Arboviruses: How Saliva Impacts the Journey from Vector to Host

Abstract

Arthropod-borne viruses, referred to collectively as arboviruses, infect millions of people worldwide each year and have the potential to cause severe disease. They are predominately transmitted to humans through blood-feeding behavior of three main groups of biting arthropods: ticks, mosquitoes, and sandflies. The pathogens harbored by these blood-feeding arthropods (BFA) are transferred to animal hosts through deposition of virus-rich saliva into the skin. Sometimes these infections become systemic and can lead to neuro-invasion and life-threatening viral encephalitis. Factors intrinsic to the arboviral vectors can greatly influence the pathogenicity and virulence of infections, with mounting evidence that BFA saliva and salivary proteins can shift the trajectory of viral infection in the host. This review provides an overview of arbovirus infection and ways in which vectors influence viral pathogenesis. In particular, we focus on how saliva and salivary gland extracts from the three dominant arbovirus vectors impact the trajectory of the cellular immune response to arbovirus infection in the skin.

Vector-Borne Viral Diseases as a Current Threat for Human and Animal Health—One Health Perspective

“…Species of particular medical importance belong to the family Culicidae , which includes about 110 genera and subgenera and about 3600 species. The majority of mosquito species responsible for the transmission of arboviruses belong to the genera of Culex , Aedes , and Anopheles [ 97 , 98 , 99 , 100 ]. Aedes mosquitoes, especially Aedes aegypti and Aedes albopictus (Asian tiger mosquito) transmit dangerous viruses from families such as Flaviviridae , Togaviridae , and Phenuiviridae including CHIKV, DENV, YFV, and RVFV [ 101 ].…”

Traditional Knowledge to Contemporary Medication in the Treatment of Infectious Disease Dengue: A Review

“…Firstly, infected mosquito feed on host and DENV gets transmitted via injecting its saliva into the host. In the meantime, when half-length proboscis is inside the dermis, the vector releases DENV plaque-forming units (nearly 50,000) and causes infection in contiguous skin cells, i.e., Langerhans and keratinocytes ( Marcial-Juárez et al, 2017 ; Schneider et al, 2021 ). Dendritic cells enter lymphatics after capturing DENV virions or antigens and transport them to local draining lymph nodes.…”

Tick Saliva and Salivary Glands: What Do We Know So Far on Their Role in Arthropod Blood Feeding and Pathogen Transmission

“…Ticks are blood-feeding arthropods that transmits various bacterial, viral and protozoan pathogens to humans and animals ( Azad, 2007 ; Wikel, 2013 ; Neelakanta and Sultana, 2015 ; Schneider et al., 2021 ; Sosa et al., 2021 ). In nature, the successful existence of ticks could be reasoned due to its ability to feed on various animals ( Anderson, 1989 ; Richter et al., 2000 ; Embers et al., 2013 ; Linske et al., 2018 ; Banovic et al., 2021 ; Sidge et al., 2021 ).…”

“…However, feeding by piercing and sucking type will occur when ticks cannulate their specialized mouthparts into the vertebrate host skin and blood capillaries/vessels to draw blood ( Hurd, 2010 ; Simo et al., 2017 ). With either of these feeding methods, ticks can successfully acquire pathogens in a blood meal from infected vertebrate host or could also transmit pathogens to a naïve host ( Wikel, 2013 ; Simo et al., 2017 ; Schneider et al., 2021 )…”

“…However, feeding by piercing and sucking type will occur when ticks cannulate their specialized mouthparts into the vertebrate host skin and blood capillaries/vessels to draw blood (Hurd, 2010;Simo et al, 2017). With either of these feeding methods, ticks can successfully acquire pathogens in a blood meal from infected vertebrate host or could also transmit pathogens to a naïve host (Wikel, 2013;Simo et al, 2017;Schneider et al, 2021) During blood feeding, ticks secrete a plethora of components into saliva that facilitates them in acquiring a blood meal from the vertebrate host. These components include several antiimmunomodulatory, anti-vasodilatory, anti-coagulants, anticomplement factors and anti-platelet aggregation factors (Schoeler and Wikel, 2001;Brossard and Wikel, 2004;Wikel, 2013;Murfin and Fikrig, 2017;Simo et al, 2017;Nuttall, 2019).…”