The therapeutic potential of the recombinant antigen from Dirofilaria immitis (rDiAg) for immune-mediated pregnancy loss

Fetal loss due to Th1-skewed Th1/Th2 balance with increase (not decrease) of regulatory T cells in abortion-prone mouse model

We used an abortion-prone mouse model, generated by mating female CBA/J mice with male DBA/2JJcl mice, to examine the effects of changes in the Th1/Th2 cell ratio and the percentage of regulatory T (Treg) cells on the maintenance of pregnancy. We subcutaneously injected female CBA/J mice once each with 50 μg/mouse of Dermatophagoides farinae (Df) extract and the squalene-based adjuvant (SquA); 10 days later, these mice were mated with male DBA/2JJcl mice. Compared with injection of vehicle or adjuvant, the Df treatment decreased the Th1/Th2 cell ratio and concomitantly increased the percentage of Treg cells in the spleen. In addition, fetal death rates were decreased. We then explored a substance which shifted the Th1/Th2 balance toward Th1 side. We found that 50 μg/mouse of keyhole limpet hemocyanin (KLH) increased the splenic Th1/Th2 cell ratio of nonpregnant female CBA/J mice. We subcutaneously injected female CBA/J mice with KLH and SquA; 10 days later, these mice were mated with male DBA/2JJcl mice. Compared with injection of vehicle or adjuvant, treatment with KLH enhanced the Th1 bias during pregnancy and increased the fetal death rate. The percentage of Treg cells, however, was increased in these KLH-injected pregnant mice contrary to our presumption. All collected data showed strong positive correlation between the Th1/Th2 cell ratio and fetal death rate. The increase in Treg cells independent of effects on the fetal death rate suggests that Treg cells do not necessarily induce maternal tolerance to the fetus but may prevent excessive Th1/Th2 imbalance during pregnancy.

Recombinant proteins of helminths with immunoregulatory properties and their possible therapeutic use

The inverse relationship between helminth infections and the development of immune-mediated diseases is a cornerstone of the hygiene hypothesis and studies were carried out to elucidate the mechanisms by which helminth-derived molecules can suppress immunological disorders. These studies have fostered the idea that parasitic worms may be used as a promising therapeutic alternative for prevention and treatment of immune-mediated diseases. We discuss the current approaches for identification of helminth proteins with potential immunoregulatory properties, including the strategies based on high-throughput technologies. We also explore the methodological approaches and expression systems used for production of the recombinant forms of more than 20 helminth immunomodulatory proteins, besides their performances when evaluated as immunotherapeutic molecules to treat different immune-mediated conditions, including asthma and inflammatory bowel diseases. Finally, we discuss the perspectives of using these parasite-derived recombinant molecules as tools for future immunotherapy and immunoprophylaxis of human inflammatory diseases.

Helminth therapy for organic diseases?

Autoimmune and chronic inflammatory organic diseases represent a "postindustrial revolution epidemics," and their frequency has increased dramatically in the last century. Today, it is assumed that the increase in hygiene standards reduced the interactions with helminth parasites that coevolved with the immune system and are crucial for its proper functioning. Several helminths have been proposed and tested in the search of the ideal therapeutic. In this review, the authors summarize the translational and clinical studies and review the caveats and possible solutions for the optimization of helminth therapies.

Inflammation, NK cells and implantation: friend and foe (the good, the bad and the ugly?): replacing placental viviparity in an evolutionary perspective

This review summarises an invited talk presented at the 2012 ESRI/ASRI meeting in Hamburg, concerning current views of inflammation in pregnancy, which is timely given that the effects of a local injury in the uterus acts to favour implantation. Recalling that inflammation can be good (it is useful and necessary for implantation), bad (in implantation failure, RSA) and ugly (at the extreme, endometriosis is associated with pain and infertility) leads to consideration of its status in pregnancy. Its role in implantation and the fact that pregnancy maintains some aspects of inflammation throughout, leads to revision of not only concepts of immunosuppression and the Th1/Th2 paradigm, but also the feto-maternal relationship as seen since Medawar's hypotheses were advanced. This is examined from an evolutionary perspective, which should lead to further review of our perception of uterine NK cells, and the emergence of Treg cells to control some aspects of adaptive immunity, which appeared long after placentation.