Trichobilharzia regenti which are capable of keratin and collagen degradation. Experiments with laboratory prepared recombinant form of the cysteine peptidase cathepsin B2 of "T. regenti" (TrCB2) confirmed its ability to cleave skin proteins (collagen, keratin and elastin). After penetration the skin, cercariae transform to schistosomula and start a migration through the host’s body. They avoid penetration into blood capillaries and rather prefer entering peripheral nerves in host’s limbs. Schistosomula are found in peripheral nerves of ducks and mice as soon as 1.5 and 1 day post infection (DPI), respectively. In both types of hosts, schistosomula exhibit a high affinity to the central
Keratin Cells in the epidermis contain a structural matrix of keratin, which makes this outermost layer of the skin almost waterproof, and along with collagen and elastin, gives skin its strength. Rubbing and pressure cause thickening of the outer, cornified layer of the epidermis and form protective calluses, which is useful for athletes and on the fingertips of musicians who play stringed instruments. Keratinized epidermal cells are constantly shed and replaced. These hard, integumentary structures are formed by intercellular cementing of fibers formed from the dead, cornified cells generated by specialized beds deep within the skin. Hair grows continuously and feathers