A New Avian Immunological Pathway Discovered
Here is one of those papers where its difficult to decide which discovered facts best refute Creationism when so many do - at least for those who understand both Creationism and biology, which sadly, hardy ever includes Creationists.
Scientists lead by biochemists from the University of California, Riverside, have discovered a hitherto unknown immunological pathway, unique to avians but absent in all other vertebrates.
Refutation No. 1. Evidence of the common descent of avians from an ancestral species which had this pathway.
There is evidence that viruses such as those that tend to infect birds, humans, and animals and spread diseases like influenza or Crimean-Congo haemorrhagic fever — may be targeting this avian immunological pathway, in other words, there is evidence of an on-going arms race.
Refutation No. 2. Parasitic viruses, that appear to be designed for no other reason than to cause illness and suffering cannot conceivably be presented as the work of an omnibenevolent creator who wishes to maximise happiness and minimise suffering. Rather, if we accept the notion of a designer, that designer must be malevolent.
Refutation No. 3. Arms races make no sense as the work of a single designer who, so Creationists need to believe, treats the solutions it designs to solve one problem as a problem to be solved for a new problem that solution produced, seen from the point of view of one component in the arms race. Arms races are also evidence of harm
Understanding these differences is critical to better understanding birds as potential reservoirs of human pathogens. Additionally, it allows researchers to better understand the immune pathways that might lead to effective vaccines for agriculture use in poultry.
We found chicken OASL contains features resembling those found in mammalian ISG15s. Our analysis of OASL sequences from six diverse bird species indicate that these features are likely conserved among avian OASLs.
This has never been shown before. We found OASL in birds has this unique LRLRGG motif at one end and it’s very functional. Additionally, the region of the protein this motif belongs to has a similar 3D atomic structure of ISG15. This, along with findings related to what it can attach to within cells, suggests that OASL plays at least part of the role in birds that ISG15 would have played.
We now know a new immune pathway in chickens. Viruses appear to be evolutionarily geared to try to interfere with this pathway. Such information allows us to develop better vaccines and treatments that seek to optimize triggering this pathway to help chickens ward off disease. It also allows animal husbandry programs to further enhance this pathway’s potency leading to poultry that is more resistant to disease
being done by one organism to another; again, consistent with a malevolent designer, if we exclude mindless, undirected evolution as an explanation.We found chicken OASL contains features resembling those found in mammalian ISG15s. Our analysis of OASL sequences from six diverse bird species indicate that these features are likely conserved among avian OASLs.
This has never been shown before. We found OASL in birds has this unique LRLRGG motif at one end and it’s very functional. Additionally, the region of the protein this motif belongs to has a similar 3D atomic structure of ISG15. This, along with findings related to what it can attach to within cells, suggests that OASL plays at least part of the role in birds that ISG15 would have played.
We now know a new immune pathway in chickens. Viruses appear to be evolutionarily geared to try to interfere with this pathway. Such information allows us to develop better vaccines and treatments that seek to optimize triggering this pathway to help chickens ward off disease. It also allows animal husbandry programs to further enhance this pathway’s potency leading to poultry that is more resistant to disease
Scott Pegan, lead author
Professor of biomedical sciences
Division of Biomedical Sciences
UC Riverside School of Medicine
Professor of biomedical sciences
Division of Biomedical Sciences
UC Riverside School of Medicine
So to the piece of research. The UC Riverside News item by Iqbal Pattalwala explains:
Birds lack a protein in their cells called ISG15. Found in mammals and other non-avian reptiles, ISG15 in those species helps mount an effective immune response to viral infection. Serving as a messenger molecule, ISG15 helps stabilize host and viral proteins and regulate many antiviral responses. Instead, birds have OASL proteins that help produce a robust immune response to viral infection. Pegan and his team focused on chicken immunity.Further details are in the abstract to the group's paper, published open access in Frontiers in Immunology:
[…]
The team found avian OASLs have a sequence motif of amino acids, namely, LRLRGG, within what is known as a ubiquitin-like domain. This motif allows OASL to attach to other host proteins as a means to stimulate certain host antiviral pathways.
