Thread by @BSPparasitology

So we begin #ParasitesOnline21 today with C.A. Wright Medal 2020 winner, Prof Sarah Reece (@ReeceLab), who is telling us about "The private life of #malaria parasites: Strategies for survival & reproduction." #Parasitology

Prof Reece describes how the #malaria parasite regulates gametocyte sex ratio; highest number of offspring depends in female gametocyte number; the highest proportion of matings depends on male gametocyte number: sciencedirect.com/science/articl… #ParasitesOnline21

For optimal #malaria gametocyte ratio, there needs to be plasticity in the gametocyte conversion rate. The @ReeceLab has investigated environmental factors that may influence this rate, such as in ncbi.nlm.nih.gov/pmc/articles/P… #ParasitesOnline21

Why is this important to know? Well, if we can understand how and why the #malaria parasite regulates the production of gametocytes (i.e. it's gametocyte conversion rate), we may learn how we can manipulate, and potentially halt, #Plasmodium transmission. #ParasitesOnline21

And now, Prof Reece asks us "can the #malaria parasites tell time?". Does replication synchronise with host circadian rhythms: feeding behaviour, body temperature, or immune system activity? Some questions answered here: royalsocietypublishing.org/doi/10.1098/rs… #ParasitesOnline21

Not only does it appear that host feeding patterns effect #malaria parasite replication and conversion rates, but that isoleucine plays a key role in this! To read more, check out this @ReeceLab preprint: biorxiv.org/content/10.110… #ParasitesOnline21

And now to begin our "Schistosome "omics"" session at #ParasitesOnline21, we have Dr Matt Berriman of the @sangerinstitute with "Towards a chromosomal view of #schistosome genome evolution." #parasitology

From the first Schistosoma mansoni genome in 2009, Matt Berriman describes how far we've come, with 2 single-cell sequencing papers out last year: nature.com/articles/s4146… and science.sciencemag.org/content/369/65… #ParasitesOnline21

Dr Berriman now focusses in on the Z chromosome of the #schistosome, the sex-determining chromosome (keep an eye out for Buddenborg et al. from the Berriman Lab soon). The use of long-read sequencing for chromosome-level assemblies can also be seen in bmcbiol.biomedcentral.com/articles/10.11…

Now Dr Berriman describes compiling a set of complete genomes for #schistosoma (& beyond) and, incredibly, describes using as little as 1-3 adult schistosomes for material for PacBio sequencing (to reduce clonal variation). More to come from PhD student Duncan Berger in future!

For analysis of ortholog groups (contractions and expansions amongst #Schistosoma species), the Berriman Lab uses KinFin: ncbi.nlm.nih.gov/pmc/articles/P… And make sure to check out the @WBParaSite poster or attend Friday's workshop this week! #ParasitesOnline21

So I've just jumped over to the #ParasitesOnline21 "Interactions with Hosts and Vectors" session to see Nick Bailey of @UniofNewcastle's talk on "The intimate and evolutionarily conserved relationship between #Trichomonas and #Mycoplasma." #Parasitology

There is an incredibly interesting symbiotic relationship between trichomonas and mycoplasma and Nick Bailey references this introductory publication: frontiersin.org/articles/10.33… #ParasitesOnline21

So we'll have to wait a bit longer to find out more about the possible co-evolution of Parabasalia and Mycoplasma from Nick Bailey! Sounds promising! #ParasitesOnline21

So I jumped back over to "Schistosome "Omics"" for this #ParasitesOnline21 talk from Roy Platt of the Texas Biomedical Research Unit on "Genomic landscape of introgression between blood flukes infecting livestock (#Schistosoma bovis) and humans (S. haematobium) across Africa."

So you can find Roy Platt's work on genome hyridization and introgression in #schistosoma at ncbi.nlm.nih.gov/pmc/articles/P… #ParasitesOnline21

And our final #ParasitesOnline21 "Schistosome "omics"" talk today is from Cyril Hammoud of Ghent University with "Simultaneous genotyping of snails and infecting trematode parasites using high-throughput amplicon sequencing." #Parasitology

And now we begin the #ParasitesOnline21 "Interactions with Hosts and Vectors" session with a talk from Dr Julius Hafalla of @LSHTM on "Disparate immunogenic properties of #malaria pre-erythrocytic stage antigens and their susceptibility to vaccine-induced CD8+ T cells."

Dr Hafalla describes the two different parasite forms of the #malaria pre-erythrocytic stages: sporozoites and exo-erythrocytic forms (EEFs) that develop within hepatocytes, citing his previous study of CD8+ T-cell responses to parasite liver stages: pnas.org/content/99/18/…

Now Dr Hafalla describes characterising CSP(SIINFEKL) and UIS4(SIINFEKL) transgenic parasites (P. berghei) to compare the immunogenicity of these lines in either sporozoite or EEF form, the results of which just came out this year!: embopress.org/doi/full/10.15… #ParasitesOnline21

Even increasing the antigen load of vacuolar EEFs does not impact CD8+ T-cell responses (EEFs expressing UIS4(SIINFEKL)) whereas infectious sporozoites (CSP(SIINFEKL)) after injection into mice resulted in sterile protection of mice against a future #malaria infection.

