[Cowpox: features of spread after cancellation of mandatory pox immunization].

Features of spread of cowpox in the contemporary conditions are examined. A decrease of population immunity to pox in the population of Russia caused by cancellation of pox immunization, hidden circulation of cowpox virus in various species of rodents, as well as lack of vigilance to pathogenic orthopoxviurses in healthcare workers were noted to create the real preconditions for the emergence of infection of humans caused by cowpox virus. Thereby presence of means of express laboratory diagnostics of cowpox and means of effective medical protection for the prevention of development of this disease in the population of Russia becomes an actual necessity.

[Monkeypox: features of spread after cancellation of mandatory pox immunization].

Features of spread of monkeypox after eradication of smallpox and cancellation of mandatory pox immunization are examined. In the condition of cancellation of mandatory pox immunization, a decrease of population immunity to pox in the population, a lack of vigilance in most of the medical specialists to diseases caused by other pathogenic for human orthopoxviruses was noted. This situation complicates the prognosis of the development of possible outbreaks of infection of humans by monkeypox.

Onconase responsive genes in human mesothelioma cells: implications for an RNA damaging therapeutic agent.

Background: Onconase represents a new class of RNA-damaging drugs. Mechanistically, Onconase is thought to internalize, where it degrades intracellular RNAs such as tRNA and double-stranded RNA, and thereby suppresses protein synthesis. However, there may be additional or alternative mechanism(s) of action.

Ribonucleases and immunoRNases as anticancer drugs.

Ribonucleases degrade RNA, now considered an important drug target. The parent member of this protein superfamily is bovine pancreatic RNase A that functions as a digestive enzyme. Other physiological roles and activities have been ascribed to more recently discovered members of this superfamily.

The notch target gene HES1 regulates cell cycle inhibitor expression in the developing pituitary.

The pituitary is an endocrine gland responsible for the release of hormones, which regulate growth, metabolism, and reproduction. Diseases such as hypopituitarism or pituitary adenomas are able to disrupt pituitary function leading to suboptimal function of the entire endocrine system. Growth of the pituitary during development and adulthood is a tightly regulated process.

Anti-CD22 Onconase: preparation and characterization.

Antibodies can be conjugated to effector molecules to derive targeted therapeutics with properties such as cell-specific cytotoxicity. The murine anti-CD22 antibody RFB4 linked to a member of the ribonuclease A superfamily, Onconase (Onc), becomes a potential drug candidate for non-Hodgkin's lymphoma. Onc is currently in Phase III clinical trials for unresectable malignant mesothelioma but conjugation to RFB4 considerably enhances its specificity for CD22+ lymphomas.

Infrasound induced instability by modulation of condensation process in the atmosphere.

A sound wave in supersaturated water vapor can modulate both the process of heat release caused by condensation, and subsequently, as a result, the resonance interaction of sound with the modulated heat release provides sound amplification. High-intensity atmospheric perturbations such as cyclones and thunderstorms generate infrasound, which is detectable at large distances from the source. The wave-condensation instability can lead to variation in the level of infrasound radiation by a developing cyclone, and this can be as a precursor of these intense atmospheric events.

Targeted therapeutic RNases (ImmunoRNases).

Immunotoxins combining antibody specificity with bacterial or plant toxins are limited by their strong immunogenicity and non-specific toxicity. Ribonucleases of the RNase A protein superfamily provide a solution to address these issues because they show potent antineoplastic activity on cell internalization but do not show appreciable immunogenicity or non-specific toxicity. Their therapeutic value is demonstrated by RNase derived from the frog (Rana pipiens), Onconase (ONC, Alfacell, Inc.

Antibody-targeted RNase fusion proteins (immunoRNases) for cancer therapy.

Ribonucleases (RNases) of the superfamily A exhibit potent antineoplastic activity yet do not mediate appreciable immunogenicity or non-specific toxicity in both animal models and cancer patients. Ranpirnase (Onconase), the first ribonuclease being evaluated as a therapeutic in humans, has progressed to phase III clinical trials in patients with unresectable mesothelioma. Conjugation of RNases to internalizing tumor-targeting monoclonal antibodies was shown to enhance specific cell killing by several orders of magnitude both in vitro and in animal models.

Antibody-onconase conjugates: cytotoxicity and intracellular routing.

Onconase, a member of the pancreatic ribonuclease A superfamily, is currently in Phase III clinical trials for treatment of unresectable malignant mesothelioma. The anticancer effect of onconase may relate to its intracellular target, a non-coding RNA. Some non-coding RNAs are aberrantly expressed in cancer cells.

