Localization of injected apolipophorin III in vivo — new insights into the immune activation process directed by this protein

Dettloff, Matthias; Kaiser, Brigitta; Wiesner, Andreas

doi:10.1016/s0022-1910(01)00069-5

Cited by 58 publications

(46 citation statements)

References 38 publications

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“…It is known that free apoLp-III injected into G. mellonella very rapidly associates with lipid to form lipophorin in vivo (22), and that to perform most of its immune stimulatory roles, apoLp-III must be in its lipid-associated structural conformation (15,22,24). In agreement, our present study shows that in vitro, significant effects on cellular immunity are generally only seen with lipidbound apoLp-III, whereas injections of both free and lipid-bound apoLp-III significantly alter hemocyte activity in vivo.…”

Section: Discussionmentioning

confidence: 99%

“…Candidates could include Toll-like receptors or SRs on hemocytes or other cell types, as it is already known that apoLp-III is taken up by granular hemocytes (22), and that Drosophila cells appear to exhibit SR binding of ␤-glucans and other pathogen-associated molecular patterns (PAMPs) and endocytosis of modified LDL (50,51). In mammals, bacterial lipoproteins bind the Toll-like receptor 2, which is itself a pattern recognition receptor (52,53).…”

Section: Discussionmentioning

confidence: 99%

“…Lipid-associated apoLp-III complexes were synthesized for functional assays, as several reports indicated that apoLp-III functions immunologically only when bound to lipid (15,(22)(23)(24). To produce the complex, 1,2-dimyristoyl-rac-glycero-3-phosphocholine (DMPC) was incubated with apoLp-III at a ratio of 2:1, respectively, as described by Dettloff and Wiesner (15).…”

Section: Purification Of Native Apolp-iii and Lipid-associated Apolp-mentioning

confidence: 99%

“…A dose-response assay was also conducted using injected apoLp-III, which is expected to rapidly associate with lipid in vivo (22,23). Pairs of insects weighing between 180 and 220 mg were injected with 20 l of 1.0, 0.1, 0.01, or 0 mg/ml apoLp-III.…”

Section: Effects On Plasmatocyte Spreading On Glassmentioning

confidence: 99%

“…Furthermore, apoLp-III stimulates increases in hemolymph antibacterial activity (3) and superoxide production by blood cells (hemocytes) (15). Under normal conditions in larval hemolymph, apoLp-III exists abundantly in a folded, lipid-free state (21); however, recent studies (15,(22)(23)(24) strongly suggest that lipid-free apoLp-III must first convert to a lipid-associated conformation to function immunologically, as is the case for mammalian apoE (10). Until now, however, no role has been identified for apoLp-III in the binding of ␤-1,3-glucans released systemically from fungal cell walls.…”

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confidence: 99%

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A Novel Role for an Insect Apolipoprotein (Apolipophorin III) in β-1,3-Glucan Pattern Recognition and Cellular Encapsulation Reactions

Whitten

Tew

Lee

et al. 2004

The Journal of Immunology

205

163

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Lipoproteins and molecules for pattern recognition are centrally important in the innate immune response of both vertebrates and invertebrates. Mammalian apolipoproteins such as apolipoprotein E (apoE) are involved in LPS detoxification, phagocytosis, and possibly pattern recognition. The multifunctional insect protein, apolipophorin III (apoLp-III), is homologous to apoE. In this study we describe novel roles for apoLp-III in pattern recognition and multicellular encapsulation reactions in the innate immune response, which may be of direct relevance to mammalian systems. It is known that apoLp-III stimulates antimicrobial peptide production in insect blood, enhances phagocytosis by insect blood cells (hemocytes), and binds and detoxifies LPS and lipoteichoic acid. In the present study we show that apoLp-III from the greater wax moth, Galleria mellonella, also binds to fungal conidia and β-1,3-glucan and therefore may act as a pattern recognition molecule for multiple microbial and parasitic invaders. This protein also stimulates increases in cellular encapsulation of nonself particles by the blood cells and exerts shorter term, time-dependent, modulatory effects on cell attachment and spreading. All these responses are dose dependent, occur within physiological levels, and, with the notable exception of β-glucan binding, are only observed with the lipid-associated form of apoLp-III. Preliminary studies also established a beneficial role for apoLp-III in the in vivo response to an entomopathogenic fungus. These data suggest a wide range of immune functions for a multiple specificity pattern recognition molecule and may provide a useful model for identifying further potential roles for homologous proteins in mammalian immunology, particularly in terms of fungal infections, pneumoconiosis, and granulomatous reactions.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Purification Of Native Apolp-iii and Lipid-associated Apolp-mentioning

confidence: 99%

Section: Effects On Plasmatocyte Spreading On Glassmentioning

confidence: 99%

mentioning

confidence: 99%

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A Novel Role for an Insect Apolipoprotein (Apolipophorin III) in β-1,3-Glucan Pattern Recognition and Cellular Encapsulation Reactions

