Genetic Engineering: An Overview

Introduction to Genetic Engineering

• Recombinant DNA technology emerged in the 1970s, which allowed scientists to manipulate genes for medicine, agriculture, and biotechnology.
• Alteration of an organism's genome is achieved through recombinant DNA technologies.
• Genetically modified organisms(GMOs) with specific desirable traits can be created through genome manipulation.
• Biotechnology involves using living organisms to enhance the quality of life.
• Modern biotechnology relies on recombinant DNA technology, genetic engineering, and genomics.
• Biotechnology dates back to ancient civilizations using microbes to produce wine, beer, vinegar, bread, and cheese.
• The biotechnology industry is rapidly growing, with nearly 5,000 companies across 54 countries.

Biological and Pharmaceutical Products

• One major application of recombinant DNA technology is the production of recombinant proteins used as biopharmaceuticals.
• Therapeutic proteins like insulin, clotting factors, and growth hormones were previously sourced from animals.
• Animals like cows and pigs were commonly used to extract proteins like insulin
• Recombinant DNA technology, allows cloning human genes with therapeutic proteins and expressing them in host cells.
• Biopharming involves producing valuable proteins in genetically modified (GM) animals and plants.
• Biotechnology companies focus on treatments for cancers, arthritis, diabetes, heart disease, and infections like AIDS using recombinant therapeutic products.

Insulin Production in Bacteria

• Recombinant DNA technology now facilitates the production of therapeutic proteins by introducing human genes into bacteria.
• The human gene is cloned into a plasmid, which is introduced into a bacterial host for large-scale growth and purification.
• The first success of this technology was human insulin (Humulin), FDA-approved in 1982.
• The insulin gene was isolated and cloned by scientists at Genentech.
• Previously, insulin for treating diabetes required extraction from the pancreases of cows and pigs.
• Diabetes affects over 2 million individuals in the U.S.
• Insulin is synthesized as preproinsulin in the pancreas, which is then cleaved to form two chains (A and B) linked by disulfide bonds.
• Genes encoding the chains are synthesized and inserted into vectors to produce fusion proteins in bacteria.
• After purification and treatment, the insulin chains combine to form active insulin for diabetic patients.
• Over 200 recombinant products have been introduced since insulin.
• Researches are now producing non-biopharmaceutical such as the antioxidant lycopene in E. coli.

Transgenic Animals and Pharmaceutical Products

• Bacteria are used for therapeutic proteins, but they lack the ability to process and modify eukaryotic proteins properly.
• Eukaryotic hosts are used to produce many biopharmaceuticals, including animal and plant cells, and transgenic farm animals.
• Transgenic goats or cows have become living bioreactors, continuously producing milk with therapeutic proteins.
• Insect cells, when infected by baculovirus, allow for high-level expression of heavily glycosylated proteins.
• A recombinant human antithrombin was approved in 2006 and was the first drug derived from the milk of farm animals.
• GTC Biotherapeutics introduced the human antithrombin gene into goats, targeting expression in the mammary gland.
• A single goat can produce a year's worth of antithrombin, previously requiring 90,000 blood collections.

Recombinant DNA Approaches for Vaccine and Antibody Production

• Recombinant DNA technology allows the production of vaccines which stimulate the immune system to generate antibodies.
• Traditional vaccines are either inactivated consisting of killed pathogens, or attenuated consisting of live but can no longer reduplicate.
• Examples include inactivated vaccines for rabies and influenza, and attenuated vaccines for tuberculosis and chickenpox.
• Subunit vaccines contain surface proteins from pathogens, produced via recombinant DNA technology and these act as antigens stimulating the immune response.
• Hepatitis B vaccine was one of the first subunit vaccines developed using cloned genes in yeast.
• In 2006, the FDA approved Gardasil, a subunit vaccine that protects against four strains of human papillomavirus (HPV).
• The vaccine provides immune protection but will not treat existing infections.

Vaccine Proteins and Antibodies Produced by Plants

• Plants are cost-effective hosts for recombinant proteins due to ease of cultivation in greenhouses or fields.
• Though no recombinant proteins from transgenic plants have been FDA approved for human therapeutic use, some are in clinical trials, including edible vaccines.
• A vaccine against cholera has been developed in genetically engineered potatoes.
• An Ebola virus outbreak in West Africa in 2014 resulted in over 1,500 deaths.
• Clinical trials have expressed antibodies in tobacco leaves and are producing promising results.
• Monoclonal antibodies against the virus were produced using mice.
• Transgenic tobacco plants are useful with large leaves and higher yields of recombinant proteins compared to other plant species.

DNA-Based Vaccines

• DNA-based vaccines involve inserting DNA encoding proteins from a pathogen into plasmid vectors.
• The vectors are then injected directly into an individual or delivered via viral vectors.
• The delivered DNA causes production pathogen proteins, and triggers an immune response.
• Trials use plasmid DNA encoding protein antigens from HIV to vaccinate individuals.
• A major challenge is that DNA-based vaccines often lead to low levels of protein production, causing a insufficient immune response.

