Pathogen infections are recognized by the immune system, which consists of two types of responses: an innate immune response that recognizes pathogenassociated molecular patterns (PAMPs) and an antigen-specific adaptive immune response. In both responses, there are several activated cells of the immune system, which play a key role in establishing the environment of cytokines, thus directing their differentiation either suppressing or promoting the immune response. This immune response is crucial against pathogen infections. In this chapter, we will describe the crucial role played by different families of cytokines during activation of the immune system to eliminate infectious pathogens.

Adipose tissue is composed mainly by adipocytes and stromal-vascular fraction, which are composed by different cell types including macrophages. There are three types of adipose tissue: brown (BrAT), white (WAT), and beige (BeAT). BrAT is less abundant and is implicated in lipid oxidation and energy balance; BeAT has the pathway of adaptive thermogenesis, and WAT is endocrine in nature and lipid storage site and is implicated as an endocrine organ that secretes hormones and different molecules. These molecules are pro-inflammatory and anti-inflammatory factors, including the adipokines leptin, adiponectin, resistin, and visfatin, as well as cytokines and chemokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, leptin, adiponectin, and others, are involved with the development of adipose tissue inflammation and obesity. This pathological condition, together with other factors such as oxidative stress, may develop insulin resistance and the pathogenesis of type 2 diabetes mellitus (T2DM).

Functionalized platinum nanoparticles have been of considerable interest in recent research due to their properties and applications, among which they stand out as therapeutic agents. The functionalization of the surfaces of nanoparticles can overcome the limits of medicine by increasing selectivity and thereby reducing the side effects of conventional drugs. With the constant development of nanotechnology in the biomedical field, functionalized platinum nanoparticles have been used to diagnose and treat diseases such as cancer and infections caused by pathogens. This review reports on physical, chemical, and biological methods of obtaining platinum nanoparticles and the advantages and disadvantages of their synthesis. Additionally, applications in the biomedical field that can be utilized once the surfaces of nanoparticles have been functionalized with different bioactive molecules are discussed, among which antibodies, biodegradable polymers, and biomolecules stand out.

Dendritic cells (DC) represent an important link between innate and adaptive immunity, which play an important role during the immune response against pathogens. There are several populations and subpopulations of DC, but mainly two subpopulations are characterized: the classic DC specialized in the processing and presentation of the antigen; and the plasmacytoid DC that have a high phagocytic activity and capacity for the production of cytokines. This chapter aims to present the current aspects related to the most relevant characteristics and functions of DC, as well as their role in host defense against infections by viruses, parasites, bacteria, and fungi.

Aim To evaluate whether treatment with resiniferatoxin (RTX) is capable of lowering the plasma levels of PGE2 and TNF‐α, as well as histopathological parameters in inflammation of pulp tissue in a mouse experimental model. Methodology Ten groups of six BALB/c mice were formed as follows: healthy group (HC), healthy group treated with RTX (HRTX), two groups with pulp inflammation at 14 and 18 hours (PI14/PI18), six groups with pulpal inflammation plus treatment with Ibuprofen (IBU14/IBU18), dexamethasone (DEX14/DEX18) and resiniferatoxin (RTX14/RTX18) at 14 and 18 hours, respectively. Pulpal inflammation was induced through occlusal exposure of the pulp of the maxillary first molar. The plasma levels of PGE2 and TNF‐α and the histological parameters of the pulp tissue of the HC and HRTX groups were evaluated at the time of acquiring the animals. In the other groups, the plasma levels of PGE2 and TNF‐α and the histopathological parameters were evaluated at 14 and 18 hours after pulp damage. Plasma levels of PGE2 and TNF‐α were quantified by ELISA, and the histopathological parameters were evaluated by H/E staining. Statistical significance was determined by one‐way analysis of variance (ANOVA) to test for overall differences between group means. Results A significant increase (*p < .05) in plasma levels of PGE2 and TNF‐α occurred 14 and 18 hours after pulp damage. In addition, treatment with RTX significantly decreased (*p < .05) the plasma levels of PGE2 and TNF‐α at 14 and 18 hours after pulp damage, as well as the infiltrate of inflammatory cells at 18 hours after pulp damage, similarly to treatment with ibuprofen and dexamethasone. Conclusion It was possible to detect systemic levels of PGE2 and TNF‐α at 14 and 18 hours after pulp damage. Likewise, treatment with RTX was associated with an anti‐inflammatory effect similar to treatment with ibuprofen and dexamethasone. These findings place resiniferatoxin as a therapeutic alternative in the treatment of inflammatory diseases in Dentistry.