Abstracts (complete list) - Wissenschaft Online

Sebastian Bunk, Iuliana Suznea, Jan Rupp, Matthias Maass, Michael Przybylski, Albrecht
Wendel, Corinna Hermann
Persisting Chlamydia pneumoniae infections are associated
with differential immune responses
The respiratory pathogen Chlamydia pneumoniae can disseminate from the lung via
infected phagocytes and persist in the host tissue for years. A reliable diagnosis, which
allows discrimination between past and persistent infection is a prerequisite to study its
association with chronic inflammatory diseases. Our project aimed to investigate
whether persistent C. pneumoniae infections are associated with specific antibody
response patterns.
Therefore, C. pneumonia proteins were prepared from elementary bodies, separated by
2D-gel electrophoresis and blotted to nitrocellulose membranes. The membranes were
incubated with 39 human sera and bound IgG antibodies were quantitatively analysed
by a LAS-3000 imaging system. Nineteen of the 39 sera revealed evidence for
persisting C. pneumoniae infections as determined by PCR analysis of monocytes or
vasculatory samples. Using high resolution MALDI-FTICR-MS, we identified 38
Chlamydia proteins originating from 33 genes which were frequently recognized among
the 39 sera. About half of the proteins, including some with high antigenic potential,
represent Chlamydia antigens not described before. Comparison of antibody response
pattern between sera from subjects with and without evidence for persisting C.
pneumoniae, resulted in differential reactivity of the two groups of sera towards twelve
proteins. While the reactivity of sera from PCR-positive donors was increased for eight
proteins, reactivity was decreased for four proteins, thereby reflecting altered protein
expression patterns of in vitro models of C. pneumoniae persistence. Taken together,
these results provide first evidence for serological differences associated with the status
of C. pneumoniae infections.