Cytokines
in Candidiasis and Aspergillosis. Pp. 235-251.
A. Mencacci,
E. Cenci, A. Bacci, C. Montagnoli, F. Bistoni, L. Romani
Immunoglobulin VH Domains and Beyond: Design and Selection of Single-Domain Binding and Targeting Reagents. Pp. 253-263.
S. D. Nuttall,
R. A. Irving and P. J. Hudson
A
Multi-Modality Assay Platform for Ultra-High Throughput Screening. Pp. 265-281.
A. Fowler, I.
Davies and C. Norey
Biopharmaceutical
Powders: Particle Formation and Formulation Considerations. Pp. 283-302.
Yuh-Fun Maa and Steven J. Prestrelski
[Back to top] Biologic Agents in the Treatment of Rheumatoid Arthritis.
Advances in the
understanding of the pathogenesis of rheumatoid arthritis (RA) as well as
improved biotechnology has enabled selective targeting of the pathogenic
elements of disease. Targeting cell
recruitment through adhesion molecules has been shown to be successful in
pre-clinical murine models. Results of
studies of an anti-ICAM-1 monoclonal antibody and anti-sense oligonucleotides
have been encouraging. An alternate
approach to inhibiting recruitment has been the targeting of chemoattractant
molecules ie. chemokines.
Important advances
have been made in cytokine directed therapy targeting TNFa and IL-1. TNF antagonists (anti-TNF monoclonal
antibody/soluble TNF receptor Fc fusion protein) have resulted in rapid and
substantial improvement in signs and symptoms of disease as well as disease
modification, shown by slowing of radiological progression. IL-1 receptor antagonist protein appears to
have a significant effect on radiological progression despite a modest effect
on symptoms and signs. Studies using
anti-inflammatory cytokines such as IL-10 are in progress.
A more recent
therapeutic approach has been to target T-cell activation by interfering with
co-stimulatory complexes such as CD40L/CD40 and CD28/CD80 and CD86. Both pre-clinical and preliminary clinical
studies in human subjects support the concept.
Another approach involving T-cell receptor peptide vaccination with VB
peptides over-utilized in RA synovium has shown to be beneficial. Targeting the cytokines driving T-cells in
the RA synovium ie. IL-12 & IL-15 has also proven beneficial in animal
studies. Recent attention has also been
directed toward the invading synovial fibroblast using Fas-FasL mediated
apoptosis.
Pre-clinical studies
in which angiogenesis and osteoclast activation are targeted have been
encouraging. In conclusion, the proof
of principle has been established that selective targeting of pathogenic
elements of disease results in substantial improvement in signs and symptoms as
well as disease progression. Improved
efficacy is expected with more aggressive targeting of the pathogenic elements.
[Back to
top] Cytokines in Candidiasis
and Aspergillosis.
Both innate and T
helper (Th) immunity play a central role in fungal infections. A bi-directional
influence exists between the two compartments of the immune system, mainly
occurring through cytokine production. On the one hand, protective Th1 or
nonprotective Th2 cells mediate resistance or susceptibility to disseminated
and localized fungal infections by secreting cytokines with activating or deactivating
signals for effector phagocytic cells. On the other hand, cells of the innate
immune system regulate the development of antifungal T helper responses by
producing directive cytokines, such as interleukin (IL)-12 and IL-10. In
experimental models of Candida albicans
and Aspergillus fumigatus infections,
the administration or neutralization of selective cytokines and the use of
cytokine-deficient mice have revealed the existence of a hierarchical pattern
of cytokine mediated regulation of antifungal Th cell development and effector
function. A finely regulated balance of directive cytokines, rather than the
relative absence of opposing cytokines, appears to be required for optimal
development and maintenance of protective Th1 reactivity to fungi. Thus, it is
conceivable that some cytokines may have beneficial or deleterious effects on
infection, depending on the dose and timing of endogenous production or
exogenous administration. A better understanding of the different, sometimes
unexpected, roles of cytokines is required for their use in prophylaxis and
therapy of fungal infections, either alone or in combination with antifungal
agents.
[Back to
top] Immunoglobulin VH
Domains and Beyond: Design and Selection of Single-Domain Binding and Targeting
Reagents.
Identification of the
smallest antibody fragment still capable of binding to antigen has progressed
from full antibody molecules to Fab and recombinant single chain Fv fragments.
Now, a further reduction to single domain binding proteins based upon
immunoglobulin VH and VH-like domains offers exciting
prospects in the development of novel immunotherapeutics and immunodiagnostics.
Minimisation of the antigen-binding fragment to such small single-domain
proteins offers the advantages of enhanced stability, and possibly access to a
class of antigenic epitopes not generally recognised by conventional
antibodies.
[Back to top] A Multi-Modality Assay Platform for Ultra-High Throughput Screening.
The demand for
increased throughput during primary screening using less reagents is changing
the way of drug discovery. Searching for hits using high throughput screening
in 96-well format plates is being replaced by the use of higher density plates,
such as 384 and 1536-well formats. The analysis of radiometric assays by
scintillation counters is becoming limiting since only 12 wells can be counted
at a time. Charged coupled device (CCD) camera based instruments, that image
the whole plate in one exposure, speed up detection and are compatible with any
microplate footprint. Researchers are also demanding a choice of detection
methods, including fluorescence, luminescence and radioactivity, and require
imagers suitable for all applications. LEADseekerä
Homogenous Imaging System is a multi-modality platform offering imaging
technology and assay toolboxes for radiometric, fluorescent and luminescent
based assays. LEADseeker allows the very rapid analysis of high density formats
enabling ultra-high throughput screening of a range of biological assays.
Research areas that can be studied using this system include enzyme assays,
receptor binding and molecular interactions.
[Back to
top] Biopharmaceutical Powders:
Particle Formation and Formulation Considerations.
It
is well known that protein/peptide-based drug formulations are more stable in
the solid state than in the liquid state, thereby offering stability advantages
in ambient temperature storage, product shipping/distribution, and long-term
shelf life. Novel powder-based drug delivery systems recently emerging for
applications in sustained release, inhalation, intradermal delivery, etc. add
more value to protein solid dosage forms. Despite great research interests in
understanding the drying effects on protein stability and a large collection of
publications focusing on this area, systematic accounts of powder formation techniques
are lacking. This review is to summarize a number of methods currently
available for protein powder preparation. Some are common methods such as
lyophilization, spray drying, pulverization, and precipitation, and some
methods are more recently developed such as supercritical fluid precipitation,
spray-freeze drying, fluidized-bed spray coating and emulsion precipitation. In
addition to examining the individual process effect on protein stability that
is always the focus of formulation scientists, this review also likes to
evaluate each method from a more practical sense in terms of process
versatility and scalability. The conclusion is that each method has its own
advantages and the use of a method is formulation and application specific.
With the understanding of the principles and advantages of these methods, it
can benefit our choice on selecting appropriate techniques for preparing a
desired protein powder formulation for specific applications.