Applications of Recombinant DNA Technology
Chapter 4
EXERCISES:
1. What do you mean by DNA fingerprinting? Explain it through RFLP.
Ans: DNA Fingerprinting Explained via RFLP:
DNA fingerprinting is a technique used to identify individuals based on their unique DNA patterns. While many methods exist, Restriction Fragment Length Polymorphism (RFLP) was one of the first and most prominent methods. Let's break it down:
1. The Concept:
Imagine DNA as a long string of beads, each representing a chemical unit called a nucleotide. These beads can be in different orders, creating variations among individuals. RFLP focuses on specific sites within this string where restriction enzymes, bacterial scissors, recognize and cut the DNA.
2. The RFLP Process:
*DNA Extraction: DNA is first isolated from a sample (blood, hair, etc.).
*Restriction Digest: Specific restriction enzymes are chosen to cut the DNA at their target sequences. Different enzymes create different sized fragments depending on where they encounter their target sites.
*Gel Electrophoresis: The DNA fragments are loaded onto a gel and an electric current is applied. Smaller fragments move faster through the gel, creating a characteristic "banding pattern" of separated fragments.
*Visualization & Analysis: The gel is treated with a dye to reveal the DNA bands. By comparing the band patterns of different samples, we can identify individual variations and establish matches or mismatches.
3. Uniqueness and Applications:
Each individual's DNA sequence is slightly different, leading to unique RFLP patterns. This makes RFLP a powerful tool for:
*Paternity testing: Comparing a child's RFLP pattern with suspected fathers to determine biological parentage.
*Forensic investigations: Matching DNA evidence from crime scenes to suspects.
*Genetic mapping and disease analysis: Identifying genes associated with specific traits or diseases by tracking their RFLP patterns in families.
4. Limitations and Advancements:
While RFLP was groundbreaking, it has limitations:
*Requires large amounts of DNA and is time-consuming.
*Not as discriminatory as newer DNA profiling methods like Short Tandem Repeat (STR) analysis, which can distinguish individuals even with very similar DNA.
Despite these limitations, RFLP paved the way for modern DNA fingerprinting techniques and continues to be used in some specific applications.
2. What are GMOs? Describe the method of development of transgenic plants.
Ans: GMOs Explained: Demystifying Genetically Modified Organisms
GMOs, short for Genetically Modified Organisms, are living beings whose genetic makeup has been altered in a lab using techniques like genetic engineering. This modification aims to introduce new traits or enhance existing ones. While most commonly associated with plants, GMOs can also be animals, microbes, and even bacteria.
Creating Transgenic Plants: A Step-by-Step Journey
Here's how scientists develop transgenic plants, a common type of GMO:
1. Identifying the Desired Trait: Scientists first determine the desired trait, such as pest resistance, drought tolerance, or increased nutritional value.
2. Isolating the Gene: The gene responsible for the desired trait is identified and isolated from another organism, which could be a related plant, a bacterium, or even a completely different species.
3. Constructing the Vector: A vector, usually a bacterial plasmid, is modified to carry the isolated gene along with regulatory elements that control its expression.
4. Transformation: The vector carrying the desired gene is then introduced into plant cells. This can be done through various methods like Agrobacterium-mediated transfer, particle bombardment, or electroporation.
5. Regeneration and Selection: The transformed plant cells are regenerated into whole plants through tissue culture techniques. These plants are then screened and selected for those that successfully integrate the desired gene and express the desired trait.
6. Testing and Regulation: Extensive testing is performed to ensure the safety and efficacy of the GM plant. Regulatory approvals are required before commercialization.
Note: This is a simplified overview, and the specific techniques and challenges involved can vary depending on the desired trait and plant species.
Benefits and Concerns of Transgenic Plants
Transgenic plants offer potential benefits like:
*Increased food production and affordability
*Improved nutritional value of crops
*Reduced pesticide use and environmental impact
*Enhanced resistance to pests, diseases, and environmental stress
However, concerns exist regarding:
*Potential risks to human health and the environment
*Ethical considerations and issues of intellectual property rights
*The potential for increased corporate control over the food system
The debate surrounding GMOs is complex and requires careful consideration of both the potential benefits and risks.
