Martín-Martín Inés, Molina Ricardo, Jiménez Maribel
Unidad de Entomología Médica, Servicio de Parasitología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
PLoS One. 2015 Nov 16;10(11):e0140722. doi: 10.1371/journal.pone.0140722. eCollection 2015.
Sand flies are hematophagous arthropods that act as vectors of Leishmania parasites. When hosts are bitten they develop cellular and humoral responses against sand fly saliva. A positive correlation has been observed between the number of bites and antibody levels indicating that anti-saliva antibody response can be used as marker of exposure to sand flies. Little is known about kinetics of antibodies against Phlebotomus perniciosus salivary gland homogenate (SGH) or recombinant salivary proteins (rSP). This work focused on the study of anti-P. perniciosus saliva antibodies in sera of mice and rabbits that were experimentally exposed to the bites of uninfected sand flies.
METHODOLOGY/PRINCIPAL FINDINGS: Anti-saliva antibodies were evaluated by ELISA and Western blot. In addition, antibody levels against two P. perniciosus rSP, apyrase rSP01B and D7 related protein rSP04 were determined in mice sera. Anti-saliva antibody levels increased along the immunizations and correlated with the number of sand fly bites. Anti-SGH antibody levels were detected in sera of mice five weeks after exposure, and persisted for at least three months. Anti-apyrase rSP01B antibodies followed similar kinetic responses than anti-SGH antibodies while rSP04 showed a delayed response and exhibited a greater variability among sera of immunized mice. In rabbits, anti-saliva antibodies appeared after the second week of exposure and IgG antibodies persisted at high levels, even 7 months post-exposure.
CONCLUSIONS/SIGNIFICANCE: Our results contributed to increase the knowledge on the type of immune response P. perniciosus saliva and individual proteins elicited highlighting the use of rSP01B as an epidemiological marker of exposure. Anti-saliva kinetics in sera of experimentally bitten rabbits were studied for the first time. Results with rabbit model provided useful information for a better understanding of the anti-saliva antibody levels found in wild leporids in the human leishmaniasis focus in the Madrid region, Spain.
白蛉是吸血节肢动物，作为利什曼原虫寄生虫的传播媒介。当宿主被叮咬时，它们会产生针对白蛉唾液的细胞和体液反应。已观察到叮咬次数与抗体水平之间呈正相关，这表明抗唾液抗体反应可作为接触白蛉的标志物。关于针对有害白蛉唾液腺匀浆（SGH）或重组唾液蛋白（rSP）的抗体动力学知之甚少。这项工作聚焦于研究经实验暴露于未感染白蛉叮咬的小鼠和兔血清中抗有害白蛉唾液抗体。
方法/主要发现：通过酶联免疫吸附测定（ELISA）和蛋白质印迹法评估抗唾液抗体。此外，还测定了小鼠血清中针对两种有害白蛉rSP（腺苷三磷酸双磷酸酶rSP01B和D7相关蛋白rSP04）的抗体水平。抗唾液抗体水平在免疫过程中升高，并与白蛉叮咬次数相关。在暴露后五周的小鼠血清中检测到抗SGH抗体水平，并持续至少三个月。抗腺苷三磷酸双磷酸酶rSP01B抗体呈现出与抗SGH抗体相似的动力学反应，而rSP04显示出延迟反应，并且在免疫小鼠的血清中表现出更大的变异性。在兔中，抗唾液抗体在暴露后第二周出现，IgG抗体持续保持高水平，甚至在暴露后7个月依然如此。
结论/意义：我们的结果有助于增加对有害白蛉唾液及个别蛋白质引发的免疫反应类型的了解，突出了rSP01B作为暴露流行病学标志物的用途。首次研究了经实验叮咬的兔血清中的抗唾液动力学。兔模型的结果为更好地理解西班牙马德里地区人类利什曼病疫源地野生兔科动物中发现的抗唾液抗体水平提供了有用信息。
