Lode João Victor Lé, Ito Lucas Takeshi Siqueira, Umino Gisele Mitsue, de Lima Valéria Marçal Felix
Department of Clinical Medicine, Surgery and Animal Reproduction, São Paulo State University (UNESP), School of Veterinary Medicine, Araçatuba, São Paulo, Brazil.
Parasite Immunol. 2025 Aug;47(8):e70021. doi: 10.1111/pim.70021.
Visceral leishmaniasis is a potentially fatal zoonosis with an increasing incidence. Most infected felines present the disease in its subclinical form and demonstrate greater resistance to parasitemia than dogs. However, the role of cellular immunity in felines is still poorly understood. This study measured serum levels of interleukin (IL)-12 and interferon-gamma (IFN-γ) in asymptomatic cats naturally infected with antibodies against Leishmania spp. and in uninfected cats. IL-12 and IFN-γ were measured in serum samples by ELISA. Parasite load quantification was performed on DNA from bone marrow samples using qPCR. Cats naturally infected by Leishmania spp. showed significantly higher serum levels of IL-12 and IFN-γ compared to control animals. IL-12 showed a positive correlation with IFN-γ suggesting a regulatory role of IL-12 in activating the Th1 immune response, which enhances macrophage function and promotes intracellular parasite elimination. Additionally, IL-12 showed a moderate negative correlation with parasite load, indicating a protective effect of IL-12 in feline leishmaniasis. These findings suggest that IL-12 and IFN-γ play critical roles in modulating the feline immune response against parasitic infection, possibly contributing to the control of parasite replication and in the prevention of clinical signs. The immune response observed in felines could be explored for future immunotherapeutic approaches, helping to mitigate the progression of leishmaniasis in cats and reducing the risk of transmission in endemic regions.
内脏利什曼病是一种发病率不断上升的潜在致命人畜共患病。大多数感染的猫科动物以亚临床形式表现出该病，并且比犬类对寄生虫血症具有更强的抵抗力。然而，细胞免疫在猫科动物中的作用仍知之甚少。本研究测量了自然感染利什曼原虫属抗体的无症状猫和未感染猫血清中的白细胞介素（IL）-12和干扰素-γ（IFN-γ）水平。通过酶联免疫吸附测定法（ELISA）检测血清样本中的IL-12和IFN-γ。使用定量聚合酶链反应（qPCR）对骨髓样本中的DNA进行寄生虫载量定量。与对照动物相比，自然感染利什曼原虫属的猫血清中IL-12和IFN-γ水平显著更高。IL-12与IFN-γ呈正相关，表明IL-12在激活Th1免疫反应中具有调节作用，可增强巨噬细胞功能并促进细胞内寄生虫清除。此外，IL-12与寄生虫载量呈中度负相关，表明IL-12在猫利什曼病中具有保护作用。这些发现表明IL-12和IFN-γ在调节猫对寄生虫感染的免疫反应中起关键作用，可能有助于控制寄生虫复制并预防临床症状。可以探索在猫科动物中观察到的免疫反应用于未来的免疫治疗方法，有助于减轻猫利什曼病的进展并降低流行地区的传播风险。
