In vivo expression of recombinant pregnancy-specific Glycoprotein 1a induces alternative activation of monocytes and enhances Th2-type immune response.

MOTRAN, CC; LOPEZ DIAZ, FERNANDO; MONTES, CAROLINA L; BOCCO, JOSE L; GRUPPI, ADRIANA

EUROPEAN JOURNAL OF IMMUNOLOGY

WILEY-V C H VERLAG GMBH

Año: 2003 p. 3007 - 3016

0014-2980

It has been proposed that pregnancy-specific factors could be responsible for shift the balance of cytokine profiles during maternal immune response from Th1-type reactivity into a "less-damaging" Th2-type reactivity. In the present work, we investigated the in vivo function of human pregnancy-specific glycoprotein (PSG)1a, the major variant of PSG polypeptides released into the circulation during pregnancy, on the modulation of the innate and adaptive immune response. For this, BALB/c mice were injected with a vaccinia virus-based vector harboring the human PSG1a cDNA (Vac-PSG1a) 4 days before immunization with ovalbumin (OVA) in complete Freund´s adjuvant, and the early specific T cell response against OVA was evaluated 8 days post-immunization. We also studied the activation status of spleen and peritoneal monocytes/macrophages (Mo) populations from Vac-PSG1a-treated mice, and explored whether PSG1a-targeted Mo could affect the Th-type commitment by investigating their impact on the differentiation of naive T cells. Our data show that the treatment with Vac-PSG1a is able to induce a state of alternative activation on Mo. Furthermore, the generation of the immune response in the context of these alternatively activated antigen-presenting cells may shift T cell differentiation to Th2-type immunity which is more compatible with a successful pregnancy.