Development of process to produce polyvalent IgY antibodies anti-African snake venom.

Polyvalent anti-Bitis and anti-Naja antivenom IgY antibodies were prepared using B. arietans, B. nasicornis, B. rhinoceros, N. melanoleuca, and N. mossambica venoms to immunize chickens. Blood and eggs were collected before and during the 10-month immunization period; the sera and yolk extracts were then prepared and assayed for the presence of antivenom antibodies by ELISA and Western blot methods. ELISA Antivenom antibody titers, referred to as U-ELISA/ml of serum or egg yolk extracts, absent in pre-immunization sera or yolk, increased sharply during the 4 weeks after immunization, reaching a plateau thereafter. Yolk extracts with high antivenom titers, as detected by ELISA were used to isolate and purify IgY. Purified IgY preparations recognized venom protein bands from 10 to 20 kDa to 60 and 70 kDa, as shown by Western blot. Recovery of antivenom antibodies from the whole yolk was over 80%. Final preparations exhibited high antivenom activity (>100,000 U-ELISA/ml) as well as efficacy in neutralizing venom lethality (1,440 microg of IgY neutralize 62.2 LD(50) of venom), and were free of toxic products, pyrogen or bacterial and fungal contaminations.

Neutrophils regulate the expression of cytokines, chemokines and nitric oxide synthase/nitric oxide in mice injected with Bothrops atrox venom.

Bothrops atrox crude venom injected intraperitoneal (i.p.) into BALB/c mice induced local afflux of inflammatory cells, one neutrophil-rich peak after 6h and another macrophage-rich peak after 48 h. A similar pattern of local cell afflux plus edema, Delta lesions of some skeletal muscle cells, and hemorrhage were observed in mice intramuscular (i.m.) injected with the venom. Measurement of serum cytokines in neutrophil-depleted (by anti-mouse rat monoclonal antibody (mAb) RB6-8C5) and non-depleted BALB/c mice was performed by ELISA. With the exception of IL-1beta (78 pg/ml), higher levels of IL-6 (1348 pg/ml), MIP-1beta (437 pg/ml) and MIP-2 (904 pg/ml) were observed in neutrophil-depleted mice, in comparison to the values found in non-neutrophil depleted mice: IL-1beta (437 pg/ml), IL-6 (750 pg/ml), MIP-1beta (165 pg/ml) and MIP-2 (90 pg/ml). TNF-alpha was not detected. NO was detected (18 microM) 24h after venom injection in neutrophil-depleted mice. RT-PCR using representative primers detected expression of mRNA in cells from BALB/c mice injected with B. atrox venom: (a) for IL-1beta, IL-6, inducible nitric oxide synthase (iNOS), CXCR2, MIP-2 and RANTES in cells from mice that were neutrophil-depleted or not; (b) for CCR1, CCR5 and MIP-1beta in cells from neutrophil-depleted mice; (c) for MIP-1alpha in cells from non-neutrophil-depleted mice; (d) TNF-alpha and TGF-beta were not detected in either of the mice. These results indicate that neutrophils play a role in regulating the production of some cytokines and chemokines as well as locally expressed or liberated iNOS/NO in tissues injected with B. atrox crude venom.