Interspecies co-feeding transmission of Powassan virus between a native tick, Ixodes scapularis, and the invasive East Asian tick, Haemaphysalis longicornis.

Background: Powassan virus, a North American tick-borne flavivirus, can cause severe neuroinvasive disease in humans. While Ixodes scapularis are the primary vectors of Powassan virus lineage II (POWV II), also known as deer tick virus, recent laboratory vector competence studies showed that other genera of ticks can horizontally and vertically transmit POWV II. One such tick is the Haemaphysalis longicornis, an invasive species from East Asia that recently established populations in the eastern USA and already shares overlapping geographic range with native vector species such as I.

The anal pore route is efficient to infect spp. ticks with and allows the assessment of the role played by infection control targets.

Adult and ticks are partially refractory to when fed on infected hosts, hindering the functional characterization of potentially protective targets in the bacterial acquisition. In the current study, we used the anal pore route to infect adult and ticks with and to assess the effects of the knockdown of microplusin in infection control. The anal pore route was efficient to infect both species, resulting in a prevalence of around 100% of infected ticks.

The survival of Amblyomma sculptum ticks upon blood-feeding depends on the expression of an inhibitor of apoptosis protein.

Background: The tick Amblyomma sculptum is the major vector of Rickettsia rickettsii, the causative agent of the highly lethal Brazilian spotted fever. It has been shown that R. rickettsii inhibits apoptosis in both human endothelial cells and tick cells.

AeMOPE-1, a Novel Salivary Peptide From , Selectively Modulates Activation of Murine Macrophages and Ameliorates Experimental Colitis.

The sialotranscriptomes of revealed a transcript overexpressed in female salivary glands that codes a mature 7.8 kDa peptide. The peptide, specific to the genus, has a unique sequence, presents a putative secretory nature and its function is unknown.

Tick Immune System: What Is Known, the Interconnections, the Gaps, and the Challenges.

Ticks are ectoparasitic arthropods that necessarily feed on the blood of their vertebrate hosts. The success of blood acquisition depends on the pharmacological properties of tick saliva, which is injected into the host during tick feeding. Saliva is also used as a vehicle by several types of pathogens to be transmitted to the host, making ticks versatile vectors of several diseases for humans and other animals.

Aedes aegypti mosquito saliva ameliorates acetaminophen-induced liver injury in mice.

Acetaminophen (N-acetyl-p-aminophenol, APAP) overdose is the most common cause of drug-induced liver injury (DILI). Although the primary hepatic damage is induced by APAP-derived toxic intermediates resulting from cytochrome P450 metabolism, immune components also play an important role in DILI pathophysiology. Aedes aegypti saliva is a source of bioactive molecules with in vitro anti-inflammatory and immunomodulatory activities.

The intracellular bacterium Rickettsia rickettsii exerts an inhibitory effect on the apoptosis of tick cells.

Background: Rickettsia rickettsii is a tick-borne obligate intracellular bacterium that causes Rocky Mountain spotted fever, a life-threatening illness. To obtain an insight into the vector-pathogen interactions, we assessed the effects of infection with R. rickettsii on the proteome cells of the tick embryonic cell line BME26.

Comparative Analysis of Infection by Sheila Smith and Taiaçu Strains in a Murine Model.

Rocky Mountain spotted fever (RMSF) is a life-threatening tick-borne disease caused by , which is widely distributed throughout the Americas. Over 4000 cases of RMSF are recorded annually in the United States, while only around 100 cases are reported in Brazil. Conversely, while case fatality rates in the United States oscillate around 5%, in Brazil they can surpass 70%, suggesting that differences in tick vectoring capacity, population sensitivity, and/or variability in virulence of the rickettsial strains may exist.

A tick cell line as a powerful tool to screen the antimicrobial susceptibility of the tick-borne pathogen Anaplasma marginale.

Anaplasma marginale is the causative agent of the severe bovine anaplasmosis. The tick Rhipicephalus microplus is one of the main vectors of A. marginale in tropical and subtropical regions of the world.

The Transcriptome of the Salivary Glands of Reveals the Antimicrobial Peptide Microplusin as an Important Factor for the Tick Protection Against Infection.

The salivary glands (SG) of ixodid ticks play a pivotal role in blood feeding, producing both the cement and the saliva. The cement is an adhesive substance that helps the attachment of the tick to the host skin, while the saliva contains a rich mixture of antihemostatic, anti-inflammatory, and immunomodulatory substances that allow ticks to properly acquire the blood meal. The tick saliva is also a vehicle used by several pathogens to be transmitted to the vertebrate host, including various bacterial species from the genus .

Salivary PGE Modulates the Dendritic Cell- Interactions and .

is an important vector of , causative agent of Rocky Mountain spotted fever and the most lethal tick-borne pathogen affecting humans. To feed on the vertebrate host's blood, secretes a salivary mixture, which may interact with skin resident dendritic cells (DCs) and modulate their function. The present work was aimed at depicting the saliva-host DC network and the biochemical nature of the immunomodulatory component(s) involved in this interface.

