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Kathryn L Kellar

Publications and source records attributed to Kathryn L Kellar.

5 recordsLinked to original sources
PubMed2004

A novel recombinant multisubunit vaccine against Chlamydia.

The administration of an efficacious vaccine is the most effective long-term measure to control the oculogenital infections caused by Chlamydia trachomatis in humans. Chlamydia genome sequencing has identified a number of potential vaccine candidates, and the current challenge is to develop an effective delivery vehicle for induction of a high level of mucosal T and complementary B cell responses. Vibrio cholerae ghosts (VCG) are nontoxic, effective delivery vehicles with potent adjuvant properties, and are capable of inducing both T cell and Ab responses in mucosal tissues. We investigated the hypothesis that rVCG could serve as effective delivery vehicles for single or multiple subunit chlamydial vaccines to induce a high level of protective immunity. rVCG-expressing chlamydial outer membrane proteins were produced by a two-step genetic process, involving cloning of Omp genes in V. cholerae, followed by gene E-mediated lysis of the cells. The immunogenicity and vaccine efficacy of rVCG-expressing single and multiple subunits were compared. Immunologic analysis indicated that i.m. immunization of mice with either vaccine construct induced a strong mucosal and systemic specific Th1 response against the whole chlamydial organism. However, there was an immunogenic advantage associated with the multiple subunit vaccine that induced a higher frequency of Th1 cells and a relatively greater ability to confer protective immunity, compared with the single subunit construct. These results support the operational theory that the ability of a vaccine to confer protective immunity against Chlamydia is a function of the level of Th1 response elicited.

Animals↗
PubMed2003

Multiplexed microsphere-based flow cytometric immunoassays for human cytokines.

Cytokines play a pivotal role in the regulation of immunologic, hematologic and wound-healing processes. They function to stimulate as well as inhibit the proliferation, differentiation and maturation of a variety of cell types. Thus, their functions are pleiotropic as well as interdependent to the extent that any cytokine may have effects that are synergistic or antagonistic with other cytokines. Cytokines also display redundancy when one mimics the functions of others. These characteristics imply that measuring the levels of one cytokine in a biologic system provides only a fraction of the information that is relevant to the existing physiologic state. A more realistic indication of the complexity of cellular interactions would include measurements of multiple cytokines at any time point. One method of multiplexed analysis can be performed by capture of the cytokines on an array of fluorescent microspheres for quantitation by flow cytometry. This technology has been applied to a variety of biomolecules, but simultaneous quantitation of multiple cytokines in a small sample volume has become rapid, inexpensive, reliable and informative.

Cytokines↗
PubMed2002

Report from a workshop on multianalyte microsphere assays.

Multiplexed assays using fluorescent microspheres is an exciting technique that has been gaining popularity among researchers, particularly those in the public health field. Part of its popularity is due to its flexibility, as both immunoassays and oligonucleotide hybridization assays can be developed on this platform. This report summarizes a workshop held by the Centers for Disease Control and Prevention that discussed issues surrounding these assays and the Luminex 100 xMAP instrument. Topics included instrumentation, assay design, sample matrix and volume, quality control, and development of commercial applications.

Animals↗
PubMed2002

Multiplexed microsphere-based flow cytometric assays.

Flow cytometry has become an indispensable tool for clinical diagnostics and basic research. Although primarily designed for cellular analysis, flow cytometers can detect any particles in the lower micron range, including inert microspheres of different sizes, dyed with various fluorochromes. Over the past 20 years, microspheres have been used as calibrators for flow cytometers and also as a solid support for numerous molecular reactions quantitated by flow cytometry. Proteins, oligonucleotides, polysaccharides, lipids, or small peptides have been adsorbed or chemically coupled to the surface of microspheres to capture analytes that are subsequently measured by a fluorochrome-conjugated detection molecule. More recently, assays for similar analytes have been multiplexed, or analyzed in the same assay volume, by performing each reaction on a set of microspheres that are dyed to different fluorescent intensities and, therefore, are spectrally distinct. Some recent applications with fluorescent microspheres have included cytokine quantitation, single nucleotide polymorphism genotyping, phosphorylated protein detection, and characterization of the molecular interactions of nuclear receptors. The speed, sensitivity, and accuracy of flow cytometric detection of multiple binding events measured in the same small volume have the potential to replace many clinical diagnostic and research methods and deliver data on hundreds of analytes simultaneously.

Adsorption↗