Project description:The screening of a cDNA derived expression library of Campylobacter jejuni NCTC 11168 expressed in E. coli using a fusion construct and specific HaloTag interaction to a modified surface is shown. 1536 different clones were screened including positive (hisJ, cjaA, peb1a) and negative (argC, pyrC, gapA) reference proteins. The goal of the screening was to identify potential novel immunogenic proteins from C. jejuni by selecting clones showing a high signal intensity in comparison to the known antigens used as positive markers. Afterwards, the most promising clones were sequenced to identify the gene and corresponding protein, and these proteins were then investigated further. Consequently, 22 novel immunogenic proteins could be identified.
Project description:A number of seven proteins were selected during immunoscreening and further analyses. The proteins were in silico divided into overlapping 15-mer oligopeptides with an overlap of 11 residues. The microarrays were incubated with different antibodies to C. jejuni, Escherichia coli and Salmonella enterica.
Project description:The screening of a cDNA derived expression library of Campylobacter jejuni NCTC 11168 expressed in E. coli using a fusion construct and specific HaloTag interaction to a modified surface is shown. 1536 different clones were screened including positive (hisJ, cjaA, peb1a) and negative (argC, pyrC, gapA) reference proteins. The goal of the screening was to identify potential novel immunogenic proteins from C. jejuni by selecting clones showing a high signal intensity in comparison to the known antigens used as positive markers. Afterwards, the most promising clones were sequenced to identify the gene and corresponding protein, and these proteins were then investigated further. Consequently, 22 novel immunogenic proteins could be identified. In total, 1536 (4 x 384) different lysates were spotted on different microarray slides. Each slide contained 3600 distinct spots, separated into two compartments of 1800 spots each. Each compartment comprised quadruplicate replicates of each sample lysate with controls being analysed with more replicates. As controls we used: hisJ, cjaA and peb1 (3 x 40 replicates) as positive reference proteins, as they have been described as immunogenic before; argC and pyrC (2 x 40 replicates) as negative reference proteins; two sets of E. coli cell lysates without fusion proteins expressed, namely Acella electrocompetent cells (40 replicates) and KRX (32 replicates); and a buffer control (24 replicates). Therefore, each set of replicate slides contained 376 different samples and 8 controls. Each screening was performed with three replicate slides. Consequently, a total number of 12 slides were screened (4 sets of samples x 3 replicates each). For identification, rabbit polyclonal antibody to C. jejuni (Acris AP24002PU-N) as primary and goat polyclonal to rabbit IgG conjugated with ChromeoTM-546 (Abcam ab60317) as secondary antibody were used. The top compartment was incubated first with primary antibody, while the bottom compartment was incubated with PBS at the same time. Afterwards, both compartments were incubated with secondary antibody.
Project description:A number of seven proteins were selected during immunoscreening and further analyses. The proteins were in silico divided into overlapping 15-mer oligopeptides with an overlap of 11 residues. The microarrays were incubated with different antibodies to C. jejuni, Escherichia coli and Salmonella enterica. Each microarray was separated into three individual incubation chambers using ProPlate 3-Well modules. Within each incubation chamber, each peptide was spotted in triplicate with the controls spotted nine times each. The controls included human-IgG, rabbit-IgG, mouse-IgG and myelin basal protein (MBP). Each chamber was incubated independently using different polyclonal antibodies to C. jejuni, and for specificity testing, with an antibody to E. coli or S. enterica. Thus, samples 4_1, 4_2, 5_1 and 5_2 represent epitope mapping of three proteins with C. jejuni antibodies, while 6_1, 6_2, 7_1 and 7_2 represent the data after incubation with an E. coli antibody investigating unspecific interactions of the antibody to the potential linear epitopes from C. jejuni. Finally, for four different proteins from C. jejuni, the set two indicated by S2 was performed. Here, S2_6_1, S2_7_1, S2_7_2, S2_8_1 and S2_8_2 indicate epitope mapping after incubation with antibodies to C. jejuni, while the remaining samples were performed to test these latter 4 proteins for specificity by incubation with antibody to S. enterica.