An Anaplasma marginale Florida msp-2 gene was cloned and expressed in Escherichia coli. Pulsed-field gel electrophoresis and Southern blot analysis revealed the presence of multiple msp-2 gene copies that were widely distributed throughout the chromosomes of all three strains examined. Genomic polymorphism among copies was greatest in the 5' end of msp-2 but also occurred in 3' regions. The presence of gene-copy-specific epitopes was indicated by the reactivity of the cloned msp-2 copy with some, but not all, monoclonal antibodies that bound native MSP-2. Multiple antigenically distinct MSP-2 molecules were expressed within strains and were coexpressed by individual A. marginak organisms. These results suggest that expression of polymorphic msp-2 gene copies is responsible for the significant percentages ofA. marginale organisms within strains that do not react with individual anti-MSP-2 monoclonal antibodies. Sequence analysis revealed highly significant MSP-2 homology with two rickettsial surface proteins, A. marginak MSP-4 and Cowdria ruminantium MAP-1. Immunization with MSP-4 has been shown to induce protective immunity in a manner similar to that of immunization with MSP-2. These findings support the hypothesis that A. marginale surface proteins are targets of protective immune responses but are antigenically polymorphic.

Antigenic variants of Anaplasma marginale major surface protein 2 (MSP-2), a target of protective immune responses, have been detected by use of copy-specific monoclonal antibodies reactive with some, but not all, organisms during acute rickettsemia. The presence of polymorphic msp-2 genes was confirmed by cloning and sequencing two gene copies, 11.2 and DF5, each of which encodes a full-length MSP-2 with a unique amino acid sequence. Transcription of msp-2 genes during acute rickettsemia was analyzed by use of cDNA cloning of hybrid-selected msp-2 mRNA. Sequencing of cDNA clones, designated AR1 to AR14, indicated that DF5 msp-2 was transcribed during acute rickettsemia. Two classes of variant msp-2 genes were also transcribed during acute rickettsemia. The first class of variant transcripts, typified by clones AR3, AR4, AR7, and AR14, each encoded a single or small number of amino acid substitutions relative to DF5. The second type, AR5, encoded a large region of amino acid polymorphism, including additions, deletions, and substitutions, as compared to DF5. Specific antibody directed against the AR5 polymorphic region bound a unique MSP-2 expressed on A. marginale that was not recognized by antibody generated against DF5. Similarly, anti-AR5 peptide antibody reacted with a different MSP-2 that was not bound by anti-DF5 antibody. This expression confirmed that variant msp-2 transcripts encode structurally distinct MSP-2 molecules which bear unique B-cell epitopes. These results support the hypothesis that the large msp-2 gene family, which constitutes a minimum of 1% of the genome, encodes antigenic variants critical to evasion of a protective immune response directed against surface MSP-2 epitopes.

Zusammenfassung. Bisherige Forschungen zu interkulturellen Job-Interviews fokussieren vorwiegend die Sicht der Bewerbenden und implizieren eine Benachteiligung kulturferner Bewerber_innen, möglich wäre jedoch auch, dass diese Bewerber_innen Kriterien nicht erfüllen. In der vorliegenden Studie wurden Kurzgutachten und numerischen Beurteilungen von N = 287 Bewerbungsinterviews regionaler Flugbegleiter_innen qualitativ und quantitativ untersucht. Eine Besonderheit lag darin, dass sich die Bewerber_innen in ihrem jeweiligen Heimatland (China, Indien, Deutschland) bei einer deutschen Fluggesellschaft auf die gleiche Stelle beworben haben. Die Ergebnisse zeigen, dass Recruiter_innen zwar meistens in der Lage sind, ihre spontanen Reaktionen zu reflektieren, dass bei ihnen aber in einigen Fällen Stereotype wirksam werden. Dies und fehlende kulturspezifische Verhaltensanker können für die deutlich höhere Ablehnungquote chinesischer Bewerber_innen mit verantwortlich sein.