3. Differentiate between direct and indirect method of gene transfer. Name one indirect method suitable for gene transfer in dicot plants.
Ans: Direct vs. Indirect Methods of Gene Transfer: Key Differences
The main difference between direct and indirect methods of gene transfer lies in the role of a vector:
*Direct methods: Introduce the desired gene directly into the host cell without using a vector. This can be achieved through techniques like microinjection, particle bombardment, and electroporation.
*Indirect methods: Employ a vector, usually a plasmid or virus, to carry the desired gene into the host cell. The vector facilitates both delivery and integration of the gene into the host genome.
Additional differences:
4. What is molecular pharming? Give applications of transgenic animals in molecular pharming.
Ans: Molecular Pharming: Harnessing Living Organisms for Medicine
Molecular pharming refers to the production of valuable pharmaceutical molecules, like proteins, antibodies, and vaccines, in living organisms such as plants and animals. These organisms are genetically modified to express the desired genes for producing the therapeutic substances. It's essentially "farming" for medical products.
Benefits of Molecular Pharming:
*Cost-effective production: Compared to traditional methods, like bacterial or mammalian cell cultures, pharming can be significantly cheaper and scalable.
*Enhanced biocompatibility: Certain proteins or sugars produced in animal or plant hosts may be more compatible with the human body, leading to fewer side effects.
*Rapid production and scalability: Plants and animals can be quickly multiplied, allowing for rapid production of the desired pharmaceutical.
Applications of Transgenic Animals in Molecular Pharming:
*Milk bioreactors: Cows, goats, and rabbits can be engineered to produce therapeutic proteins in their milk. This makes for easy extraction and purification.
*Eggs as factories: Chickens can be modified to lay eggs containing human proteins like antibodies or hormones. This offers a non-invasive and easily scalable production method.
*Blood serum production: Transgenic sheep or goats can be used to produce therapeutic proteins in their blood serum. This offers high yields and potential post-translational modifications similar to humans.
Examples of Transgenic Animal-derived Pharmaceuticals:
*ATryn® (alpha-1-antitrypsin for lung disease) produced in the milk of transgenic goats.
*Elelyso® (iduronate sulfatase for Hunter syndrome) produced in the milk of transgenic pigs.
*Hemlibra® (bispecific antibody for hemophilia A) produced in the eggs of transgenic chickens.
Challenges and Concerns:
*Regulatory hurdles: Obtaining regulatory approval for transgenic animal-derived pharmaceuticals can be a lengthy and expensive process.
*Public perception: Ethical concerns and public acceptance of transgenic animal-based production of pharmaceuticals need to be addressed.
*Potential immune response: Humans might develop an immune response to the therapeutic protein if it's produced in a transgenic animal.
5. Differentiate between gene gun and gene therapy.
Ans: Both gene gun and gene therapy involve introducing genetic material into cells, but they do so in vastly different ways and for distinct purposes:
Gene Gun:
*Method: A physical tool resembling a gun shoots DNA-coated gold particles directly into cells.
*Applications: Primarily used in research, particularly for introducing genes into plant cells for functional studies or crop improvement. It can also be used in vaccine development and studying gene function in animal models.
*Pros: Relatively straightforward and affordable technique, effective for some organisms like plants.
*Cons: Inefficient and imprecise targeting, can damage cells, not suitable for therapeutic use in humans due to safety concerns.
Gene Therapy:
*Method: Utilizes vectors, often viruses or engineered plasmids, to carry therapeutic genes into target cells.
*Applications: Aims to treat genetic diseases by correcting faulty genes or introducing missing ones. It's a rapidly evolving field with potential for treating various conditions like cystic fibrosis, hemophilia, and even some cancers.
*Pros: More targeted and potentially permanent solutions for genetic diseases, holds significant promise for future medical advancements.
*Cons: Complex and expensive, potential for side effects or immune response against vectors, ethical considerations regarding germline editing techniques.
In essence:
*Gene gun: A research tool for introducing genes, mostly in plants, with limited accuracy and not used for human therapy.
