Do Fetal Microchimeric Cells Influence Experimental Autoimmune Myocarditis?

Abstract

Objective: We investigated the presence and influence of fetal microchimerism in the cardiac tissue of mated female mice submitted to experimental autoimmune myocarditis. Materials and methods: Nulliparous BALB/c females and BALB/c females mated with either BALB/c males (syngeneic mating) or C57BL/6 males (allogeneic mating) were immunized with cardiac myosin peptide MyHC-α_614-629 or kept as non-immunized controls. Immunization occurred 6-8 weeks after delivery and mice were assessed after 21 days. Results: Immunized mice of allogeneic mating had a lower production of anti-MyHC-α_614–629 antibodies compared to immunized nulliparous mice. Immunized nulliparous females had an intense mononuclear inflammatory infiltrate in cardiac tissue, associated with fibroplasia, while mated females had a lower inflammatory reaction. An increase in the frequency of microchimeric fetal cells was observed in mice submitted to allogeneic mating following immunization. Conclusion: Allogeneic cells of fetal origin could contribute to mitigating the inflammatory response in experimental myocarditis.

Keywords:

• Pregnancy
• microchimerism
• fetal cells
• semi-allogeneic cells
• myocarditis

Acknowledgments

The authors are thankful to CAPES and their colleagues from the Cell Biomorphology Laboratory, Institute of Biomedicine, Federal Fluminense University, Brazil, that helped with the production of histological slides.

Disclosure statement

The authors have no conflict of interest.

Funding

This work was supported by Research Support Foundation of the State of Rio de Janeiro (FAPERJ – No. E-26/200.927/2017).