Cross-reactive HIV-1 neutralizing monoclonal antibodies selected by screening of an immune human phage library against an envelope glycoprotein (gp140) isolated from a patient (R2) with broadly HIV-1 neutralizing antibodies.

Elicitation of broadly cross-reactive neutralizing antibodies (bcnAbs) in HIV infections is rare. To test the hypothesis that such antibodies could be elicited by HIV envelope glycoproteins (Envs) with unusual immunogenic properties and to identify novel bcnAbs, we used a soluble Env ectodomain (gp140) from a donor (R2) with high level of bcnAbs as an antigen for panning of an immune phage-displayed antibody library. The panning with the R2 Env resulted in significantly higher number of cross-reactive antibody clones than by using Envs from two other isolates (89.

Proteomic analysis of plasma membrane from hypoxia-adapted malignant melanoma.

Hypoxic conditions often persist within poorly vascularized tumors. At the cellular level constitutive activation of transcriptional regulators of the hypoxic response leads to the emergence of clones with aggressive phenotypes. The primary interface between the cell and the hypoxic environment is the plasma membrane.

Ribonucleases in HIV type 1 inhibition: effect of recombinant RNases on infection of primary T cells and immune activation-induced RNase gene and protein expression.

Ribonucleases (RNases) have therapeutic potential against cancer and viral diseases and have been reported to inhibit replication of the human immunodeficiency virus type 1 (HIV-1) in chronically infected cell lines. The ribonuclease eosinophil-derived neurotoxin (EDN) is responsible for the anti-HIV-1 activity of a soluble factor produced in response to human alloantigens (ASF). Four recombinant RNases (EDN; a four amino acid extension of the N-terminus EDN, -4EDN; RNase A; and angiogenin) were tested for inhibition of HIV-1 replication in PHA blasts.

Efficient killing of CD22+ tumor cells by a humanized diabody-RNase fusion protein.

We report on the generation of a dimeric immunoenzyme capable of simultaneously delivering two ribonuclease (RNase) effector domains on one molecule to CD22(+) tumor cells. As targeting moiety a diabody derived from the previously humanized scFv SGIII with grafted specificity of the murine anti-CD22 mAb RFB4 was constructed. Further engineering the interface of this construct (V(L)36(Leu-->Tyr)) resulted in a highly robust bivalent molecule that retained the same high affinity as the murine mAb RFB4 (K(D)=0.

A dimeric angiogenin immunofusion protein mediates selective toxicity toward CD22+ tumor cells.

To improve selective cytotoxicity and pharmacokinetics of an anti-CD22 antibody single chain Fv (scFv)-ribonuclease fusion protein, a dimeric derivative was generated. Human angiogenin was fused via a (G4S)3 spacer peptide to the carboxy-terminal end of the stable dimeric anti-CD22 VL-VH zero-linker scFv MLT-7. The dimeric fusion protein and a monovalent counterpart were produced as soluble proteins in the periplasm of Escherichia coli.

Targeting malignant B-cell lymphoma with a humanized anti-CD22 scFv-angiogenin immunoenzyme.

We report on the generation and functional characterization of a humanized immunoenzyme comprising a stable humanized single chain Fv (scFv) with grafted specificity of the anti-CD22 murine monoclonal antibody RFB4 and the human ribonuclease angiogenin (ANG). The fusion protein produced from transiently transfected mammalian Chinese hamster ovary cells could easily be purified to homogeneity, retained full ribonucleolytic activity, and efficiently killed CD22(+) tumour cells with an IC(50) of 56 nmol/l. In contrast, incubation of tumour cells with either ANG or scFv alone did not result in any cytotoxicity.

Antigen binding and stability properties of non-covalently linked anti-CD22 single-chain Fv dimers.

By varying linker length and domain orientation three multivalent derivatives of a monovalent anti-CD22 single-chain fragment variable (scFv) antibody were generated. Shortening the linker of the V(H)-V(L) oriented scFv to 5 or 0 residues resulted in the formation of diabodies or a mixture of tetramers and trimers, respectively. Unexpectedly, a V(L)-0-V(H) scFv assembled to homogenous dimers, remained substantially more stable than the V(H)-5-V(L) diabody when incubated in human serum at 37 degrees C, and retained its dimeric state when concentrated up to 4 mg/ml.

Human ribonuclease A superfamily members, eosinophil-derived neurotoxin and pancreatic ribonuclease, induce dendritic cell maturation and activation.

