Peptidome profiling of venom from the social wasp Polybia paulista

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudos da atividade geral, antinociceptiva/nociceptiva, anti-inflamatória/inflamatória da β-feniletilamina (FEA), uma substância isolada do veneno de vesta Polybia paulista

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Exometaboloma do tegumento da vespa social Polybia paulista por análises GC-MS: bases moleculares do reconhecimento de tipos parentais

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Otimização dos métodos de expressão e solubilização do alérgeno fosfolipase A1 do veneno de Polybia paulista

A vespa social Polybia paulista (Hymenoptera, Vespidae) é bastante abundante e endêmica nos Estados de São Paulo e sul de Minas Gerais. Os indivíduos da espécie causam um elevado número de acidentes de importância médica. Após a ferroada a vítima pode experimentar reações imunológicas locais e/ou sistêmicas, que em alguns casos podem conduzir a anafilaxia e morte. O diagnóstico e terapia de alergia à ferroada de P. paulista é baseado no uso de extrato de veneno bruto o que se associa à ocorrência de reatividade cruzada e reações imunológicas adversas durante a imunoterapia. O uso de alérgenos recombinantes (r) tem-se mostrado como uma alternativa interessante para reduzir o impacto destas desvantagens. Neste trabalho, foram avaliadas diferentes condições para otimizar a expressão recombinante e solubilização dos corpúsculos de inclusão da fosfolipase A1 (Poly p 1) (70kDa) do veneno de P. paulista previamente obtida mediante expressão heteróloga no sistema procariótico, Escherichia coli. Os resultados aqui obtidos contribuirão para aumentar as quantidades do r Poly p 1 necessárias para sua avaliação bioquímica e imunológica, e finalmente para melhorar os resultados do diagnóstico e imunoterapia específica de alergia ao veneno de P. paulista

Termofisiolofia da vespa Polybia (Trichothorax) ignobilis (Haliday, 1836) (Hymenoptera, Vespidae, Epiponini) durante a atividade de forrageamento

Many social wasps are known to use thermogenesis to warm up their flight muscles and are therefore able to forage under a broad range of ambient temperatures. However it is uncertain whether there exists a possible relation between ambient temperature and thermogenic capacity for tropical species, as we lack studies focusing on these species. Therefore, we examined the use of this mechanism in the neotropical Epiponini wasp Polybia ignobilis. More specifically, we used a thermographic camera to obtain data of the surface temperatures of three body regions (head, thorax and abdomen) of wasps during foraging activities (pre-flight, flight and post-flight) in cold [initial pe- riod of foraging activity: TAM : 15 − 20◦C] and warm [final period of foraging activity: TPM : 30 − 35◦C] conditions. Thorax temperature (Tth) was always higher than head (Th) and abdomen temperature (Tabd). In general, the lowest body temperatures were observed during the pre-flight period, while the highest values occurred upon the return of the wasps from the foraging flight. Except for the pre-flight period, Tth was always higher than Tabd, indicating that heat generated at the thorax was preferentially directed to the cephalic region. Therefore we confirmed the use of thermogenesis by a neotropical social wasp, although its magnitude was found modest compared to temperate species, which suggests a link between thermal environment and thermogenic capacity. We also showed that P. ignobilis modulates heat production as a function of ambient temperature (TA), maintaining a greater temperature difference (Tbody − TA) at cooler temperatures. Finally, we identified the cephalic region of wasps as an important route for the dissipation of the heat generated during flight

Otimização dos métodos de expressão e solubilização do alérgeno fosfolipase A1 do veneno de Polybia paulista

A vespa social Polybia paulista (Hymenoptera, Vespidae) é bastante abundante e endêmica nos Estados de São Paulo e sul de Minas Gerais. Os indivíduos da espécie causam um elevado número de acidentes de importância médica. Após a ferroada a vítima pode experimentar reações imunológicas locais e/ou sistêmicas, que em alguns casos podem conduzir a anafilaxia e morte. O diagnóstico e terapia de alergia à ferroada de P. paulista é baseado no uso de extrato de veneno bruto o que se associa à ocorrência de reatividade cruzada e reações imunológicas adversas durante a imunoterapia. O uso de alérgenos recombinantes (r) tem-se mostrado como uma alternativa interessante para reduzir o impacto destas desvantagens. Neste trabalho, foram avaliadas diferentes condições para otimizar a expressão recombinante e solubilização dos corpúsculos de inclusão da fosfolipase A1 (Poly p 1) (70kDa) do veneno de P. paulista previamente obtida mediante expressão heteróloga no sistema procariótico, Escherichia coli. Os resultados aqui obtidos contribuirão para aumentar as quantidades do r Poly p 1 necessárias para sua avaliação bioquímica e imunológica, e finalmente para melhorar os resultados do diagnóstico e imunoterapia específica de alergia ao veneno de P. paulista

