Infectious disease
Abstract
Acute rheumatic fever is a serious autoimmune sequel of Streptococcus pyogenes infection. This study shows that serotype M3 and M18 S. pyogenes isolated during outbreaks of rheumatic fever have the unique capability to bind and aggregate human basement membrane collagen type IV. M3 protein is identified as collagen-binding factor of M3 streptococci, whereas M18 isolates bind collagen through a hyaluronic acid capsule, revealing a novel function for M3 protein and capsule. Following in vivo mouse passage, conversion of a nonencapsulated and collagen-binding negative M1 S. pyogenes into an encapsulated, collagen-binding strain further supports the crucial role of capsule in mediating collagen binding. Collagen binding represents a novel colonization mechanism, as it is demonstrated that S. pyogenes bind to collagen matrix in vitro and in vivo. Moreover, immunization of mice with purified recombinant M3 protein led to the generation of anti–collagen type IV antibodies. Finally, sera from acute rheumatic fever patients had significantly increased titers of anti–collagen type IV antibodies as compared with healthy controls. These findings may suggest a link between the potential of rheumatogenic S. pyogenes isolates to bind collagen, and the presence of collagen-reactive autoantibodies in the serum of rheumatic fever patients, which may form a basis for post-streptococcal rheumatic disease. These anti-collagen antibodies may form a basis for poststreptococcal rheumatic disease.
Authors
Katrin Dinkla, Manfred Rohde, Wouter T.M. Jansen, Edward L. Kaplan, Gursharan S. Chhatwal, Susanne R. Talay
Abstract
We previously reported that laboratory reference strains of Chlamydia trachomatis differing in infection organotropism correlated with inactivating mutations in the pathogen’s tryptophan synthase (trpBA) genes. Here, we have applied functional genomics to extend this work and find that the paradigm established for reference serovars also applies to clinical isolates — specifically, all ocular trachoma isolates tested have inactivating mutations in the synthase, whereas all genital isolates encode a functional enzyme. Moreover, functional enzyme activity was directly correlated to IFN-γ resistance through an indole rescue mechanism. Hence, a strong selective pressure exists for genital strains to maintain a functional synthase capable of using indole for tryptophan biosynthesis. The fact that ocular serovars (serovar B) isolated from the genital tract were found to possess a functional synthase provided further persuasive evidence of this association. These results argue that there is an important host-parasite relationship between chlamydial genital strains and the human host that determines organotropism of infection and the pathophysiology of disease. We speculate that this relationship involves the production of indole by components of the vaginal microbial flora, allowing chlamydiae to escape IFN-γ–mediated eradication and thus establish persistent infection.
Authors
Harlan D. Caldwell, Heidi Wood, Debbie Crane, Robin Bailey, Robert B. Jones, David Mabey, Ian Maclean, Zeena Mohammed, Rosanna Peeling, Christine Roshick, Julius Schachter, Anthony W. Solomon, Walter E. Stamm, Robert J. Suchland, Lacey Taylor, Sheila K. West, Tom C. Quinn, Robert J. Belland, Grant McClarty
Abstract
Research Article
Authors
Enrique Lara-Pezzi, Maria Victoria Gómez-Gaviro, Beatriz G. Gálvez, Emilia Mira, Miguel A. Iñiguez, Manuel Fresno, Carlos Martínez-A., Alicia G. Arroyo, Manuel López-Cabrera
Abstract
Research Article
Authors
Stephanie L. Constant, Jennifer L. Brogdon, Damani A. Piggott, Christina A. Herrick, Irene Visintin, Nancy H. Ruddle, Kim Bottomly
Abstract
Research Article
Authors
Lawrence Y. Lee, Yuko J. Miyamoto, Bradley W. McIntyre, Magnus Höök, Kirk W. McCrea, Damien McDevitt, Eric L. Brown
Abstract
Research Article
Authors
Yasushi Hanakawa, Norman M. Schechter, Chenyan Lin, Luis Garza, Hong Li, Takayuki Yamaguchi, Yasuyuki Fudaba, Koji Nishifuji, Motoyuki Sugai, Masayuki Amagai, John R. Stanley
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ISSN: 0021-9738 (print), 1558-8238 (online)