Host-parasite Responses Outcome Regulate the Expression of Antimicrobial Peptide Genes in the Skin of BALB/c and C57BL/6 Murine Strains Following MRHO/IR/75/ER Infection.

BACKGROUND

Different background of immunity responses determine resistance or susceptibility of certain mouse strains to infection. Some have been well known previously. Antimicrobial peptides (AMPs) such as cathelicidins and defensins are unique fragments of innate immunity system with well-known effects against the invasion pathogens. Despite their outstanding roles and being of extensive cases of cutaneous leishmaniasis (CL) caused by , they have been less studied in fields. The aim of present study was to determine whether these components play a role in the protection of skin against infections.

METHODS

The animal model of infection was established by the subcutaneous inoculation of 5×10(parasites/ml) from the stationary phase of promastigotes to BALB/c and C57BL/6 mice from January 2016 to August 2016 in Kerman Province, southeast of Iran. After 1, 3 and 7 d of post-infection (PI), the samples needed for detecting of the mRNA levels of mouse beta-defensin (mBD)-1, mBD2, mBD3, mBD4, mBD6, cathlin-related antimicrobial peptide (CRAMP), interleukin (IL)-10, IL-12 and parasite load were taken under standard methods.

RESULTS

The findings related to cytokines profiles in BALB/c (↑IL-10, ↓IL-12) and C57BL/6 mouse strains (↓IL-10, ↑IL-12) demonstrated that immunity system has been accurately activated during CL caused by parasites. We also observed a significant up-regulation of all aforementioned AMPs genes in BALB/c mice at selected times compared to another strain.

CONCLUSION

CL occurred in BALB/c mice in spite of the fact that the expression of AMPs was higher than the other strain. AMPs genes are well expressed to provide defense against the parasites that have increased and escaped from immunity system but cannot create an absolute protection.