Whitten

Tew

Lee

et al. 2004

The Journal of Immunology

205

163

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Kinases, intracellular calcium, and apolipophorin‐III influence the adhesion of larval hemocytes of the lepidopterous insect, Galleria mellonella

Zakarian

Dunphy

Rau

et al. 2003

Arch Insect Biochem Physiol

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Based on the results from the use of selective inhibitors and activators, active protein kinase A, protein tyrosine kinase, and protein kinase C (PKC) isoforms decreased the adhesion of larval Galleria mellonella hemocytes to glass slides. The protein kinase A inhibitor at all concentrations increased granular cell adhesion only whereas protein tyrosine kinase elevated both granular and plasmatocyte attachment at the lowest concentration. Active, Ca(2+)- and lipid-dependent PKC isoforms limited plasmatocyte and granular cell adhesion whereas PKC that was inhibited by selected compounds (with differed modes of PKC inhibition) enhanced hemocyte attachment. The granular cells were more sensitive to the PKC inhibitors than were plasmatocytes. Phospholipase C and its diacylglyceride product were necessary to reduce hemocyte adhesion and maintain PKC activity. Extracellular Ca(2+), possibly transported through L-channels, was required for plasmatocyte attachment. In contrast, lowering the levels of cytosolic Ca(2+) was associated with decreased PKC activity and was required for hemocyte adhesion.

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SERINE PROTEINASE LIKE ACTIVITY IN APOLIPOPHORIN III FROM THE HEMOLYMPH OF DESERT LOCUST, Schistocerca gregaria

Malik

Amir

Venekei

2012

Arch Insect Biochem Physiol

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Apolipophorin III (apoLp-III) has been known as a lipid transport protein of insects. Recent studies indicated the involvement of apoLp-III in immune reactions and in the control of cell destruction, but no enzymatic activity has so far been detected. In the present study, a protease from the hemolymph of Schistocerca gregaria was purified to homogeneity and its enzymatic activity was examined. Identity as chymotrypsin-like proteinase was established by its high affinity toward bulky aromatic substrates and its catalytic specificity for amide or ester bonds on the synthetic substrates, Suc-Ala-Ala-Pro-Xaa-AMC (where Xaa was Phe, Tyr, Trp, and Lys, and AMC is 7-amino-4-methyl-coumarin) and thiolbenzyl ester substrate Suc-Ala-Ala-Pro-Phe-SBzl. The sensitivity for serine protease and chymotrypsin-specific covalent inhibitors, PMSF, TPCK, and noncovalent inhibitors SGCI, showed that it is a chymotrypsin-like proteinase. It showed its maximum activity at pH 8.0 and 55°C for the hydrolysis of Suc-Ala-Ala-Pro-Tyr-AMC. According to similarities in the amino terminal sequence, molar mass (19 kDa) and retention on reversed-phase analytical high-performance liquid chromatography (HPLC) column, this protein is S. gregaria homologue of Locusta migratoria apoLp-III. Our data suggest that apoLp-III also has an inherent proteolytic activity. Results indicated that S. gregaria apoLp-III is a good catalyst and could be used as a biotechnological tool in food processing and in agricultural biotechnology.

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Localization of injected apolipophorin III in vivo — new insights into the immune activation process directed by this protein

Cited by 58 publications

References 38 publications

A Novel Role for an Insect Apolipoprotein (Apolipophorin III) in β-1,3-Glucan Pattern Recognition and Cellular Encapsulation Reactions

A Novel Role for an Insect Apolipoprotein (Apolipophorin III) in β-1,3-Glucan Pattern Recognition and Cellular Encapsulation Reactions

Kinases, intracellular calcium, and apolipophorin‐III influence the adhesion of larval hemocytes of the lepidopterous insect, Galleria mellonella

SERINE PROTEINASE LIKE ACTIVITY IN APOLIPOPHORIN III FROM THE HEMOLYMPH OF DESERT LOCUST, Schistocerca gregaria

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