Now Dr Hafalla is describing the study of various CSP immunodominant epitopes and that in fact the immunodominant epitope is dispensible in conferring immunity. A prime-boost CSP vaccination induces strong anti-CSP and CD8+ T-cell responses in BALB/c mice. But not in C57BL/6s.

Interesting talk! Read that Mueller paper for more info, but definitely a lot more questions to answer! Are there better vaccine targets? Can any of this immunogenicity be replicated in humans? #ParasitesOnline21

And now our 2nd "Interactions with Hosts and Vectors" talk for today is from Joseph Verdi of @DKFZ with "Turning #trypanosomes into a vaccine: The design and application of a brucei-based carrier platform for the targeting of a wide variety of "difficult" antigens."

This talk is WILD! Joseph Verdi describes a VSG immunogen array by sortase-tagging (VAST) and developing a vaccine to prevent fentanyl overdose! You can find the patent at data.epo.org/publication-se… and more at the Hepione website at hepionetx.com/our-tech

Now for the 3rd talk of this #ParasitesOnline21 session: Philip Milton of @imperialcollege with "Combining a Novel Immunoassay to Quantify Antibodies to Salivary Antigens with Antibody Acquisition Models to Estimate Exposure to Simulium damnosum s.l. Bites."

So Philip Milton describes using exposures estimated from antibody data in EPIONCHO-IBM transmission model such as in ncbi.nlm.nih.gov/pmc/articles/P… but the novel anti-saliva IgG ELISA to understand age- and sex-specific patterns of blackfly bites is still to come! #ParasitesOnline21

And now for the final talk of this #ParasitesOnline21 session: Katie Hildersley of @UofGlasgow describes "Identification and RNA profiling of ovine tuft cells in response to gastro-intestinal #nematode infections." #parasitology

scRNAseq carried out by @polyomics of ovine abomasum epithelium identifies a tuft cell cluster and conservation with functional murine tuft cell types. This work isn't out but here's a taster paper about ovine intestinal responses to nematodes: ncbi.nlm.nih.gov/pmc/articles/P…

And now for the final "Interactions with Hosts and Vectors" #ParasitesOnline21 session for Day 3: Dr Rob Dillon (@Sandflyman!) of @LancasterUni with "Scientist at play; artful science to explore #Leishmania, sand flies and their gut microbiota." #parasitology

Quite incredible how the sandfly gut microbiota influence not only their health and survival, but the transmission of #leishmania when the host sandfly becomes infected with the parasite! One example at ncbi.nlm.nih.gov/pmc/articles/P… #ParasitesOnline21

Going even further, what is the effect of sandfly microbiota on the mammalian host upon a blood feed and when #leishmania is released into this mammalian host? Quite a nice review of Leishmania, microbiota and sandfly immunity in ncbi.nlm.nih.gov/pmc/articles/P… #ParasitesOnline21

Dr Rob Dillon also goes into how it's important to explain science and engage the public, introducing us to Para-SITE-seeing at para-site-seeing.org/about/ and at @ldbob72 and if you want a catalogue about it, contact Rob himself at @Sandflyman!

And this talk was in memory of a former PhD student of @Sandflyman, the wonderful @heckie_diaz (who also helped with para-site-seeing.org/about/!)

And now for talk 2 of this session of #ParasitesOnline21: Gabriel Negreira of the Institute of Tropical Medicine Antwerp with "High throughput single-cell genome sequencing gives insights into the generation and evolution of mosaic aneuploidy in #Leishmania donovani."

And wonderfully, you can check out @GHnegreira's work in preprint form on @biorxivpreprint at biorxiv.org/content/10.110… #ParasitesOnline21

And now for our penultimate talk of today's "Interactions with Hosts and Vectors" session at #ParasitesOnline21: Dr Nicola Moloney of @Cambridge_Uni with "Functionally mapping the diversification of African #trypanosomes using spatial proteomics."

hyperLOPIT was used in this study to spatially map the proteome of African trypanosomes (bloodstream and procyclic forms each of T. brucei and T. congolense). An example of hyperLOPIT in Toxo at sciencedirect.com/science/articl…

As in the Barylyuk paper, unsupervised clustering was used to visualise the data and possible subcellular compartment clusters (upon which GO term analysis was carried out). But you'll have to wait to see the full TAGM-MAP classifications and results! Keep an eye out for it!

And our final #ParasitesOnline21 "Interactions with Hosts and Vectors" talk today is from Éden Ferreira of the Federal University of Sao Paulo with "Rapid egress of #Trypanosoma cruzi follows actin cytoskeleton rearrangement and membrane rupture." #chagas

Some really striking SEM images of T. cruzi in this study! And here it is! Just on @mbiojournal (as of yesterday as far as I can see!). Hot off the presses: journals.asm.org/doi/10.1128/mB… #ParasitesOnline21