Transgenic Animals and Biotechnology

• Transgenic animals have had their genome modified.
• A foreign gene is inserted to alter its DNA.
• It is performed to improve the genetic traits of a target animal.

Methods for Creating Transgenic Animals

• Physical Transfection
• Chemical Transfection
• Retrovirus-Mediated Gene Transfer
• Bactofection

Applications of Transgenic Animals

• Studies can be performed on Normal Physiology and Development
• Study of Diseases
• Biological Products
• Vaccine Safety

Genetically Modified Organism (GMO)

• A GMO is a plant, animal, or microorganism with changed genetic material.
• DNA is changed using a technology that generally involves the specific modification of DNA, including the transfer of DNA from one organism to another.
• Scientists often refer to this process as genetic engineering.

How GMOs Are Made

• Identify the desired trait
• Copy the gene
• Insert the gene
• Grow

Applications of Genetically Modified Products

• Crops can be engineered for resistance to pests, diseases, and herbicides, to increase crop yields and reduce reliance on pesticides in agriculture.
• Therapeutic substances, such as insulin and vaccines, are produced in Pharmaceuticals
• GMOs are used to improve animal health and growth rates in animal feed

Genetically Modified Crop Examples

• Bt Corn
• Soybeans
• Cotton
• Potato
• Summer squash
• Canola
• Alfalfa

Synthetic Biology

• Redesigning organisms for useful purposes by engineering them to have new abilities.

How Synthetic Biology Works

• Synthetic biology combines engineering principles with existing biotechnology techniques, such as DNA sequencing and genome editing.
• This is to modify organisms or create new ones.

Applications of Synthetic Biology

• By Engineering bacteria to produce drugs or target cancer cells.
• For Agriculture, through creating crops that are more resistant to pests or diseases.
• By Modify organisms to clean up pollution or produce biofuels in the Environment.
• By Designing organisms to produce new materials in Materials Science.

Opportunities in Synthetic Biology

• Widely adaptable
• Creates More equitable access to biotechnology
• Benefits Conservation efforts

Challenges in Synthetic Biology

• Safety and security concerns
• Environmental effects
• Public acceptance and access

Genetic Testing

• Genetic testing involves analysing changes in DNA to identify genetic mutations.

Genetic Counseling

• Genetic counseling provides patients with diagnosed or suspected inherited conditions, or a strong family history.
• The genetic counselor helps patients understand the genetic cause, and risks to family is the goal to provide support, promote informed decision-making, and help families adapt to the diagnosis.

Gene Therapy

• Human gene therapy modifies or manipulates the expression of a gene used in living cells for therapeutic use.
• Gene therapy modifies a person’s genes to treat or cure disease.

Genetic Engineering

• Genetic engineering manipulates an organism's genes using technology.
• Inserting, deleting, or modifying specific DNA sequences.

Genomics

• Genomics encompasses the study of an organism's genome.
• Including mapping, sequencing, and analysis.

Biotechnology

• Biotechnology involves the use of biological systems and organisms.
• This is to develop products and services, often using genetic engineering and genomics.

Ethical Concerns: Informed Consent

• Obtaining informed consent for genetic testing or gene therapy is challenging.
• This is because of dealing with children and the elderly.
• Genetic information impacts family members who haven't consented.

Ethical: Reproductive Rights

• Preimplantation genetic diagnosis (PGD), selective abortion, and "designer babies" raise ethical dilemmas.
• PGD: Raises concerns about discrimination against people with genetic disorders because it enables the selection of embryos based on their genetic composition.

Ethical Reproductive Rights Concerns

• Selective Abortion - Presents moral questions regarding the worth of human life and the discrimination toward people with disabilities.
• Designer Babies - Concerns include what is "normal", social stratification, and eugenics when using genetic engineering used to select eye color, IQ, or athletic prowess.

Ethical: Equity and Access

• Unequal access to genetic technologies poses a challenge.
• Socioeconomic Status - A two-tiered healthcare system has the wealthy having access to the edge treatments.
• Geographic Location - Rural and developing countries may lack infrastructure, expertise, or resources.

Social Concerns of Genetic engineering

• Privacy - Protecting sensitive genetic information from misuse and discrimination.
• Public Acceptance - Education is important to address concerns.
• Social Impact - Genetic information used for discrimination in employment, relationships, and social interactions.
• Food System - Genetically modified foods have benefits and risks for farmers, consumers, and the environment.

Legal Genetic engineering

• Intellectual Property Rights involves patents must balance the need for protection with accessibility.
• Regulation and Oversight is needed, and laws need improved frameworks
• Liability and Responsibility is difficult with adverse effects from genetic technologies complexity, plus guidelines are needed for responsibility and informed consent.
• And laws protecting against is important, plus stronger protections and enforcement are necessary to prevent misuse of genetic information in employment and insurance.