*Gene therapy: A potential treatment for genetic diseases by delivering therapeutic genes precisely into target cells, but still under development and facing ethical and safety hurdles.
6. Give the procedure of development of recombinant subunit vaccines.
Ans: Developing Recombinant Subunit Vaccines: A Step-by-Step Guide
Recombinant subunit vaccines offer a safe and effective way to fight various diseases by utilizing specific antigenic parts of a pathogen. Here's a simplified breakdown of their development process:
1. Identifying the Target Antigen:
*Researchers first identify the specific protein or other molecule on the pathogen that triggers a strong immune response (the antigen).
*This typically involves studying the pathogen's structure and function to pinpoint the crucial elements involved in its infectivity or virulence.
2. Isolating the Antigen Gene:
*Once the target antigen is identified, its corresponding gene is isolated from the pathogen's genome.
*This can be achieved through various techniques like DNA extraction, enzymatic isolation, and PCR amplification.
3. Constructing the Expression Vector:
*The isolated antigen gene is then inserted into a vector, usually a plasmid or virus, designed to deliver and express the gene in host cells.
*The vector also contains regulatory elements that control the timing and amount of antigen production.
4. Transformation and Antigen Production:
*The engineered vector is introduced into suitable host cells, often bacteria or yeast, through techniques like electroporation or viral infection.
*These cells then take up the vector and start producing the targeted antigen protein in large quantities.
5. Purification and Quality Control:
*The produced antigen protein is then purified from the host cells using various chromatography and filtration techniques.
*Extensive quality control checks are performed to ensure the purity, potency, and safety of the extracted antigen.
6. Formulation and Adjuvants:
*The purified antigen alone may not be sufficient to trigger a strong enough immune response. Therefore, it's often combined with adjuvants, substances that enhance the immune system's activation.
*The antigen and adjuvant mixture is then formulated into a stable and injectable vaccine suspension.
7. Preclinical and Clinical Trials:
*Before human use, the vaccine undergoes rigorous testing in animals (preclinical trials) to evaluate its safety, efficacy, and potential side effects.
*If successful, the vaccine progresses to controlled clinical trials involving human volunteers to further assess its safety and effectiveness in different population groups.
8. Regulatory Approval and Production:
*If clinical trials demonstrate satisfactory results, the vaccine receives regulatory approval for mass production and distribution.
*Large-scale manufacturing processes are then established to ensure widespread availability of the vaccine.
9. Monitoring and Surveillance:
*Even after vaccine rollout, continuous monitoring and surveillance are crucial to track its long-term effectiveness and potential adverse effects in a broader population.
`It's important to note that this is a general overview, and specific details may vary depending on the targeted pathogen and chosen technology.
7. Write a short note on DNA vaccines.
Ans: DNA Vaccines: A New Generation of Immunization
DNA vaccines, also called plasmid DNA vaccines, are a novel type of vaccine that uses engineered DNA to induce an immune response against a specific pathogen. Unlike traditional vaccines, which often contain weakened or inactive viruses or bacteria, DNA vaccines directly introduce the genetic code for a viral or bacterial antigen into the recipient's cells. This triggers the cells to produce the antigen themselves, essentially turning them into mini-factories for vaccine production.
Here's how DNA vaccines work:
1. Plasmid Injection: A plasmid, a small circular piece of DNA containing the desired antigen gene, is injected into the muscle or skin.
2. Cellular Uptake: The plasmid is taken up by nearby cells.
3. Antigen Production: The cell machinery reads the antigen gene and produces the antigen protein.
4. Immune Response: The immune system recognizes the foreign antigen protein and launches an immune response, including the production of antibodies and T cells specific to the pathogen.
Advantages of DNA vaccines:
*Highly targeted: They can be precisely engineered to target specific antigens, potentially offering greater protection against specific strains or variants of a pathogen.
*Stable and easy to store: Plasmids are more stable than traditional vaccines and don't require refrigeration, making them easier to transport and store, especially in resource-limited settings.
*Potentially longer-lasting immunity: DNA vaccines may induce more durable immune responses compared to some traditional vaccines.
