Pregnancy impairs resistance of C57BL/6 mice to Leishmania major infection.
To determine if gestational factors affect the severity of L. major infection, this study assessed the levels of IL-4 mRNA and IFN-gamma mRNA in popliteal lymph node cells of pregnant C57BL/6 mice mated at 5 hours, 16 hours and 15 days post L. major infection using PCR. Infected pregnant C57BL/6 mice developed larger cutaneous footpad lesions compared with non-pregnant infected C57BL/6 mice. The resolution of footpad lesions commenced after 8th week in C57BL/6 mice mated at 16 hrs post L. major infection but 12 weeks in C57BL/6 mice mated at 5 hrs and 15 days post L. major infection. C57BL/6 mice that were infected 20 days post partum resolved L. major infection effectively. But, the lesions in infected pregnant C57BL/6 mice and infected non-pregnant C57BL/6 mice were not as large as in susceptible BALB/c mice. The mean litter weights were similar in pregnant infected C57BL/6 mice mated at different stages of L. major infection but were slightly lower than weights of litters from pregnant uninfected C57BL/6 mice. In 5 days infected pregnant C57BL/6 mice, the levels of IFN-gamma were raised compared with the levels of IL-4 but those mated at 15 days post L. major infection had highest level of IFN-gamma mRNA. In 10 days pregnant infected C57BL/6 mice, levels of IL-4 were raised compared with IFN-gamma but mice mated at 16 hrs post L. major infection had highest level of IL-4. In 15 days pregnant infected mice, the levels of IL-4 were higher than IFN-gamma irrespective of the stage of L. major infection when the mice were mated. Mice infected with L. major 20 days post-partum produced more IFN-gamma than IL-4 from 16 hrs post L. major infection onwards. It may be concluded that increased IL-4 in pregnant infected C57BL/6 mice impairs the resistance of C57BL/6 mice to L. major infection especially in mice that were pregnant before effective immunity (5 hours post L. major infection) is mounted against L. major infection.
Arinola
O G
OG
Department of Chemical Pathology and Immunology, College of Medicine, University of Ibadan, Oyo State, Nigeria. arinolaog@doctor.com
Louis
J S
JS
Tacchini-Cottier
F
F
Aseffa
A
A
Salimonu
L S
LS
D000818:Animals; D005260:Female; D006790:Host-Parasite Interactions; D015847:Interleukin-4; D018320:Leishmania major / Q000472:pathogenicity*; D016773:Leishmaniasis, Cutaneous / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000276:immunology*; D012307:Risk Factors; D018417:Th1 Cells; D018418:Th2 Cells
D015847:Interleukin-4