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The variability and heterogeneity of tumor antigens and the tumor-driven development of immunosuppressive mechanisms leading to tumor escape from established immunological surveillance. Here, the tumor cells were genetically modified to achieve an inducible overexpression of the N-terminal domain of gasdermin D (GSDMD-NT) and effectively cause pyroptosis under a strict control. Pyroptotic tumor cells release damage-associated molecular patterns (DAMPs) and inflammatory cytokines to promote the maturation and migration of bone marrow-derived dendritic cells (BMDCs). Furthermore, local tumor delivery, and preventive or therapeutic subcutaneous immunization of the modified cells, followed by the induction of GSDMD-NT expression, significantly stimulated both the systemic and local responses of antitumor immunity, and reprogrammed the tumor microenvironment, leading to the dramatic suppression of tumor growth in mice. This study has explored the application potency of inducing the pyroptosis of tumor cells in the field of tumor immunotherapy, especially for developing a new and promising personalized tumor vaccine.

Effect of LIPUS on the efficacy of osteoarthritis of the knee.

T-cells are central to our success as a species. They confer specific and long-term immunity in a process known as adaptive immunity. During adaptive immune response, pathogen ingested by peripheral sentinel cells are brought to the local lymph nodes and presented to T-cells. T-cell recognizes the antigen via its receptor complex (TCR-CD3). The high affinity binding primes the cell for activation. With a positive costimulationary signal from CD28, the T-cell is fully activated, resulting in IL-2 secretions and cellular proliferation. Clinicians are increasingly harnessing the adaptive immune system to combat diseases such as cancer. Specifically, T-cells are activated and expanded ex vivo for adoptive immunotherapies. The ability to modulate T-cell activation is crucial in engineering appropriate effector cell populations for therapeutics. The focus of this thesis is to address the functional impact of CD28 spatial organization on T-cell activation. It has been observed that the spatial segregation of CD3 and CD28 by a few microns has resulted in poor activation of human T-cells. Lck, a Src family kinase (SFK) emerges as the instigator of the phenomenon. The kinase is associated with both CD3 and CD28 signal cascades. We propose a reaction diffusion model to describe the delicate balance between protein mobility and Lck de-activation. The work in this dissertation describes two probes to investigate Lck kinase activity, which permit real-time imaging of both the initiation of pLck activity and its duration. A FRET reporter is constructed to study the spatial and temporal initiation of the kinase activity. Embedded with the Lck membrane domain and contained a substrate for pLck to phosphorylate, the FRET biosensor reports the Lck kinase activity in real-time. Using microprinting to control CD3 and CD28 spatial organizations, the FRET reporter reveals that while T-cells require CD28 for significant IL-2 secretion, CD3 engagement is essential to initiate cellular activation through a spike in pLck kinase activity. Spatially, the reporter shows heightened kinase activity concentrated at the center of the cells upon CD3 engagement. To study the duration of pLck activity, a recruitment reporter is made. CD3 is found ubiquitously throughout the cellular membrane. And its activation by pLck induces the recruitment of a pair of tandem SH2-domain. The recruitment probe (also containing a pair of tandem SH2-domain) revealed curtailed pLck kinase activity due to CD3-CD28 segregation. Ultimately, understanding CD28 modulation of T-cell activation is clinically relevant as it provides new opportunities and targets for the development of therapeutics.