Dendritic cells matured with recombinant human sperm associated antigen 9 (rhSPAG9) induce CD4+, CD8+ T cells and activate NK cells: a potential candidate molecule for immunotherapy in cervical cancer

Background Dendritic cell (DC)-based immunotherapy is capable of activating the immune system and in particular tumor-specific cytotoxic T lymphocytes (CTLs) to eradicate the tumor. However, major limitations are the availability of autologous tumor cells as antigenic source and the selection of antigen that may have potential to activate both CD4+ and CD8+ T cells in immune-specific manner. Recently, we reported the expression of sperm associated antigen 9 (SPAG9) that is associated with various types of malignancies including cervical cancer. We examined the recombinant human SPAG9 (rhSPAG9) as an antigenic source for generating efficient DCs to stimulate CD4+ and CD8+ T cell responses for future DCs-based vaccine trials in cervical cancer patients. Methods Human monocytes derived DCs were pulsed with different concentrations (250 ng/ml to 1000 ng/ml) of recombinant human SPAG9 (rhSPAG9) and evaluated for their phenotypic and functional ability. The efficacy of DCs primed with 750 ng/ml of rhSPAG9 (SPDCs) was compared with DCs primed with autologous tumor lysates (TLDCs), to induce CD4+, CD8+ T cells and activating NK cells. In addition, we investigated the effect of the chemotherapeutic drug cisplatin on phenotypic and functional potential of SPDCs. Results Phenotypic and functional characterization of DCs pulsed with 750 ng/ml rhSPAG9 was found to be optimal and effective for priming DCs. SPDCs were also capable of stimulating allogeneic T cells similar to TLDCs. SPDCs showed a statistically insignificant increase in the expression of maturation marker CD83 and migration towards CCL19 and CCL21 compared with TLDCs (CD83; P = 0.4; migration; P = 0.2). In contrast, although TLDCs showed better proliferation and secretion of Th1 cytokines (IL12p40, IL12p70 and IFNγ) compared to SPDCs, this difference was not statistically significant (IL12p40, P = 0.06). Further we also observed that clinical dose of cisplatin (200 µM) treated SPDCs were able to stimulate the proliferation of cytotoxic T lymphocytes without increasing the FOXP3+ Tregs in autologous co-cultures. Conclusions In summary, in order to overcome the limitation of the availability of autologous tumor cells as antigenic sources, our present strategy provides an insight to consider rhSPAG9 as a strong immunogen for DC-based immunotherapy for cervical cancer trials and warrants further studies. This is the first report to suggest that rhSPAG9 is an effective antigen for pulsing DCs that are capable of eliciting a potent Th1 response which, in turn, may help in decreasing the tumor burden when used along with a cisplatin based combinatorial regimen for therapeutic intervention.

Dendritic cells matured with recombinant human sperm associated antigen 9 (rhSPAG9) induce CD4+, CD8+ T cells and activate NK cells: A potential candidate molecule for immunotherapy in cervical cancer

Background Dendritic cell (DC)-based immunotherapy is capable of activating the immune system, and in particular tumour-specific cytotoxic T lymphocytes (CTLs) to eradicate the tumour. However, major limitations are the availability of autologous tumour cells as antigenic source and the selection of antigen that may have potential to activate both CD8 + and CD4 + T cells in immune-specific manner. Recently, we reported the expression of sperm associated antigen 9 (SPAG9) that is associated with various types of malignancies including cervical cancer. We examined the recombinant human SPAG9 (rhSPAG9) as an antigenic source for generating efficient DCs to stimulate CD4 + and CD8 + T cell responses for future DCs-based vaccine trials in cervical cancer patients. Methods Human monocytes derived DCs were pulsed with different concentrations (250 ng/ml to 1000 ng/ml) of recombinant human SPAG9 (rhSPAG9) and evaluated for their phenotypic and functional ability. Subsequently, the efficacy of DCs primed with 750 ng/ml of rhSPAG9 (SPDCs) was compared with DCs primed with autologous tumour lysate (TLDCs), to induce CD4+, CD8 + T cells and activating NK cells. In addition, we investigated the effect of the chemotherapeutic drug cisplatin on phenotypic and functional potential of SPDCs. Results Phenotypic and functional characterization of DCs pulsed with 750 ng/ml rhSPAG9 was found to be optimal and effective for priming DCs. SPDCs were also capable of stimulating allogeneic CD4 + and CD8 + T cells similar to TLDCs. SPDCs showed a statistically insignificant increase in the expression of maturation marker CD83 and migration towards CCL19 and CCL21 compared with TLDCs (CD83 p = 0.4; for migration p = 0.2). In contrast, TLDCs showed better proliferation and secretion of Th1 cytokines (IL12p40, IL12p70 and IFNγ) compared to SPDCs, but this was also not statistically significant (IL12p40, p = 0.06). We also found that clinical dose of cisplatin (200 µM) treated SPDCs were able to stimulate the proliferation of cytotoxic T lymphocytes without increasing the FOXP3+Tregs in autologous co-cultures. Conclusions This is the first report to suggest that rhSPAG9 is an effective antigen for pulsing DCs that are capable of eliciting a potent Th1 response which, in turn, may help in decreasing the tumour burden when used along with a cisplatin based combinatorial regimen for therapeutic intervention. This strategy provides an insight to consider rhSPAG9 as a strong immunogen for DC-based immunotherapy for cervical cancer.

