Abstract 4232: TLR2 agonist as a novel therapeutic approach to treat pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with an overall 5-year survival rate of <10% due to late stage diagnosis and poor clinical outcome with existing therapies. PDAC displays a high degree of tumor heterogeneity and immunosuppressive tumor microenvironment with lower tumor infiltrating lymphocytes (TIL). These factors contribute to resistance against chemotherapies and immunotherapies. Immunotherapies have shown activities across different tumor types including chemotherapy or targeted therapy resistant cancers however these options have little efficacy in the PDAC tumor. Here, in this study we tested the efficacy of gemcitabine in combination with Cadi-05 (TLR2 agonist) against established murine PDAC tumor models (Pan02 in C57/BL6 and 688M in B6129SF1/J). Animals were randomized to receive gemcitabine, Cadi-05, their combination or no treatment when they had tumor size ≈ 50 mm3, 65mm3 and 100 mm3. The weekly treatment of gemcitabine, Cadi-05 and their combination inhibited the tumor progression across all tumor sizes. At the end of study, PBMC and tumors were collected and analyzed for different immune parameters. Results revealed that Cadi-05 treatment alone was associated with increase in CD4+ and CD8+ T cells in PBMC as well as amongst TIL with significant decrease in their expression of immunosuppressive markers like FOXP3 and PD-1. Its combination with gemcitabine synergized the effect of each other. There was further increase in absolute TIL as well as TIL expressing CD4+ and CD8+ markers with decrease in FOXP3 and PD-1 expressing CD4+ and CD8+ TIL. Inhibition of tumor progression was associated with improved effector function of PBMC. Synergy between Cadi-05 and gemcitabine was also evident in effector function. In presence of established tumor, TLR2 agonist Cadi-05 improves effector function, increases CD4+ and CD8+ expressing TIL, decreases immune suppressive TIL and retards tumor growth. Our study suggests that combination of gemcitabine and Cadi-05 inhibits the tumor growth irrespective of its size and it is coupled with increased anti-tumor response and decreased immunosuppressive function

Citation Format: Arpit Dheeraj, Chandreshwar Shukla, Dhanir Tailor, Nayan K. Jain, Kirsten Stefan, Chintan D. Patel, Rajiv Modi, Bakulesh M. Khamar, Sanjay V. Malhotra. TLR2 agonist as a novel therapeutic approach to treat pancreatic adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4232.

BLIMP-1 Mediated Downregulation of TAK1 and p53 Molecules Is Crucial in the Pathogenesis of Kala-Azar

Precise regulation of inflammasome is critical during any pathogenic encounter. The whole innate immune system comprising of pattern recognition receptors (PRRs) relies on its ability to sense microbes. The fate of cellular death in infected cells depends mostly on the activation of these inflammasome, the dysregulation of which, due to functional manipulation by various pathogens, leads to be the cause of many human diseases. Here, an interesting finding has been observed which is related to how Leishmania donovani parasites exploit various host mediator molecules to cause immunosuppression. Here we report for the first time that the parasites check pyroptosis in the infected cells in-vitro by BLIMP-1 mediated suppression of TAK1 and p53 proteins. This might be one of the reasons how parasites evade the pro-inflammatory response of the host cells. Further understandings and validations are required to come up with better therapeutic approaches against kala-azar.

BLIMP-1 Plays Important Role in the Regulation of Macrophage Pyroptosis for the Growth and Multiplication of Leishmania donovani

