INFLAMMATORY IMMUNE RESPONSE ELICITED BY THE CROSS-INTERACTION BETWEEN TROPHOBLASTS, MONOCYTES AND NEUTROPHILS INFECTED WITH BRUCELLA ABORTUS

FERNANDEZ AG; FERRERO MC,; HIELPOS S; FOSSATI CA; PC BALDI,

Mar del Plata

Workshop; LXII Reunión Anual Sociedad Argentina de Inmunología.; 2014

SAI-SAIC

It is well known that Brucella induces abortion in humans and animals, very likely due to a shift towards an inflammatory profile of cytokines present at the maternal-fetal interface. In this work we evaluated cytokines and chemokines secreted after the interaction of human trophoblasts, monocytes and neutrophils infected with B. abortus. The trophoblastic cell line Swan-71 (Sw71), the monocytic cell line THP-1, and neutrophils isolated from peripheral blood were infected with B. abortus 2308 at a multiplicity of infection of 100 for 2 h. After treatment with gentamicin, supernatants were collected at 24 or 48 h post infection and filter-sterilized. THP-1 and neutrophils were stimulated with conditioned medium (CM) from infected Sw71 cells. An increase in IL-8 (p<0,05) and IL-6 (p<0,001) levels was detected after stimulation only in THP-1 cells. In a reciprocal experiment, when Sw71 cells were stimulated with CM from infected monocytes (CM-m) or neutrophils (CM-n), an increase in MCP-1, IL-8 and IL-6 was observed (p<0,001 to p<0,05 in all cases). To analyze the possible involvement of TNF-α and IL-1β in these stimulations, two series of experiments were performed. First, we confirmed that trophoblastic cells respond to recombinant human TNF-α and IL1-β with an increased production of IL-8 and MCP-1 (p<0,001 at all concentrations tested). Second, CM-m and CM-n were treated with a neutralizing anti-human TNF antibody or recombinant human IL-1ra (IL-1 receptor antagonist) before using them to stimulate Sw71 cells. IL-1ra produced a significant decrease in the secretion of IL-8 and IL-6 in response to both CM (p<0,05), whereas both blocking agents decreased MCP-1 production in response to CM-n (p<0,05). These findings show that cross-interaction between trophoblasts and immune cells during B. abortus infection lead to an inflammatory cytokine profile which might be involved in fetus miscarriage.