Brief Summary of Minutes of Annual Meeting

Mark Berres (U. Madison Wisconsin)

Goal: Characterize genetic variation of Vietnamese jungle fowl, specifically immunologically active genes, distribution of allelic variation, risk of genetic endangerment, new reference genome for red jungle fowl. Work done in South East Asia

MHC Genetic diversity

-84 SNP chip panel is used from 199 individuals, high MHC nucleotide diversity was detected and high levels of heterozygocity

-This suggests diversifying selection of MHC

-A substantial amount of recombination was found, certain areas much higher than the normal rate. This suggests that recombination is an important factor contributing to diversity

-Compared to domestic lines the amount of diversity is huge.

 Genome wide neutral variation (not MHC related)

-Lots of private alleles

-Global scale and local scale differentiation was detected

-Lowland shows less intraspecific variation, highlands show more intraspecific variation

-Twelve or thirteen populations were detected

-Population discontinuity was demonstrated due to physical barriers such as a river

-Landscape genetic model was created. Is used to observe and evaluate the effect of topography and landscape on the diversity of these chickens. No effect of topography was found.

-Movement monitoring will be needed to explain their genetic differences      

Conclusions

• MHC high diversity, no population structure, huge array of novel haplotypes
• Neutral sites, high diversity, high global and local structure
  • 5km home size range
  • not influenced by landscape, or land cover
  • No evidence of domestic introgression

Future 

• Re-sequencing RJF with PacBio SMRT
• Apply genotyping by sequencing
• Investigate regulation patterns (methylation)

The methylation patterns of RJF are extremely different than the methylation seen in commercial leghorn lines.

Susan Lamont (Iowa State University)

Poultry immunogenetics

3 focus areas:

-Adapting chicken production to climate change through breeding

-Improving food security in Africa by enhancing resistance to NDV and heat stress in chickens

-Host resistance to avian pathogenic E. Coli.

Harderian gland transcriptome response to NDV

Oculo-nasal site of exposure with NDV (lentogenic), mostly T cells, produces antibodies; also T cells increase with immune stimulation. This is the first time the HG transcriptome is investigated.

-Fayoumi’s (village type bird rep) and leghorns (relatively susceptible) were used in live bird studies in order to come up with a resistance – susceptible model.

-In terms of viral load Fayumi’s are able to clear the virus faster than leghorns at 2 and 6dpi.

-Fayoumi’s are producing much more antibodies than leghorns confirming the resistance – susceptibility model.

 Harderian Gland Transcriptome:      

-High level of difference between lines as early as 2dpi, becoming lower as we reach 10dpi.

-Regardless of the challenge there are lots of differences in the gene expression of these birds.

-Hyper expressed genes are related with IF2 signaling in response to viruses, cytokines, B cell receptor signaling, etc.

-Leghorns have a big difference at 6dpi, this change can be unsuccessful efforts of leghorns to deal with the infection.

Since the challenge was done with a lentogenic strain a confirmation of the model were done submitting birds to SEPRL for challenges with Velogenic strains (Burkina Faso).

 Conclusions:

-Important immune related pathways were detected

-Large difference detected between lines specially at 2dpi

-Additional studies are needed to understand 6dpi leghorn responses

-HD11 cells reacted to heat stress by activation of protective mechanisms and inhibition of apoptosis

-HSPs were not activated by LPS alone

-Heat stress reinforced expression of LPS-activated chemokines: CCL4, CCL5, IL-8, pro-inflammatory IL-1.

Mohammad Heidari (USDA)

 MDV and Skin interaction

-RNA seq was used to understand better the skin infection by MDV

-10, 20 and 30dpi virus was detected Upregulation was detected mostly at 20dpi

-Differential expression of different genes is under characterization

-The gene expression of the virus in the skin was also investigated, in order to compare them the different days post infection were compared.

 Mechanisms of vaccine induced protection

-It has been demonstrated protection after vaccination as early as 1 dpi

-Interestingly there is an involvement of the innate immune system most likely NK cells, studies by Lee have shown that at 1 day post vaccination there is some protection, full protection is acquired after 5dpv.

-5 Days post infection there is production of IFNg, a, CD107a, suggesting NK involvement.

