Gli autori ringraziano Bloomberg Philanthropies per il sostegno finanziario al Johns Hopkins Malaria Research Institute (JHMRI). Questo lavoro non sarebbe stato possibile senza l'esperienza fornita dalle strutture di base per insetti e parassitologia JHMRI.

<ol>
	<li>World Health Organization. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=World+Malaria+Report.">World Malaria Report.</a> World Health Organization. , (2018).</li><li>Sinden, R. E., Smalley, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gametocytogenesis+of+Plasmodium+falciparum+in+vitro:+The+cell-cycle.">Gametocytogenesis of Plasmodium falciparum in vitro: The cell-cycle.</a> Parasitology. 79 (2), 277-296 (1979).</li><li>Sinden, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sexual+Development+of+Malarial+Parasites.">Sexual Development of Malarial Parasites.</a> Advances in Parasitology. 22, 153-216 (1983).</li><li>Joice, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasmodium+falciparum+transmission+stages+accumulate+in+the+human+bone+marrow.">Plasmodium falciparum transmission stages accumulate in the human bone marrow.</a> Science Translational Medicine. 6 (244), 5 (2014).</li><li>Abdulsalam, A. H., Sabeeh, N., Bain, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immature+Plasmodium+falciparum+gametocytes+in+bone+marrow.">Immature Plasmodium falciparum gametocytes in bone marrow.</a> American Journal of Hematology. 85 (12), 943 (2010).</li><li>Ghosh, A. K., Jacobs-Lorena, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasmodium+sporozoite+invasion+of+the+mosquito+salivary+gland.">Plasmodium sporozoite invasion of the mosquito salivary gland.</a> Current Opinion in Microbiology. 12 (4), 394-400 (2009).</li><li>Bennink, S., Kiesow, M. J., Pradel, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+development+of+malaria+parasites+in+the+mosquito+midgut.">The development of malaria parasites in the mosquito midgut.</a> Cellular Microbiology. 18 (7), 905-918 (2016).</li><li>Trager, W., Jenson, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cultivation+of+malarial+parasites.">Cultivation of malarial parasites.</a> Nature. 273 (5664), 621-622 (1978).</li><li>Duffy, S., Loganathan, S., Holleran, J. P., Avery, V. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large-scale+production+of+Plasmodium+falciparum+gametocytes+for+malaria+drug+discovery.">Large-scale production of Plasmodium falciparum gametocytes for malaria drug discovery.</a> Nature Protocols. 11 (5), 976-992 (2016).</li><li>Delves, M. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Routine+in+vitro+culture+of+P.+Falciparum+gametocytes+to+evaluate+novel+transmission-blocking+interventions.">Routine in vitro culture of P. Falciparum gametocytes to evaluate novel transmission-blocking interventions.</a> Nature Protocols. 11 (9), 1668-1680 (2016).</li><li>Habtewold, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Streamlined+SMFA+and+mosquito+dark-feeding+regime+significantly+improve+malaria+transmission-blocking+assay+robustness+and+sensitivity.">Streamlined SMFA and mosquito dark-feeding regime significantly improve malaria transmission-blocking assay robustness and sensitivity.</a> Malaria Journal. 18 (1), 24 (2019).</li><li>Demanga, C. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+development+of+sexual+stage+malaria+gametocytes+in+a+Wave+Bioreactor.">The development of sexual stage malaria gametocytes in a Wave Bioreactor.</a> Parasites and Vectors. 10 (1), 216 (2017).</li><li>Brockelman, C. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conditions+favoring+gametocytogenesis+in+the+continuous+culture+of+Plasmodium+falciparum.">Conditions favoring gametocytogenesis in the continuous culture of Plasmodium falciparum.</a> Journal of Eukaryotic Microbiology. 29, 454-458 (1982).</li><li>Meibalan, E., Marti, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biology+of+malaria+transmission.">Biology of malaria transmission.</a> Cold Spring Harbor Perspectives in Medicine. 7, (2017).</li><li>Essuman, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+gametocyte+biomarker+for+superior+molecular+detection+of+the+plasmodium+falciparum+infectious+reservoirs.">A novel gametocyte biomarker for superior molecular detection of the plasmodium falciparum infectious reservoirs.</a> Journal of Infectious Diseases. 216 (10), 1264-1272 (2017).</li><li>Sim&#245;es, M. L., Mlambo, G., Tripathi, A., Dong, Y., Dimopoulos, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immune+regulation+of+plasmodium+is+anopheles+species+specific+and+infection+intensity+dependent.">Immune regulation of plasmodium is anopheles species specific and infection intensity dependent.</a> mBio. 8 (5), 01631 (2017).</li><li>Oakley, M. