Anti-idiotypic monoclonal antibody to a T-cell chronic lymphatic leukemia

Summary A murine anti-idiotypic monoclonal antibody (mAb), F1, (IgG_2a) was produced against the variable part of the T-cell receptor for antigen (T_i, /) on the tumor cells of a patient with T-cell chronic lymphatic leukemia (CD3⁺, 8⁺, 4^–). The molecular weight of the protein reactive with mAb F1, comodulation and coprecipitation with anti-CD3 antibody, and the restricted tumor-cell reactivity strongly support the anti-idiotypic nature of mAb F1. MAb F1 also stained 4% of peripheral blood lymphocytes of healthy donors. MAb F1 did not stimulate the tumor cells to DNA synthesis, but stimulated a fraction of the normal peripheral blood lymphocytes, mAb F1 did not mediate antibody-dependent cellular cytotoxicity or complement lysis to any significant degree in vitro. Three infusions of 1–10 mg anti-idiotypic mAb were given over a period of 4 weeks. The plasma half-life for mAb F1 was 3 h in the first 2 h after infusion and 44 h from 2 h to 120 h after infusion. After each treatment a rapid decrease of circulating tumor cells was seen. During the observation period an 80% reduction of the total circulating tumor cells was noted. After the second infusion, IgM and IgG antimouse antibodies were detected. Side-effects from therapy were fever, chills, nausea, vomiting, diarrhea, tachycardia, increase in systolic blood pressure and shortness of breath. Thus, in T-cell malignancies a major reduction of circulating tumor cells can be accomplished by low doses of anti-idiotypic mAb. Anti-idiotypic mAb might be a therapeutic agent of significant importance.     

The wind-orientation of walking carrion beetles

The wind-orientation of carrion beetles (Necrophorus humator F.) was studied by use of a locomotion-compensator.

Mallomonas alphaphora (Chrysophyceae), a new species from Western Australia

A new species ofMallomonas, M. alphaphora (Chrysophyceae), was found in freshwater ponds in the Perth region, Western Australia. It is distinguished from other species ofMallomonas by its very distinctive scale and bristle morphology and is placed in a new section,Alphaphorae, of the genusMallomonas. Dedicated to Prof. DrL. Geitler on the occasion of the 90th anniversary of his birthday.     

Differential Ultrastructural Localization of Myelin Basic Protein, Myelin/Oligodendroglial Glycoprotein, and 2'',3''-Cyclic Nucleotide 3''-Phosphodiesterase in the CNS of Adult Rats

In a light and electron microscopic immunocytochemical study we have examined the distribution of myelin basic protein (MBP), 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP), and myelin/oligodendroglial glycoprotein (MOG) within CNS myelin sheaths and oligodendrocytes of adult Sprague-Dawley rats. Ultrastructural immunocytochemistry allowed quantitative analysis of antigen density in different myelin and oligodendrocyte zones: MBP was detectable in high density over the whole myelin sheath, but not in regions of loops, somata, or the oligodendrocyte plasma membrane. CNP reactivity was highest at the myelin/axon interface, and found in lower concentration over the outer lamellae of myelin sheaths, at the cytoplasmic face of oligodendrocyte membranes, and throughout the compact myelin. MOG was preferentially detected at the extracellular surface of myelin sheaths and oligodendrocytes and in only low amounts in the lamellae of compacted myelin and the myelin/axon border zone. Our studies, thus, indicate further the presence of different molecular domains in compact myelin, which may be functionally relevant for the integrity and maintenance of the myelin sheath.     

Cysteine: Depolarization-Induced Release from Rat Brain In Vitro

Compounds released on depolarization in a Ca2+-dependent manner from rat brain slices were screened to identify candidates for neuroactive substances. Lyophilized superfusates were analyzed by reversed-phase HPLC after derivatization with 9-fluorenyl N-succinimidyl carbonate. One of the compounds that showed an increase of concentration in superfusates in the presence of iodoacetamide was identified as the cysteine (Cys) derivative, S-carboxamidomethylcysteine, by fast atom bombardment mass spectrometry and other methods. This stable Cys derivative originates from endogenous, extracellular Cys. The finding led to a method for quantification of Cys in superfusates by immediate cooling of the superfusates to 0 degrees C and reaction of Cys with N-ethylmaleimide. Depolarization-induced Ca2+-dependent release of Cys was most prominent in the neocortex, followed by the mesodiencephalon, striatum, and cerebellum. This suggests that Cys is released from a neuronal compartment and might be involved in neurotransmission.     

