Interferon tau

Key takeaways

Interferon tau belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Interferon tau to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Interferon tau from memory before moving on to harder problems.

Reference excerpt

Interferon tau (IFNτ, IFNT) is a Type I interferon made of a single chain of amino acids. IFN-τ was first discovered in ruminants as the signal for the maternal recognition of pregnancy and originally named ovine trophoblast protein-1 (oTP-1). It has many physiological functions in the mammalian uterus, and also has anti-inflammatory effect that aids in the protection of the semi-allogeneic conceptus trophectoderm from the maternal immune system. IFN-τ genes have only been found in ruminants that belong to the Artidactyla order, and multiple polymorphisms and several variants of IFN-τ have been identified. Although IFN-τ has been shown not to be produced in humans, both human and mouse cells respond to its effects. IFN-τ binds to the same IFN receptors as IFN-α and induces intracellular signalling through STAT1, STAT2, and Tyk2. This leads to the production of antiviral and immunomodulatory cytokines, including IL-4, IL-6, and IL-10.

Structure IFN-τ consists of 172 amino acids with two disulfide bridges (1–99, 29–139) and amino terminal proline. Similar to other Type I interferons, IFN-τ binds to the Interferon-alpha/beta receptor (IFNAR). Its molecular weight is between 19 and 24 kDa, depending on glycosylation state. Not all variants of IFN-τ are glycosylated. Bovine IFN-τ is N-glycosylated at ASN78, caprine IFN-τ is a combination between nonglycosylated and glycosylated forms and ovine IFN-τ is not glycosylated. Receptor binding site can be found at the C-terminus, biologically active site is located at the N-terminus. Compared to other interferons, IFN-τ shares about 75% of its identity to IFN-ω, which can be found quite commonly in mammals. However, Southern blot analysis and genome sequencing data proved that genes encoding IFN-τ can be found only in ruminant species. Studies also show 85% sequence identity between human trophoblast IFN in placental trophoblast cells and IFN-τ.

Function and biological activity IFN-τ is constitutively secreted by trophoblast and endometrial cells during ovine pregnancy. Its secretion begins around tenth day and increases between days 13 and 16, when it reaches its peak, and then stopping after day 24 of pregnancy. IFN-τ is essential to maintain the levels of progesterone production by the corpus luteum for the maternal recognition of pregnancy, and together with progesterone increases expression of genes for transport of nutrients into the uterine lumen, growth factors for hematopoiesis and angiogenesis and other molecules that are crucial for implantation and placentation. It has both endocrine and paracrine effects, immunomodulatory influence on several types of cells including neutrophils, and antiproliferative, antiluteolytic and immunosuppressive effects on the endometrium. IFN-τ binds to IFNAR cell membrane receptor and induces dimerization of its subunits, IFNAR1 and IFNAR2, which leads to activation of canonical and noncanonical signaling pathways. The canonical pathway involves Janus kinase-signal transducer and activator of transcription-interferon regulatory factor (JAK-STAT-IRF) signaling. This leads to induction of classical interferon stimulated genes (ISGs). The noncanonical signaling pathway includes mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase thymoma viral proto-onco- gene 1 (PI3K-AKT1) cascades. IFN-τ can also stimulate expression of interleukins IL-6 and IL-8. However, the mechanism is not STAT1, but STAT3 dependent. Synthetic gene for ovine IFN-τ was produced using Pichia pastoris yeast system. The recombinant IFN-τ had the same antiviral, antiluteolytic and immunosuppressive properties as native IFN-τ.

Clinical use Understanding the role of IFN-τ in pregnancy recognition in ruminants and its mechanism of action led to its use in pregnancy diagnosis, as it can be measured directly from blood, and knowledge of its actions can be used to improve the reproductive efficiency in ruminants. Since the effects of IFN-τ are not limited to ruminants and pregnancy, it has been studied for its anti-inflammatory properties as a treatment for diabetes. NOD mice that were treated with IFN-τ, which was administered either orally, intraperitoneally, or subcutaneously, have shown delayed or even inhibited development of diabetes. IFN-τ is able to inhibit human immunodeficiency virus replication in vitro more effectively than human IFN-α. It was observed that IFN-τ decreased intracellular HIV RNA in human macrophages and inhibited reverse transcription of viral RNA into proviral DNA. Because of difference in both selectivity of individual N-termini towards receptors and different degree of receptor avidity, IFN-τ displays much less cytotoxicity than IFNT-α. This can be useful in treatment of viral diseases. IFN-τ has also demonstrated biological effects against influenza virus. However, IFN-τ has high species specificity which can cause a significant decrease in biological activity when administered to another species.

References

Worked examples

Example 1 — a first encounter with Interferon tau

Start with the simplest possible case. Write down what Interferon tau claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Interferon tau before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Interferon tau ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Interferon tau

In research: Interferon tau appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Interferon tau in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Interferon tau is common in secondary-school and first-year university syllabi. It links to neighbouring topics Antiviral drugs, so understanding it makes those chapters shorter.
In everyday life: Look for Interferon tau outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Interferon tau in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Interferon tau means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Interferon tau out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Interferon tau in simple terms?

Interferon tau (IFNτ, IFNT) is a Type I interferon made of a single chain of amino acids. IFN-τ was first discovered in ruminants as the signal for the maternal recognition of pregnancy and originally named ovine trophoblast protein-1 (oTP-1).

Why does Interferon tau matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Interferon tau?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Interferon tau.