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcriptome+analysis+based+detection+of+Plasmodium+falciparum+development+in+Anopheles+stephensi+mosquitoes.">Transcriptome analysis based detection of Plasmodium falciparum development in Anopheles stephensi mosquitoes.</a> Scientific Reports. 8, 11568 (2018).</li><li>Saraiva, R. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chromobacterium+spp.+mediate+their+anti-Plasmodium+activity+through+secretion+of+the+histone+deacetylase+inhibitor+romidepsin.">Chromobacterium spp. mediate their anti-Plasmodium activity through secretion of the histone deacetylase inhibitor romidepsin.</a> Scientific Reports. 8, 6176 (2018).</li><li>Tao, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sex-partitioning+of+the+Plasmodium+falciparum+stage+V+gametocyte+proteome+provides+insight+into+falciparum-specific+cell+biology.">Sex-partitioning of the Plasmodium falciparum stage V gametocyte proteome provides insight into falciparum-specific cell biology.</a> Molecular and Cellular Proteomics. 13 (10), 2705-2724 (2014).</li><li>Grabias, B., Zheng, H., Mlambo, G., Tripathi, A. K., Kumar, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+sensitive+enhanced+chemiluminescent-ELISA+for+the+detection+of+Plasmodium+falciparum+circumsporozoite+antigen+in+midguts+of+Anopheles+stephensi+mosquitoes.">A sensitive enhanced chemiluminescent-ELISA for the detection of Plasmodium falciparum circumsporozoite antigen in midguts of Anopheles stephensi mosquitoes.</a> Journal of Microbiological Methods. 108, 19-24 (2015).</li><li>Ferrer, P., Vega-Rodriguez, J., Tripathi, A. K., Jacobs-Lorena, M., Sullivan, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antimalarial+iron+chelator+FBS0701+blocks+transmission+by+Plasmodium+falciparum+gametocyte+activation+inhibition.">Antimalarial iron chelator FBS0701 blocks transmission by Plasmodium falciparum gametocyte activation inhibition.</a> Antimicrobial Agents and Chemotherapy. 59 (3), 1418-1426 (2015).</li><li>Sanders, N. G., Sullivan, D. J., Mlambo, G., Dimopoulos, G., Tripathi, A. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gametocytocidal+screen+identifies+novel+chemical+classes+with+Plasmodium+falciparum+transmission+blocking+activity.">Gametocytocidal screen identifies novel chemical classes with Plasmodium falciparum transmission blocking activity.</a> PLoS One. 9 (8), 105817 (2014).</li><li>Lindner, S. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcriptomics+and+proteomics+reveal+two+waves+of+translational+repression+during+the+maturation+of+malaria+parasite+sporozoites.">Transcriptomics and proteomics reveal two waves of translational repression during the maturation of malaria parasite sporozoites.</a> Nature Communications. 10, 4964 (2019).</li><li>McLean, K. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+Transmission-Competent+Human+Malaria+Parasites+with+Chromosomally-Integrated+Fluorescent+Reporters.">Generation of Transmission-Competent Human Malaria Parasites with Chromosomally-Integrated Fluorescent Reporters.</a> Scientific Reports. 9, 13131 (2019).</li><li>Espinosa, D. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proteolytic+Cleavage+of+the+Plasmodium+falciparum+Circumsporozoite+Protein+Is+a+Target+of+Protective+Antibodies.">Proteolytic Cleavage of the Plasmodium falciparum Circumsporozoite Protein Is a Target of Protective Antibodies.</a> Journal of Infectious Diseases. 212 (7), 1111-1119 (2015).</li><li>Swearingen, K. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interrogating+the+Plasmodium+Sporozoite+Surface:+Identification+of+Surface-Exposed+Proteins+and+Demonstration+of+Glycosylation+on+CSP+and+TRAP+by+Mass+Spectrometry-Based+Proteomics.">Interrogating the Plasmodium Sporozoite Surface: Identification of Surface-Exposed Proteins and Demonstration of Glycosylation on CSP and TRAP by Mass Spectrometry-Based Proteomics.</a> PLoS Pathogens. 12 (4), 1005606 (2016).</li><li>Ifediba, T., Vanderberg, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complete+in+vitro+maturation+of+Plasmodium+falciparum+gametocytes.">Complete in vitro maturation of Plasmodium falciparum gametocytes.</a> Nature. 294 (5839), 364-366 (1981).</li><li>Miura, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+inter-laboratory+comparison+of+standard+membrane-feeding+assays+for+evaluation+of+malaria+transmission-blocking+vaccines.">An inter-laboratory comparison of standard membrane-feeding assays for evaluation of malaria transmission-blocking vaccines.</a> Malaria Journal. 15, 463 (2016).</li><li>Miura, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Qualification+of+Standard+Membrane-Feeding+Assay+with+Plasmodium+falciparum+Malaria+and+Potential+Improvements+for+Future+Assays.">Qualification of Standard Membrane-Feeding Assay with Plasmodium falciparum Malaria and Potential Improvements for Future Assays.</a> PLoS One. 8 (3), 57909 (2013).</li></ol>

