Abstract
Background and Objectives: Experimental autoimmune encephalomyelitis (EAE), as a model for human multiple sclerosis, is an inducible inflammatory and demyelinating disease of the central nervous system. It is suggested that females are more susceptible than males to develop EAE. Objective of this study is detection of the role of sex of rat in sensitivity of animal to disease.
Materials and Methods: In this study, we induced EAE and investigated the susceptibility of male and female C57BL/6 mice to EAE, using a myelin oligodendrocyte glycoprotein peptide (MOG35-55). Mice were immunized subcutaneously in the flanks with 200μg of MOG35-55 peptide and complete Fround’s adjuvant. Also, mice received intraperitoneally with 400ng pertussis toxin in 300-400μl phosphate buffer on the day of immunization and 2 days later. The mice were observed daily for clinical signs and scores were assigned based on the following scale: 0: no clinical signs, 1: affected tail tonus, 2: tail paralysis, 3: mild hind leg paresis, 4: severe hind leg paresis, 5: one hind leg paralysis, 6: complete hind legs paralysis, 7: complete hind and fore legs paralysis and 8: death.
Results: The results show that, incidence of EAE was 100 percent in both male and female groups. The onset of disease was faster in the female mice (day 9±1) in comparison with the male mice (day 11±1). Also mean clinical score of disease between male and female were different (4.7±1 and 5.8±0.4, respectively), but this difference was not significant.
Conclusion: These findings suggest that MOG35-55 induced EAE is not gender-related in C57BL/6 mice. Other factors like the type of encephalitogen antigen might be involved in the differences seen in other strain.