Termofisiolofia da vespa Polybia (Trichothorax) ignobilis (Haliday, 1836) (Hymenoptera, Vespidae, Epiponini) durante a atividade de forrageamento

Many social wasps are known to use thermogenesis to warm up their flight muscles and are therefore able to forage under a broad range of ambient temperatures. However it is uncertain whether there exists a possible relation between ambient temperature and thermogenic capacity for tropical species, as we lack studies focusing on these species. Therefore, we examined the use of this mechanism in the neotropical Epiponini wasp Polybia ignobilis. More specifically, we used a thermographic camera to obtain data of the surface temperatures of three body regions (head, thorax and abdomen) of wasps during foraging activities (pre-flight, flight and post-flight) in cold [initial pe- riod of foraging activity: TAM : 15 − 20◦C] and warm [final period of foraging activity: TPM : 30 − 35◦C] conditions. Thorax temperature (Tth) was always higher than head (Th) and abdomen temperature (Tabd). In general, the lowest body temperatures were observed during the pre-flight period, while the highest values occurred upon the return of the wasps from the foraging flight. Except for the pre-flight period, Tth was always higher than Tabd, indicating that heat generated at the thorax was preferentially directed to the cephalic region. Therefore we confirmed the use of thermogenesis by a neotropical social wasp, although its magnitude was found modest compared to temperate species, which suggests a link between thermal environment and thermogenic capacity. We also showed that P. ignobilis modulates heat production as a function of ambient temperature (TA), maintaining a greater temperature difference (Tbody − TA) at cooler temperatures. Finally, we identified the cephalic region of wasps as an important route for the dissipation of the heat generated during flight

EXTERNAL MORPHOLOGY OF THE IMMATURES OF POLYBIA PAULISTA (HYMENOPTERA: VESPIDAE)

The immatures of Polybia paulista Ihering were described using light and scanning electron microscopy and the results are compared with previous descriptions within the same or related wasps. This study is based on 2 whole nests collected in the municipality of Rio Claro, Sao Paulo, in Brazil. We have detected the existence of 5 larval instars. The main morphological alterations over development occur in the relative size of structures, yet certain structures appear with subsequent instars and become more evident later in development: increasing density in the number of body spines and papillae; the appearance of body setae in fifth-instar larvae; opening of spiracles upon second-instar larvae; 2 body shapes in fifth-instar larvae; the appearance of a lateral tooth on the mandibles of fourth instar; presence of spines on the maxillae of fifth-instar larvae; altered shape of galea and palps upon third-instar larvae from a cluster of sensilla to a conical elevation; and the appearance of spines on postmentum upon fourth-instar larvae. This way, the present study presents a detailed description of the immatures of P. paulista, and we hope the presented information can be useful to morphological, taxonomic, and phylogenetic studies.

Thrombopoietin, the Mp1 ligand, is essential for full megakaryocyte development.

The development of megakaryocytes (MKs) from their marrow precursors is one of the least understood aspects of hematopoiesis. Current models suggest that early-acting MK colony-stimulating factors, such as interleukin (IL) 3 or c-kit ligand, are required for expansion of hematopoietic progenitors into cells capable of responding to late-acting MK potentiators, including IL-6 and IL-11. Recently, the Mp1 ligand, or thrombopoietin (Tpo), has been shown to display both MK colony-stimulating factor and potentiator activities, at potencies far greater than that of other cytokines. In light of these findings, we tested the hypothesis that Tpo is absolutely necessary for MK development. In this report we demonstrate that neutralizing the biological activity of Tpo eliminates MK formation in response to c-kit ligand, IL-6, and IL-11, alone and in combination, but that these reagents only partially reduce MK formation in the presence of combinations of cytokines including IL-3. However, despite the capacity of IL-3 to support the proliferation and initial stages of MK differentiation, elimination of Tpo prevents the full maturation of IL-3-induced MK. These data indicate that two populations of MK progenitors can be identified: one that is responsive to IL-3 but can fully develop only in the presence of Tpo and a second that is dependent on Tpo for both proliferation and differentiation. Thus, our results strongly suggest that Tpo is the primary regulator of MK development and platelet production.

Renal- and calcium-dependent vascular effects of Polybia paulista wasp venom

In the present study, the effects of Polybia paulista venom (PPV) on renal and vascular tissues were investigated. Isolated kidneys perfused with PPV (1 and 3 mu g/mL) had increased perfusion pressure, renal vascular resistance, urinary flow, and glomerular filtration rate; and reduced sodium tubular transport. Histological evaluation demonstrated deposits of proteins in Bowman's space and tubular lumen, and focal areas of necrosis. The venom promoted a cytotoxic effect on Madin-Darby canine kidney (MDCK) cells. A significant increase in lactic dehydrogenase levels was observed in response to venom exposure. In isolated mesenteric vascular beds, pressure and vascular resistance augmented in a dose-dependent manner. PPV increased the contractility of aortic rings maintained under basal tension. This contractile response was inhibited when preparations were maintained in Ca2+-free medium. Likewise, verapamil, a voltage-gated calcium channel blocker, also inhibited the contractile response. In this study, phentolamine, a blocker of a-adrenergic receptor blocker, significantly reduced the contractile effect of PPV in the aortic ring. In conclusion, PPV produced nephrotoxicity, which suggests a direct effect on necrotic cellular death in renal tubule cells. The vascular contractile effect of PPV appears to involve calcium influx through voltage-gated calcium channels via adrenergic regulation.