Commercial Bovine Proteoglycan Is Highly Arthritogenic and Can Be Used as an Alternative Antigen Source for PGIA Model

Rheumatoid arthritis (RA) is the most common systemic autoimmune disease. It affects mainly the joints, causing synovitis, cartilage destruction, and bone erosion. Many experimental models are used to study the mechanisms involved in immunopathogenesis and new therapies for this disease. Proteoglycan-induced arthritis (PGIA) is a widely used model based on the cross-reactivity of injected foreign (usually human) PG and mice self-PG. Considering the complexity of the extraction and purification of human PG, in this study we evaluated the arthritogenicity of bovine PG that is commercially available. Bovine PG was highly arthritogenic, triggering 100% incidence of arthritis in female BALB/c retired breeder mice. Animals immunized with bovine PG presented clinical symptoms and histopathological features similar to human RA and other experimental models. Moreover, bovine PG immunization determined higher levels of proinflammatory and anti-inflammatory cytokines in arthritic mice compared to healthy ones. As expected, only the arthritic group produced IgG1 and IgG2a antibodies against PG. Thus, commercial bovine PG can be used as an alternative antigenic source to PGIA for the study of many RA aspects, including the immunopathogenesis of the disease and also the development of new therapies.

Ileal Inflammation May Trigger the Development of GP2-Specific Pancreatic Autoantibodies in Patients with Crohn’s Disease

Why zymogen glycoprotein 2 (GP2), the Crohn’s disease (CD)-specific pancreatic autoantigen, is the major target of humoral autoimmunity in inflammatory bowel diseases (IBD) is uknown. Recent evidence demonstrates that GP2 is also present on the apical surface of microfold (M) intestinal cells. As the colon lacks GP2-rich M cells, we assumed that patients with colonic CD are seronegative for anti-GP2. Anti-GP2 antibodies were tested in 225 CDs, including 45 patients with colonic location (L2), 45 with terminal ileum (L1) and 135 with ileocolonic involvement; 225 patients with ulcerative colitis (UC) were also tested. Anti-GP2 reactivity was detected in 59 (26.2%) CDs and 15 (6.7%) UCs(P<0.001). Only 5 CDs with L2 had anti-GP2 antibodies, compared to 54/180 (30.0%,P=0.0128) of the CDs with L1 and L3. Anti-GP2 antibody positive CD patients had higher ASCA titres compared to seronegative cases. Amongst the 128 CD patients with previous surgical intervention, 45 (35.0%) were anti-GP2 antibody positive compared to 14/97 (14.0%) without surgical(P<0.001). Our data support the assumption that ileal inflammation is required for the development of anti-GP2 antibodies in CD, and suggest that the intestine rather than the pancreatic juice is the antigenic source required for the initiation of anti-GP2 antibodies.

Light microscopic, immunohistochemical localization of the pia-glial basal lamina.

The current histologic methods for studying the pia-glial basal lamina (BL) are inappropriate for high contrast, permanent light microscopy preparation. We have developed a staining technique for epithelial BL which is highly specific, extremely sensitive, permanent, relatively inexpensive, and suitable for light or electron microscopy (EM). Central nervous system (CNS) basement membrane zone (BMZ) antigens were isolated by the technique of Meezan (1975) from female albino Wistar rats. Using this CNS BMZ preparation as an antigenic source, a hyperimmune rabbit serum was developed. This serum was exhaustively adsorbed with rat splenic pulp to remove undesirable antibodies to endothelial BL and collagen. The peroxidase-antiperoxidase indirect antibody technique was used to test the staining specificity of this splenic adsorbed serum on different tissues containing BLs of known origin and/or function. The results indicated that this BL staining technique was specific for epithelial BL of the rat and of some other species.