CCBPE Lec 10: PTM & Cell Culture Meat

Types of Postranslational Modification

• Chemical changes (usually additions)

  • Methylation

  • Acetylation

  • Hydroxylation

  • Sulfation

• Phosphorylation

• Glycosylation

• Disulphode bond formation

• Proteolytic cleavage

Biological roles of PTM

1. Targetting

2. Stability

3. Function

4. Control of activity

Why use mammalian cells for Glycosylation?

• Amenable to genetic modification

• Can perform appropriate glycosylation of recombinant human glycoproteins

• Capable of complex type N-glycans processing

Importance of glycosylation

Glycosylation can affect many properties of biologics:

1. Pharmacokinetics

2. Bioactivity

3. Secretion

4. In-vivo clearance

5. Solubility

Glycosylation in prokaryotes

• easily manipulated and grown in large scale

• prteins produced are not glycosylated (no Endoplasmic Reticulum)

Glycosylation in Yeast/Fungi

• Hypermannosylation

• O-glycosylation in different Serine residues

Glycosylation in Insects and Plants

• Produce different glycans from human glycoproteins

• Share same features of N-linked glycan processing in the ER

• Different glycan processing in the Golgi

• Glycosyltransferase enzyme absent/low level of activity

• Lower yield in plants cells

Advantages of using Cell Cultured Meat

• Sustainability: reduce environmental impact of meat production

• Animal Welfare

• Food safety: Reduced risk of bacterial contaminaiton/illnesses (e.g. Salmonella)

• Customisation: Able to modify the nutritional value/make up to specific dietary requirements

Natural scaffold

• Derived from natural materials

• Decellularised ECM from animal tissue

Synthetic scaffold

• Made from synthetic materials

Hybrid scaffold

• Combination of natural and synthetic materials

• Take advantage of the benefits of both

Steps of Cell Culture Meat Production

1) Isolation of Cells

2) Cell Expansion

3) Differentiation & Maturation of muscle tissue

4) Harvesting and Processing of Muscle Tissue

Describe the Cell Isolation step

• Muscle cells isolated from muscle tissue

• Animal tissue typically obtained from biopsy

• Tissue washed, minced, treated with enzymes (trypsin, colleganse) → Release cells into the ECM

Describe the Cell Expansion step

• In bioreactor

• Proliferate to acheive large cell numbers

• Process should use economical serum-free medium, and monitor various parameters (pH, D.O, CO2, nutrient and metabolic waste)

Describe the Differentiation and Maturation step

• Desird cell no. achieved

• Induced to differentiate into myotubes, adipocytes, other mature cell types in muscle tissues

• Feature structure and nutritent content are significantly affected by cell maturity

Describe the Harvesting and Processing of Muscle Tissue

• Mature cells obtained are processed (moulding, colouring, seasoning) → end-product: Cultured Meat

• Advances in 3D bio-printing technology makes it promising for creating muscle tissue with relative large size and complex composite constructs

How did companies tackle cost challenges in the production of Cell Culture meat?

• optimised porduction processes → reduce cost

• switched to more economical alternatives for serum-free culture conditions and growth media

• up-scale production

How did companies tackle scalability challenges in the produciton of Cell Culture meat?

• optimise product processes → reduce time

• bioreactor with greater capacity

• more efficient cell lines

How did companies tackle Nutrient requirement challenges in the production of Cell Culture meat?

• Identify optimal media formulations and growth factors

• Develop novel sources of nutrients → reduce reliance on expensive comp.

How did companies tackle Regulatory framework challenges in the production of Cell Culture meat?

• Work closely with regulatory agencies → ensure compliance

• Advocate for supportive policies & regulations

How did companies tackle Consumer acceptance challenges in the production of Cell Culture meat?

• educate the public onthe importance

• address concerns

• meet the consumers’ demands (nutrients, textures, taste)