Fig. 4 | Nature Communications

Fig. 4

From: Genetically engineered red cells expressing single domain camelid antibodies confer long-term protection against botulinum neurotoxin

Fig. 4

RBCs expressing heterodimers of neutralizing VHHs are more protective than those expressing monomers. a Bispecific or monospecific antitoxin proteins were engineered for expression on RBCs as GPA fusions. Chimeras were engineered to include the different protein segments as shown (yellow signal peptide of human glycophorin A; red myc epitope; grey spacer). b RBC potency to neutralize BoNT/A assessed by SNAP25 immunoblot following overnight treatments of primary rat neurons exposed to 20 pM BoNT/A preincubated with the indicated number of myc+ RBCs. The percentage of SNAP25 cleaved by BoNT/A was estimated by image analysis and shown below the immunoblots. c Survival plot of transfusion recipient mice challenged with BoNT/A. C57BL/6J mice were transfused with 100 μl blood from chimeric mice with blood containing 3.5% RBCs expressing either GPA-VNA/A or GPA-VHH7. Mice were then challenged with 25, 50, 100, or 200 LD50 BoNT/A and monitored for 7 days (n = 5/group)

Back to article page