Molecular cloning,nucleotide sequence and expression in Escherichia coli of the β-cyclodextrin glycosyltransferase gene from Bacillus circulans strain no. 8

Summary The -cyclodextrin glycosyltransferase (-CGTase) gene was isolated from a -library prepared from Bacillus circulans strain no. 8. It was subcloned into plasmid pTZ and expressed by its endogenous regulatory sequences in Escherichia coli JM 103. The structural gene was sequenced and showed an open reading frame for a polypeptide of 718 amino acid residues. The recombinant -CGTase had the same enzymatic properties as the extracellular CGTase (684 amino acid residues, corresponding to a mol. wt. of 74416) produced by B. circulans strain no. 8. The amino acid sequence showed the highest homology (74.6% identical amino acids) with the CGTase of B. circulans strain F-2, which had been erroneously described as an amylase. The homology with the enzyme from the alkalophilic Bacillus sp. strain no. 1011 was 71.4%. The amino acid sequence derived will be used for elucidating the three-dimensional structure of the enzyme. Offprint requests to: H. Bender     

Lactose- and galactose-utilizing strains of poly(hydroxyalkanoic acid)-accumulating Alcaligenes eutrophus and Pseudomonas saccharophila obtained by recombinant DNA technology

Summary Transposon Tn 951-encoded -galactosidase was expressed in Pseudomonas saccharophila and enabled this bacterium to grow on lactose as sole carbon source. In contrast, -galactosidase was not expressed in Alcaligenes eutrophus even if the lacZ gene of Tn 951 was separated from the lacI gene. However, -galactosidase was expressed in A. eutrophus, if a DNA fragment, which was suspected to harbour the promoter of the A. eutrophus poly(3-hydroxybutyric acid)-synthetic genes, was ligated to the promoter probe vector pMC1403, which employs lac Z, Y as reporter genes. Plasmid pPL76, which harboured one of the promoter-lac fusions, enabled A. eutrophus not only to express -galactosidase but also to grow slowly on lactose (doubling time = 25–30 h). Subsequently, the promoter-lac fusion was ligated to Tn5 in pSUP5011 and was inserted into the genome of A. eutrophus H16 and of the glucose-utilizing mutant H16-G⁺1 by applying the suicide plasmid technique. Two recombinant strains, H16-cPL and H16-G⁺1-cPL, which grow with a doubling time of 16–23 h on lactose, were investigated in detail. The cells only utilized the glucose residue of lactose as a carbon source for grouth and excreted galactose into the medium. Only after the Escherichia coli gal operon had been cloned in vector pVK101 and had been mobilized to H16-cPL or H16-G⁺1-cPL, was lactose completely utilized; no galactose was detected in the medium and the growth yields increased twofold. Depending on the orientation of the gal operon in pVK101, the expression of galactokinase seems to be dependent either on the promoter of aminoglycoside phosphotransferase gene (kan) or on the promoter of the tetR gene. Offprint requests to: A. Steinbüchel     

Sea snake (Microcephalophis gracilis) hemoglobin: Primary structure and relationships to other forms

The hemoglobin of the sea snakeMicrocephalophis gracilis was purified and the primary structure of the α and β chains determined. This is the first sea snake hemoglobin structure characterized, and apparently also the first complete structure of any snake hemoglobin (an α chain of a viper was known), allowing judgments of reptilian variants. Variations between the sea snake form and other reptilian forms are large (52–65 differences for the α chains), of similar order as those between the sea snake and avian (56–65 differences) or human (58 differences) forms. Functionally, 19 residues at α/β contact areas and 7 at heme contacts are exchanged in relation to the human α and β chains. Four positions of the sea snake hemoglobin contain residues thus far unique to this form. However, all replacements appear compatible with conserved overall functional properties.