Insect Hemolymph Proteins from the Ig Superfamily

Kanost, Michael R.; Zhao, Li‐Ming

doi:10.1007/978-3-642-79693-7_7

Cited by 20 publications

(17 citation statements)

References 25 publications

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“…Hemolin is the major protein synthesized in fat body in response to both Gram‐negative and Gram‐positive bacteria in lepidopteran insects (Andersson and Steiner, 1987; Ladendorff and Kanost, 1990), suggesting that it has an important function in the immune response of these insects. Hemolin has been shown to bind to E. coli (Sun et al ., 1990; Zhao and Kanost, 1996) and to increase the association of E. coli with haemocytes (Kanost and Zhao, 1996). Similarly, PGRP is rapidly induced to high concentration levels in haemolymph following bacterial challenge (Yu et al ., 2002).…”

Section: Discussionmentioning

confidence: 99%

The immunoglobulin family protein Hemolin mediates cellular immune responses to bacteria in the insect Manduca sexta

et al. 2007

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SummaryBacterial recognition in the lepidopteran insect, Manduca sexta, is mediated by pattern recognition proteins including Hemolin, Peptidoglycan recognition protein (PGRP) and Immulectin-2. These proteins bind to molecular patterns present on the surface of bacteria and trigger a protective response involving humoral and cellular reactions. Cellular mechanisms mediated by haemocytes include phagocytosis, encapsulation, and the formation of melanotic nodules. Here, we show that a non-pathogenic strain of Escherichia coli induces mRNA transcription and protein expression of Hemolin and PGRP but not Immulectin-2 in Manduca haemocytes. This upregulation can be effectively prevented (knocked-down) using RNA interference (RNAi) following injection of double-stranded (ds) RNA. Knock-down of Hemolin significantly decreased the ability of insects to clear E. coli from the haemolymph and caused a reduction in the number of free haemocytes. RNAi of Hemolin reduced the ability of haemocytes to engulf bacteria through phagocytosis and to form melanotic nodules in vivo. Importantly, washed haemocytes taken from RNAi-treated insects showed reduced ability to form microaggregates around bacteria in vitro. This shows that the immune function affected by RNAi knockdown of Hemolin is intrinsic to the haemocytes. In contrast, RNAi of PGRP had no effect on any of these cellular immune functions. These results demonstrate the vital role of Hemolin in Manduca cellular immune responses.

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Section: Discussionmentioning

confidence: 99%

The immunoglobulin family protein Hemolin mediates cellular immune responses to bacteria in the insect Manduca sexta

et al. 2007

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“…Instead, its role may be related to its ability to bind to the surface of hemocytes [5,[13][14][15] and to bacteria. Hemolin has been shown to bind to E. coli [4,23] and to increase the association of E. coli with hemocytes [14]. We have found that hemolin also binds to Gram-positive bacteria and to a lesser degree to yeast.…”

Section: Discussionmentioning

confidence: 99%

“…Binding of hemolin to bacteria and yeast cells M. sexta hemolin was reported to bind to E. coli [23] and to enhance the association of E. coli with hemocytes [14]. To assess the binding of hemolin to different types of micro-organisms, we performed a binding assay using 125 I-labeled hemolin.…”

Section: Agglutination Of Bacteria and Yeast By Hemolinmentioning

confidence: 99%

“…It binds to hemocytes and bacteria, and its binding to hemocytes inhibits hemocyte aggregation [5,[13][14][15]. Hemolin from H. cecropia interacts with bacterial lipopolysaccharide (LPS) and its lipid A component [15,16] and binds to hemocytes in a calcium-dependent manner [17].…”

mentioning

confidence: 99%

“…A membrane-bound form of hemolin has also been reported [18]. It has been suggested that hemolin may modulate hemocytic activities in development and during immune responses [12], and may function as an opsonin or as a pathogen-recognition molecule in the defense against infection [ [14][15][16]. The horseshoe-shape arrangement of the Ig domains in the structure of H. cecropia hemolin suggested a mechanism for homophilic binding of hemolin to molecules on the surface of hemocytes or micro-organisms [6].…”

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confidence: 99%

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Binding of hemolin to bacterial lipopolysaccharide and lipoteichoic acid. An immunoglobulin superfamily member from insects as a pattern-recognition receptor

Kanost

2002

Eur J Biochem

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Putative multiadhesive protein from the marine spongeGeodia cydonium: Cloning of the cDNA encoding a fibronectin-, an SRCR-, and a complement control protein module†

et al. 1998

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Sponges (Porifera) representing the simplest metazoan phylum so far have been thought to possess no basal lamina tissue structures. One major extracellular matrix protein that is also a constitutive glycoprotein of the basal lamina is fibronectin. It was the aim of the present study to identify the native protein from the marine sponge Geodia cydonium and to isolate the corresponding cDNA. In crude extracts from this sponge protein(s) of Mr of Ý230 and Ý210 kDa could be visualized by Western blotting using an anti‐fibronectin [human] antibody. By PCR cloning from a cDNA library of G. cydonium we isolated a cDNA comprising one element of fibronectin, the type‐III (FN3) module. The cDNA (2.3 kb long), encoding a 701 amino acid [aa] long putative “multiadhesive protein” termed MAP―GEOCY, was found to contain (i) a fibronectin‐, (ii) a scavenger receptor cysteine‐rich [SRCR]‐, and (iii) a short consensus repeat [SCR] module. The 89 aa long fibronectin module comprises the characteristic topology and conserved aa found in fibronectin type‐III (FN3) elements. The SRCR module (101 aa) features the characteristics of group B SRCR molecules. The predominant proteins belonging to this group are the mammalian WC1‐, M130‐, CD6‐ and CD5 antigens that probably are involved in immunological reactions. The SCR module (54 aa) shows the characteristics of type III SCR modules found in complement receptors. Phylogenetic analyses performed with all three building blocks of the “multiadhesive protein” showed that the respective sponge modules form independent, possibly basal, lineages in trees that include the corresponding modules from higher metazoan animals. In summary, these data demonstrate for the first time that the phylogenetically oldest Metazoa, the sponges, contain protein modules seen in higher animals in proteins of the extracellular matrix and in molecules involved in cell‐mediated immune reactions in vertebrates. J. Exp. Zool. 282:332–343, 1998. © 1998 Wiley‐Liss, Inc.

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Insect Hemolymph Proteins from the Ig Superfamily

Cited by 20 publications

References 25 publications

The immunoglobulin family protein Hemolin mediates cellular immune responses to bacteria in the insect Manduca sexta

The immunoglobulin family protein Hemolin mediates cellular immune responses to bacteria in the insect Manduca sexta

Binding of hemolin to bacterial lipopolysaccharide and lipoteichoic acid. An immunoglobulin superfamily member from insects as a pattern-recognition receptor

Putative multiadhesive protein from the marine spongeGeodia cydonium: Cloning of the cDNA encoding a fibronectin-, an SRCR-, and a complement control protein module†

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