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E L Becker

Publications and source records attributed to E L Becker.

At least 91 records · Page 5Linked to original sources
PubMed1982

Anti-idiotype as antibody against the formyl peptide chemotaxis receptor of the neutrophil.

Anti-idiotypic antibodies have been produced in mice, guinea pigs, and goat against rabbit antibodies to the chemoattractant f Met-Leu-Phe. The anti-idiotypic antibodies were demonstrated by their capacity in the presence of preimmune rabbit serum to block the binding of 125I anti-f Met-Leu-Phe to f Met-Leu-Phe-human transferrin absorbed to microtiter plates. Goat anti-idiotypic antibodies were further demonstrated by their ability, when absorbed to Staphylococcus aureus, to selectively bind 125I anti-f Met-Leu-Phe. In addition, some of the goat anti-idiotypic IgG was able to bind nearly all rabbit and rat anti-f Met-Leu-Phe antibodies examined. This was shown by 1) the ability of antibodies produced in rabbits immunized with either f Met-Leu-Phe conjugated to goat IgG or f Met-Leu-Phe conjugated to keyhole limpet hemocyanin (KLH) when adsorbed to S. aureus to bind the 125I F(ab')2 goat anti-idiotype, and 2) the ability of various rat anti-f Met-Leu-Phe antibodies to block the binding of 125I rabbit anti-f Met-Leu-Phe to goat anti-idiotype absorbed to S. aureus. Finally, goat anti-idiotypic antibodies can also cross-react with the receptor on the rabbit neutrophil for the formyl peptides as evidenced by 1) the direct binding of goat anti-idiotypic IgG to the PMN, 2) the ability of F(ab')2 fragments to goat anti-idiotype to partially inhibit the binding of f Met-Leu-(3H)Phe to rabbit PMN, and 3) loss of anti-idiotype and anti-PMN receptor activity after passage over an anti-f Met-Leu-Phe column. These data support Jerne's hypothesis of "internal image" and suggest a feasible experimental approach for producing anti-cell receptor antibody without purifying the receptor.

Animals↗
PubMed1981

N alpha-formyl-norleucyl-leucyl-phenylalanyl chloromethylketone. A possible covalent agonist of the N alpha-formyl-methionyl-peptide receptor.

N alpha-formyl-norleucyl-leucyl-phenylalanine-chloromethyl ketone is chemotactic for, and induces lysosomal enzyme release from rabbit peritoneal neutrophils over essentially the same range of concentrations as does the free acid form of the same peptide (N alpha-formyl-norleucyl-leucyl-phenylalanine-OH). The chloromethyl ketone derivative does however differ from the free acid in respect to its ability to interact with the neutrophil and cause deactivation or desensitization to cytochalasin B. Neutrophils preincubated in the cold with the chloromethyl ketone followed by washing have cytochalasin B sensitivity conferred upon them, as measured by the release of lysosomal enzymes. The degree of release induced by this pre-treatment appears to be related to the initial responsiveness of the cells. This is in contrast to the free acid where no cytochalasin B sensitivity is conferred under any circumstances. Thus, the chloromethyl ketone, unlike the free acid, appears to irreversibly activate the cell. Desensitization to the late addition of cytochalasin B is also significantly retarded when the chloromethyl ketone derivative is compared to the free acid form of the peptide. These studies suggest that the chloromethyl ketone derivative of the peptide may covalently interact with the neutrophil receptor.

Amino Acid Chloromethyl Ketones↗
PubMed1980

Surface membrane enzyme, chemotactic peptide binding activities, and chemotactic responsiveness of rabbit peripheral and peritoneal neutrophils.

The chymotrypsin-like esterase activity of plasma membrane and the ecto-5'nucleotidase and ecto-p-nitrophenyl phosphatase activities in peritoneal neutrophils are 2- and 3-fold higher than peripheral blood neutrophils. The binding of the chemotactic peptide, formyl norleucyl-leucyl-phenyl-alanine to peritoneal neutrophils is 6- to 7-fold higher than to peripheral blood neutrophils. The chemotactic responsiveness of peritoneal neutrophils to the chemotactic peptide is 5-fold greater than peripheral blood neutrophils. However, there was no significant difference in the chemotactic responsiveness to complement component C5a between the blood and peritoneal cells.

Animals↗
PubMed1980

Chemotaxis.

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Animals↗
PubMed1980

Chemotaxis.

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Actins↗
PubMed1980

The ionic basis of chemotaxis. Separate cation requirements for neutrophil orientation and locomotion in a gradient of chemotactic peptide.

The behavior of cells undergoing chemotaxis may be analyzed in terms of their orientation, a static characteristic, and of their locomotion. We have examined the extracellular divalent cation requirements for orientation and locomotion of rabbit polymorphonuclear leukocytes (neutrophils) in a gradient of the chemotactic peptide N-formyl-methionyl-leu-cyl-phenylalanine (F-Met-Leu-Phe) using the chemotaxis chamber recently developed by Zigmond. This chamber allows direct observation of cells attached to glass coverslips as they move up a gradient of chemotactic agent established across a 1-mm bridge. The orientation of neutrophils in the direction of the gradient was equally efficient whether cells and F-Met-Leu-Phe were suspended in merium supplemented with both Ca2+ and Mg2+ (complete medium), with Mg2+ but not Ca2+ (by simple omission of Ca2+ or by addition of EGTA), or with nonsupplemented medium (by omission of Ca2+ and Mg2+ or by addition of EDTA). These data confirm and extend Zigmond's earlier observation that exogenous divalent cations are not required for polymorphonuclear leukocyte orientation toward the chemotactic peptide. In contrast, cell locomotion, determined by linking the chemotaxis chamber to a time-lapse videocassette recorder and TV monitor, is markedly affected by the medium's content of divalent cations. Cells suspended in medium supplemented with Mg2+ but not calcium (by omission or chelation) or in nonsupplemented medium moved on the average 25% more rapidly than cells in complete Ca2+ and Mg2+ medium. Although the simple omission of Mg2+ does not prevent chemotaxis, chelation of Mg2+ in the medium completely abolishes leukocyte locomotion. Addition of varying concentrations of Mg2+ to the buffer in the presence of EDTA established that cell movement is fully restored by Mg2+ concentrations in the range of 3 X 10(-9) M, concentrations easily attained in the absence of added Mg2+. It was concluded that neither Ca2+ nor Mg2+ is needed for orientation in response to F-Met-Leu-Phe. However, low levels of exogenous Mg2+ but not Ca2+ are required for effective locomotion of neutrophils in the Zigmond changer. This result contrasts with data obtained in the Boyden chamber, where exogenous Ca2+ is considered essential for maximum chemotactic response.

Animals↗