Monoclonal antibody AHN-1 inhibits phagocytosis by human neutrophils

The granulocyte-specific monoclonal antibody, AHN-1, immunoprecipitates two major surface-iodinated proteins of 105,000 and 145,000 to 150,000 daltons from normal human neutrophils. In this study, the effect of AHN- 1 on a number of neutrophil functions was evaluated in vitro. Both complement- and antibody-mediated phagocytosis were inhibited when human neutrophils were pretreated with AHN-1 and opsonized bacteria were used as targets. The inhibition of phagocytosis was specific, in that lysosomal enzyme release and chemotaxis were not altered by treatment with AHN-1. AHN-1 did inhibit superoxide production by neutrophils in response to particulate stimuli, but not in response to the soluble stimulus, 12-O-tetradecanoylphorbol-13-acetate. The data indicate that one or both of these surface proteins may be important in the process of phagocytosis. AHN-1 should be useful in isolating and further characterizing the nature of these molecules.

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Monoclonal antibody AHN-1 inhibits phagocytosis by human neutrophils

Blood ◽

10.1182/blood.v65.2.333.333 ◽

1985 ◽

Vol 65 (2) ◽

pp. 333-339 ◽

Cited By ~ 14

Author(s):

KM Skubitz ◽

DJ Weisdorf ◽

PK Peterson

Keyword(s):

Monoclonal Antibody ◽

Lysosomal Enzyme ◽

Surface Proteins ◽

Superoxide Production ◽

Human Neutrophils ◽

Enzyme Release ◽

Specific Monoclonal Antibody ◽

Normal Human ◽

Major Surface

Abstract The granulocyte-specific monoclonal antibody, AHN-1, immunoprecipitates two major surface-iodinated proteins of 105,000 and 145,000 to 150,000 daltons from normal human neutrophils. In this study, the effect of AHN- 1 on a number of neutrophil functions was evaluated in vitro. Both complement- and antibody-mediated phagocytosis were inhibited when human neutrophils were pretreated with AHN-1 and opsonized bacteria were used as targets. The inhibition of phagocytosis was specific, in that lysosomal enzyme release and chemotaxis were not altered by treatment with AHN-1. AHN-1 did inhibit superoxide production by neutrophils in response to particulate stimuli, but not in response to the soluble stimulus, 12-O-tetradecanoylphorbol-13-acetate. The data indicate that one or both of these surface proteins may be important in the process of phagocytosis. AHN-1 should be useful in isolating and further characterizing the nature of these molecules.

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Production of Peptides Inducing Chemotaxis and Lysosomal Enzyme Release in Human Neutrophils by Intestinal Bacteria in Vitro and in Vivo

Scandinavian Journal of Gastroenterology ◽

10.3109/00365528809093861 ◽

1988 ◽

Vol 23 (1) ◽

pp. 121-128 ◽

Cited By ~ 71

Author(s):

V. S. Chadwick ◽

D. M. Mellor ◽

D. B. Myers ◽

A. C. Selden ◽

A. Keshavarzian ◽

...

Keyword(s):

Lysosomal Enzyme ◽

Intestinal Bacteria ◽

Human Neutrophils ◽

Enzyme Release

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Lipoproteins Are Responsible for the Pro-Inflammatory Property of Staphylococcus aureus Extracellular Vesicles

International Journal of Molecular Sciences ◽

10.3390/ijms22137099 ◽

2021 ◽

Vol 22 (13) ◽

pp. 7099

Author(s):

Pradeep Kumar Kopparapu ◽

Meghshree Deshmukh ◽

Zhicheng Hu ◽

Majd Mohammad ◽

Marco Maugeri ◽

...

