Mollusk Hemocyanins as Natural Immunostimulants in Biomedical Applications

Hemocyanins, the massive oxygen-transporting glycoproteins found freely dissolved in the hemolymph of some mollusks, are potent natural immunostimulants when inoculated in mammals, enhance the innate and adaptive immune response with beneficial clinical outcomes. Hemocyanins are easily purified and molecularly correspond to large multisubunit structures, some over 107 Da (van Holde and Miller, 1995). Currently, hemocya‐ nins are commonly used as carriers/adjuvants for producing antibodies against different antigens. These antigens include tumor-associated antigens (TAAs), such as glycolipid and glycoprotein (mucin-like) antigens in cutting-edge therapeutic vaccines for cancer, along with idiotypes, the most commonly used tumor antigen to prepare vaccines for nearly all non-Hodgkin lymphomas. Other therapeutic strategies using hemocyanins include their use as adjuvants to disrupt self-tolerance to tumor antigens in the generation of ex vivo autologous tumor cell lysate-loaded dendritic cells (DCs) to induce T-cell responses in cancer patients (Del Campo et al., 2011). Furthermore, hemocyanins can be used as non-specific immunostimulants during therapy for recurrent superficial bladder cancer after transure‐ thral surgical resection with negligible toxic side effects, thus making them ideal for longterm on going treatments (Arancibia et al., 2012b).