Introduction

The spike protein, produced by mRNA vaccines or natural SARS-CoV-2 infection, is eventually broken down and removed by the body. This process involves different organs, cells, and enzymes. Here’s how it works:

Step-by-Step Process of Spike Protein Breakdown and Removal

Production of the Spike Protein

mRNA Vaccines: These vaccines provide instructions for cells to make the spike protein. Inside the cell, ribosomes in the cytoplasm read the mRNA and create the spike protein.

Natural Infection: When the SARS-CoV-2 virus enters a cell, it uses the cell's ribosomes to make its spike protein during replication.

Presentation and Immune Response

The spike protein appears on the surface of the cell through special molecules called MHC. This alerts the immune system, which responds by making antibodies and activating T-cells.

Breakdown Inside the Cell

Ubiquitination: Unneeded or damaged spike proteins inside the cell get tagged with small molecules called ubiquitin.

Proteasome: Tagged proteins go to a large complex called the proteasome, which breaks them down into smaller pieces.

Lysosomal Pathway

Autophagy: Some spike proteins are enclosed in structures called autophagosomes that then merge with lysosomes. Enzymes in lysosomes degrade the spike protein into amino acids.

Systemic Breakdown

Endocytosis: Other cells can take in spike proteins through a process called endocytosis, leading to further breakdown in lysosomes.

Lysosomes: Lysosomal enzymes continue to break down the spike protein into amino acids.

Elimination

Amino Acid Reuse: The resulting amino acids are released back into the cell and can be reused for making new proteins or for other functions.

Excretion

Kidney Pathway: Some products and free amino acids are filtered by the kidneys and excreted in urine.

Liver Pathway: The liver also helps break down protein fragments and aids in their removal through bile.

Organs and Enzymes Involved

Organs

Liver: Breaks down protein fragments and helps with detoxifying.

Kidneys: Filter small peptides and amino acids for urine excretion.

Immune System Organs: Lymph nodes and spleen help present antigens and trigger an immune response.

Enzymes

Proteasomes: Complexes that break down tagged proteins.  

Lysosomal Enzymes: Enzymes that break down biomolecules.  

Aminopeptidases: Enzymes that further break down peptides into amino acids.  

Conclusion

The spike protein, whether from mRNA vaccines or natural infections, is ultimately broken down by the body's biological processes. This breakdown occurs through two main pathways: the proteasomal system and the lysosomal system.

After this, the body recycles or excretes the resulting amino acids and peptides. The liver, kidneys, and various enzymes play essential roles in these processes, ensuring that the spike protein is effectively removed from the system.