Tracheal cytotoxin

[8] It is classified as a DAP (diaminopimelic acid)-type PGN due to the third amino group within the chain being a diaminopimelyl peptide.

The DAP residue is responsible for directly bonding to the D-alanine peptide of another PGN molecule, thus aiding TCT's attachment within the cell wall.

[12] In gonorrhea infections, vaginal ciliated epithelial cells have also displayed the same cytopathogenic effects due to TCT recognition.

[13] The extensive damage to ciliated epithelial tissue caused by TCT results in major disruption to the ciliary escalator; an important asset of the host's non-specific defenses.

TCT is thought to work synergistically with LOS to mediate an inflammatory response, thus causing damage to ciliated epithelial cells.

[citation needed] TCT has been classified as an adjuvant molecule because of the stimulating effects it has on the immune system.

[15] In humans, peptidoglycan recognition proteins, e.g. PGRPIαC, appear to bind with TCT and consequently induce the Tumor Necrosis Factor Receptor (TNFR) pathway.

[18] Peptidoglycan recognition protein 4 (PGLYRP4), in mammals (mice), interacts with TCT and reduces damage from pertussis inflammation.

Molecular structure of TCT
Configuration of TCT within the cell wall of a bacterium
Analogs of TCT. LacAEDapA retains the peptide chain of TCT along with toxicity despite the lack of disaccharide. LacAEαApmA loses the diamino group of TCT along with a significant level of toxicity.
Illustration showing the effects of TCT on human ciliated epithelial cells. Figure A illustrates normal human epithelial tissue. Figure B illustrates normal human epithelial tissue after incubation with TCT. Notice the damaged and extruded ciliated epithelial cells in Figure B.