Visceral leishmaniasis, one of the fatal forms of the disease, is caused by Leishmania donovani and presents morbid clinical manifestations. The parasite evades pro-inflammatory immune responses by several reported mechanisms and modulates the host immune system to cause fatal symptoms. A plethora of reports related to the role of BLIMP-1 and its involvement in suppressing the immune response in various infectious diseases have been documented. Higher parasitic burden due to increased BLIMP-1 production has been reported earlier for malaria and leishmaniasis with no detailed information. We report for the first time the role of BLIMP-1 in suppressing macrophage pyroptosis during L. donovani infection and thereby tweaking the tight regulation of the NFκβ-NLRP3 signaling pathway. Expression analyses of BLIMP-1 and NFκβ have been measured using real-time PCR and Western blotting. The importance of BLIMP-1 has been validated using a siRNA-mediated experiment along with caspase 1 activity, LDH release assay, and infectivity index analyses. An inverse relationship between BLIMP-1 and NFκβ expression has been highlighted during L. donovani infection, which is reversed in blimp-1 deficient cells infected with promastigotes. The above fact has been further validated with caspase 1 activity assay, and LDH release along with IFNγ and TNF-α release assay. Finally, resumption of pyroptosis has been concluded in infected blimp-1 deficient cells in contrast to wild type infected cells. We conjecture that parasites modulate the NFκβ-NLRP3 signaling pathway by taking advantage of BLIMP-1 dependent IL-10 production and finally disrupting an inflammation-mediated pyroptosis cell death pathway in infected cells.

A randomized trial of TLR-2 agonist CADI-05 targeting desmocollin-3 for advanced non-small-cell lung cancer

Background

Randomized controlled trial to evaluate synergy between taxane plus platinum chemotherapy and CADI-05, a Toll like receptor-2 agonist targeting desmocollin-3 as a first-line therapy in advanced non-small-cell lung cancer (NSCLC).

Patients and methods

Patients with advanced NSCLC (stage IIIB or IV) were randomized to cisplatin-paclitaxel (chemotherapy group, N = 112) or cisplatin-paclitaxel plus CADI-05 (chemoimmunotherapy group, N = 109). CADI-05 was administered a week before chemotherapy and on days 8 and 15 of each cycle and every month subsequently for 12 months or disease progression. Overall survival was compared using a log-rank test. Computed tomography was carried out at baseline, end of two cycles and four cycles. Response rate was evaluated using Response Evaluation Criteria in Solid Tumors criteria by an independent radiologist.

Results

As per intention-to-treat analysis, no survival benefit was observed between two groups [208 versus 196 days; hazard ratio, 0.86; 95% confidence interval (CI) 0.63-1.19; P = 0.3804]. In a subgroup analysis, improvement in median survival by 127 days was observed in squamous NSCC with chemoimmunotherapy (hazard ratio, 0.55; 95% CI 0.32-0.95; P = 0.046). In patients receiving planned four cycles of chemotherapy, there was improved median overall survival by 66 days (299 versus 233 days; hazard ratio, 0.64; 95% CI 0.41 to 0.98; P = 0.04) in the chemoimmunotherapy group compared with the chemotherapy group. This was associated with the improved survival by 17.48% at the end of 1 year, in the chemoimmunotherapy group. Systemic adverse events were identical in both the groups.

Conclusion

There was no survival benefit with the addition of CADI-05 to the combination of cisplatin-paclitaxel in patients with advanced NSCLC; however, the squamous cell subset did demonstrate a survival advantage.

