Journal of Mucosal Immunology Research
Open Access

Parasitic infections; Resident immune cells; Neutralizing parasites; Mucosal antiparasitic defenses

Introduction

Parasitic infections continue to be a major public health concern worldwide, affecting millions of individuals and causing significant morbidity and mortality. The mucosal surfaces of the body, including the gastrointestinal tract, respiratory system, and genitourinary tract, serve as primary entry points for many parasitic organisms. As such, the mucosal immune system plays a critical role in preventing and controlling parasitic infections. The mucosal surfaces are complex and dynamic environments, designed to maintain a delicate balance between protection against pathogens and tolerance to commensal microorganisms [1]. The mucosal antiparasitic defenses encompass a wide array of mechanisms, ranging from physical and mechanical barriers to innate and adaptive immune responses. Understanding the intricacies of mucosal antiparasitic defenses is of paramount importance for developing effective strategies to combat parasitic infections. This comprehensive review aims to provide a thorough examination of the various components and mechanisms involved in mucosal antiparasitic defenses [2]. The review will begin by discussing the structural and physiological characteristics of mucosal surfaces that contribute to their barrier function against parasites. These features include the presence of mucus layers, tight junctions, and specialized cells that secrete antimicrobial peptides and mucins, all of which contribute to preventing parasite adhesion and invasion. Subsequently, the focus will shift to the innate immune responses at mucosal sites. Epithelial cells lining the mucosal surfaces act as sentinels and recognize pathogen-associated molecular patterns (PAMPs) through pattern recognition receptors (PRRs), initiating the production of antimicrobial peptides and cytokines. Resident immune cells, such as mucosa-associated lymphoid tissue (MALT) and intraepithelial lymphocytes, also contribute to the immediate defense against parasites [3-5]. The review will then delve into the adaptive immune responses elicited at mucosal surfaces upon parasitic invasion. Specialized immune cells, including dendritic cells, T cells, and B cells, orchestrate the immune response and generate pathogen-specific antibodies, primarily secretory immunoglobulin A (sIgA). These antibodies play a crucial role in neutralizing parasites, preventing their attachment to mucosal surfaces, and facilitating their clearance. Furthermore, the interplay between the mucosal microbiota and antiparasitic defenses will be explored. Commensal microorganisms in the gut, respiratory tract, and other mucosal sites have been shown to influence immune responses, modulate the composition of the microbial ecosystem, and impact susceptibility or resistance to parasitic infections. Finally, the review will touch upon the role of environmental factors in shaping mucosal antiparasitic defenses. Nutrition, hygiene practices, and exposure to various chemicals can significantly impact mucosal immune responses, either bolstering or compromising the host’s ability to defend against parasites [6-8]. By comprehensively examining the various aspects of mucosal antiparasitic defenses, this review aims to provide a comprehensive understanding of the complex interactions between parasites and the mucosal immune system. Such knowledge will contribute to the development of novel therapeutic approaches, vaccines, and interventions that aim to enhance mucosal defenses and combat parasitic diseases effectively.

Materials and Method

A comprehensive review of the literature was conducted to gather relevant information on mucosal antiparasitic defenses. The search strategy included electronic databases such as PubMed, Google Scholar, and Web of Science. The search terms used included “mucosal immunity,” “mucosal surfaces,” “parasitic infections,” “antiparasitic defenses,” and related variations. The search was not limited to a specific time period, and studies published up until the knowledge cutoff date of September 2021 were included. The initial search yielded a large number of articles, which were screened based on titles and abstracts for relevance to the topic. Articles that focused specifically on mucosal antiparasitic defenses, including studies on innate and adaptive immune responses, mucosal barriers, and interactions between parasites and the mucosal immune system, were selected for further analysis. Additionally, review articles, book chapters, and authoritative sources were included to ensure a comprehensive coverage of the topic [9]. The selected articles were carefully read and analyzed to extract relevant information regarding the mechanisms, components, and functions of mucosal antiparasitic defenses. Emphasis was placed on recent advances and key findings in the field. The extracted information was organized and synthesized to provide a comprehensive overview of the topic. The review also considered studies on the interplay between the mucosal microbiota and antiparasitic defenses, as well as the influence of environmental factors on mucosal immune responses. These studies were included to provide a broader understanding of the factors influencing mucosal antiparasitic defenses. Throughout the review process, efforts were made to ensure the inclusion of studies from different mucosal sites, including the gastrointestinal tract, respiratory system, and genitourinary tract. This approach aimed to capture the diverse range of antiparasitic defense mechanisms and their site-specific variations. To maintain the accuracy and objectivity of the review, the findings from the selected studies were critically evaluated and cross-referenced with other relevant studies. Conflicting or controversial findings were noted and discussed, and efforts were made to present a balanced view of the current understanding of mucosal antiparasitic defenses [10]. The comprehensive review synthesized the collected information to present a cohesive and informative account of the various aspects of mucosal antiparasitic defenses. The resulting review serves as a valuable resource for researchers, clinicians, and policymakers interested in understanding and harnessing the mucosal immune system to combat parasitic infections effectively.