[…]
Pegan explained that to suppress the human immune system, a virus contains a protein that performs two jobs: remove ISG15 as well as ubiquitin, which a small protein that helps regulate the processes of other proteins in the body from host and viral proteins. Compared to these small proteins, OASLs are four times larger and with other areas carrying out different functions. Although mammals have OASL proteins, they lack this additional motif to conjugate to other proteins, suggesting that birds may have evolved to centralize functions carried out by ISG15 and other immune pathways. This immunological pathway in birds, which is a substitute for ISG15, is what Pegan’s team discovered.
Figure 3 Electrostatic surface potential and residue conservation of chOASL Ubl and human ISG15. (A) Surface rendering of each Ubl with surface potential ranging from +4 to -4. Negatively charged regions are shown in red and positively charged regions are shown in blue. Potentials were generated using the PDB2PQR server and the surface was rendered using the adaptive Poisson-Boltzmann solver (APBS). (B) Surface rendering of each Ubl with surface residues color coded to represent degree of conservation across species based on the alignments in Figure 4. Color scale ranges from bright green for perfectly conserved residues to orange for residues that are one third conserved.
AbstractRefutation No. 5. Two different solutions to the same problem. No intelligent designer would set about designing an entirely new solution to a problem it has designed a solution to earlier. An evolutionary process, however is capable of breaking a solution then starting afresh when the problem arises again, so ending up with several different solutions to the same problem - e.g. different wing designs; different eye designs, different respiratory systems for fishes and aquatic mammals and reptiles, and many more, hence the present biodiversity.
Post-translational modification of host and viral proteins by ubiquitin and ubiquitin-like proteins plays a key role in a host's ability to mount an effective immune response. Avian species lack a ubiquitin-like protein found in mammals and other non-avian reptiles; interferon stimulated gene product 15 (ISG15). ISG15 serves as a messenger molecule and can be conjugated to both host and viral proteins leading them to be stabilized, degraded, or sequestered. Structurally, ISG15 is comprised of a tandem ubiquitin-like domain (Ubl), which serves as the motif for post-translational modification. The 2'-5' oligoadenylate synthetase-like proteins (OASL) also encode two Ubl domains in series near its C-terminus which binds OASL to retinoic acid inducible gene-I (RIG-I). This protein-protein interaction increases the sensitivity of RIG-I and results in an enhanced production of type 1 interferons and a robust immune response. Unlike human and other mammalian OASL homologues, avian OASLs terminate their tandem Ubl domains with the same LRLRGG motif found in ubiquitin and ISG15, a motif required for their conjugation to proteins. Chickens, however, lack RIG-I, raising the question of structural and functional characteristics of chicken OASL (chOASL). By investigating chOASL, the evolutionary history of viruses with deubiquitinases can be explored and drivers of species specificity for these viruses may be uncovered. Here we show that the chOASL tandem Ubl domains shares structural characteristics with mammalian ISG15, and that chOASL can oligomerize and conjugate to itself. In addition, the ISG15-like features of avian OASLs and how they impact interactions with viral deubiquitinases and deISGylases are explored.
Shepard JD, Freitas BT, Rodriguez SE, Scholte FEM, Baker K, Hutchison MR, Longo JE, Miller HC, O'Boyle BM, Tandon A, Zhao P, Grimsey NJ, Wells L, Bergeron É, Pegan SD.
The Structure and Immune Regulatory Implications of the Ubiquitin-Like Tandem Domain Within an Avian 2'-5' Oligoadenylate Synthetase-Like Protein.
Frontiers in Immunology. 2022 Jan 4;12:794664. doi: 10.3389/fimmu.2021.794664. PMID: 35058932; PMCID: PMC8764230.
Copyright: © 2022 The authors. Published by Frontiers
Open access
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)
As so often with science, research ends up quite casually and incidentally, refuting creationism, simply by revealing the facts. The reason for this is obvious - Creationism, unlike evolution, is not a conclusion from the evidence but a primitive guess made from a position of ignorance before the scientific method gave us the tools to discover the truth.
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