Gli Autori non hanno nulla da rivelare.

I metodi qui descritti sono stati utilizzati con successo presso il Johns Hopkins Malaria Research Institute per più di 10 anni15,16,17,18,19,20,21,22. I gametociti prodotti utilizzando questo protocollo sono stati utilizzati per saggi gametocitocidi ad al...

La malaria è causata dai parassiti Plasmodium e viene trasmessa ai loro ospiti vertebrati attraverso il morso infettivo delle zanzare Anopheles femminili. Secondo il rapporto 2019 dell'Organizzazione Mondiale della Sanità (OMS), ci sono stati circa 405.000 decessi, su un totale di 228 milioni di casi di malaria1. La maggior parte dei decessi correlati alla malaria sono stati concentrati nella regione africana, specialmente tra i bambini sotto i cinque anni di età. Mentre il tasso di incidenza complessivo della malaria è diminuito a livello globale dal 2010, negli ultimi anni il declino si è stabilizzato e sono urgentemente necessarie ulteriori strategie di controllo per eliminare la malattia.
Gli stadi ciclici del sangue asessuato dei parassiti della malaria causano patogenesi della malattia e un piccolo sottoinsieme di questi si differenzia in gametociti femminili e maschili. I gametociti del Plasmodium falciparum sono unici in natura in quanto impiegano 7-10 giorni per svilupparsi attraverso cinque stadi morfologicamente distinti. I gametociti immaturi dallo stadio I al IV sono sequestrati nel parenchima del midollo osseo e rimangono in gran parte assenti dalla circolazione periferica2,3,4,5. Gli eritrociti infettati da gametociti maturi allo stadio V vengono rilasciati nel flusso sanguigno e circolano liberamente per essere assorbiti dalle zanzare. Una volta all'interno del midgut della zanzara, i gametociti vengono attivati, attraverso un cambiamento di temperatura e l'esposizione all'ambiente midgut, si trasformano in gameti femminili e maschili e iniziano lo sviluppo degli stadi di zanzara, che culmina con gli stadi infettivi degli sporozoiti nelle ghiandole salivari della zanzara6,7.
Da quando Trager e Jenson8 hanno descritto un metodo standardizzato per la coltura di P. falciparum, gli studi sugli stadi del sangue asessuato sono notevolmente progrediti. Tuttavia, la mancanza di un sistema di coltura affidabile per le fasi sessuali ha reso difficile lo studio dei gametociti di P. falciparum, della biologia della trasmissione e degli stadi delle zanzare. Negli ultimi anni sono stati pubblicati diversi metodi che hanno aiutato i laboratori a stabilire colture di gametociti9,10,11,12. Questo manoscritto descrive un protocollo standardizzato e affidabile per la coltura di gametociti di P. falciparum che può rappresentare una risorsa preziosa per la comunità di ricerca sulla malaria. Questo metodo consente la robusta produzione di gametociti maturi e infettivi che, insieme a un protocollo standardizzato di alimentazione delle zanzare, si traduce in un'infettività delle zanzare altamente affidabile. Questi metodi sono stati stabiliti per mantenere la fornitura ininterrotta di gametociti e parassiti dello stadio di zanzara. In questo manoscritto, descriviamo un protocollo di coltura dei gametociti approfondito (Figura 1), la preparazione di alimentatori a membrana di vetro e l'infezione delle zanzare usando questi alimentatori a membrana (Figura 2), la dissezione del midgut (Figura 3) e la ghiandola salivare delle zanzare (Figura 4) e la quantificazione dell'infezione nella zanzara dopo la dissezione del midgut e della ghiandola salivare.

