High-grade glioma is a type of cancerous tumor found in the brain that affects glial cells, Gliomas make up around 30 percent of all brain tumors and central nervous system tumors, and 80 percent of all malignant brain tumors. Unlike many other treatments, Temozolomide (TMZ) is able to pass through the blood-brain barrier (BBB). TMZ works by binding to the DNA in highly proliferative cells and disrupting the cell replication process by damaging the DNA. A more recent development is a treatment called immune checkpoint inhibitors (ICIs) which are antibodies that prevent tumor cells from turning off immune cells, specifically T cells. If we combine the two treatments, we can have two productive treatments/fights against glioma — the natural human immune system and chemotherapy. Before we combine the two treatments, the systemic immune effects of TMZ must be realized so that the ICIs’ secondary effects can be expected and we can alter individual treatments so they can work together. This study analyzes spleen and bone marrow samples of mice infected with glioma and treated using TMZ. SHAM, treated, and control groups are being used. The data analysis software FlowJo is being used to quantify cells with different immune markers, such as CD3, CD45, Gamma Delta, CD8, MHC II, and CD4. A slight decrease in immune effectiveness was noticed, specifically with decreases in CD4, Gamma Delta, CD3, and slightly for CD45. Therefore, it is possible that combining checkpoint inhibitors with TMZ will be effective.