-10DPI you also see IFNg, even though this will reflect more the adaptive immune response

-At CT there were some changes in the expression of IFNg

 Deletion of adaptive immune system

No time to present

B and T cells are the target cells, if you deplete them and vaccinate you can weight the innate immune response.

Ramesh Selvaraj (Ohio State University)

 Salmonella infection on splenic macrophages

T Regs were involved in the suppression of Salmonella growth

Macrophages role:

IL-10. Upregulated, TLR-2 down regulated after salmonella infection (in vitro)

IL-10. similar to what was see in vitro, IFNg down regulated, NO production decreased in salmonella infected chickens (In vivo)

Conclusion:

Salmonella survives in macrophages

Nanoparticle based vaccine for Salmonella

The goal is to target the M cells, they are designing a methyl vinyl ether and maleic anhydride based nanoparticles for mucosal delivery.

The idea is to include the Salmonella in the nanoparticle, no outside

Cecal tonsil cells were imaged after labeling the nanoparticles with DAPI and red fluorescent protein. 24 hours after feeding the nanoparticles the image shows that the nanoparticles are sticking to the CT.

Matt Koci (North Carolina State University) 

How does the chicken Microbiome develops and how do probiotics affect it? What happens over time?

-Age has the strongest impact on composition of the microbiome

-The diversity gets more complex with age (microbiome)

-Complexity increases rapidly post hatch

-Early events have long term effects, early colonizers set the biome, their residue impacts what happens later on. Is very difficult to change this setting later in life.

-Individual species do not affect much the function in the chicken gut. The gut inly cares about what it needs.

-Enterobacterias dominate early, firmicutes in maturity

-Early exposure to microbial treatments changes microbiome development

 How do different regions of the GI compare?

-Location has strongest impact in composition, major influence of population ecology and composition

-Cyanobacteria and firmicutes dominate

-Ileal segmented filamented bacterias (SFB’S) decrease, Ruminococcaceae increases

-Probiotics are able to reduce the existence of clostridiaceaes

-Diet and probiotic status impact composition of the ceca and ileum biome

Bob Taylor (West Virginia University)

-Golden Sebright and Lakenvelder have been studied in terms of their MHC with a high-density panel.

-Lakenvelders there is only one MHC haplotype in the Sebrights 3 MHC haplotypes segregating

-BSNP-Q02: New similar to others

-BSNP-K02

-BSNP-A09A

 Lakenvelders: BSNP-C06 similar to one described in broilers

 Conclusions

-High density chicken MHC SNP panel revealed multiple, non serologically defined haplotypes

-Novel and defined haplotype differences may indicate recombination

 Chicken RBC alloantigens

 The idea is to detect the location of the different alloantigens

 There is no information about the susceptibility and resistance of the two described lines

Gisela Erf (University of Arkansas)

 Spontaneous autoimmune disease

 -Smithline autoimmune vitiligo used as a model for human vitiligo

-Hashimoto thyroiditis in the obese strain chickens  

-UCD200 autoimmune scleroderma

They are important models for non-communicable multifactorial diseases

-Genetic susceptibility

-Environmental factors

-Immunopathology

Growing feathers as dermal test site to monitor in-vivo cellular tissue responses

Need to be growing feathers because it has living tissue, you can find dermis and epidermis.

Feather infections are done (18ds old regenerating feathers).

Barbs are cutted above the epidermis and they are inoculated, feathers are collected different time after infection and the pulp is extracted, these are digested and strained in nylon mesh fir cell suspensions, they can be fixed and histo analyzed.

LPS, PGN were injected and profiles in blood and tissues was investigated:

-Blood heterophyl increased

-Macrophages and heterophyls in feathers. Lymphocytes came in in great number B and T cells too very diverse response.

-Cytokine expression in tissues LPS increased IL-1B

-Same profile was detected when chickens were inoculated with LPS and PGN at the same time

-Cutaneous GF in vitro test reveals differences in the responses of different lines of chickens

-She also has studied adjuvant effects on cellular and humoral adaptive immune responses to mouse IgG using this technique showing how powerful is this technique.

