Crotoxin Isolated from Crotalus durissus terrificus Venom Modulates the Functional Activity of Dendritic Cells via Formyl Peptide Receptors

Figure 5

CTX and CB inhibit the proliferative response and IL-2 production of CD3⁺ T cells cocultured with DCs preincubated with LPS. DCs differentiated in vitro from bone marrow of BALB/c mice were incubated for CTX, CB, and CA (250 ng/mL); LPS (250 ng/mL); and LPS + CTX, LPS + CB, and LPS + CA (250 ng/mL and 250 ng/mL) for 18 h. The cells (0.6 × 10⁵) were cocultured with CD3⁺ lymphocytes (3 × 10⁵) purified from C57BL/6 mice. As controls, DCs and CD3⁺ cells were maintained in culture medium (date not shown). (a) The proliferative response was analyzed at 72 h of culture as described in Materials and Methods. (b) The coculture supernatants were collected for IL-2 detection by ELISA. The results were expressed as the mean of the optical density obtained from the samples in quadruplicate ± SD for the lymphocyte proliferation assay. The data are representative of two independent experiments. IL-2 secretion was expressed as the mean of the samples in triplicate ± SD. The dashed line represents the detection limit of the assay. Statistical analyses were performed by one-way ANOVA, followed by Tukey’s test (GraphPad Prism 5.0, GraphPad Software). —CD3⁺ T cells plus DCs incubated with LPS compared with CD3⁺ T cells plus DCs previously incubated with medium, CTX, CB, or CA; —CD3⁺ T cells plus DCs incubated with LPS compared with CD3⁺ T cells plus DCs stimulated with LPS + CTX or LPS + CB.

(a)

(b)