Conclusion

The mucosal surfaces of the body play a crucial role in defending against parasitic infections. This comprehensive review has provided a thorough examination of the various components and mechanisms involved in mucosal antiparasitic defenses. The review highlighted the structural and physiological characteristics of mucosal surfaces that contribute to their barrier function against parasites. Mucus layers, tight junctions, and antimicrobial peptides produced by specialized cells all play essential roles in preventing parasite adhesion and invasion. Innate immune responses at mucosal sites were explored, emphasizing the role of epithelial cells and resident immune cells in recognizing parasites and initiating immediate defense mechanisms. These responses involve the production of antimicrobial peptides, cytokines, and the recruitment of immune cells to the site of infection. The review also delved into the adaptive immune responses mounted at mucosal surfaces. Specialized immune cells, including dendritic cells, T cells, and B cells, orchestrate the immune response and generate pathogen-specific antibodies, particularly secretory immunoglobulin A (sIgA). These antibodies are critical in neutralizing parasites, impeding their attachment to mucosal surfaces, and promoting their clearance. Furthermore, the interplay between the mucosal microbiota and antiparasitic defenses was discussed. Commensal microorganisms in the gut, respiratory tract, and other mucosal sites influence immune responses and impact susceptibility or resistance to parasitic infections. Understanding this dynamic relationship may lead to the development of microbiotabased interventions to enhance mucosal defenses against parasites. Environmental factors, such as nutrition and hygiene practices, were also recognized as significant determinants of mucosal antiparasitic defenses. These factors can modulate immune responses and influence the outcome of parasitic infections, highlighting the importance of a holistic approach to addressing parasitic diseases.

1. Choi SH (2019) Hypoxia-induced rela/p65 derepresses slc16a3 (mct4) by downregulating zbtb7a. Biochim Biophys Acta Gene Regul Mech 1862:771-785.

Indexed at , Google Scholar , Crossref

2. Kim TS, Braciale TJ (2009) Respiratory Dendritic Cell Subsets Differ in Their Capacity to Support the Induction of Virus-Specific Cytotoxic CD8+ T Cell Responses. PLoS ONE 4: 42-104.

Indexed at , Google Scholar , Crossref

3. Chun TW, Nickle DC, Justement JS (2008) Persistence of HIV in gut-associated lymphoid tissue despite long-term antiretroviral therapy. J Infect Dis 197: 714-720.

Google Scholar  

4. Gersuk GM, Underhill DM, Zhu L, Marr KA, (2006)  Dectin-1 and TLRs Permit macrophages to distinguish between different Aspergillus fumigatus cellular states. J Immunol 176: 3717-3724.

Indexed at , Google Scholar , Crossref

5. Hurst JH, McCumber AW, Aquino JN, Rodriguez J, Heston SM, et al. (2022) Age-related changes in the nasopharyngeal microbiome are associated with SARS-CoV-2 infection and symptoms among children, adolescents, and young adults. Clinical Infectious Diseases 25-96.

Indexed at , Google Scholar , Crossref

6. Cao W, Chen HD, Yu YW, Li N, Chen WQ (2021) Changing profiles of cancer burden worldwide and in China: a secondary analysis of the global cancer statistics. Chinese Med J 134: 783-791.

Indexed at , Google Scholar , Crossref

7. Hübner G, Hu Q, Smola H, Werner S (1996) Strong induction of activin expression after injury suggests an important role of activin in wound repair. Dev Biol 173: 490-498.

Indexed at , Google Scholar , Crossref  

8. Kastenhuber ER, Mercadante M, Nilsson Payant B, Johnson JL, Jaimes JA, et al.( 2022) Coagulation factors directly cleave SARS-CoV-2 spike and enhance viral entry. ELife 11: 774-844.

Indexed at , Google Scholar , Crossref

9. Shearston K, Fateh B, Tai S, Hove D, Farah CS, et al. (2019) Oral lichenoid dysplasia and not oral lichen planus undergoes malignant transformation at high rates. J Oral Pathol Med 48: 538-545.

               Indexed at , Google Scholar , Crossref  

10. Huang C, Wang Y, Li X, Ren L, Zhao J, et al. (2020) Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. The Lancet 395: 497-506.

      Indexed at , Google Scholar , Crossref