Mab17061

C57BL/6 red blood cells infected with Plasmodium berghei ANKA parasites expressing a green fluorescent protein (PbA GFPcon 259cl2, MRA-865, deposited by CJ Janse and AP Waters) were stored in liquid nitrogen and thawed and passed into wild-type mice that served as parasite donor. All mice, unless otherwise stated, were inoculated intravenously (i.v.) into the tail vein with 1×10⁴ parasitized red blood cells (pRBC). Parasitemia was monitored daily (from day 4) by flow cytometry using the FL3 channel (PbA-GFP) and TER-119 APC (erythrocytes) in a BD FACScalibur cytometer (BD Biosciences). Clinical score was assessed using the following clinical scale: 1 = no signs; 2 = ruffled fur and/or abnormal posture; 3 = lethargy; 4 = reduced responsiveness to stimulation and/or ataxia and/or respiratory distress/hyperventilation; and 5 = prostration and/or paralysis and/or convulsions. All animal that reachs stage 4 developped ECM. Recombinant murine IL-33 (Biolegend) was injected intraperitoneally (0.2 μg/mouse/200 μl) daily, routinely from the beginning of infection (day 0). As a control for IL-33 effects, non-infected (NI) mice also received IL-33 for 5 consecutive days. For some experiments, mice were administered with anti-Siglec F (MAB17061, R&D Systems, 50 μg daily) or anti-IL-10 (MAB417, R&D Systems, 40 μg daily) or appropriate isotype control Abs.

At day 12 following orthotopic transplantation with WT FC1245 mouse PDAC cells, male C57BL/6 mice were imaged by ultrasound to record tumor areas and were randomized into treatment groups, including mice that were treated with isotype-matched control IgG or Siglec-F-depleting antibody (20 μg of IgG or antibody per mouse; Siglec-F antibody, R&D Systems, MAB17061; control rat IgG antibody, R&D Systems, MAB006). Tumors were measured, and mice were killed after 10 d of treatment (Siglec-F or IgG intraperitoneal injections every alternate day, five doses total), and pancreata were collected, sliced and flash-frozen in liquid nitrogen or immediately fixed in formalin.