Immunisation against chlamydia trachomatis

Abstract

The published genomic sequence of Chlamydia trachomatis reveals over 1000 putative encoded proteins but does not itself indicate which of these might be useful antigens for immunisation and vaccination or for diagnosis. This difficulty is addressed by the invention, which provides a number of C.trachomatis protein sequences suitable for vaccine production and development and / or for diagnosis purposes.

Description

[0001] All documents cited herein are incorporated by reference in their entirety. TECHNICAL FIELD [0002] This invention is in the field of immunisation against chlamydial infection, in particular against infection by Chlamydia trachomatis. BACKGROUND ART [0003] Chlamydiae are obligate intracellular parasites of eukaryotic cells which are responsible for endemic sexually transmitted infections and various other disease syndromes. They occupy an exclusive eubacterial phylogenic branch, having no close relationship to any other known organisms—they are classified in their own order (Chlamydiales) which contains a single family (Chlamydiaceae) which in turn contains a single genus (Chlamydia, also referred to as Chlamydophila). A particular characteristic of the Chlamydiae is their unique life cycle, in which the bacterium alternates between two morphologically distinct forms: an extracellular infective form (elementary bodies, EB) and an intracellular non-infective form (reticulate bo...

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Benefits of technology

[0109] The modified insect cells may then be grown in an appropriate nutrient medium, which allows for stable maintenance of the plasmid(s) present in the modified insect host. Where the expression product gene is under inducible control, the host may be grown to high density, and expression induced. Alternatively, where expression is constitutive, the product will be continuously expressed into the medium and the nutrient medium must be continuously circulated, while removing the product of interest and augmenting depleted nutrients. The product may be purified by such techniques as chromatography, e.g. HPLC, affinity chromatography, ion exchange chromatography, etc.; electrophoresis; density gradient centrifugation; solvent extraction, or the like. As appropriate, the product may be further purified, as required, so as to remove substantially any insect proteins which are also secreted in the medium or result from lysis of insect cells, so as to provide a product which is at least substantially free of host debris, e.g. proteins, lipids and polysaccharides.

[0226] Alternatively, the polymerase chain reaction (PCR) is another well-known means for detecting small amounts of target nucleic acids. The assay is described in: Mullis et al. {Meth. Enzymol. (1987) 155: 335-350}; U.S. Pat. Nos. 4,683,195 & 4,683,202. Two ‘primers’ hybridize with the target nucleic acids and are used to prime the reaction. The primers can comprise sequence that does not hybridize to the sequence of the amplification target (or its complement) to aid with duplex stability or, for example, to incorporate a convenient restriction site. Typically, such sequence will flank the desired Chlamydial sequence.

Problems solved by technology

Failure to clear the infection results in persistent immune stimulation and, rather than helping the host, this results in chronic infection with severe consequences, including sterility and blindness {10}.

In addition, the protection conferred by natural chlamydial infection, is usually incomplete, transient, and strain-specific.

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