<table>
	<tbody>
		<tr>
			<td>10% Sugar solution</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>10ml serological pipet</td>
			<td>Falcon</td>
			<td>357551</td>
			<td></td>
		</tr>
		<tr>
			<td>15 ml conical tube</td>
			<td>Falcon</td>
			<td>352096</td>
			<td></td>
		</tr>
		<tr>
			<td>1ml serological pipet</td>
			<td>Falcon</td>
			<td>357521</td>
			<td></td>
		</tr>
		<tr>
			<td>25 ml serological pipet</td>
			<td>Falcon</td>
			<td>357535</td>
			<td></td>
		</tr>
		<tr>
			<td>37&#176;C Incubator</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>50 ml conical tube</td>
			<td>Falcon</td>
			<td>352070</td>
			<td></td>
		</tr>
		<tr>
			<td>5ml serological pipet</td>
			<td>Falcon</td>
			<td>357543</td>
			<td></td>
		</tr>
		<tr>
			<td>6 well tissue culture plates</td>
			<td>Falcon</td>
			<td>353046</td>
			<td></td>
		</tr>
		<tr>
			<td>70% Ethanol</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>9&#34; glass pipet</td>
			<td>Fisherbrand</td>
			<td>13-678-6B</td>
			<td></td>
		</tr>
		<tr>
			<td>Anopheles Mosquitoes</td>
			<td>JHMRI, Insectary core</td>
			<td></td>
			<td>We use A. stephensi or A. gambiae (keele)</td>
		</tr>
		<tr>
			<td>cell counter</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Circulating water bath</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>fine tip forceps</td>
			<td>Fisherbrand</td>
			<td>12-000-122</td>
			<td></td>
		</tr>
		<tr>
			<td>Geimsa stain</td>
			<td>Sigma</td>
			<td>GS1L</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass desiccator</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Glass membrane feeder</td>
			<td>Chemglass Life Sciences</td>
			<td>CG183570</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass slides</td>
			<td>Fisherbrand</td>
			<td>12-552-3</td>
			<td></td>
		</tr>
		<tr>
			<td>HBSS</td>
			<td>Sigma</td>
			<td>H6648</td>
			<td></td>
		</tr>
		<tr>
			<td>Human Blood O+</td>
			<td>JHU</td>
			<td></td>
			<td>Wash RBCs three times with RPMI and refrigerate at 50% heamatocrit</td>
		</tr>
		<tr>
			<td>Human Serum O+</td>
			<td>Interstate blood bank</td>
			<td></td>
			<td>Pool at-least 6 units of serum from different donors and freeze down aliquots at -20&#176;C.</td>
		</tr>
		<tr>
			<td>Hypoxanthine</td>
			<td>Sigma</td>
			<td>H9337</td>
			<td>Make 500x stock in 1M NaOH</td>
		</tr>
		<tr>
			<td>Mercurochrome</td>
			<td>Sigma</td>
			<td>M7011</td>
			<td>Prepare 1% stock solution in PBS that can be diluted to 0.1% when needed</td>
		</tr>
		<tr>
			<td>Micro Pipette</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope</td>
			<td>Olympus</td>
			<td></td>
			<td>Any microscope with 10x, 40x and 100x objective will work.</td>
		</tr>
		<tr>
			<td>Mosquito cups</td>
			<td>Neptune cups</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>N-acetylglucosamine</td>
			<td>Sigma</td>
			<td>A3286</td>
			<td>Optional and needed only when pure gametocytes are required.</td>
		</tr>
		<tr>
			<td>Netting</td>
			<td></td>
			<td></td>
			<td>Make sure it can contain mosquitoes and allow blood feeding</td>
		</tr>
		<tr>
			<td>Parafilm</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>PBS</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Petri dish</td>
			<td>Thermo Scientific</td>
			<td>249964</td>
			<td></td>
		</tr>
		<tr>
			<td>Pipet tips</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Pipetman</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Plasmodium falciparum NF54</td>
			<td>BEI Resources</td>
			<td>MRA-1000</td>
			<td>Freeze down large numbers of early passage culture to make sure you have a constant supply</td>
		</tr>
		<tr>
			<td>RPMI 1640</td>
			<td>Corning</td>
			<td>CV-041-CV</td>
			<td>Media contains glutamine and HEPES</td>
		</tr>
		<tr>
			<td>Slide warmer</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium bicarbonate</td>
			<td>Sigma</td>
			<td>S6297</td>
			<td>Optional for media, add only when using malaria gas mix during culture incubation</td>
		</tr>
		<tr>
			<td>water bath</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Xanthurenic Acid</td>
			<td>Sigma</td>
			<td>D120804</td>
			<td>For flagellation media</td>
		</tr>
	</tbody>
</table>

