Toxinological and immunological studies of capillary electrophoresis fractionated Chrysaora quinquecirrha (Desor) fishing tentacle and Chironex fleckeri Southcott nematocyst venoms

Cloning and Expression of N-CFTX-1 Antigen from Chironex fleckeri in Escherichia coli and Determination of Immunogenicity in Mice

Background:

Most jellyfish species are poisonous. Human victims of jellyfish sting each year are 120 million. Chironex fleckeri is a venomous box jellyfish that inflicts painful and potentially fatal stings to humans. The CfTX-1 is one of the antigenic proteins of venom that is suggested to stimulate the immune system for treatment and vaccine. This study aimed to clone and express the CfTX-1 antigen in E. coli and then to determine the synthesis of related antibody in the mice.

Methods:

The study was performed in the Persian Gulf and Oman Sea Ecology Research Center, Bandar Abbas, Iran in autumn 2016. The synthetic CfTX-1 gene in PUC57 plasmid was purchased from Nedaye Fan Company. The 723 bp fragment of N-CfTX-1 was amplified by PCR, PUC57 plasmid containing CfTX-1 with BamHI SalI restriction enzyme sites were subcloned in pET28a [+] expression vector and transformed into E. coli BL21 (DE3). The CfTX-1 gene expression was induced by IPTG. Then antibody produced from the mice serum were isolated and confirmed by ELISA. After protein purification, resulted antigen was injected to mice in 4 repeats and then evaluated the rate of antibody in mice serum. Mice were challenged by the Carybdea alata.

Results:

The 726 bp of N-CfTX-1 were cloned in a vector of expression pET28a [+] and confirmed by PCR, sequencing and enzymatic analysis. Moreover, the recombinant protein was confirmed by SDS-PAGE and Western blotting. Then the antibody was isolated from mice serum and confirmed by ELISA test. The results showed that immunized mice tolerated 50x LD50¹ of jellyfish venom.

Conclusion:

The CfTX-1 recombinant protein was able to protect the BALB/c mice against jellyfish venom. The produced protein can be used as a candidate for vaccine against jellyfish venom.

Multigene phylogeny of the scyphozoan jellyfish family Pelagiidae reveals that the common U.S. Atlantic sea nettle comprises two distinct species (Chrysaora quinquecirrha and C. chesapeakei)

BACKGROUND

Species of the scyphozoan family Pelagiidae (e.g., Pelagia noctiluca, Chrysaora quinquecirrha) are well-known for impacting fisheries, aquaculture, and tourism, especially for the painful sting they can inflict on swimmers. However, historical taxonomic uncertainty at the genus (e.g., new genus Mawia) and species levels hinders progress in studying their biology and evolutionary adaptations that make them nuisance species, as well as ability to understand and/or mitigate their ecological and economic impacts.

METHODS

We collected nuclear (28S rDNA) and mitochondrial (cytochrome c oxidase I and 16S rDNA) sequence data from individuals of all four pelagiid genera, including 11 of 13 currently recognized species of Chrysaora. To examine species boundaries in the U.S. Atlantic sea nettle Chrysaora quinquecirrha, specimens were included from its entire range along the U.S. Atlantic and Gulf of Mexico coasts, with representatives also examined morphologically (macromorphology and cnidome).

RESULTS

Phylogenetic analyses show that the genus Chrysaora is paraphyletic with respect to other pelagiid genera. In combined analyses, Mawia, sampled from the coast of Senegal, is most closely related to Sanderia malayensis, and Pelagia forms a close relationship to a clade of Pacific Chrysaora species (Chrysaora achlyos, Chrysaora colorata, Chrysaora fuscescens, and Chrysaora melanaster). Chrysaora quinquecirrha is polyphyletic, with one clade from the U.S. coastal Atlantic and another in U.S. Atlantic estuaries and Gulf of Mexico. These genetic differences are reflected in morphology, e.g., tentacle and lappet number, oral arm length, and nematocyst dimensions. Caribbean sea nettles (Jamaica and Panama) are genetically similar to the U.S. Atlantic estuaries and Gulf of Mexico clade of Chrysaora quinquecirrha.

