Improved in vivo anti-tumor effects of IgA-Her2 antibodies through half-life extension and serum exposure enhancement by FcRn targeting

Antibody therapy is a validated treatment approach for several malignancies. All currently clinically applied therapeutic antibodies (Abs) are of the IgG isotype. However, not all patients respond to this therapy and relapses can occur. IgA represents an alternative isotype for antibody therapy that engages FcαRI expressing myeloid effector cells, such as neutrophils and monocytes. IgA Abs have been shown to effectively kill tumor cells both in vitro and in vivo. However, due to the short half-life of IgA Abs in mice, daily injections are required to reach an effect comparable to IgG Abs. The relatively long half-life of IgG Abs and serum albumin arises from their capability of interacting with the neonatal Fc receptor (FcRn). As IgA Abs lack a binding site for FcRn, we generated IgA Abs with the variable regions of the Her2-specific Ab trastuzumab and attached an albumin-binding domain (ABD) to the heavy or light chain (HC_ABD/LC_ABD) to extend their serum half-life. These modified Abs were able to bind albumin from different species in vitro. Furthermore, tumor cell lysis of IgA-Her2-LC_ABD Abs in vitro was similar to unmodified IgA-Her2 Abs. Pharmacokinetic studies in mice revealed that the serum exposure and half-life of the modified IgA-Her2 Abs was extended. In a xenograft mouse model, the modified IgA1 Abs exhibited a slightly, but significantly, improved anti-tumor response compared to the unmodified Ab. In conclusion, empowering IgA Abs with albumin-binding capacity results in in vitro and in vivo functional Abs with an enhanced exposure and prolonged half-life.     

Fossile Hydrozoen — Kenntnisstand und Probleme

A critical review on fossil Hydrozoa reveals the following questions and problems:

1. Microstructure, skeleton formation and morphology: According toKazmierczak’s morphogenetical model the formation of the ectodermal basal skeleton depends on a progressive folding of the coenosarc. Can this model be used for all polypoid hydrozoans? Another very important question deals with the possibility of distinctions between systematically important “primary” microstructures and taxonomically worthless “secondary” microstructures which are produced by diagenetical alteration effects.
2. Determination and classification: There is no general agreement on the morphological elements which can be used for the definition of Paleozoic and Mesozoic stromatoporoid genera and species, special problems refer to the taxonomical value of the astrorhizae and of quantitative criteria. About 2000 “species“ from the Paleozoic and about 500 “species“ from the Mesozoic have been described within the Stromatoporoidea but there exists no generally recognized classification system for this group.
3. Paleobiogeography: The oldest polypoid hydrozoans are known from Llanvirnian to Llandeiloverian reef- and shelf-carbonate-deposits; some species described from the Middle Cambrian of Western Sibiria may belong to Archaeocyatha. Tab. 3 shows the temporal distribution of hydrozoan groups. Stricking gaps of knowledge exist for Carboniferous and Permian, Lower Triassic, Liassic, Middle Jurassic and for Tertiary hydrozoan faunas.
4. Palecology: Main factors governing the distribution of polypoid hydrozoans seem to be consistence of substrate, different types of water movement, and eventually differences in salinity. These ecofactors may be recognized by the interpretation of growth forms and growth patterns together with investigations of hydrozoan associations and communities. According to the problems mentioned above no sound evolutionary scheme of all hydrozoan groups is possible just now. Questions dealing with the systematical position of Paleozoic and Mesozoic Chaetetida and with the relationships between Hydrozoa and Sclerospongia have to be studied first (see page 406).

     

Regulation of membrane transport by rab GTPases

Membrane flow through the cell is a highly dynamic process in which intracellular compartments communicate via tubulo-vesicular structures shuttling cargo molecules to their destinations. Transport carriers are formed at a donor compartment and navigate through the cytoplasm to the target organelle, on which they subsequently dock and fuse. Many of these events are regulated by the cooperative action of monomeric rab GTPases and their effector proteins. Research in recent years resulted in the identification of many rab effectors, providing first glimpses how the GTPase switch of individual rab proteins is utilized in discrete transport steps.     

DNA analysis of insect iridescent virus 6: evidence for circular permutation and terminal redundancy

DNA analysis of small insect iridovirus 6 was performed. Combined exonuclease-restriction endonuclease digestions revealed that all resulting fragments were degraded without preference for any one DNA fragment. Upon denaturation and reannealing of native linear Chilo iridescent virus DNA (158 × 10⁶ daltons), duplex DNA circles of a smaller size (140 × 10⁶ daltons) with protruding tails were formed.     