plasmodium falciparum gametocyte culture and mosquito infection through artificial membrane feeding

La malaria rimane uno dei più importanti problemi di salute pubblica, causando morbilità e mortalità significative. La malaria è una malattia trasmessa dalle zanzare trasmessa attraverso un morso infettivo dalla zanzara femmina Anopheles. Il controllo della malaria alla fine si baserà su una moltitudine di approcci, che includono modi per bloccare la trasmissione da, attraverso e dalle zanzare. Per studiare in laboratorio gli stadi delle zanzare dei parassiti della malaria, abbiamo ottimizzato un protocollo per la coltura di gametociti di Plasmodium falciparum altamente infettivi, uno stadio parassitario necessario per la trasmissione dall'ospite umano al vettore della zanzara. I gametociti di P. falciparum maturano attraverso cinque fasi morfologicamente distinte, che richiedono circa 1-2 settimane. La coltura dei gametociti descritta in questo protocollo viene completata in 15 giorni e sono infettive per le zanzare dai giorni 15-18. Questi protocolli sono stati sviluppati per mantenere un ciclo continuo di infezione dei gametociti competenti e per mantenere l'apporto ininterrotto degli stadi di zanzara del parassita. Qui, descriviamo la metodologia della coltura dei gametociti e come infettare le zanzare con questi parassiti usando alimentatori a membrana di vetro.

Qui presentiamo i risultati di una serie di alimentazioni a membrana utilizzando colture di gametociti P. falciparum NF54 generate utilizzando il protocollo sopra (vedi (Figura 5). La coltura dei gametociti è stata iniziata con circa lo 0,5% di coltura asessuata a stadio misto il giorno 0, che è cresciuta fino a un picco di parassitemia di circa il 15% entro il giorno 4 e il giorno 5. Come mostrato nella Figura 5A a questa alta parassitemia, i parassi...

Watch this Scientific Journal Video about Plasmodium falciparum Gametocyte Culture and Mosquito Infection Through Artificial Membrane Feeding at JoVE.com

Plasmodium falciparum Gametocyte Culture and Mosquito Infection Through Artificial Membrane Feeding

Indagini dettagliate sugli stadi delle zanzare dei parassiti della malaria sono fondamentali per progettare efficaci strategie di blocco della trasmissione. Questo protocollo dimostra come coltura efficacemente gametociti infettivi e quindi nutrire questi gametociti alle zanzare per generare stadi di zanzara di P. falciparum.

Plasmodium falciparum Coltura di gametociti e infezione da zanzare attraverso l'alimentazione artificiale della membrana

Malaria remains one of the most important public health problems, causing significant morbidity and mortality. Malaria is a mosquito borne disease ...

plasmodium-falciparum-gametocyte-culture-mosquito-infection-through

Research

JoVE Journal

Biology

Plasmodium falciparum Gametocyte Culture and Mosquito Infection Through Artificial Membrane Feeding

7.2K Views.  Johns Hopkins University. Indagini dettagliate sugli stadi delle zanzare dei parassiti della malaria sono fondamentali per progettare efficaci strategie di blocco della trasmissione. Questo protocollo dimostra come coltura efficacemente gametociti infettivi e quindi nutrire questi gametociti alle zanzare per generare stadi di zanzara di P. falciparum.