Keyword(s):

Extracellular Vesicles ◽

Inflammatory Responses ◽

Surface Proteins ◽

Host Cells ◽

Immune Stimulation ◽

Domains Of Life ◽

Major Surface ◽

Staphylococcal Aureus

Staphylococcal aureus (S. aureus), a Gram-positive bacteria, is known to cause various infections. Extracellular vesicles (EVs) are a heterogeneous array of membranous structures secreted by cells from all three domains of life, i.e., eukaryotes, bacteria, and archaea. Bacterial EVs are implied to be involved in both bacteria–bacteria and bacteria–host interactions during infections. It is still unclear how S. aureus EVs interact with host cells and induce inflammatory responses. In this study, EVs were isolated from S. aureus and mutant strains deficient in either prelipoprotein lipidation (Δlgt) or major surface proteins (ΔsrtAB). Their immunostimulatory capacities were assessed both in vitro and in vivo. We found that S. aureus EVs induced pro-inflammatory responses both in vitro and in vivo. However, this activity was dependent on lipidated lipoproteins (Lpp), since EVs isolated from the Δlgt showed no stimulation. On the other hand, EVs isolated from the ΔsrtAB mutant showed full immune stimulation, indicating the cell wall anchoring of surface proteins did not play a role in immune stimulation. The immune stimulation of S. aureus EVs was mediated mainly by monocytes/macrophages and was TLR2 dependent. In this study, we demonstrated that not only free Lpp but also EV-imbedded Lpp had high pro-inflammatory activity.

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The roles of extracellular and intracellular calcium in lysosomal enzyme release and superoxide anion generation by human neutrophils

Biochimica et Biophysica Acta (BBA) - General Subjects ◽

10.1016/0304-4165(81)90267-1 ◽

1981 ◽

Vol 677 (3-4) ◽

pp. 512-520 ◽

Cited By ~ 131

Author(s):

James E. Smolen ◽

Helen M. Korchak ◽

Gerald Weissmann

Keyword(s):

Intracellular Calcium ◽

Lysosomal Enzyme ◽

Superoxide Anion ◽

Human Neutrophils ◽

Enzyme Release ◽

Superoxide Anion Generation

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Stobadine inhibits lysosomal enzyme release in vivo and in vitro

Life Sciences ◽

10.1016/s0024-3205(99)00445-2 ◽

1999 ◽

Vol 65 (18-19) ◽

pp. 1905-1907 ◽

Cited By ~ 2

Author(s):

Jana Navarová ◽

Tatiana Mačičková ◽

Katarina Horáková ◽

Miroslava Urbančíková

Keyword(s):

Lysosomal Enzyme ◽

Enzyme Release

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Leishmania mexicana Mutants Lacking Glycosylphosphatidylinositol (GPI):Protein Transamidase Provide Insights into the Biosynthesis and Functions of GPI-anchored Proteins

Molecular Biology of the Cell ◽

10.1091/mbc.11.4.1183 ◽

2000 ◽

Vol 11 (4) ◽

pp. 1183-1195 ◽

Cited By ~ 59

Author(s):

James D. Hilley ◽

Jody L. Zawadzki ◽

Malcolm J. McConville ◽

Graham H. Coombs ◽

Jeremy C. Mottram

Keyword(s):

Normal Growth ◽

Surface Proteins ◽

Host Cells ◽

Mammalian Host ◽

Putative Protein ◽

Major Class ◽

Major Surface Proteins ◽

Major Surface

The major surface proteins of the parasitic protozoonLeishmania mexicana are anchored to the plasma membrane by glycosylphosphatidylinositol (GPI) anchors. We have cloned the L. mexicana GPI8 gene that encodes the catalytic component of the GPI:protein transamidase complex that adds GPI anchors to nascent cell surface proteins in the endoplasmic reticulum. Mutants lacking GPI8 (ΔGPI8) do not express detectable levels of GPI-anchored proteins and accumulate two putative protein–anchor precursors. However, the synthesis and cellular levels of other non–protein-linked GPIs, including lipophosphoglycan and a major class of free GPIs, are not affected in the ΔGPI8 mutant. Significantly, the ΔGPI8 mutant displays normal growth in liquid culture, is capable of differentiating into replicating amastigotes within macrophages in vitro, and is infective to mice. These data suggest that GPI-anchored surface proteins are not essential to L. mexicana for its entry into and survival within mammalian host cells in vitro or in vivo and provide further support for the notion that free GPIs are essential for parasite growth.