Summary:

-Is a window to look into cellular/tissue responses

-Is minimally invasive

-You can examine responses also in blood

Marleen Visker (Wageningen University)

Natural antibodies (Nab)

-High levels of maternal antibodies provides a longer and productive life to hens

-Antibodies in individuals generated without the exposure to an antigen

-Generation 5 generated low and high Nab subsets

-There has been an increase in the total Ig production over lines and generations

 Breeding for general disease resistance

-High Nab birds were able to reduce the mortality compared with med and low lines after infection with E. Coli.

-Next experiments will compare different challenge titers

-A field test was planned

Checking fir maturity, egg production etc. they need to make sure the high levels of Nabs do not affect the productive parameters 

 Summary

-Nabs are heritable and selection is possible

-Low or no relation between Nabs and productive traits

-Chromosome 4 seems to play a huge role in the production of Nab

B cells can be activated by different cells, they have several receptors. Nabs can be produced by B cells activated in a non-conventional route and provide an effect. They are part of the innate immune response.        

 Marcia Miller (City of Hope Beckman Research Institute)

MHC-Y

On chromosome 16 near MHC-B, CD1 is on the same chromosome, MHC B is highly polymorphic

1. Genome assembly

four contigs. In addition, two more trying to fill the gaps

2. Polymorphism of the YF class I-like genes

It has been detected that YF is similar to MR1 in humans, their role in humans is to basically respond to bacterias

3. PCR based method for MHC-type binding

 Summary

-Doubled MHC-Y sequence

-Strong data revealed nature of YF ligands

-Insights on YF molecular signaling

-Developed a simpler MHC-Y typing method

Mark Parcells (University of Delaware)

Mechanism of MD vaccine response

Meq gene products

Polycomb Bmi-1, upregulated in several cancer’s, binds to DNA elements and represses transcription.

Polycomb repressive complexes are recruited through tissue development, used by herpesvirus to establish latency  

Bmi-1 localizes primarily to nucleoplasm

Christina Swaggerty (USDA)

Selection of broilers for innate immune response

-Early studies

-Initial selection

-Current selection

Selecting for innate immune response is considered as a pre-harvest intervention for reducing food borne pathogens

The selection strategy was to obtain a high and a low line

Challenge models; high line birds had lower pathology scores than low lines (Eimeria tenella, SE, NE)

New project:

They will be screening and selecting using dams and sires.

Jeb Owens (Washington State University)

 Agriculture, Ecology, Immunology and Disease

Reality resides in co-infection

1. Northern fowl mite

The chicken MHC confers protection to chickens against this parasite B15 resistant B21 susceptible, this is due to the inflammation

A study involved the association of the resting metabolic rate, feed conversion and mite intensity (Murillo, 2016)

17% decline of the feed conversion In infested birds

The cost has been calculated in 10C per bird per week…

Resting metabolic rate is not significantly different

Changing production environment, increasing complexity and decreasing biosecurity= INCREASED RISK.

Robert Beckstead (North Carolina State University)

Blackhead Disease

Culture system is still the best way of screening compounds that inhibit H. Meleagridis

Sometimes they do not correlate with in vivo experiments

Future: Screen resistance to Blackhead

            Screen different industry genetic lines

            Genomic comparison between chickens and turkeys

            Targeted probiotic RNAi

 Henk Parmentier (Wageningen University)

 Nabs are heritable

Natural autoantibodies, there is a certain level of normal autoantibodies

1/3 of your B cells are autoimmune

Nat autoab are potential markers for health, diseases and disorders

By ELISA they checked the presence of diff antibodies      

The location of the Auto Ab is in chromosome 4

Conclusion:

Common genetic components underlying the b cell recognizing different antigens

CLL recognized by self IgM and IgG antibodies, they show different binding patterns based on lines and individuals    

The IgM auto-antibody profiles at hatch seems species related (no correspondence with mother)

The IgG auto-antibody profiles at hatch are related to the mother

 M.G.R. Matthijs (Utrecht University)

 Hypothesis: Differences in susceptibility of broilers to colibacillosis

 They found differences on susceptibility to colibacillosis in differebt broilers lines

 Jason Payne (NC State)

CRISPR/CAS used for gene editing and reincorporating DNA to the animal

Paul Cotter Present (Framingham University)

Bashophia and basophiliosis

Normal expected presence of basophils is around 2 to 3%