Video: Plasmodium falciparum Gametocyte Culture and Mosquito Infection Through Artificial Membrane Feeding

Harvesting Sperm and Artificial Insemination of Mice

Rodents of the genus Peromyscus (deer mice) are the most prevalent native North American mammals. Peromyscus species are used in a wide range of research including toxicology, epidemiology, ecology, behavioral, and genetic studies. Here they provide a useful model for demonstrations of artificial insemination. 

Methods similar to those displayed here have previously been used in several deer mouse studies, yet no detailed protocol has been published. Here we demonstrate the basic method of artificial insemination. This method entails extracting the testes from the rodent, then isolating the sperm from the epididymis and vas deferens. The mature sperm, now in a milk mixture, are placed in the female&#x2019;s reproductive tract at the time of ovulation. Fertilization is counted as day 0 for timing of embryo development. Embryos can then be retrieved at the desired time-point and manipulated.

Artificial insemination can be used in a variety of rodent species where exact embryo timing is crucial or hard to obtain. This technique is vital for species or strains (including most Peromyscus) which may not mate immediately and/or where mating is hard to assess. In addition, artificial insemination provides exact timing for embryo development either in mapping developmental progress and/or transgenic work. Reduced numbers of animals can be used since fertilization is guaranteed. This method has been vital to furthering the Peromyscus system, and will hopefully benefit others as well.

This protocol demonstrates methods for extracting sperm from the testes of males and then inseminating female mice. This procedure is useful when precise time is needed in developmental studies as well as transgenic work.

Lo sperma raccolto e l&#39;inseminazione artificiale di topi

Rodents of the genus Peromyscus (deer mice) are the most prevalent native North American mammals.  Peromyscus species are used in a wide range of research ...

Ricerca

Biologia

Protocol for Plasmodium falciparum Infections in Mosquitoes and Infection Phenotype Determination

Once a gene is identified as potentially refractory for malaria, it must be evaluated for its role in preventing Plasmodium infections within the mosquito.    This protocol illustrates how the extent of plasmodium infections of mosquitoes can be assayed.  The techniques for preparing the gametocyte culture, membrane feeding mosquitoes human blood, and assaying viral titers in the mosquito midgut are demonstrated.

Once a gene is identified as potentially refractory for malaria, it must be evaluated for its role in preventing Plasmodium infections within the mosquito. This protocol illustrates how the extent of plasmodium infections of mosquitoes can be assayed. The techniques for preparing the gametocyte culture, membrane feeding mosquitoes human blood, and assaying viral titers in the mosquito midgut are demonstrated.

Protocollo per Plasmodium falciparum infezioni in Fenotipo Determinazione Zanzare e infezione

Once a gene is identified as potentially refractory for malaria, it must be evaluated for its role in preventing Plasmodium infections within the ...

Crystallizing Membrane Proteins for Structure Determination using Lipidic Mesophases

A detailed protocol for crystallizing membrane proteins by using lipidic mesophases is described. This method has variously been referred to as the lipidic cubic phase or in meso method. The method has been shown to be quite versatile in that it has been used to solve X-ray crystallographic structures of prokaryotic and eukaryotic proteins, proteins that are monomeric, homo- and hetero-multimeric, chromophore-containing and chromophore-free, and alpha-helical and beta-barrel proteins. Recent successes using in meso crystallization are the human engineered beta2-adrenergic and adenosine A2a G protein-coupled receptors. Protocols are presented for reconstituting the membrane protein into the monoolein-based mesophase, and for setting up crystallizations in the manual mode. Additional steps in the overall process, such as crystal harvesting, are to be addressed in future video articles. The time required to prepare the protein-loaded mesophase and to set up a crystallization plate manually is about one hour.

Herein is described the procedure implemented in the Caffrey Membrane Structural and Functional Biology Group to set up manually crystallization trials of membrane proteins in lipidic mesophases.

