Mast-Cell Response to Leishmania mexicana and Sand-Fly Salivary Proteins Is Modulated by Orchiectomy

• Published in: Pathogens (Basel) Vol. 11; no. 4; p. 398
• Main Authors: Sánchez-García, Laura, Pérez-Torres, Armando, Muñoz-Cruz, Samira, Salaiza-Suazo, Norma, Morales-Montor, Jorge, Becker, Ingeborg
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 25.03.2022; MDPI
• Subjects: Degranulation; Endocrine system; Exocrine glands; Gender; Histamine; Histology; Hormones; Immune response; Immune system; Infections; Inflammation; Inflammatory response; Leishmania; Leishmania mexicana; Leukocytes (neutrophilic); Macrophages; Males; Mast cells; Neutrophils; Parasites; Pathogens; Proteins; Recruitment; Saliva; sand fly salivary proteins; Sex hormones; sexual hormones; Tryptase; Tumor necrosis factor-α; mast cells; sand fly salivary proteins; sexual hormones; Leishmania mexicana
• ISSN: 2076-0817; 2076-0817
• DOI: 10.3390/pathogens11040398

Mast cells (MCs) play a crucial role during infections, which is transmitted through the bite of an infected sand fly that injects saliva together with the parasite. Sand fly saliva is a complex fluid that modulates the host immune response. In addition, hormonal factors modulate the host immune response and alter susceptibility to infections. Thus, to assess the impact of male sex hormones on the mast-cell (MC) response to infections, we orchiectomized male mice, infected them with the parasite in the presence of sand fly salivary proteins, and analyzed the inflammatory response of MCs. Our results showed that the MC response to the parasite and vector salivary proteins differed between orchiectomized and sham-operated mice. In orchiectomized mice, MC showed a retarded activation pattern, associated with slower degranulation and weaker TNF-α, histamine, and tryptase staining in response to the infection with combined with vector-salivary proteins, as compared to sham mice. Furthermore, neutrophil infiltration was slower in orchiectomized mice, and numbers of infected macrophages and lesion sizes were smaller. Our results show that, during infection, male sex hormones modulate the mast-cell response against the parasite and salivary proteins of the sand fly vector, inducing an intense inflammatory response. Their absence in orchiectomized mice retards the inflammatory response, enabling better control of the infection and slower disease progression.