[HTML][HTML] Specific killing of HIV-infected lymphocytes by a recombinant immunotoxin directed against the HIV-1 envelope glycoprotein
Background 3B3 is a high-affinity anti-gp120 antibody that neutralizes a wide range of
primary and laboratory isolates of HIV-1. The parental antibody was isolated from a
combinatorial phage display library constructed from bone marrow RNA of an HIV-infected
individual. We have generated a highly active immunotoxin using the 3B3 single-chain Fv
(scFv) which can specifically kill lymphocytes infected by HIV-1. Materials and Methods We
used recombinant DNA technology to clone the Fv fragment of 3B3 and produce a single …
primary and laboratory isolates of HIV-1. The parental antibody was isolated from a
combinatorial phage display library constructed from bone marrow RNA of an HIV-infected
individual. We have generated a highly active immunotoxin using the 3B3 single-chain Fv
(scFv) which can specifically kill lymphocytes infected by HIV-1. Materials and Methods We
used recombinant DNA technology to clone the Fv fragment of 3B3 and produce a single …
Background
3B3 is a high-affinity anti-gp120 antibody that neutralizes a wide range of primary and laboratory isolates of HIV-1. The parental antibody was isolated from a combinatorial phage display library constructed from bone marrow RNA of an HIV-infected individual. We have generated a highly active immunotoxin using the 3B3 single-chain Fv (scFv) which can specifically kill lymphocytes infected by HIV-1.
Materials and Methods
We used recombinant DNA technology to clone the Fv fragment of 3B3 and produce a single-chain Fv (scFv). 3B3 scFv was then fused to a truncated version of Pseudomonas exotoxin A (PE38), giving rise to a recombinant immunotoxin 3B3(Fv)-PE38 that was expressed in E. coli and purified to near homogeneity.
Results
3B3(Fv)-PE38 binds with the same affinity as the parental Fab antibody to the MN strain of gp120. The immunotoxin specifically kills a gp120-expressing transfected cell line and a chronically HIV-infected lymphocytic cell line. The immunotoxin is very stable at 37°C, retaining 80% of its original activity after 24 hr.
Conclusions
Potent immunotoxins such as 3B3(Fv)-PE38 could be utilized in combination with multidrug cocktails that limit viral replication to help reduce viral reservoirs in patients with AIDS.
Springer