The role of complement system in a gerbil model of cutaneous leishmaniasis

Leishmania species are intracellular protozoans responsible for causing both cutaneous and visceral infections. In recent years, the prevalence of leishmaniasis, a systemic and chronic disease, has been on the rise. Complement pathway mechanisms, part of the immune response of host organisms against Leishmania species, have not been fully revealed in leishmaniasis, which is very important for public health. This study aimed to explore the role of the complement system, an integral part of the immune response to Leishmania infections, in gerbil (Meriones unguiculatus) models of cutaneous leishmaniasis. This was achieved by assessing the expression levels of complement system genes (MBL-1, MBL-2, C2, and C3) and quantifying the protein levels of MBL-1, C2, and C3. Additionally, the study aimed to conduct biochemical tests, specifically measuring GSH and MDA levels, to detect oxidative stress in response to infection in gerbils. Finally, hematological analyses were performed to evaluate leukocyte counts in the blood. The expression of complement system genes and some complement system proteins were significantly increased in infected gerbils. Oxidative stress was evident, as indicated by reduced GSH levels and increased MDA levels. Additionally, a significant rise in leukocyte counts was observed as a consequence of the infection. The study concluded that complement system pathways are activated in cutaneous leishmaniasis infections. It was also determined that a thorough evaluation of genomic, proteomic, and immunopathological mechanisms is essential for understanding the pathogenesis of the disease.