biology

Lymphocyte T-cell immunomodulator

Lymphocyte T-cell immunomodulator is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Lymphocyte T-cell immunomodulator rather than just read about it. In short: Lymphocyte T-cell immunomodulator (LTCI) is an immune regulating polypeptide, which is a potent regulator of CD-4 lymphocyte production and function. It increases lymphocyte numbers and interleukin-2 (IL-2) production in animals.

Key takeaways

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Reference excerpt

Lymphocyte T-cell immunomodulator (LTCI) is an immune regulating polypeptide, which is a potent regulator of CD-4 lymphocyte production and function. It increases lymphocyte numbers and interleukin-2 (IL-2) production in animals. It is extracted from bovine thymus.

History Prior to 1960, the thymus gland, which lies in the cervical thoracic area, was thought to be of little importance. In adult animals, the thymus is almost non-existent because it atrophies as animals reach adulthood. It was observed, however, that when pre-adolescent animals are thymectomized, they experience a variety of maladies including increased incidence of infection, failure to grow, neuromuscular disorders, cancer, etc., collectively known as “wasting disease”. The greater susceptibility to infection was shown to be directly attributable to a dramatic decrease in peripheral blood lymphocytes in thymectomized animals. By 1964 it had been demonstrated that regulatory factors extracted from the thymus gland could prevent many of the manifestations of wasting disease. This suggested that the thymus produces substances important in the development of immunity. It was not until 1971 that it was discovered that thymus-derived lymphocytes (T-cells) were important regulators of bone-marrow-derived antibody-producing lymphocytes (B-cells). After the discovery that the thymus was producing profound regulatory factors, several groups of scientists began trying to extract and purify this factor from thymus glands in much the same manner that insulin was prepared from the pancreas for therapeutic use in diabetes. The difficulty was that the thymus is a very small gland and produces very small quantities of the factor. Thus, purification techniques did not allow appropriate pure fractions to be produced in sufficient quantities. Thymus is a preferred tissue for viral replication of feline immunodeficiency virus, which results in lesions and dysfunction. In 1983 scientists succeeded in cloning epithelial cell lines from the thymus of various species and began to biochemically and biologically characterize these thymus derived regulatory factors. A protein with a molecular weight of about 50,000 daltons was subsequently described and shown to augment the immune responses of both immature and mature T-cells. This protein came to be known as lymphocyte T-cell immunomodulator.

Production and identity Lymphocyte T-cell immunomodulator, or T-4 immune stimulating factor (TISF), is a single chain polypeptide that is a strongly cationic glycoprotein and is purified with cation exchange resin. Purification of protein from bovine-derived type II thymic epithelial cell supernatants produces a substantially homogeneous factor, free of extraneous materials. The bovine protein is homologous with other mammalian species and is a homogeneous 50 kDa glycoprotein with an isoelectric point of 6.5. The protein is prepared in a lyophilized 1 microgram dose. Reconstitution in sterile diluent produces a solution for subcutaneous injection. It is unknown what LTCI is in terms of its sequence. It is not interleukins 1-7 nor G-CSF. The manufacturer verifies its potency by checking for stimulation of IL-2 production.

Mechanism of action Generally, a proportion of immature thymus-derived lymphocytes differentiate into mature CD4+ T-cells which produce a certain amount of cytokines, such as interleukin-2 (IL-2) and gamma interferon. To attack tumor cells and viruses, CD-4 cells coordinate the overall immune response and help activate CD8 T-lymphocytes. Often called “effector” or “cytotoxic” T-cells, CD-8+ T-lymphocytes they respond to intracellular pathogens and cancer cells. Under viral attack CD-4+ T-cells fail to mature, fail to produce IL-2 and gamma interferon, and consequently fail to coordinate CD-8 responses to viruses. LTCI increases the production of CD-4+ T-cells and can subsequently overcome this immunosuppression.

Veterinary uses

Viral diseases in cats LTCI, manufactured by T-Cyte Therapeutics, has been conditionally approved by the United States Department of Agriculture (USDA) as an aid in the treatment of cats infected with feline leukemia virus (FeLV) and/or feline immunodeficiency virus (FIV), and the associated symptoms of lymphopenia, opportunistic infection, anemia, granulocytopenia, or thrombocytopenia. Peer-reviewed literature disputes the benefit claims from the manufacturer. T-Cyte data as of 2011 does not strongly support the medication's ability to significantly increase the length or quality of life of treated cats.

Canine osteoarthritis LTCI increases the immune response to foreign antigens and dampens the immune-mediated response to self-antigens by increasing the number of precursors of a regulatory T-Cell population. In a double-blind placebo-controlled study, 11 of the 12 LTCI-treated canines had a 40 percent increase in function while the placebo group had a 17 percent decrease in function. Following the study, LTCI was approved by the USDA to treat osteoarthritis in dogs in 2016.

References

External links T-Cyte Therapeutics

Worked examples

Example 1 — a first encounter with Lymphocyte T-cell immunomodulator

Start with the simplest possible case. Write down what Lymphocyte T-cell immunomodulator claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, 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 Lymphocyte T-cell immunomodulator 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 Lymphocyte T-cell immunomodulator 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 Lymphocyte T-cell immunomodulator

In research: Lymphocyte T-cell immunomodulator appears in biology 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 Lymphocyte T-cell immunomodulator 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: Lymphocyte T-cell immunomodulator is common in secondary-school and first-year university syllabi. It links to neighbouring topics Lymphocytes, Veterinary drugs, so understanding it makes those chapters shorter.
In everyday life: Look for Lymphocyte T-cell immunomodulator 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.

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How to study Lymphocyte T-cell immunomodulator in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Lymphocyte T-cell immunomodulator 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 Lymphocyte T-cell immunomodulator out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Lymphocyte T-cell immunomodulator in simple terms?

Why does Lymphocyte T-cell immunomodulator matter?

Because it connects several biology 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 Lymphocyte T-cell immunomodulator?

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 Lymphocyte T-cell immunomodulator.