*Fewer side effects: They generally have fewer side effects than traditional vaccines because they don't contain live or attenuated viruses or bacteria.
Challenges and limitations:
*Delivery efficiency: Delivering the DNA plasmid into cells efficiently can be challenging, limiting the vaccine's effectiveness.
*Regulation and approval: DNA vaccines are a relatively new technology and face stricter regulatory hurdles compared to established vaccine types.
*Cost of development: Developing and manufacturing DNA vaccines can be more expensive than traditional vaccines.
Despite these challenges, DNA vaccines hold immense promise for the future of vaccination. They offer a safe, targeted, and potentially durable approach to protecting against a wide range of infectious diseases. With ongoing research and development, DNA vaccines have the potential to revolutionize the way we prevent and control infectious diseases.
Here are some additional points to consider:
*DNA vaccines are still in their early stages of development, and more research is needed to fully understand their potential and address existing challenges.
*Several DNA vaccines are currently in clinical trials for various diseases, including COVID-19, HIV, and influenza.
*The future of DNA vaccines may lie in combination with other vaccine technologies, such as viral vectors, to improve their delivery and effectiveness.
8. Describe the advantages of monoclonal antibodies developed by rDNA technology over that developed by Hybridoma technology.
Ans: Advantages of rDNA-developed monoclonal antibodies over Hybridoma-developed ones:
While both Hybridoma and rDNA technologies can produce monoclonal antibodies (mAbs), rDNA offers several advantages:
1. Specificity and homogeneity:
*Hybridoma: May contain unintended antibodies alongside the desired one, impacting purity and targeting accuracy.
*rDNA: Allows precise engineering of the desired antibody sequence, ensuring high specificity and purity for targeted therapy or diagnostics.
2. Scalability and consistency:
*Hybridoma: Cell lines can be unstable and production batches may vary slightly in quality.
*rDNA: Enables large-scale, cost-effective production of consistent, uniform mAbs with predictable properties.
3. Safety and immunogenicity:
*Hybridoma: Mouse-derived antibodies can trigger an immune response in humans, requiring modifications like humanization.
*rDNA: Allows creation of fully humanized mAbs, reducing immunogenicity and potential side effects.
4. Design flexibility:
*Hybridoma: Limited to naturally occurring antibodies.
*rDNA: Enables engineering of mAbs with improved properties like enhanced affinity, stability, or effector functions.
5. Ethical considerations:
*Hybridoma: Requires immunization of animals, raising ethical concerns.
*rDNA: Eliminates the need for animal use, aligning with animal welfare principles.
Overall, rDNA technology offers greater precision, control, and flexibility in developing mAbs, making it a more versatile and reliable approach for therapeutic and diagnostic applications.
However, Hybridoma technology remains relevant in situations where rDNA is still under development or more challenging to implement.
Here are some additional points to consider:
*Cost of development can be higher for rDNA, although large-scale production can offset this.
*Engineering complex antibody functions may still be easier with Hybridoma in some cases.
*Both technologies continue to evolve, and hybrid approaches combining their strengths are also being explored.
9. Briefly describe the development of Humulin through rDNA technology.
Ans: Humulin: A Pioneer in rDNA Technology
Humulin, an insulin product for managing diabetes, holds a significant place in history as the first pharmaceutical product developed using recombinant DNA (rDNA) technology. Here's a brief overview of its development:
1. The Need for Human Insulin:
Prior to Humulin, diabetics relied on insulin extracted from animal pancreases (mainly pigs and cows). These animal insulins had limitations, including potential allergic reactions and inconsistent effectiveness. The dream was to produce human insulin for better compatibility and efficacy.
2. Isolating the Insulin Gene:
In the 1970s, scientists at Genentech successfully isolated the human insulin gene from pancreatic cells. This was a crucial breakthrough, providing the template for rDNA production.
3. Creating the Expression Vector:
The insulin gene was then inserted into a plasmid, a circular piece of DNA, acting as a "vehicle" to carry the gene into host cells. This engineered plasmid is called an expression vector.
4. Choosing the Host Cells:
Scientists explored various options for host cells to produce human insulin. Ultimately, modified bacteria (E. coli) were chosen due to their rapid growth and ease of manipulation.