Cristallizzare proteine ​​di membrana per la determinazione della struttura utilizzando Mesophases lipidica

A detailed protocol for crystallizing membrane proteins by using lipidic mesophases is described. This method has variously been referred to as the ...

High-fat Feeding Paradigm for Larval Zebrafish: Feeding, Live Imaging, and Quantification of Food Intake

Zebrafish are emerging as a model of dietary lipid processing and metabolic disease. This protocol describes how to feed larval zebrafish a lipid-rich meal, which consists of an emulsion of chicken egg yolk liposomes created by sonicating egg yolk in embryo media. Detailed instructions are provided to screen larvae for egg yolk consumption so that larvae that fail to feed will not confound experimental results. The chicken egg yolk liposomes can be spiked with fluorescent lipid analogs, including fatty acids and cholesterol, enabling both systemic and subcellular visualization of dietary lipid processing. Several methods are described to mount larvae that are conducive to short- and long-term live imaging with both upright and inverted objectives at high and low magnification. Additionally presented is an assay to quantify larval food intake by extracting the lipids of larvae fed fluorescent lipid analogs, spotting the lipids on a thin layer chromatography plate, and quantifying the fluorescence. Finally, critical aspects of the procedures, important controls, options for modifying the protocols to address specific experimental questions, and potential limitations are discussed. These techniques can be applied not only to focused, hypothesis driven inquiries, but also to a variety of screens and live imaging techniques to study dietary lipid metabolism and the control of food intake.

Zebrafish are emerging as a valuable model of dietary lipid processing and metabolic disease. Described are protocols of lipid-rich larval feeds, live imaging of dietary fluorescent lipid analogs, and quantification of food intake. These techniques can be applied to a variety of screening, imaging, and hypothesis driven inquiry techniques.

Alto contenuto di grassi alimentazione paradigma per larvale Zebrafish: Alimentazione, l&#39;imaging dal vivo, e la quantificazione del cibo

Zebrafish are emerging as a model of dietary lipid processing and metabolic disease. This protocol describes how to feed larval zebrafish a lipid-rich ...

Ground State Depletion Super-resolution Imaging in Mammalian Cells

Advances in fluorescent microscopy and cell biology are intimately correlated, with the enhanced ability to visualize cellular events often leading to dramatic leaps in our understanding of how cells function. The development and availability of super-resolution microscopy has considerably extended the limits of optical resolution from ~250-20 nm. Biologists are no longer limited to describing molecular interactions in terms of colocalization within a diffraction limited area, rather it is now possible to visualize the dynamic interactions of individual molecules. Here, we outline a protocol for the visualization and quantification of cellular proteins by ground-state depletion microscopy&#160;for fixed cell imaging. We provide examples from two different membrane proteins, an element of the endoplasmic reticulum translocon, sec61&#946;, and a plasma membrane-localized voltage-gated L-type Ca2+ channel (CaV1.2). Discussed are the specific microscope parameters, fixation methods, photo-switching buffer formulation, and pitfalls and challenges of image processing.

This article outlines a protocol for the detection of one or more plasma and/or intracellular membrane proteins using Ground State Depletion (GSD) super-resolution microscopy in mammalian cells. Here, we discuss the benefits and considerations of using such approaches for the visualization and quantification of cellular proteins.

Stato fondamentale lo svuotamento super-resolution Imaging in cellule di mammifero

Advances in fluorescent microscopy and cell biology are intimately correlated, with the enhanced ability to visualize cellular events often leading to ...

Mosquito-Associated Virus Isolation from Field-Collected Mosquitoes

With the broad application of sequencing technologies, many novel virus-like sequences have been discovered in arthropods, including mosquitoes. The two main categories of these new mosquito-associated viruses are &#34;mosquito-borne viruses (MBVs)&#34; and &#34;mosquito-specific viruses (MSVs)&#34;. These novel viruses might be pathogenic to both vertebrates and mosquitoes, or they could just be symbiotic with mosquitoes. Entity viruses are essential to confirm the biological characters of these viruses. Thus, a detailed protocol has been described here for virus isolation and amplification from field-collected mosquitoes. First, the mosquito samples were prepared as supernatants of mosquito homogenates. After centrifugation twice, the supernatants were then inoculated into either mosquito cell line C6/36 or vertebrate cell line BHK-21 for virus amplification. After 7 days, the supernatants were collected as the P1 supernatants and stored at -80 &#176;C. Next, P1 supernatants were passaged twice more in C6/36 or BHK-21 cells while the cell status was being checked daily. When cytopathogenic effect (CPE) on the cells was discovered, these supernatants were collected and used to identify viruses. This protocol serves as the foundation for future research on mosquito-associated viruses, including MBVs and MSVs.

