T11TS immunotherapy repairs PI3K-AKT signaling in T-cells: Clues toward enhanced T-cell survival in rat glioma model.

Malignant glioma is the most fatal of astrocytic lineage tumors despite therapeutic advances. Onset and progression of gliomas is accompanied by severe debilitation of T-cell defense and T-cell survival. One of the chief contributors to T-cell survival downstream of activation is the PI3K-AKT pathway. Our prior studies showed that the novel immunotherapeutic molecule T11-target structure (T11TS) blocks T-cell apoptosis in glioma. We also showed activation of immunological synapse components and calcineurin-NFAT pathway following T11TS immunotherapy of glioma-bearing rats. This lead to investigations whether such T-cell activation upon T11TS therapy translates into activation of downstream PI3K/AKT signals which may be related to observed blockade of T-cell apoptosis. For the purpose, we assessed by flowcytometry and immunoblotting, expressions of PI3K, PDK1, AKT, p-AKT, and PTEN in splenic T-cells of normal, experimentally-induced glioma-bearing rats and glioma-bearing rats receiving first, second and third doses of T11TS. We also determined comparative nuclear translocation of NF-κB across groups. We found significant increases in T-cell expressions of PDK1, PI3K, and p-AKT in T11TS-treated animal groups compared to sharp downregulations in glioma. AKT levels remained unchanged across groups. PTEN levels declined sharply after T11TS immunotherapy. T11TS also caused enhanced NF-κB translocation to the T-cell nucleus compared to glioma group. Results showed heightened activation of the PI3K-AKT pathway in glioma-bearing rats following T11TS immunotherapy. These results illustrate the novel role of T11TS immunotherapy in ameliorating the PI3K pathway in T-cells in glioma-bearing animals to enhance T-cell survival, according greater defense against glioma. The study thus has far-reaching clinical outcomes.

Unravelling the apoptotic mechanisms in T-lymphocytes in an animal model for pollen induced airway allergy and studying the impact of specific immunotherapy.

Asthma is a chronic inflammatory disorder of the airways, increasing in prevalence worldwide. Reduced T cell apoptosis may interfere with the down-regulation of an immune response resulting in T cell accumulation contributing to the chronic inflammation of asthma. Most studies focused so far on apoptosis of eosinophils but the detailed role of T lymphocytes apoptosis in allergic diseases is unclear yet. The present experimental study was designed to discern the modulation of various apoptotic proteins of splenic T lymphocytes in a previously established rat model of Alstonia scholaris pollen induced airway allergy. Flowcytometry, immunoblotting, and immunofluorescence imaging techniques were employed for the present investigation. Annexin-V studies registered early apoptotic rate of lymphocytes with allergen sensitization and challenge which was corrected following mucosal immunotherapy. The study demonstrates that allergen sensitization and challenge reduced apoptosis of splenic T-lymphocytes via Fas mediated extrinsic pathway, Bax/Bcl2 regulated intrinsic pathway and also perforin/granzyme mediated pathway which were normalized following allergen specific intranasal immunotherapy. Inadequate T cell apoptosis in asthma appears to interfere with normal T cell elimination, resulting in T cell accumulation, which contributes to chronic inflammation and may be the major underlying cause for tissue damage which can be modulated by intranasal immunotherapy. Thus the apoptosis inducing effect of allergen immunotherapy necessitates more studies to elaborate on its effects on various effector cells of airway inflammation.

Modulation of regulatory T cells by intranasal allergen immunotherapy in an experimental rat model of airway allergy.

Allergic airway diseases such as asthma and allergic rhinitis are increasing in prevalence worldwide. The theory of an altered Th1/Th2 balance in allergic diathesis has recently been termed a "procrustean paradigm" as it failed to explain many preclinical findings. Regulatory T cells (Treg) have now been shown to be critical in T-cell homeostasis and in the maintenance of peripheral tolerance to allergens. Allergen specific immunotherapy (SIT) has been shown to induce regulatory T cells in allergic patients. Among various types of SIT, intranasal immunotherapy had not been studied in detail for the treatment of allergic airway diseases. So, there was a need to study the contribution of regulatory T cells and their mechanistic pathways following intranasal immunotherapy in-vivo. It had been previously shown that intranasal allergen immunotherapy using Alstonia scholaris pollen extract abrogates allergic airway inflammation with decline in IgE and Th2 cytokine levels. The present study for the first time offers a multi-targeted approach towards attenuation of airway allergy by the generation of CD4+CD25+Foxp3+T cells and other subsets of Treg cells like Tr1 cells, Th3 cells, CTLA4+Treg cells, and also modulation of various Treg cell surface molecules like GITR, OX40, CD39 and CD73 by intranasal immunotherapy in the same animal model. This animal experiment will thus help to chart out newer molecular targets for treating allergic asthma or rhinitis.