5. Insulin Production and Purification:
The engineered bacteria containing the insulin gene were grown in large fermentation tanks. These bacteria efficiently produced human insulin, which was then extracted and purified through intricate chemical processes.
6. Regulatory Approval and Commercialization:
Humulin went through rigorous testing and safety evaluations before receiving FDA approval in 1982. This marked a monumental step forward in medicine and paved the way for numerous rDNA-based pharmaceuticals.
Humulin's Impact:
*Improved treatment for diabetes: Human insulin in Humulin offered better compatibility and reduced side effects compared to animal insulins.
*Pioneering rDNA technology: Humulin's success demonstrated the potential of rDNA for producing safe and effective therapeutic proteins.
*Revolutionizing drug development: It opened doors for countless rDNA-based drugs and vaccines, impacting various diseases and treatments.
Humulin's story reflects the transformative power of scientific innovation and its potential to change healthcare landscapes. It serves as a testament to the ingenuity and perseverance of researchers who dared to push the boundaries of biotechnology.
10. Write a short note on humatrope and Protropin.
Ans: Humatrope and Protropin: Growth Hormone in Two Forms
Humatrope and Protropin are both recombinant human growth hormone (rhGH) medications used to treat growth hormone deficiency (GHD) in children and adults. However, they differ in their origin and delivery methods:
Humatrope:
*Origin: Produced by E. coli bacteria using rDNA technology.
*Delivery: Injected daily under the skin (subcutaneously).
*Features: FDA-approved, widely used and studied, considered the gold standard for rhGH therapy.
Protropin:
*Origin: Extracted from the pituitary glands of deceased humans.
*Delivery: Implanted under the skin, releasing the hormone slowly over several months.
*Features: Less common than Humatrope, approved for specific circumstances where daily injections are impractical.
Key Differences:
*Source: Humatrope is synthetic, while Protropin is derived from human pituitary glands.
*Delivery: Humatrope requires daily injections, while Protropin offers a long-term implant option.
*Regulation: Humatrope has broader FDA approval, while Protropin has more specific indications.
*Cost: Humatrope is generally more expensive than Protropin.
Choosing the Right Option:
The choice between Humatrope and Protropin depends on individual needs and factors like:
*Severity of GHD: Protropin might be suitable for severe cases requiring constant hormone levels.
*Patient compliance: Daily injections may be challenging for some, making Protropin an alternative.
*Cost considerations: Humatrope is typically more expensive, but insurance coverage may vary.
Ultimately, the decision should be made in consultation with a healthcare professional specializing in GHD treatment.
Additional Notes:
*Both Humatrope and Protropin can have side effects like headaches, muscle pain, and fluid retention.
*Misuse of rhGH can have serious health consequences, highlighting the importance of using it under medical supervision.
11. Briefly describe the applications of rDNA technology in crop improvement.
Ans: Recombinant DNA (rDNA) technology has revolutionized crop improvement by offering targeted and efficient ways to enhance desirable traits in plants. Here's a glimpse into its diverse applications:
1. Enhanced Resistance:
*Pest and disease resistance: Introducing genes for natural insecticides (Bt toxin) or disease resistance mechanisms from other plants allows for reduced reliance on pesticides and fungicides.
*Herbicide resistance: Crops engineered to tolerate specific herbicides simplify weed control for farmers, improving efficiency and reducing herbicide use.
2. Improved Quality and Yield:
*Increased nutritional value: Adding genes for micronutrients like Vitamin A or iron can produce biofortified crops with enhanced nutritional content, addressing malnutrition in resource-limited regions.
*Stress tolerance: Engineering resistance to drought, salinity, or extreme temperatures helps crops thrive in challenging environments, improving yields and food security.
*Modified product traits: Modifying oil content, seed size, or fruit ripening can cater to specific market demands and improve processing efficiency.
3. Other Applications:
*Production of pharmaceuticals and industrial enzymes: Plants can be engineered to produce valuable proteins for medical or industrial applications, offering a cost-effective and sustainable alternative to traditional production methods.
