Science Sub-journal: The Sunson/Zhang Ling team at Sichuan University found that regulating nanoparticle aperture sized improves the cellular immune response of subunit antigens.

Vaccines, as the most cost-effective way to control infectious diseases, have saved countless lives.vaccines mainly eliminate pathogens or target cells by inducing humoral immune response and / or cellular immune response, among which cellular immune response plays a decisive role in eliminating intracellular pathogens such as viruses or treating tumors and other diseases.the following four cascade steps are often required to induce an effective cellular immune response: (1) targeting lymph nodes; (2) being absorbed by dendritic cells; (3) inducing maturation and activation of dendritic cells; (4) presenting antigens to CD8 + T cells in the form of antigen peptide MHC I molecular complex.these four steps are referred to as dump cascade.recently, the research team of Professor Sun Xun of West China Pharmaceutical College of Sichuan University and Zhang Ling, associate researcher of College of polymer science and engineering, published a research paper entitled "the pore size of mesoporous silica nanoparticles regulations their anti delivery efficiency" in science advances.in this study, the researchers used mesoporous silica nanoparticles (MSNs) as vaccine delivery carrier and adjuvant, and found that the intensity of immune response induced by vaccine can be adjusted by adjusting the pore size of MSNs.the preparation of MSNs and the four processes of inducing immune response in vivo, the researchers synthesized three kinds of MSNs with particle size of 85nm, but mesoporous pore size of 12.9 nm, 10.3 nm and 7.8nm, respectively. Subsequently, ova was encapsulated with three kinds of MSNs, and the effect of pore size change on the in vivo efficiency of MSNs was investigated.the results showed that the change of mesoporous pore size had no effect on lymph node delivery, dendritic cell uptake, maturation and activation (i.e., the first three steps of dump cascade), but in the fourth step of dump: antigen MHC However, the efficiency of class I presentation increased with the increase of mesoporous pore size, and the intensity of cellular immune response increased with the increase of mesoporous pore size. The large pore size MSNs can induce effective cellular immune response without using other adjuvants.what is surprising is that when the lysate and membrane of melanoma cells are used as antigens, MSNs with large pore size can efficiently encapsulate these two kinds of antigens with different hydrophilicity and hydrophobicity at the same time, and induce the body to produce strong cellular immune response against melanoma.MSNs can induce anti-tumor immune response.B-C: the ability of MSNs to induce anti-b16f10-ova tumor immune response increased with the increase of mesoporous pore size; D-E: large pore size MSNs (msns-l) encapsulated BM (B16F10 tumor cell membrane) and BL (B16F10 tumor cell lysate) could enhance the anti-b16f10 tumor immune response of the organism.in general, this work has proved that the ability of MSNs to induce immune response can be changed by adjusting the pore size of MSNs; at the same time, the delivery of tumor antigen by MSNs can induce the body to produce effective anti-tumor immune response, indicating that MSNs have a great development prospect in the field of vaccine delivery.paper links: