Rapid Characterization of S. mansoni Expression Library Clones of Potential Interest

Abstract

A S. mansoni adult worm cDNA expression library was screened with sera from baboons in a early phase after infection. The clones that were positive with the early infection sera were examined for reactivity with pre-infection sera and heterologous infection sera. In order to discriminate a positive antibody reaction from the reactivity due to residual anti-E. coli antibodies, an unrelated cDNA clone was plated with the positive clone. The unrelated clone provided the negative background and the contrast necessary to discern a positive antibody reaction. In this way, we were able to eliminate selected clones that were positive with the pre-infection sera or heterologous infection sera. This characterization of the expression library clones enabled us to quickly target only clones with the desired pattern of antibody reactivity for sequencing, subcloning, and expressing.

Schistosoma mansoni heat shock protein 70 elicits an early humoral immune response in S. mansoni infected baboons

“…Screening of cDNA library -A S. mansoni adult worm cDNA expression library, constructed in the vector lambda UniZap XR (Stratagene, La Jolla, CA), was screened using standard methods (Sambrook et al 1989), as already described (Kanamura & Hancock 1997).…”

“…A lambda UniZap XR phage clone isolated from a Cryptosporidium parvum cDNA library and coding for C. parvum elongation factor 1-alpha was used to provide the surrounding background of negative plaques. We refer to this method as the immunoenzymatic plaque expression assay (Kanamura & Hancock 1997). At the tertiary screening, the antibody reactive positive clones were also examined with a pool of preinfection sera from baboons AC-1, AC-2, AC-4, and AC-5, with the C. parvum clone as a negative background clones.…”

Characterization of a clone from an adult worm cDNA library selected with anti-Schistosoma mansoni human antibodies dissociated from immune complexes: a preliminary report

“…S. mansoni cDNA clones were selected through an alternative method, by using human antibodies against Sm31/32 fraction for screening of an adult worm cDNA expression library 4 .…”