Hematobin is a novel immunomodulatory protein from the saliva of the horn fly Haematobia irritans that inhibits the inflammatory response in murine macrophages.

Background: The horn fly Haematobia irritans is a blood-sucking ectoparasite responsible for substantial economic loss of livestock. Like other hematophagous arthropods species, the successful blood-feeding of H. irritans is highly dependent on the modulation of the host's hemostasis and immune system.

Analysis of the Salivary Gland Transcriptome of Unfed and Partially Fed Ticks and Descriptive Proteome of the Saliva.

Ticks are obligate blood feeding ectoparasites that transmit a wide variety of pathogenic microorganisms to their vertebrate hosts. is vector of , the causative agent of Rocky Mountain spotted fever (RMSF), the most lethal rickettsiosis that affects humans. It is known that the transmission of pathogens by ticks is mainly associated with the physiology of the feeding process.

CDKN2A (p14(ARF)/p16(INK4a)) and ATM promoter methylation in patients with impalpable breast lesions.

Early detection of breast cancer increases the chances of cure, but the reliable identification of impalpable lesions is still a challenge. In spite of the advances in breast cancer detection, the molecular basis of impalpable lesions and the corresponding circulating biomarkers are not well understood. Impalpable lesions, classified by radiologists according to the Breast Imaging Reporting and Data System in the categories 3 and 4, can be either benign or malignant (slow growing or aggressive).

Knockdown of the Rhipicephalus microplus cytochrome c oxidase subunit III gene is associated with a failure of Anaplasma marginale transmission.

Rhipicephalus microplus is an obligate hematophagous ectoparasite of cattle and an important biological vector of Anaplasma marginale in tropical and subtropical regions. The primary determinants for A. marginale transmission are infection of the tick gut, followed by infection of salivary glands.

Differential expression of genes in salivary glands of male Rhipicephalus (Boophilus)microplus in response to infection with Anaplasma marginale.

Background: Bovine anaplasmosis, caused by the rickettsial tick-borne pathogen Anaplasma marginale (Rickettsiales: Anaplasmataceae), is vectored by Rhipicephalus (Boophilus)microplus in many tropical and subtropical regions of the world. A. marginale undergoes a complex developmental cycle in ticks which results in infection of salivary glands from where the pathogen is transmitted to cattle.

Structure and mode of action of microplusin, a copper II-chelating antimicrobial peptide from the cattle tick Rhipicephalus (Boophilus) microplus.

Microplusin, a Rhipicephalus (Boophilus) microplus antimicrobial peptide (AMP) is the first fully characterized member of a new family of cysteine-rich AMPs with histidine-rich regions at the N and C termini. In the tick, microplusin belongs to the arsenal of innate defense molecules active against bacteria and fungi. Here we describe the NMR solution structure of microplusin and demonstrate that the protein binds copper II and iron II.

Functional genomics and evolution of tick-Anaplasma interactions and vaccine development.

The genus Anaplasma (Rickettsiales: Anaplasmataceae) includes several tick-transmitted pathogens that impact veterinary and human health. Tick-borne pathogens cycle between tick vectors and vertebrate hosts and their interaction is mediated by molecular mechanisms at the tick-pathogen interface. These mechanisms have evolved characteristics that involve traits from both the tick vector and the pathogen to insure their mutual survival.

Exogenous insulin stimulates glycogen accumulation in Rhipicephalus (Boophilus) microplus embryo cell line BME26 via PI3K/AKT pathway.

Ticks are obligatory blood-feeding arthropods and important vectors of both human and animal disease agents. Besides its metabolic role, insulin signaling pathway (ISP) is widely described as crucial for vertebrate and invertebrate embryogenesis, development and cell survival. In such cascade, Phosphatidylinositol 3-OH Kinase (PI3K) is hierarchically located upstream Protein Kinase B (PKB).

Cellular and molecular characterization of an embryonic cell line (BME26) from the tick Rhipicephalus (Boophilus) microplus.

The cellular and molecular characteristics of a cell line (BME26) derived from embryos of the cattle tick Rhipicephalus (Boophilus) microplus were studied. The cells contained glycogen inclusions, numerous mitochondria, and vesicles with heterogeneous electron densities dispersed throughout the cytoplasm. Vesicles contained lipids and sequestered palladium meso-porphyrin (Pd-mP) and rhodamine-hemoglobin, suggesting their involvement in the autophagic and endocytic pathways.

Cysteine-rich antimicrobial peptides of the cattle tick Boophilus microplus: isolation, structural characterization and tissue expression profile.

Antimicrobial peptides (AMPs) are components of the immune system of both vertebrate and invertebrate animals. This study describes the isolation, primary structure, cDNA cloning, and tissue expression profile of two cysteine-rich AMPs from the hemolymph of the cattle tick Boophilus microplus. A 10,204 Da polypeptide, with six cysteine residues and no sequence similarity to any known molecule, was isolated from the cell-free hemolymph.