The initial step in the second strategy is to develop an efficient cancer vaccine that specifically triggers antitumor T cell responses (8). IgG2b and greater secretion of the Th1 cytokines IL-1 and IFN- from splenocytes. ABP-AW1 is a promising immunoadjuvant therapy candidate, due to its ability to boost the Th1 immune response when co-administered with a cancer vaccine intended to inhibit cancer progression. Murrill polysaccharide, ovalbumin, Th1, cancer immunity, immunoadjuvant Introduction Four general therapeutic approaches have been developed during the long fight with cancer: Surgery, chemotherapy, radiotherapy and immunotherapy (1). Unlike the first three, which target the tumor directly, immunotherapy works indirectly through the immune system (2). The initial evidence demonstrating that immunotherapy could be effective in targeting cancer was from a study published by Coley in 1893 (3). Coley injected streptococcal organisms (Coley’s toxin) into patients with cancer, and, in a number of cases, tumor regression was observed, presumably due to the host’s immune system (3). Since then, attitudes towards cancer immunotherapy Angpt2 have fluctuated, although efforts by oncologists and immunologists to develop treatments have never ceased (4,5). Recently, immunotherapy has received positive results as a cancer treatment, with clinical successes with blocking antibodies at two immune checkpoints, cytotoxic T-lymphocyte-associated protein 4 and programmed cell death protein 1, and with chimeric antigen receptor-transduced T cells (6). Cancer immunotherapy has adopted two basic strategies: Passive transfer of anticancer monoclonal antibodies and immune-active T cells, without activating endogenous immunity; and the active stimulation of specific antitumor immunity in patients with cancer (7). The initial step in the second strategy is to develop an efficient cancer vaccine that specifically triggers antitumor T cell responses (8). Although many tumor-specific antigens have been identified, when activated alone, the majority lack a strong immunogenic activity and fail Amikacin disulfate to initiate effective antitumor immunity (9). The key limiting factor is the lack of an optimal Amikacin disulfate adjuvant therapy that could enhance, in terms of the magnitude, quality and duration, specific immune responses to antigens, while exerting minimal toxicity or immune effects of its own (7). Although novel adjuvant therapies, including saponin (10), bacterial DNA (11), and cytokines (12), have been reported, aluminum salts (alum) remain the sole adjuvant therapy for the majority of therapeutic vaccines (13). Alum effectively induces the antibody-producing type 2 T-helper (Th2) response, but has no effect on cellular immunity, including the type 1 Th (Th1) response, and is associated with toxicity from aluminum accumulation (14). Therefore, in cancer immunotherapy research there is a great demand for a non-toxic adjuvant therapy that stimulates Th1 responses. Successful anticancer immunity requires the activation of CD8+ and CD4+ T cells (15). CD8+ cytotoxic T cells directly target and destroy tumor cells expressing major histocompatibility complex class I molecules. CD4+ T cells, specifically the Th1 cells, orchestrate multiple cell types to eradicate tumor cells through the secretion of Th1 cytokines, including interferon (IFN)- and interleukin (IL)-2 (15). Cell types affected by CD4+ T cells include CD8+ T cells, macrophages and natural killer cells (16); therefore, an immunoadjuvant therapy that promotes Th1 responses may benefit the development of antigen-specific antitumor immunity. Polysaccharides are natural, low-toxicity macromolecules with various biological functions, including immune-modulation (17). In the laboratory, the mechanisms underlying polysaccharides isolated from fungi and plants and their functions, in regulating immune responses, were investigated. The previous study demonstrated that the low-molecular-weight polysaccharides of the fungus Murrill, ABP-AW1, function as a potent Th1-immunity-stimulating adjuvant therapy in wild-type Institute for Cancer Research mice (18). In the present study, the functional significance and underlying mechanisms of ABP-AW1 in cancer immunity were examined, using ovalbumin (OVA) as the model tumor antigen. Materials and methods Experimental animals and cells This study was approved by the Institutional Animal Care and Use Committee of Qiqihar Medical University (Heilongjiang, China). A total of 50 female C57BL/6 mice (6C8 weeks old; body weight, 202 g) were purchased from Yisi Experimental Animal Technology Co., Ltd. Amikacin disulfate (Jilin, China). The mice were housed in a specific pathogen-free facility at 241C and 5010% relative humidity under a 12/12 h light/dark cycle, with food and water provided were treated under reflux 3 times with 95% ethanol at 75C for 6 h to remove lipids. Amikacin disulfate The residue was extracted 3 times with distilled water at.