Study of gamma delta T lymphocytes responses to bacterial and damage associated molecules in the presence of Shiga toxin type 2

MELILLO, NADIA CAROLINA; ROSSO, DAVID ANTONIO; ROSATO, MICAELA; SHIROMIZU, CAROLINA MAIUMI; KEITELMAN, IRENE ANGÉLICA; SABBIONE, FLORENCIA; ANALÍA, TREVANI SILVINA; AMARAL, MARÍA MARTA; JANCIC, CAROLINA CAROLINA

Mar del Plata

Congreso; Reunión de Sociedades de Biociencias 2022. LXX Reunión Anual de la Sociedad Argentina de Inmunología y 3er Congreso Franco-Argentino de inmunología; 2022

The hemolytic uremic syndrome (HUS) mainly affects children younger than 5 years old, who have a higher risk of developing severe consequences such as acute or chronic renal failure. HUS associated with diarrhea, hemolytic anemia, and thrombocytopenia is a consequence of Shiga toxin (Stx)-producing Escherichia coli (STEC) infection. Stx type 2 (Stx2)-producing strains are associatedwith severe cases of HUS in Argentina. γδ T cells are a specialized subset of T cells, which act as early sensors of cellular stress and infection. They can exert cytotoxicity against infected cells and produce cytokines and chemokines. Previously, we demonstrated that Stx2-treated human glomerular endothelial cells modulate the γδ T cell functions. In this work, we studied the activation of human peripheral blood γδ T cells in response to Stx2 (0.01ng/ml), in the presence of different agonists to emulate an inflammatory microenvironment that could be developed at the gut epithelial barrier. For that purpose, we used: 1) the phosphoantigen HMBPP (1μM), a potent γδ T cell bacterial agonist; 2) lipopolysaccharide (LPS: 100ng/ml), an integral component of Gram-negative bacteria; and 3) monosodium urate crystals (MSU: 200μg/ml) which act as molecular associated damage pattern. To evaluate γδ T cell activation, we analyzed CD69 expression by flow cytometry, and cytokine production by ELISA, after 24 h incubation with the agonist alone or in combination with Stx2. As result, we observed an increase in CD69 expression, IFN-γ, and TNF-α production (p