*Improved environmental impact: Reduced pesticide use and increased stress tolerance can lead to more environmentally friendly agricultural practices.
Challenges and Concerns:
*Regulatory hurdles: Ensuring biosafety and addressing ethical concerns can delay commercialization and public acceptance.
*Potential ecological impact: Unforeseen consequences on ecosystems and unintended gene transfer to wild relatives need careful monitoring.
*Economic disparities: Unequal access to rDNA technology can widen the gap between developed and developing countries.
Overall, rDNA technology holds immense potential for transforming agriculture and improving food security. Balancing its benefits with responsible development and addressing concerns are crucial for ensuring its sustainable and ethical application in crop improvement.
12. List the ethical issues related to the use of transgenic animals?
Ans: The use of transgenic animals raises a wide range of ethical concerns, both on an individual and societal level. Here are some key issues to consider:
Animal welfare:
*Potential for suffering: Introducing foreign genes can cause unintended side effects, leading to pain, discomfort, or even early death for animals.
*Unnatural modifications: Some modifications may alter an animal's natural behaviors or instincts, raising questions about their well-being and agency.
*Increased instrumentalization: Transgenic animals might be seen primarily as tools for research or production, rather than sentient beings deserving of respect.
Environmental concerns:
*Unforeseen ecological impact: Escape or intentional release of transgenic animals could disrupt ecosystems and threaten biodiversity.
*Gene transfer and biosecurity: Horizontal gene transfer from transgenic animals to wild populations is a potential risk, with unknown consequences.
*Industrial-scale animal exploitation: Large-scale production of transgenic animals for food or research raises concerns about intensive farming practices and animal welfare.
Social and economic issues:
*Patenting and ownership of life: Who owns the genetic modifications made to animals? Does patenting lifeforms raise ethical concerns and limit access to technology?
*Access and equity: Will the benefits of transgenic technology be accessible to all countries and individuals, or exacerbate existing inequalities?
*Public perception and trust: Public acceptance of transgenic animals depends on addressing concerns about safety, animal welfare, and ethical implications.
Additionally, specific applications of transgenic animals raise their own ethical dilemmas:
*Xenotransplantation: Using animal organs for human transplants involves complex considerations about animal rights and patient well-being.
*Animal enhancement and designer pets: Modifying animals for purely aesthetic purposes raises questions about the appropriate uses of technology and respect for animal autonomy.
Addressing these ethical concerns requires ongoing dialogue and collaboration between scientists, policymakers, industry representatives, and the public. Developing and implementing strong ethical frameworks, ensuring animal welfare standards, and engaging in open communication are crucial for responsible and sustainable application of transgenic animal technology.
13. What is the role of vaccinia virus in the development of recombinant vaccine?
Ans: The vaccinia virus (VACV) plays a key role in the development of recombinant vaccines, particularly for viral and bacterial diseases. Here's why:
VACV Advantages:
*Replication and Expression: VACV efficiently replicates inside human cells, expressing foreign genes inserted into its genome. This makes it a strong platform for producing large amounts of vaccine antigens.
*Safety: Although VACV once caused smallpox, modern strains like Modified Vaccinia Ankara (MVA) are attenuated, meaning they're weakened and non-replicative in humans, offering good safety profiles.
*Versatility: VACV allows insertion of multiple foreign genes, potentially enabling simultaneous protection against several diseases through a single vaccine.
*Immunogenicity: VACV triggers a strong immune response in humans, effectively stimulating protection against the target pathogen.
VACV Applications:
*Smallpox eradication: The original vaccinia virus vaccine played a crucial role in eradicating smallpox in the 20th century.
*Current recombinant vaccines: MVA strains of VACV are used in recombinant vaccines against Ebola, rabies, HIV, and Zika, among others.
*Future potential: VACV is being explored for vaccines against emerging infectious diseases and even cancer.
Challenges and Considerations:
*Pre-existing immunity: Some populations may have pre-existing immunity to VACV, potentially reducing vaccine efficacy.
*Safety concerns: Although attenuated, rare side effects may occur. Careful risk-benefit assessments are crucial.