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Correlation between the stimulation of human neutrophil function by monoclonal antibody and by colony-stimulating factor

Blood ◽

10.1182/blood.v66.3.738.738 ◽

1985 ◽

Vol 66 (3) ◽

pp. 738-741 ◽

Cited By ~ 4

Author(s):

MA Vadas ◽

C Clarke ◽

NA Nicola ◽

AF Lopez

Keyword(s):

Monoclonal Antibody ◽

Neutrophil Function ◽

Common Mechanism ◽

Human Neutrophils ◽

Target Cells ◽

Colony Stimulating Factor ◽

Positive Correlation ◽

Stimulating Factor ◽

Stimulation Of

Abstract Purified human neutrophils from 48 individuals were tested for their capacity to kill antibody-coated target cells in vitro in the absence or presence of stimulating agents. The agents used to stimulate cytotoxic capacity were the monoclonal antibody (MAb) WEM-G1, colony- stimulating factor (CSF-alpha), or mononuclear cell supernatant (MNC- SN). There existed an heterogeneity among the neutrophils of different individuals in the capacity to kill target cells both in the unstimulated (“resting”) or the stimulated state. A positive correlation was found between the ability of neutrophils to kill in the “resting” state and their capacity to be stimulated by MAb WEM-G1, CSF- alpha, or MNC-SN. Furthermore, a strong positive correlation in the ability of neutrophils to be stimulated by the MAb WEM-G1 and either CSF-alpha (r = .76) or MNC-SN (r = .68), as well as between CSF-alpha and MNC-SN (r = .79) was demonstrated. No correlation was seen, however, between stimulation of neutrophil function in vitro and total blood leukocyte counts, neutrophil counts, monocyte counts, or intensity of binding of MAb WEM-G1. The observation that neutrophils respond to a similar extent to different types of stimulators, -such as cytokines (CSF-alpha and MNC-SN) and MAb, suggests that these two factors may be operating through a common mechanism and the degree of stimulation may reflect an intrinsic responsiveness of neutrophils that differs among individuals. Our results also suggest a potential clinical use of WEM-G1 in measuring neutrophil functional capacity in vitro and predicting the capacity to respond to CSF-like cytokines.

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Identification of Novel Surface Proteins of Anaplasma phagocytophilum by Affinity Purification and Proteomics

Journal of Bacteriology ◽

10.1128/jb.00866-07 ◽

2007 ◽

Vol 189 (21) ◽

pp. 7819-7828 ◽

Cited By ~ 45

Author(s):

Yan Ge ◽

Yasuko Rikihisa

Keyword(s):

Anaplasma Phagocytophilum ◽

Affinity Purification ◽

The United States ◽

Capillary Liquid Chromatography ◽

Etiologic Agent ◽

Surface Proteins ◽

Mass Spectrometry Analysis ◽

Spectrometry Analysis ◽

Major Surface

ABSTRACT Anaplasma phagocytophilum is the etiologic agent of human granulocytic anaplasmosis (HGA), one of the major tick-borne zoonoses in the United States. The surface of A. phagocytophilum plays a crucial role in subverting the hostile host cell environment. However, except for the P44/Msp2 outer membrane protein family, the surface components of A. phagocytophilum are largely unknown. To identify the major surface proteins of A. phagocytophilum, a membrane-impermeable, cleavable biotin reagent, sulfosuccinimidyl-2-[biotinamido]ethyl-1,3-dithiopropionate (Sulfo-NHS-SS-Biotin), was used to label intact bacteria. The biotinylated bacterial surface proteins were isolated by streptavidin agarose affinity purification and then separated by electrophoresis, followed by capillary liquid chromatography-nanospray tandem mass spectrometry analysis. Among the major proteins captured by affinity purification were five A. phagocytophilum proteins, Omp85, hypothetical proteins APH_0404 (designated Asp62) and APH_0405 (designated Asp55), P44 family proteins, and Omp-1A. The surface exposure of Asp62 and Asp55 was verified by immunofluorescence microscopy. Recombinant Asp62 and Asp55 proteins were recognized by an HGA patient serum. Anti-Asp62 and anti-Asp55 peptide sera partially neutralized A. phagocytophilum infection of HL-60 cells in vitro. We found that the Asp62 and Asp55 genes were cotranscribed and conserved among members of the family Anaplasmataceae. With the exception of P44-18, all of the proteins were newly revealed major surface-exposed proteins whose study should facilitate understanding the interaction between A. phagocytophilum and the host. These proteins may serve as targets for development of chemotherapy, diagnostics, and vaccines.

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