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Olga Lissina

Publications and source records attributed to Olga Lissina.

5 recordsLinked to original sources
PubMed2006

An antivector vaccine protects against a lethal vector-borne pathogen.

Vaccines that target blood-feeding disease vectors, such as mosquitoes and ticks, have the potential to protect against the many diseases caused by vector-borne pathogens. We tested the ability of an anti-tick vaccine derived from a tick cement protein (64TRP) of Rhipicephalus appendiculatus to protect mice against tick-borne encephalitis virus (TBEV) transmitted by infected Ixodes ricinus ticks. The vaccine has a "dual action" in immunized animals: when infested with ticks, the inflammatory and immune responses first disrupt the skin feeding site, resulting in impaired blood feeding, and then specific anti-64TRP antibodies cross-react with midgut antigenic epitopes, causing rupture of the tick midgut and death of engorged ticks. Three parameters were measured: "transmission," number of uninfected nymphal ticks that became infected when cofeeding with an infected adult female tick; "support," number of mice supporting virus transmission from the infected tick to cofeeding uninfected nymphs; and "survival," number of mice that survived infection by tick bite and subsequent challenge by intraperitoneal inoculation of a lethal dose of TBEV. We show that one dose of the 64TRP vaccine protects mice against lethal challenge by infected ticks; control animals developed a fatal viral encephalitis. The protective effect of the 64TRP vaccine was comparable to that of a single dose of a commercial TBEV vaccine, while the transmission-blocking effect of 64TRP was better than that of the antiviral vaccine in reducing the number of animals supporting virus transmission. By contrast, the commercial antitick vaccine (TickGARD) that targets only the tick's midgut showed transmission-blocking activity but was not protective. The 64TRP vaccine demonstrates the potential to control vector-borne disease by interfering with pathogen transmission, apparently by mediating a local cutaneous inflammatory immune response at the tick-feeding site.

Amino Acid Sequence↗
PubMed2005

A cross-reactive tick cement antigen is a candidate broad-spectrum tick vaccine.

Truncated constructs of 64P (64TRPs), a secreted cement protein from salivary glands of the tick Rhipicephalus appendiculatus, provided cross-protection against Rhipicephalus sanguineus and Ixodes ricinus, apparently by targeting antigens in the midgut and salivary glands of adults and nymphs, causing mortality. Tick feeding on 64TRP-immunised animals stimulated local inflammatory immune responses (involving basophils, eosinophils, lymphocytes, mast cells, macrophages and dendritic-like cells) that boosted the immune status of vaccinated animals. The vaccine trial results, and antigenic cross-reactivity of 64TRPs with R. sanguineus, I. ricinus, Amblyomma variegatum and Boophilus microplus, indicate the potential of 64TRPs as a broad-spectrum anti-tick vaccine.

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PubMed2005

Complement inhibitor of C5 activation from the soft tick Ornithodoros moubata.

Blood-feeding ticks must control C activation or be damaged by the host inflammatory response. We report the characterization and expression of a novel, relatively small, broad-acting C inhibitory protein (termed OmCI) from the soft tick Ornithodoros moubata. The native 17-kDa nonglycosylated protein inhibits both human and guinea pig classical and alternative C activation pathways. The IC50 values for each pathway were 12 and 27 nM, respectively, in hemolytic assays using human serum diluted 40-fold. The cDNA encodes a protein of 168 aa, including an 18-aa secretion signal sequence that is absent in the mature form. The inhibitor has 46% amino acid identity with moubatin, a platelet aggregation inhibitor also from O. moubata that is an outlying member of the lipocalin family. Native OmCI had no inhibitory effect on the addition of C8 and C9 to preformed C5b-C7 and C5b-C8 to form the membrane attack complex and no effect on the rate of C3a production by the C3 convertase enzymes C4bC2a, C3(H2O)Bb, or C3bBb. Both recombinant and native OmCI abolish production of C5a by human classical (C4bC3bC2a) and alternative (C3bC3bBb) C5 convertases. Addition of excess C5 but not C3 competes away the inhibitory activity of OmCI, indicating that OmCI targets C5 itself rather than inhibiting the C5 convertase C4bC3bC2a itself. Direct binding of OmCI to C5 was demonstrated by Western blotting and gel filtration chromatography using 125I-labeled proteins. OmCI is the first lipocalin family member shown to inhibit C and also the first natural inhibitor that specifically targets the C5 activation step.

Amino Acid Sequence↗
PubMed2005

Arthropod-derived protein EV131 inhibits histamine action and allergic asthma.

Histamine is an important mediator of allergic responses. Arthropods express several biologically active proteins in their saliva, which may allow a prolonged blood meal on the host. Proteins identified and expressed include histamine, serotonin, tryptase, and complement binding proteins. We review here data that scavenging of endogenous histamine by the histamine-binding protein EV131 has a profound inhibitory effect on allergic asthma. Aerosol administration of EV131 prevented airway hyperreactivity and abrogated peribronchial inflammation, eosinophil recruitment, mucus hypersecretion, and IL-4 and IL-5 secretion. Saturation with histamine abrogated the inhibitory effect of EV131 on bronchial hyperreactivity. The data suggest that histamine plays a role in allergies and that scavenging of histamine by EV131 may represent a novel therapeutic strategy in the treatment of allergic diseases.

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