Incorporation of a 35-kilodalton purified protein from Loxosceles intermedia spider venom transforms human erythrocytes into activators of autologous complement alternative pathway

• DOI: 10.4049/jimmunol.155.9.4459
• Publication Date: 2022-12-31T12:18:43Z
• Authors: D V Tambourgi; F C Magnoli; V R Von Eickstedt; Z C Benedetti; V L Petricevich; W D da Silva
• Keywords: EGTA

Cutaneous inoculation of Loxosceles spp. spider venoms produces local necrosis, occasionally accompanied by systemic intravascular clotting and hemolysis. In this work, we analyzed the role C system on lysis human erythrocytes (Eh) induced in vitro. Eh were treated with whole venom laeta, gaucho, or intermedia, purified proteins, incubated C-sufficient (Cs-NHS) C9-depleted autologous (C9d-NHS) serum. Hemolysis was determined spectrophotometrically, deposition components removal regulatory proteins FACS. suspensions exposed to a 35-kDa protein from L. intermedia lysed after incubation Cs-NHS, but not C9d-NHS. Lysis blocked heating serum at 50 degrees Ca2+/Mg2+ chelation EDTA, Ca2+ EGTA. Deposition C1, C2, C3, C4, C5, factor B venom-treated occurred during activation C. Regulatory decay-accelerating (DAF) CD59 altered significantly. Conversion C-resistant into C-susceptible incorporation onto cell surface. Thirty-five-kilodalton-related detected two other ELISA, using rabbit antiserum against protein. These data suggest that mediates and, extension, types able incorporate lytic their surfaces.