DISCUSSION

Our phylogenetic hypothesis for Pelagiidae contradicts current generic definitions, revealing major disagreements between DNA-based and morphology-based phylogenies. A paraphyletic Chrysaora raises systematic questions at the genus level for Pelagiidae; accepting the validity of the recently erected genus Mawia, as well as past genera, will require the creation of additional pelagiid genera. Historical review of the species-delineating genetic and morphological differences indicates that Chrysaora quinquecirrha Desor 1848 applies to the U.S. Coastal Atlantic Chrysaora species (U.S. Atlantic sea nettle), while the name C. chesapeakei Papenfuss 1936 applies to the U.S. Atlantic estuarine and Gulf of Mexico Chrysaora species (Atlantic bay nettle). We provide a detailed redescription, with designation of a neotype for Chrysaora chesapeakei, and clarify the description of Chrysaora quinquecirrha. Since Caribbean Chrysaora are genetically similar to Chrysaora chesapeakei, we provisionally term them Chrysaora c.f. chesapeakei. The presence of Mawia benovici off the coast of Western Africa provides a potential source region for jellyfish introduced into the Adriatic Sea in 2013.

Comparative study of the toxic effects of Chrysaora quinquecirrha (Cnidaria: Scyphozoa) and Chironex fleckeri (Cnidaria: Cubozoa) venoms using cell-based assays

The venoms of jellyfish cause toxic effects in diverse biological systems that can trigger local and systemic reactions. In this study, the cytotoxic and cytolytic effects of Chrysaora quinquecirrha and Chironex fleckeri venoms were assessed and compared using three in vitro assays. Venoms from both species were cytotoxic to fish gill cells and rat cardiomyocytes, and cytolytic in sheep erythrocytes. Both venoms decreased cell viability in a concentration-dependent manner; however, the greatest difference in venom potencies was observed in the fish gill cell line, wherein C. fleckeri was 12.2- (P = 0.0005) and 35.7-fold (P < 0.0001) more potently cytotoxic than C. quinquecirrha venom with 30 min and 120 min cell exposure periods, respectively. Gill cells and rat cardiomyocytes exposed to venoms showed morphological changes characterised by cell shrinkage, clumping and detachment. The cytotoxic effects of venoms may be caused by a group of toxic proteins that have been previously identified in C. fleckeri and other cubozoan jellyfish species. In this study, proteins homologous to CfTX-1 and CfTX-2 toxins from C. fleckeri and CqTX-A toxin from Chironex yamaguchii were identified in C. quinquecirrha venom using tandem mass spectrometry. The presence and relative abundance of these proteins may explain the differences in venom potency between cubozoan and scyphozoan jellyfish and may reflect their importance in the action of venoms.

Studies on the hemolytic activity of tentacle extracts of jellyfish Rhopilema esculentum Kishinouye: Application of orthogonal test

The present work is first reporting the hemolytic activity of venom from jellyfish Rhopilema esculentum Kishinouye extracted by different phosphate buffer solutions and incubated at different temperature according to the orthogonal test L6(1) x 3(6). Of the seven controllable independent variables, incubated temperature and phenylmethylsulfonyl fluoride (PMSF) had strongest effect on the hemolytic activity.

A functional comparison of the venom of three Australian jellyfish—Chironex fleckeri, Chiropsalmus sp., and Carybdea xaymacana—on cytosolic Ca2+, haemolysis and Artemia sp. lethality

Cnidarian venoms produce a wide spectrum of envenoming syndromes in humans ranging from minor local irritation to death. Here, the effects of Chironex fleckeri, Chiropsalmus sp., and Carybdea xaymacana venoms on ventricular myocyte cytosolic Ca2+, haemolysis and Artemia sp. lethality are compared for the first time. All three venoms caused a large, irreversible elevation of cytosolic Ca2+ in myocytes as measured using the Ca2+ sensitive fluorescent probe Indo-1. The L-type Ca2+ channel antagonist verapamil had no effect on Ca2+ influx whilst La3+, a non-specific channel and pore blocker, inhibited the effect. Haemolytic activity was observed for all venoms, with C. xaymacana venom displaying the greatest activity. These activities are consistent with the presence of a pore-forming toxin existing in the venoms which has been demonstrated by transmission electron microscopy in the case of C. fleckeri. The venom of C. fleckeri was found to be more lethal against Artemia sp. than the venom of the other species, consistent with the order of known human toxicities. This suggests that the observed lytic effects may not underlie the lethal effects of the venom, and raises the question of how such potent activities are dealt with by envenomed humans.

