RESUMO
PROBLEM: Several studies indicate that RANTES (regulated on activation, normal T cell expressed and secreted) is able to downregulate T-cell responses which suggest it might be relevant for fetal tolerance induction. However, the role of RANTES in pregnancy had not been established. Here we investigate RANTES regulation during early pregnancy and potential failures leading to losses of pregnancies. METHOD OF STUDY: RANTES and progesterone levels were determined in sera and feto-placental units from high resorption rate CBA/JxDBA/2 pregnant females and compared with CBA/JxBALB/c normal pregnant mice. RANTES in vitro modulation was also studied in nulliparous, primiparous and multiparous CBA/J and BALB/c cells in response to paternal alloantigen and progesterone stimulation. RESULTS: Nulliparous CBA/J females were quantitatively deficient in RANTES sera levels, whereas pregnancies with male BALB/c or DBA/2 increased its production. However, feto-placental units from CBA/J females are high producers of progesterone and RANTES. CONCLUSION: These data suggest that the beneficial effect of RANTES on feto-maternal interface requires an optimal concentration range and might be modulated by progesterone, hence exacerbated placental expression could be associated with high resorption rate.
Assuntos
Aborto Espontâneo/imunologia , Quimiocina CCL5/imunologia , Progesterona/imunologia , Aborto Espontâneo/sangue , Aborto Espontâneo/metabolismo , Animais , Quimiocina CCL5/sangue , Quimiocina CCL5/metabolismo , Feminino , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos CBA , Camundongos Endogâmicos DBA , Placenta/imunologia , Placenta/metabolismo , Gravidez , Progesterona/biossíntese , Progesterona/sangueRESUMO
PROBLEM: Previous studies have demonstrated a requirement for RANTES (regulated on activated normal T-cell expressed, and secreted) at immune privileged sites; we have investigated the role of RANTES in the induction of maternal-fetal tolerance. METHOD OF STUDY: Endometrial and peripheral T lymphocytes were obtained from women with recurrent pregnancy losses (RPLs) and fertile women. RANTES modulation by progesterone or paternal alloantigens was measured by enzyme-linked immunosorbent assay or flow cytometry analysis. RESULTS: Progesterone significantly increased intracellular RANTES expression in CD4+ and CD8+ endometrial T cells. Moreover, alloreactive lymphocytes from RPL patients produced lower RANTES levels when compared with those from fertile women. At the local level, treatment with recombinant RANTES induced a decrease in CCR5 and CXCR4 messenger RNA that correlated with an increase in T-bet expression. RPL patients and normally fertile women express RANTES similarly, but differ in their patterns of RANTES receptor expression. CONCLUSION: RANTES may be implicated in the local induction of a Th1-type response necessary for successful implantation. Altered response to RANTES stimulation among some RPL patients may be responsible for poor pregnancy outcomes.
Assuntos
Quimiocina CCL5/biossíntese , Feto/imunologia , Feto/metabolismo , Tolerância Imunológica/imunologia , Isoantígenos/imunologia , Aborto Habitual/imunologia , Biomarcadores , Transferência Embrionária , Endométrio/imunologia , Endométrio/metabolismo , Feminino , Fertilidade , Humanos , Mães , Progesterona/metabolismo , Células Th1/metabolismo , Células Th2/metabolismoRESUMO
We investigated the immunomodulatory role of chemokines in the maternal allogeneic T-cell response. In comparison with fertile women, we found in patients with recurrent spontaneous abortions (RSA), a significant decreased sera level of RANTES that increased after immunization with paternal leukocytes. Since blocking factors with unknown identity are detected in sera from fertile women, we hypothesized that RANTES might function as a novel blocking factor and therefore we explored its cell growth inhibitory properties during the allogenic T-cell response. We demonstrated that RANTES inhibits the mixed lymphocyte reaction (MLR) in a dose-dependent manner. Investigation of the mechanisms involved in cell growth inhibition revealed that this beta-chemokine induces T-cell apoptosis through modulation of Bcl-2 protein levels and by a caspase-independent mechanism and does not involve modulation of Fas (CD95) antigen expression. Our results provides experimental evidence implicating RANTES as a suppressor of alloantigen specific T-cell responses and indicates that this beta-chemokine might function as a novel blocking factor and reliable marker for successful allotreatment of RSA patients.