Enhancing T Cell Immune Responses by B Cell-based Therapeutic Vaccine Against Chronic Virus Infection

Micellar nanoparticles inhibit breast cancer and pulmonary metastasis by modulating the recruitment and depletion of myeloid-derived suppressor cells

Myeloid-derived suppressor cells (MDSCs) are notorious for their pathological characteristics of immunosuppression and their promoting effect on cancers. They can induce the formation of pre-metastatic niche (PMN) characterized by inflammation, immunosuppression and vascular leakage, and promote pulmonary metastasis of breast cancer. Herein, a tumor targeting c(RGDfk) peptide modified low molecular-weight-heparin-all-trans-retinoic-acid (LMWH-ATRA) micellar nanoparticle loaded with chemotherapeutic drug doxorubicin (DOX) and immune adjuvant α-galactosylceramide (αGC) (RLA/DOX/αGC NP) was developed. The hydrophilic segment LMWH inhibited the recruitment of MDSCs by competitively binding with P-selectin on the surface of vascular endothelial cells (VECs), while the hydrophobic segment ATRA promoted the depletion of MDSCs by inducing their differentiation. Through the modulation of MDSCs, micelles can significantly improve the inflammatory and immunosuppressive microenvironment of the lung and tumor sites, and inhibit the formation of PMN. Not only this, the micelles also produced a synergistic effect with αGC, which effectively improved the anti-tumor immunity of tumor bearing mice and provided a promising therapeutic strategy for breast cancer and pulmonary metastasis.

Immune evasion of the CD1d/NKT cell axis

Many reviews on the CD1d/NKT cell axis focus on the ability of CD1d-restricted NKT cells to serve as effector cells in a variety of disorders, be they infectious diseases, cancer or autoimmunity. In contrast, here, we discuss the ways that viruses, bacteria and tumor cells can evade the CD1d/NKT cell axis. As a result, these disease states have a better chance to establish a foothold and potentially cause problems for the subsequent adaptive immune response, as the host tries to rid itself of infections or tumors.