Abstract 1582: Therapeutic vaccine for pancreatic cancer

Cadi-05 (Heat killed mycobacterium w) is a potent TLR 2 agonist and induces pure potent Th1 response. In advanced Non small cell lung cancer, Cadi-05 is found to potentiate efficacy of chemotherapy (Paclitaxel + Cisplatin) with improvement in response rate and overall survival in a randomized controlled clinical trial. Cadi-05 is also a potent vaccine adjuvant for prophylactic vaccines providing faster, higher and sustained antibody titers in animals and humans. The therapeutic vaccine for pancreatic cancer, with killed pancreatic cancer cells as an antigen with Cadi-05 as an adjuvant was evaluated for its ability to induce cell mediated immune responses (by ELISPOT for IFN - α, IL-2 and Granzyme B) and effector function (By BrDu incorporation). The vaccine made using Mia PaCa-2 cell line induced cell mediated immune responses against the Mia PaCA-2 as well as against the other cell lines (Panc-1, ASPC-1, SW-1990). The vaccine also generated effector function of similar magnitude against all four cell lines. Effect of vaccine on tumor size and survival following intradermal immunization was also studied. For evaluating efficacy, C57BL/6 BYJ mice were injected Pan-02 cells (1x106) subcutaneously for developing pancreatic cancer model. At day 10 post tumor induction tumor size achieved was∼200-225 mm3. Mice were randomized to receive vaccine or placebo (18 mice each) on day 10. No other therapy was used in the experiment. In Vaccine arm tumor regression was seen in 61% of animals before progression. Tumor regression was not seen in placebo arm. Tumor progression was found to be slower in vaccinated animals with mean tumor size 35% and 59% of placebo arm on day7 (633 mm3 vs. 223 mm3) and day 12 (740 mm3 vs. 437 mm3) respectively resulting in survival benefit of 36% on day 40 following immunisation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1582. doi:1538-7445.AM2012-1582

First report of evaluation of K-M media: a new corneal preservation medium

PURPOSE

To analyze the outcome of keratoplasty performed using Kalevar-Majumdar (K-M) media, a new synthetic viscous medium for preservation of the cornea.

MATERIALS AND METHODS

The K-M media-preserved donor eye balls were kept in a bottle in a refrigerator at 4 degrees C till the corneas were used. Forty-eight consecutive keratoplasty cases of pseudophakic bullous keratopathy with vision less than counting fingers at one meter and operated by a single surgeon have been analyzed. Corneal donor button of 7.5 mm was used on the 7.0 mm recipient bed in all cases. Surgery was done with a standard technique. All the cases were examined daily for the first week and at the end of one month for graft clarity, epithelial defect and stromal edema.

RESULTS

The K-M media-preserved corneal grafts remained clear at the end of the first week in 95.8% (46 of 48) cases and at the end of one month in 93.7% (45 of 48) cases. Donor epithelial haze cleared in 24 h in all cases. The stromal edema got cleared in the majority (91.7%, 44 of 48) within 24 h. Epithelial defect was seen in only 10.4% (five cases). There was no primary graft failure.

CONCLUSION

K-M medium, a new viscous, synthetic corneal preservation medium, is a safe (no primary donor failure) alternative to conventional liquid corneal preservation media. K-M media-preserved eyes appear to have better preserved corneal epithelium with faster achievement of graft clarity postoperatively.

New standardized visual acuity charts in Hindi and Gujarati

Conventional Snellen visual acuity chart has unequal difficulty score and irregular progression in letter size causing jumping effect at different visual acuity levels. There is also increase in number of letters from above downwards. Consequently one or two mistakes per line has different meaning of visual acuity at different levels. We designed a new visual acuity chart of fourteen lines in Hindi and Gujarati to facilitate standardization in visual acuity measurement. These charts are designed for use at six meter distance, and the illumination is provided from front. These charts provide a standardized way of measuring visual acuity using local languages.

Anomalous kinetic visual fields found in family members of patients with a confirmed diagnosis of Gilles de la Tourette syndrome

Three visual manifestations of Gilles de la Tourette syndrome (TS), a neuropsychiatric disorder, have been previously reported. In this paper we report anomalies in the measured kinetic paracentral visual field of TS patients and their family members. We found that 96% of TS patients exhibited paracentral kinetic visual field defects (nasal and temporal steps, enlargement, "ringing," and/or baring of the blind spot). Ninety-three percent of fathers of TS children and, surprisingly, about 80% of mothers exhibit these characteristic visual field anomalies. Sample data and examples of family studies are reported.

Dopamine and myopia

Dopamine may play a role in form-deprivation myopia in chickens. Anomalies of the dopaminergic system are believed to be responsible for manifestations of symptoms in Tourette Syndrome (TS), a neuropsychiatric disorder. Visual anomalies have been identified in TS. In this paper, refractive error in people suffering from TS is compared with available population studies. Refractive errors in TS are found to be similar to those in the normal population.