Anti-CD80 polyclonal antibody

Overcoming tolerance to tumor-associated antigens remains a hurdle for cancer vaccine-based immunotherapy. A strategy to enhance the anti-tumor immune response is the inclusion of adjuvants to cancer vaccine protocols. In this report, we generated and systematically screened over twenty gene-based molecular adjuvants composed of cytokines, chemokines, and T cell co-stimulators for the ability to increase anti-tumor antigen T cell immunity. We identified several robust adjuvants whose addition to vaccine formulations resulted in enhanced T cell responses targeting the cancer antigens STEAP1 and TERT. We further characterized direct T cell stimulation through CD80-Fc and indirect T cell targeting via the dendritic cell activator Flt3L-Fc. Mechanistically, intramuscular delivery of Flt3L-Fc into mice was associated with a significant increase in infiltration of dendritic cells at the site of administration and trafficking of activated dendritic cells to the draining lymph node. Gene expression analysis of the muscle tissue confirmed a significant up-regulation in genes associated with dendritic cell signaling. Addition of CD80-Fc to STEAP1 vaccine formulation mimicked the engagement provided by DCs and increased T cell responses to STEAP1 by 8-fold, significantly increasing the frequency of antigen-specific cells expressing IFN gamma, TNF alpha, and CD107a for both CD8(+) and CD4(+) T cells. CD80-Fc enhanced T cell responses to multiple tumor-associated antigens including Survivin and HPV, indicating its potential as a universal adjuvant for cancer vaccines. Together, the results of our study highlight the adjuvanting effect of T cell engagement either directly, CD80-Fc, or indirectly, Flt3L-Fc, for cancer vaccines.

Background Chagas disease or American trypanosomiasis is caused by the protozoanTrypanosoma cruziand is endemic of the Americas. The control of the disease is restricted to toxic and potentially teratogenic drugs, which limit the use during pregnancy. The use of food supplementation offers a safe and low-cost form to alleviate Chagas disease symptoms, mostly in areas with alimentary risk. For example, zinc demonstrates positive effects in immune response, including in Chagas disease during pregnancy. Purpose This study describes the innate response in pregnant rats chronically infected withT. cruziand supplemented with zinc. Methods Pregnant female Wistar rats, infected withT. cruzi, were treated with 20 mg/kg/day zinc sulfate and euthanized on the 18th day. Samples (plasma, splenocytes, and peritoneal exudate) were collected and several immune parameters (nitric oxide, RT1B, CD80/CD86, MCP-1, CD11b/c, NK/NKT, IL-2, IL-10, INF-cc, and apoptosis) evaluated. Results Under Zinc supplementation and/orT. cruziinfection, the gestation developed normally. Several innate immune parameters such as RT1B, CD80/CD86, MCP-1 expressing lymphocytes, IL-2, and IL-17 were positively altered, whereas nitric oxide, CD11b/c, NK/NKT, apoptosis, INF-gamma, and corticosterone demonstrated a pro-pregnancy pattern. Conclusion Our results indicated that zinc has diverse effects on immune response during pregnancy. An anti-T. cruziimmunity, as well as a pro-gestation response, were observed after zinc supplementation. The complete comprehension of zinc supplementation in pregnancy will base an adequate strategy to alleviate Chagas disease symptoms and propagation, especially for populations from endemic areas.