Humoral response and citokine profile in Lama Glama pregnant females

AM CANELLADA, N SACCODOSSI, E JULIÁ, E DE SIMONE, ; ABRAHAM MF, AC PARRADO, N SACCODOSSI, A RUGNA, E REY, MT GENTILE, A CANELLADA; T GENTILE.

Congreso; XXXIX Congress of the Brazilian Society of Immunology. Immuno Buzios 2014; 2014

Little is known about the immune response during pregnancy in camelids. In mice, rats and humans it is known that fetal rejection is prevented as a result of the greater ratio of TH2 compared to TH1 cytokines produced by maternal leukocytes. We propose to study the immunoregulatory effect of pregnancy on the llamas. Humoral immune response analyzing the different isotypes of immunoglobulins, the Th1/Th2 cytokines profile and its correlation with Progesterone P4 hormone levels. Methods: Immunization schedules were performed with Ovalbumin (OVA) and a fraction of T. cruzi (F105) in pregnant and non pregnant llamas. The presence of specific Abs isotypes, both in sera and in PBMC culture supernatants (SN), was analyzed by ELISA. The PBMC were obtained and cultured in the presence of ConA, LPS, OVA and F105, separately. The expression of IL-6, IFN-γ, IL-2, IL-4 e IL-10 RNAm was detected by RT-PCR. In parallel, the levels of IL-6 and TNF-α were determined by ELISA in the SN of different cultures. Finally, the Th1/Th2 profile was analyzed by RT-PCR in non pregnant PBMC cultures in the presence or absence of P4. Results: A significant difference was observed in the specific IgM titers against OVA between the sera of pregnant and non-pregnant llamas (2.301 + 1.534 vs 0.1229 + 0.7670 p menor a 0.05 log 1/title). No significant differences were observed in the IL-6 and TNF-α levels obtained from the SN of PBMC cultured with LPS or antigens, between pregnant and non-pregnant llamas. Only if the PBMC of pregnant llamas are cultured in the presence of ConA, a decreased in the IL-6 expression is observed compared to the PBMC of non-pregnant llamas. The PBMC stimulated with mitogens or specific antigens showed no significant difference in the cytokines RT-PCR. However, when performing the in vitro culture of non pregnant llamas PBMC in the presence of P4, a decrease in the expression of IL-6 mRNA is observed compared to PBMC without P4. Conclusions: The increased titers of IgM anti-OVA obtained from the pregnant llamas sera, could be related to the increased concentration of IgM obtained in colostrum samples, as described previously. The association observed between the decreased levels of IL-6, obtained by ELISA, from the SN of pregnant llamas PBMC cultured with ConA; and the decreased levels of IL-6 RNAm, analyzed by RT-PCR, from cultured non-pregnant llamas PBMC with P4 and ConA; suggests that the pregnant llamas? immune system like mice, rats and humans, is under an immune regulated state.