Numerous novel virus-like sequences have been found in mosquitoes due to the extensive use of sequencing technologies. We provide an effective procedure for isolating and amplifying viruses using vertebrate and mosquito cell lines, which might serve as the basis for future studies on mosquito-associated viruses, including mosquito-borne and mosquito-specific viruses.

Isolamento del virus associato alle zanzare dalle zanzare raccolte sul campo

With the broad application of sequencing technologies, many novel virus-like sequences have been discovered in arthropods, including mosquitoes. The two ...

Tick Artificial Membrane Feeding for Ixodes scapularis

Ticks and their associated diseases are an important topic of study due to their public health and veterinary burden. However, the feeding requirements of ticks during both study and rearing can limit experimental questions or the ability of labs to research ticks and their associated pathogens. An artificial membrane feeding system can reduce these problems and open up new avenues of research that may not have been possible with traditional animal feeding systems. This study describes an artificial membrane feeding system that has been refined for feeding and engorgement success for all Ixodes scapularis life stages. Moreover, the artificial membrane feeding system described in this study can be modified for use with other tick species through simple refinement of the desired membrane thickness. The benefits of an artificial membrane feeding system are counterbalanced by the labor intensiveness of the system, the additional environmental factors that may impact feeding success, and the need to refine the technique for each new species and life stage of ticks.

Tick Artificial Membrane Feeding for Ixodes scapularis

Presented here is a method to blood feed ticks in vitro via an artificial membrane system to allow for partial or full engorgement of a variety of tick life stages.

Alimentazione a membrana artificiale di zecche per Ixodes scapularis

Ticks and their associated diseases are an important topic of study due to their public health and veterinary burden. However, the feeding requirements of ...

Valutazione degli effetti fitochimici su Helicoverpa armigera attraverso il saggio di alimentazione

Developing a Feeding Assay System for Evaluating the Insecticidal Effect of Phytochemicals on Helicoverpa armigera

Helicoverpa armigera, a lepidopteran insect, is a polyphagous pest with a worldwide distribution. This herbivorous insect is a threat to plants and agricultural productivity. In response, plants produce several phytochemicals that negatively impact the insect's growth and survival. This protocol demonstrates an obligate feeding assay method to evaluate the effect of a phytochemical (quercetin) on insect growth, development, and survival. Under controlled conditions, the neonates were maintained until the second instar on a pre-defined artificial diet. These second-instar larvae were allowed to feed on a control and quercetin-containing artificial diet for 10 days. The insects' body weight, developmental stage, frass weight, and mortality were recorded on alternate days. The change in body weight, the difference in feeding pattern, and developmental phenotypes were evaluated throughout the assay time. The described obligatory feeding assay simulates a natural mode of ingestion and can be scaled up to a large number of insects. It permits one to analyze phytochemicals' effect on the growth dynamics, developmental transition, and overall fitness of H. armigera. Furthermore, this setup can also be utilized to evaluate alterations in nutritional parameters and digestive physiology processes. This article provides a detailed methodology for feeding assay systems, which may have applications in toxicological studies, insecticidal molecule screening, and understanding chemical effects in plant-insect interactions.

Autore in primo piano: Sviluppo e sfide dei saggi di alimentazione per la gestione dei parassiti degli insetti 

This protocol describes the obligate feeding assay to evaluate the potentially toxic effect of a phytochemical on the lepidopteran insect larvae. This is a highly scalable insect bioassay, easy to optimize the sublethal and lethal dose, deterrent activity, and physiological effect. This could be used for screening eco-friendly insecticides.

Sviluppo di un sistema di dosaggio per l'alimentazione per la valutazione dell'effetto insetticida di sostanze fitochimiche su Helicoverpa armigera

Helicoverpa armigera, a lepidopteran insect, is a polyphagous pest with a worldwide distribution. This herbivorous insect is a threat to plants and ...