Immunologic Crosstalk and Host-Specific Immune Signature Associated with Dengue

In tropical and subtropical regions, dengue fever is a common febrile illness that is mostly spread by Aedes mosquitoes. Urban population migration, inadequate water storage facilities, and high mosquito density are features associated with this disease. The severity of the illness ranges from mild to deadly dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS), often with severe cases causing profound shock from extensive plasma leakage, and may result in demise. The symptoms of the illness include headache, myalgia, retro-orbital pain, and hemorrhagic signs. There may also be an intermittent shift in blood vessel integrity and coagulation, but recovery is typically complete and rapid. In this review, we emphasize the immunological aspects of this illness. The intricate interactions among the virus, host genes, and host immune systems impact the pathophysiology of dengue. Postinfection antibody-dependent enhancement is prominent, which significantly influences the etiology and virulence of the disease. Whereas the severe form only manifests when the host immune system is actively working to eradicate the infection by secreting several inflammatory cytokines, chemokines, and lipid mediators, for example, early dengue virus infection (DVI) resulted in the production of Interleukin 2 (IL-2), IL-6, and later infection, IL-4, IL-5, and IL-10. Higher concentrations of interferons gamma (IFN-gamma), granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage migration inhibitory factor (MIF), IL-1, IL-2, IL-4, IL-6, IL-7, IL-10, IL-12, and IL-13 were found in DHF patients. These are significantly more prevalent in severe infections than in mild ones. Numerous immunopathogenic processes involving both virus and host variables influence the severity of dengue. There is growing evidence that a compromised immune system limits viral clearance and causes severe inflammation, which in turn causes dengue hemorrhagic fever and dengue shock syndrome. Furthermore, the capacity of DENV to infect a broad range of immune cells, such as macrophages, dendritic cells, mast cells, T and B cells, and monocytes, further dysregulates these cells' antiviral activities, leading to the spread of the virus. Even though a number of risk factors linked to the advancement of the disease have been suggested, further research and evaluation of novel technologies are necessary to understand the complicated etiology and develop reliable and effective vaccines to fight against this febrile illness.