Antimycobacterial activity of a new peptide Polydim-I isolated from Neotropical Social Wasp Polybia dimorpha..

2016

Bait and Habitat Preferences, and Temporal Variability of Social Wasps (Hymenoptera: Vespidae) Attracted to Vertebrate Carrion

In addition to feeding on carrion tissues and fluids, social wasps can also prey on immature and adult carrion flies, thereby reducing their populations and retarding the decomposition process of carcasses. In this study, we report on the occurrence and behavior of social wasps attracted to vertebrate carrion. The collections were made monthly from September 2006 to October 2007 in three environments (rural, urban, and forest) in six municipalities of southeast Brazil, using baited bottle traps. We collected Agelaia pallipes (Olivier, 1791) (n = 143), Agelaia vicina (Saussure, 1854) (n = 106), Agelaia multipicta (Haliday, 1836) (n = 18), and Polybia paulista Ihering, 1896 (n = 3). The wasps were observed feeding directly on the baits and preying on adult insects collected in the traps. Bait and habitat associations, temporal variability of social wasps, and possible forensic implications of their actions are discussed.

Nestmate recognition in a Neotropical swarm-founding wasp: no effect of seasonality on tolerance of alien conspecifics

Previous study revealed that the swarm-founding wasp Polybia paulista is accurately able to distinguish nestmates from non-nestmates in the summer. However, the risk of accepting alien intruders is considered to be low in winter colonies, and additionally brood production is limited in 30-40% of colonies during the winter in this species. Thus, it is expected that colonies might lower their acceptance threshold and accept some conspecific wasps from alien colonies in winter. We conducted field experiments to examine tolerance of conspecific (nestmate and non-nestmate) females in winter. In contrast to our prediction, our colonies did not accept any individuals from alien colonies. We suggest that P. paulista exhibits the colony-specific acceptance threshold in winter, and colonies that produced brood in their nests may have raised the acceptance threshold even if the risk of accepting alien intruders is low in winter.

Worker demography in a large-colony, swarm-founding wasp

Neotropical swarm-founding wasps build nests enclosed in a covering envelope, which makes it difficult to count individual births and deaths. Thus, knowledge of worker demography is very limited for swarm-founding species compared with that for independent-founding species. In this study, we explored the worker demography of the swarm-founding wasp Polybia paulista, the colony size of which usually exceeds several thousand adults. We considered each wasp colony as an open-population and estimated the survival probability, recruitment rate, and population size of workers using the developments of the Cormack-Jolly-Seber model. We found that capture probability varied considerably among the workers, probably due to age polyethism and/or task specialization. The daily survival rate of workers was high (around 0.97) throughout the season and was not related to the phase of colony development. On the other hand, the recruitment rate ranged from 0 to 0.37, suggesting that worker production was substantially less important than worker survival in determining worker population fluctuations. When we compared survival rates among worker groups of one colony, the mean daily survival rate was lower for founding workers than for progeny workers and tended to be higher in progeny workers that emerged in winter. These differences in survivorship patterns among worker cohorts would be related to worker foraging activity and/or level of parasitism.

Nest site selection by a neotropical swarm-founding wasp: seasonal alternation of nest orientation

Nest orientation in social insects has been intensively studied in warmer and cooler climates, particularly in the northern hemisphere. Previous studies have consistently shown that species subjected to these climatic conditions prefer to select mostly southern locations where the nests can gain direct sunlight. However, very little is known on nest orientation in tropical and subtropical social insects. We studied nest orientations initiated by swarms throughout a year in a Brazilian swarm-founding wasp, Polybia paulista von Ihering (Hymenoptera: Polistinae). Swarms selected various orientations as nest sites, but there was a particular trend in that swarms in the winter period (May-August) preferred to build northward-facing nests. This preference is opposite from that of social wasps observed in the northern hemisphere. Colonies of this species can potentially last for many years with continuous nesting, but nesting activities of colonies during the winter are severely limited due to cool temperature and a shortened day length. Northward-facing nests are warmer through the gain of direct solar heat during the winter period; consequently, choosing northward-facing sites may be advantageous for swarms in terms of a shortened brood development and shortened time needed to increase metabolic rates during warm-up for flight.