The in vitro effects of two chirodropid (Chironex fleckeri and Chiropsalmus sp.) venoms: efficacy of box jellyfish antivenom

The pharmacological and biochemical isolation of cnidarian venoms has been hindered by difficulties with both extracting pure venom from nematocysts and venom stability. The development of a new technique to extract active, pure venom of Chironex fleckeri and Chiropsalmus sp. has enabled identify both neurotoxic and myotoxic activity in their venoms. These activities are similar, but not identical in each species. Venom (50 micro g/ml) from both species significantly inhibited indirect and direct twitches of the chick biventer nerve-muscle preparation. Pre-incubation with 1U/ml box jellyfish antivenom did not have any significant effect on venom-induced reductions of indirect twitches. However, this activity was markedly attenuated by prior addition of 5U/ml antivenom, albeit to a lesser degree for Chiropsalmus sp. In contrast, prior addition of 5U/ml box jellyfish antivenom did not neutralise the myotoxic activity of C. fleckeri venom (50 micro g/ml), although it did inhibit the myotoxicity produced by Chiropsalmus sp. venom (50 micro g/ml). Antivenom (5U/ml) added 1h after the addition of C. fleckeri venom (50 micro g/ml) had no effect on the indirect or direct twitches of the skeletal muscle preparation. However, it partially restored the reduction in indirect twitch height caused by Chiropsalmus sp. venom (50 micro g/ml). Myotoxicity was confirmed in muscle preparations stained with hematoxylin and eosin.Therefore, although antivenom was able to neutralize the neurotoxic effects of both species, and the myotoxic effects of Chiropsalmus sp., when added prior to venom, it was unable to reverse the effects after venom addition. This suggests that antivenom is unlikely to be useful in the treatment of neurotoxic or myotoxic effects in patients, although these effects are rarely seen clinically.

Temperature effects on box jellyfish venom: a possible treatment for envenomed patients?

OBJECTIVE

To determine the effect of temperature on lethality of venom from Chironex fleckeri (the potentially fatal box jellyfish).

DESIGN

Venom extracted from nematocysts of mature Chironex fleckeri specimens was exposed to temperatures between 4 degrees C and 58 degrees C for periods of two, five or 20 minutes, and then injected into freshwater crayfish (Cherax quadricarinatus) to assess lethality.

MAIN OUTCOME MEASURE

Venom lethality, assessed as time to cardiac standstill in crayfish after intramuscular injection.

RESULTS

Venom lethality was significantly affected by both temperature (F(7,34) = 21915; P < 0.0001) and time of exposure (F(2,34) = 9907; P < 0.0001). No significant loss of lethality was seen after exposure to temperatures <or= 39 degrees C, even after 20 minutes' exposure. At temperatures >or= 43 degrees C, venom lost its lethality more rapidly the longer the exposure time. Venom was non-lethal after exposure to 48 degrees C for 20 minutes, 53 degrees C for five minutes, and 58 degrees C for two minutes.

CONCLUSION

Exposure to heat dramatically reduces the lethality of extracted C. fleckeri venom. Although heat application may be of limited use in treating C. fleckeri envenoming because of the speed of symptom onset, its use in other box-jellyfish envenomings, such as Irukandji syndrome, requires investigation.

Capillary electrophoresis of proteins 1999-2001

This review article with 223 references describes recent developments in capillary electrophoresis (CE) of proteins and covers papers published during last two years, from the previous review (V. Dolnik, Electrophoresis 1999, 20, 3106-3115) through Spring 2001. It describes the topics related to CE of proteins including modeling of the electrophoretic properties of proteins, sample pretreatment, wall coatings, improving selectivity, detection, special electrophoretic techniques, and applications.