Cognitive profile of students who enter higher education with an indication of dyslexia

For languages other than English there is a lack of empirical evidence about the cognitive profile of students entering higher education with a diagnosis of dyslexia. To obtain such evidence, we compared a group of 100 Dutch-speaking students diagnosed with dyslexia with a control group of 100 students without learning disabilities. Our study showed selective deficits in reading and writing (effect sizes for accuracy between d = 1 and d = 2), arithmetic (d≈1), and phonological processing (d>0.7). Except for spelling, these deficits were larger for speed related measures than for accuracy related measures. Students with dyslexia also performed slightly inferior on the KAIT tests of crystallized intelligence, due to the retrieval of verbal information from long-term memory. No significant differences were observed in the KAIT tests of fluid intelligence. The profile we obtained agrees with a recent meta-analysis of English findings suggesting that it generalizes to all alphabetic languages. Implications for special arrangements for students with dyslexia in higher education are outlined.     

Vitamin D inhibition of pro-fibrotic effects of transforming growth factor β1 in lung fibroblasts and epithelial cells

The mechanisms that control fibroproliferation and matrix deposition in lung fibrosis remain unclear. We speculate that vitamin D deficiency may contribute to pulmonary fibrosis since vitamin D deficiency has been implicated in several diseases. First, we confirmed the presence of vitamin D receptors (VDRs) in cultured NIH/3T3 and lung fibroblasts. Fibroblasts transfected with a vitamin D response element–reporter construct and exposed to the active vitamin D metabolite, 1,25(OH)₂D₃, showed increased promoter activity indicating VDR functionality in these cells. Testing the effects of 1,25(OH)₂D₃ on fibroblasts treated with transforming growth factor β1 (TGFβ1), considered a driver of many fibrotic disorders, we found that 1,25(OH)₂D₃ inhibited TGFβ1-induced fibroblast proliferation in a dose-dependent fashion. 1,25(OH)₂D₃ also inhibited TGFβ1 stimulation of α-smooth muscle actin expression and polymerization and prevented the upregulation of fibronectin and collagen in TGFβ1-treated fibroblasts. Finally, we examined how 1,25(OH)₂D₃ affects epithelial–mesenchymal transformation of lung epithelial cells upon exposure to TGFβ1. We showed that the TGFβ1-induced upregulation of mesenchymal cell markers and abnormal expression of epithelial cell markers were blunted by 1,25(OH)₂D₃. These observations suggest that under TGFβ1 stimulation, 1,25(OH)₂D₃ inhibits the pro-fibrotic phenotype of lung fibroblasts and epithelial cells.     

Cyclodextrins differentially mobilize free and esterified cholesterol from primary human foam cell macrophages

Human monocyte-derived foam cell macrophages (HMFCs) are resistant to cholesterol efflux mediated by physiological acceptors. The role of the plasma membrane in regulating depletion of free cholesterol (FC) and of cholesteryl ester (CE) was investigated using cyclodextrins (CDs). HMFCs were incubated in media containing CDs (1.0 mg/ml, approximately 0.7 mM) with low [hydroxypropyl-beta-CD (HP-CD)] or high [trimethyl-beta-CD (TM-CD)] affinity for cholesterol in the presence or absence of phospholipid vesicles (PLVs). Low-affinity HP-CD caused minimal cholesterol efflux on its own, but HP-CD+ PLV depleted cell FC and CE to 54.5 +/- 6.7% of control by 24 h. TM-CD depleted FC at least as well as HP-CD+PLV but without depleting CE, even when combined with PLV. This was not explained by acceptor saturation, instability of PLV vesicles, de novo cholesterol synthesis, kinetically distinct cholesterol pools, or inhibition of CE hydrolysis. TM-CD did, however, deplete CE when lower concentrations of TM-CD were combined with PLV and when acetyl-CoA cholesteryl acyltransferase was inhibited. TM-CD caused much greater depletion of plasma membrane cholesterol than HP-CD without depleting plasma membrane sphingomyelin. It is concluded that differential depletion of plasma membrane cholesterol pools regulates cholesterol efflux and CE clearance in human macrophages.     

Microfacies-based provenance analysis of Roman imperial mosaic and sculpture materials from Bavaria (Southern Germany)

Summary Microfacies-based provenance analysis of Roman mosaics found in Southern Bavaria near Augsburg indicates the use of Mesozoic carbonates and sandstones occurring as boulders within Pleistocene and Holocene deposits near to the mosaic sites. In addition, local allochthonous Late Jurassic ooid-peloid grainstones were used for the fabrication of white tesserae. Microfacies criteria provide a means for evaluating the original location of sculptures as demonstrated by the study of the head of a Roman Goddess made of Alpine Late Triassic limestone.