges & Future Perspectives 2022 | 63 ROLE OF INNATE IMMUNITY IN PERIODONTAL DISEASE: A BRIEF UPDATE Review Article PRADEEP KOPPOLU, RASHEED ABDULSALAM * Faculty of Dentistry, Lincoln University College, Malaysia * Email: dr_rashed68@yahoo.com Received: 15 Apr 2021, Revised and Accepted: 30 May 2022 ABSTRACT Periodontitis disease is the most condition caused by the inflammatory response in the periodontal tissue. It is well known and established that alone the presence of pathogenic bacteria is insufficient in causing periodontitis disease. Immune response and pathways play a key role in the development of lesions and hence it is necessary to understand the same to assess on how the disease is progressing. Further, it is observed that a comprehensive immune response is initiated in cases with periodontal disease. It is essential to summarize the mechanisms of the immune system involved in periodontal disease. Hence, to understand the immune mechanism and pathways that are also contributory factors for the progression of the disease, a database search is conducted with the keywords and two research articles are shortlisted and reviewed in this review article. Keywords: NLRP3, Inflammasome, Innate immunity © 2022 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (https://creativecommons.org/licenses/by/4.0/) DOI: https://dx.doi.org/10.22159/ijap.2022.v14ti.44 Journal homepage: https://innovareacademics.in/journals/index.php/ijap INTRODUCTION Periodontitis is an inflammatory disease and its diagnosis is most common. The primary cause of the disease can be genetic, traumatic, developmental or metabolic origin. The two primary forms of periodontitis which are reported according to the literature are Chronic periodontitis and Aggressive periodontitis. The chronic periodontitis is a condition which is caused due to the inflammatory response in the tissue and also due to the presence of microorganisms in dental plaque. In aggressive case a progressive form of periodontal disease is observed, which results in rapid destruction or damage of complex tissue support of the dentition. This aggressive periodontitis occurs relatively at a very early age, and the leading cause of the disease can be hereditary issues. The severity of periodontitis depends on three key factors: pathogenic bacteria, genetic factors, and environmental factors. Though the main etiological factor of the periodontal disease is the bacteria that is present in the plaque, the fundamental element for the development of illness is the host's immune response toward the bacteria in order to damage or destroy both hard and soft tissues in either aggressive or chronic periodontitis [1]. It is well known and established that the presence of pathogenic bacteria is insufficient in causing periodontitis disease. The development of the disease happens because of a combination of factors. This includes other than the presence of periodontopathic bacteria, such as the presence of very high levels of pro-inflammatory cytokines and MMPs (matrix metalloproteinase), PGE2 (prostaglandin E2) combined with low levels of anti-inflammatory cytokines including IL-10 (interleukin- 10) (IL-10) and TIMP’s (Tissue inhibitors of MMPs). Further, the immune response initiated in the cases of periodontal disease is comprehensive. It is essential to summarize the mechanisms of the immune system involved in periodontal disease. Rationale of the review In order to understand complex diseases like periodontitis and its pathogenesis, it is critical to understand the inflammatory responses and the immune mechanisms are regulated. The innate immunity is invaded by the bacteria that are colonized in the subgingival plaque biofilm. Studies found that the immune response of the host against the pathogens is the key part in the disease. Hence it is important to study the interaction between the immune system of the host and the periodontophatic bacteria. Furthermore, it is critical to comprehend the influence of oral bacteria on host immunological responses. and the response of the immune system as the disease progresses into chronic and aggressive periodontitis. The primary aim of this article is to review the role of immunity as periodontal disease progresses and to study the problems due to immune responses that may lead to periodontal disease. The systematic review approach is adopted for this research and the same is done by compiling and evaluating the discussions of appropriate studies in order to conclude the role of immunity in the development of the disease [2]. There are various databases are available for review of medical literature. A database search is conducted on PubMed, CINHAL Plus, EMBASE databases and the Health Technology Assessment Database and Cochrane Reviews. Also, relevant articles available online from Emerald and Springer were also searched for research objectives. The database search is conducted with several keywords, and the results which are not relevant to the research questions and the research older than the year 2010 are excluded from the study. After the same two research articles are shortlisted for review. The keywords used in the database search are Immunity, Periodontal Disease, inflammation, and Immune Pathways. One of the shortlisted pieces of literature is a brief review of the immune system's role in developing the condition of periodontal disease. The rest of the research focuses on the role of inflammatory and immunological pathways in the disease's pathogenesis. Current knowledge on the disease Rather than pathology, Initially, the periodontal tissues experience inflammation and is observed as a physiologic defence mechanism to fight the microbes. Furthermore, at this early stage of the disease, clinical findings include plaque formation in supragingival and subgingival tissues, which is accompanied by inflammation and calculus formation. When this plaque is eliminated, there is a resolution with a return to homeostasis and still when the lesion persists, then it is to be considered a pathology [3]. There are different lesions, such as initial, early, established, and advanced lesions. As gingivitis progresses to periodontitis, the advanced lesion is referred to as the destructive phase. The overlapping of immunologic processes at various stages of the illness might be perplexing. As a result, the division of immune response into subsystems such as innate and adaptive immunity should be emphasised. Though the differentiation and description of inflammation in compartments is comparatively easy but the healing and inflammation mechanisms often include the total immune system International Journal of Applied Pharmaceutics ISSN- 0975-7058 Thematic Special Issue 2022