A number of mammalian antimicrobial proteins produced by neutrophils and cells of epithelial origin have chemotactic and activating effects on host cells, including cells of the immune system. Eosinophil granules contain an antimicrobial protein known as eosinophil-derived neurotoxin (EDN), which belongs to the RNase A superfamily. EDN has antiviral and chemotactic activities in vitro.

Impact of antibody framework residue VH-71 on the stability of a humanised anti-MUC1 scFv and derived immunoenzyme.

Anti-MUC1 single-chain Fv (scFv) fragments generated from the humanised antibody huHMFG1 had adequate antigen-binding properties but very poor stability irrespective of the applied linker or domain orientation. Mutagenesis of heavy-chain framework residue V(H)-71, previously described as a key residue for maintaining the CDR-H2 main-chain conformation and thus important for antigen binding, markedly stabilised the scFv while having only a minor effect on the binding affinity of the molecule. Because of its improved stability, the engineered fragment exhibited immunoreactivity with tumour cells even after 7 days of incubation in human serum at 37 degrees C.

Broadly cross-reactive HIV neutralizing human monoclonal antibody Fab selected by sequential antigen panning of a phage display library.

Identification of broadly cross-reactive human monoclonal antibodies (mAbs) has major implications for development of vaccines, inhibitors and research tools. Here we describe a sequential antigen panning (SAP) methodology that may facilitate the selection of such antibodies. An HIV-specific antibody Fab (m18) was selected from a human Fab phage-display library by SAP against several recombinant soluble HIV envelope glycoproteins (Envs) and Env-sCD4 complexes.

Specificity grafting of human antibody frameworks selected from a phage display library: generation of a highly stable humanized anti-CD22 single-chain Fv fragment.

A prerequisite for the enrichment of antibodies screened from phage display libraries is their stable expression on a phage during multiple selection rounds. Thus, if stringent panning procedures are employed, selection is simultaneously driven by antigen affinity, stability and solubility. To take advantage of robust pre-selected scaffolds of such molecules, we grafted single-chain Fv (scFv) antibodies, previously isolated from a human phage display library after multiple rounds of in vitro panning on tumor cells, with the specificity of the clinically established murine monoclonal anti-CD22 antibody RFB4.

Generation of a highly stable, internalizing anti-CD22 single-chain Fv fragment for targeting non-Hodgkin's lymphoma.

The generation of a single chain Fv (scFv) fragment derived from the anti-CD22 monoclonal antibody LL2 resulted in a molecule with good antigen binding but very poor stability properties, thus hampering its clinical applicability. Here we report on the construction of an engineered LL2 scFv fragment by rational mutagenesis. The contribution of uncommon wild-type sequence residues for providing stability to the conserved common core structure of immunoglobulins was examined.

"Vasocrine" formation of tumor cell-lined vascular spaces: implications for rational design of antiangiogenic therapies.

Here we report that B16F10 murine melanoma cells mimic endothelial cell behavior and the angiogenic process in vitro and in vivo. Cord formation in vitro by tumor cells is stimulated by hypoxia and vascular endothelial growth factor (VEGF) and inhibited by antibodies against VEGF and the VEGF KDR receptor (VEGF receptor 2). We define regulation of tumor cell-derived vascular space formation by these vasoactive compounds as "vasocrine" stimulation.

Ribonuclease is partly responsible for the HIV-1 inhibitory effect activated by HLA alloantigen recognition.

Objective: This study was performed to determine whether ribonucleases (RNases) contribute to the soluble HIV-1 inhibitory activity that results from the recognition of HLA alloantigens.

Design And Methods: Supernatants from mixed lymphocyte reactions of peripheral blood mononuclear cells from healthy HLA-discordant individuals exhibited HIV-1 inhibitory activity (alloantigen-stimulated factors; ASF). These supernatants were tested for their sensitivity to heating (90 degrees C for 3 min), and for the presence of three RNases belonging to the RNase A superfamily: eosinophil-derived neurotoxin (EDN); RNase A; and angiogenin.

RNA cleavage and inhibition of protein synthesis by bleomycin.

Bleomycin is a clinically used antitumor antibiotic long thought to function therapeutically at the level of DNA cleavage. Recently, it has become clear that bleomycin can also cleave selected members of all major classes of RNA. Using the computer program COMPARE to search the database established by the Anticancer Drug Screening Program of the National Cancer Institute, a possible mechanism-based correlation was found between onconase, an antitumor ribonuclease currently being evaluated in phase III clinical trials, and the chemotherapeutic agent bleomycin.