*Ethical considerations: Developing and deploying VACV-based vaccines requires transparency and public engagement to address concerns and ensure trust.
Overall, vaccinia virus, especially MVA strains, remains a valuable tool for recombinant vaccine development due to its efficiency, safety, and versatility. Ongoing research aims to overcome challenges and further refine VACV-based vaccines to offer broader protection against various diseases.
14. Write a short note on recombinant therapeutic agents.
Ans: Recombinant Therapeutic Agents: Revolutionizing Medicine
Recombinant therapeutic agents are proteins or other molecules produced via recombinant DNA (rDNA) technology. This means their genes are isolated, manipulated, and inserted into host cells (often bacteria or yeast) to be produced in large quantities. These agents offer a revolutionary approach to treating various diseases and have become an indispensable part of modern medicine.
Here's how rDNA technology transforms the production of therapeutic agents:
*Specificity: Unlike traditional methods relying on extraction from natural sources, rDNA allows precise engineering of the desired protein, ensuring greater purity and activity.
*Scalability: Host cells can be readily multiplied to produce large quantities of the therapeutic agent, ensuring consistent supply and affordability.
*Improved properties: Through genetic modification, researchers can design proteins with enhanced stability, potency, or even novel functionalities.
Examples of Recombinant Therapeutic Agents:
*Insulin: Humulin, the first rDNA-derived drug, revolutionized diabetes treatment by providing a safe and reliable source of human insulin.
*Growth hormones: Humatrope and Protropin are used to treat growth hormone deficiency, offering significant benefits for children and adults.
*Blood clotting factors: Recombinant factors VIII and IX have transformed the management of hemophilia, replacing risky treatments with safer and more effective options.
*Monoclonal antibodies: These highly targeted proteins are used for cancer treatment, immune system disorders, and numerous other conditions, offering precision targeting and potent therapeutic effects.
*Vaccines: Recombinant viral vectors and antigens play a crucial role in vaccines against hepatitis B, rabies, and Ebola, contributing to disease prevention and global health initiatives.
Benefits of Recombinant Therapeutic Agents:
*Improved safety and efficacy: Compared to traditional or animal-derived treatments, rDNA agents often offer fewer side effects and greater effectiveness.
*Targeted therapies: This technology allows for the development of personalized medicine approaches, tailoring treatments to specific patient needs and genetic profiles.
*Cost-effectiveness: Scalable production and improved purity can lead to lower costs and wider accessibility of vital medications.
Challenges and Considerations:
*High initial development costs: The research and development process for rDNA agents can be expensive and time-consuming.
*Regulatory hurdles: Ensuring safety and efficacy requires stringent regulatory approval processes.
*Ethical concerns: Potential risks of unintended side effects, environmental impact, and access discrepancies need careful consideration.
Despite these challenges, recombinant therapeutic agents hold immense promise for the future of medicine. Their potential to address previously untreatable diseases, personalize treatment, and improve healthcare outcomes makes them a truly transformative technology with a profound impact on human health.
15. Write a short note on humanised antibodies.
Ans: Humanized Antibodies: Bridging the Gap for Better Therapies
Humanized antibodies, a marvel of biotechnology, are revolutionizing the way we treat diseases. Imagine taking the best of both worlds – the precision of antibodies and the compatibility of your own body. That's exactly what humanized antibodies do!
What are they?
Antibodies are our body's natural defense against invaders like viruses and bacteria. Traditionally, therapeutic antibodies used in medicine were derived from mice or rabbits. However, these "foreign" antibodies could trigger unwanted immune responses in humans, limiting their effectiveness and safety.
Enter humanized antibodies! Scientists take the most effective parts of the mouse antibody (the antigen-binding region) and "humanize" them by replacing the rest with human genetic sequences. This cleverly engineered antibody retains its target specificity but becomes much more compatible with the human immune system.
What are the benefits?
*Reduced side effects: Humanized antibodies are less likely to cause allergic reactions or immune system complications compared to their mouse counterparts.
*Increased efficacy: Their human-like structure allows them to better interact with our immune system, potentially leading to improved therapeutic outcomes.
*Longer-lasting treatment: Humanized antibodies often have longer half-lives in the body, requiring less frequent administration.
*Tailored therapies: With targeted modification, scientists can design humanized antibodies for specific diseases and patient needs, paving the way for personalized medicine.
Applications across the spectrum:
From fighting cancer to tackling autoimmune diseases, humanized antibodies are finding diverse applications in medicine. Here are some examples:
*Herceptin: Used to treat breast and other cancers, it targets a specific growth factor receptor.
*Rituximab: Effective against some blood cancers and autoimmune diseases like rheumatoid arthritis.
*Avastin: Targets blood vessel development in tumors, hindering their growth and spread.
The future is bright:
Humanized antibodies represent a giant leap forward in medical science. Their potential to combat previously untreatable diseases and offer safer, more personalized treatments is truly exciting. As research continues, we can expect even more innovative applications of this groundbreaking technology in the years to come.
16. Assertion: In hybridoma technology, B cells are fused with myeloma cells.
Reason: Myeloma cells are immortal.
(a) Both assertion and reason are true and the reason is the correct explanation of the assertion.
(b) Both assertion and reason are true but the reason isnot the correct explanation of the assertion.
(c) Assertion is true but reason is false.
(d) Both assertion and reason are false.
Ans: (a) Both assertion and reason are true and the reason is the correct explanation of the assertion.
17. Assertion: In Humulin, polypeptide A and polypeptide B are linked with disulfide bridges.
Reason: C peptide is removed from proinsulin to
biological active insulin.
(a) Both assertion and reason are true and the reason is the correct explanation of the assertion.
(b) Both assertion and reason are true but the reason is not the correct explanation of the assertion.
(c) Assertion is true but reason is false.
(d) Both assertion and reason are false.
Ans: (c) Assertion is true but reason is false.
18. DNA fingerprinting depends on identifying specific:
(a) Coding sequences
(b) Non-coding sequences
(c) mRNA
(d) Promoter
Ans: (b) Non-coding sequences.
19. Short stretch of DNA used to identify complementary sequences in a sample is called:
(a) Probe
(b) Marker
(c) VNTR
(d) Minisatellite
Ans: (a) Probe.
20. Variable number tandem repeat (VNTR) are:
(a) Repetitive coding short DNA sequences
(b) Non-repetitive non-coding short DNA sequences
(c) Repetitive non-coding short DNA sequences
(d) Non-repetitive coding short DNA sequences
Ans: (c) Repetitive non-coding short DNA sequences.
21. Cry genes or Bt genes are obtained from:
(a) Cotton pest
(b) Tobacco plant
(c) Bacillus thuringiensis
(d) E. coli
Ans: (c) Bacillus thuringiensis.
22. When gene therapy is done in somatic cells, it is ______.
(a) not-heritable
(b) heritable
(c) rarely heritable
(d) not related to heritability
Ans: (a) not-heritable.
23. In gene augmentation therapy, genetic material is ______.
(a) modified
(b) replaced
(c) suppressed
(d) removed
Ans: (a) modified.
24. Germ cell therapy if used for ____________.
(a) RBC
(b) Stomach cells
(c) Egg cells
(d) Bone marrow cells
Ans: (c) Egg cells.
25. For the first time, from which animal material was isolated for vaccination?
(a) Cat
(b) Cow
(c) Goat
(d) Horse
Ans: (b) Cow.
26. Vaccination was invented by:
(a) Jenner
(b) Pasteur
(c) Watson
(d) Crick
Ans: (a) Jenner.
27. For the production of insulin by rDNA technology, which bacterium was used?
(a) Saccharomyces
(b) Rhizobium
(c) Escherichia
(d) Mycobacterium
Ans: (c) Escherichia.
28. Genetically engineered insulin is called __________.
(a) Humulin
(b) Promulin
(c) Bovulin
(d) Proculin
Ans: (a) Humulin.
29. Monoclonal antibodies are produced by_________.
(a) Mutations
(b) Transfection
(c) Hybridoma technology
(d) RNA interference
Ans: (c) Hybridoma technology.
Questions And Answer Type By: Himashree Bora.
DABP007089
