Immunologic Modification Research Articles

Abstract 5289: Pre-clinical evaluation of CDK4/6 inhibitor resistance and immunologic modification in liposarcoma

Abstract Soft tissue sarcomas are heterogeneous mesenchymal neoplasms and account for 1% of all cancers in adults. One of the most common diagnosed soft tissue sarcomas is well-differentiated (WD)/dedifferentiated (DD) liposarcoma which is characterized by amplification of CDK4. We have previously reported that the CDK4 inhibitor palbociclib induces cell cycle arrest in the CDK4 amplified, LS141 and DDLS liposarcoma cell lines in vitro (Barretina J. et al Nature Genet. 2010) and in clinical trial results palbociclib results in prolonged progression free survival in patients with WD/DD-liposarcoma (Dickson M Et al. J Clin Oncol. 2013). We have now studied the mechanisms of CDK4/6 resistance in liposarcoma by exposing LS141 and DDLS cell lines to increasing concentrations of the CDK4/6 inhibitor, ribociclib, for an extended time period of 1-2 months. Cell survival, as measured by cell proliferation assays, indicated IC50s of 10µM for CDK4/6 Resistant LS141 and 15 µM for CDK4/6 Resistant DDLS, which is more than ten times higher than the sensitive parental cells. We also compared the established CDK4/6 resistant cell lines to palbociclib and found that resistance was similar to the ribociclib effect. Cell cycle changes to CDK4/6 resistant cell lines exhibited no effect of G1 arrest when exposed to higher concentrations of the drug. We also examined the effect of ribociclib and palbociclib on p-RB after treatment in sensitive parental and CDK4/6 resistant liposarcoma cell lines and showed that inhibition of p-Rb occurred at lower doses of 250-500 nM in the sensitive cell lines compared to higher doses of 2-8 µM in the resistant cell lines. Overexpression of cyclin E1 and p-CDK2 were prominent in the resistant cell lines when examined by western blot. siRNA suppression of cyclin E showed a reversal of resistance as determined by proliferation assays. We also observed induction of immunological markers including PD-L1, HLA-A2 and B2M (MHC-1 class) with CDK4/6 inhibitor treatment in the sensitive cell lines. Flow cytometry showed HLA-A2 and B2M increased in the resistant LS141 while B2M only increased in the resistant DDLS compared to their parental cell lines. We also observed PD-L1 increased in the resistant LS141 while it decreased in the resistant DDLS when exposed to the drug over long periods of time. Cytokine production in the CDK4/6 resistant liposarcoma was also seen with IL-8 increasing in resistant LS141 and IL-6 increasing in resistant DDLS cell line. Taken together these results indicate that cyclin E1/CDK2 activation is a mechanism of resistance to CDK4/6 inhibitors in WD/DD-liposarcoma and that CDK4/6 inhibition induces immunologic effects including induction of PD-L1 that are modified over time in CDK4/6 resistant liposarcoma cells. These results would support CDK2/4/6 targeting in this disease and the development of combination trials with PD-L1 inhibitors. Citation Format: Elgilda Musi, Parag P. Patwardhan, Matthew Ingham, Gary K. Schwartz. Pre-clinical evaluation of CDK4/6 inhibitor resistance and immunologic modification in liposarcoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5289.

Comparison of immunologic modification after 2 years of sublingual immunotherapy with house dust mite extract between mono- and poly-sensitized patients

Comparison of immunologic modification after 2 years of sublingual immunotherapy with house dust mite extract between mono- and poly-sensitized patients

Immunologic modification in mono- and poly-sensitized patients after sublingual immunotherapy.

To compare immunologic modification and treatment outcomes after 2 years of sublingual immunotherapy (SLIT) with house dust mite extracts (HDM) between monosensitized and polysensitized patients with allergic rhinitis. Retrospective cohort study. Among the patients who were prospectively enrolled in the SLIT cohort study, patients with allergic rhinitis who were sensitized to HDM and treated with SLIT for at least 2 years were studied. All participants underwent serologic tests at baseline and after SLIT to evaluate changes in immunologic parameters. The total nasal symptom score (TNSS) was measured before and after SLIT, and effective and less effective responder groups were categorized depending on whether patients had a TNSS reduction of 50%, as compared with baseline. The increase in Dermatophagoides pteronyssinus and Dermatophagoides farinae specific immunoglobulin G4 levels was significantly higher in monosensitized patients than in polysensitized patients (P = .020 and P = .005, respectively). The TNSS significantly improved after SLIT in both the monosensitized and polysensitized groups (P < .001 in both groups). However, the difference in the changes in TNSS from baseline was not significant between the two groups (P = .374). This study demonstrated different immunologic modifications after SLIT between monosensitized and polysensitized patients. However, patients in the polysensitized group who were treated with single-allergen SLIT experienced clinical improvement in TNSS that was comparable with that in the monosensitized group despite demonstrating different immunologic changes. 2b Laryngoscope, 129:E170-E177, 2019.

Self-expandable stented valve with glutaraldehyde-fixed cardiac xenograft treated by novel anticalcification protocols including immunologic modification for perventricular pulmonic valve implantation

The conventional glutaraldehyde (GA) fixation for cardiac xenograft causes dystrophic calcification, and there is also a significant immune reaction to the galactose-α-1,3 galactose β-1,4-N-acetylglucosamine (α-Gal), leading to calcification. So, future investigation should be redirected in the quest for the αGal-free long-lasting substitutes.

Development of Novel Combined Anticalcification Protocols Including Immunologic Modification for Prolonged Durability of Cardiac Xenograft

Development of Novel Combined Anticalcification Protocols Including Immunologic Modification for Prolonged Durability of Cardiac Xenograft

Development of novel combined anticalcification protocols including immunologic modification for prolonged durability of cardiac xenograft: preclinical study using large-animal long-term circulatory models.

Cardiac xenografts are conventionally cross-linked with glutaraldehyde (GA) to impart tissue stability, reduce antigenicity, and maintain tissue sterility. However, GA-fixed xenografts are prone to calcification after long-term implantation in humans, because of phospholipids, free aldehyde groups, and residual antigenicity. We evaluated preclinical safety and efficacy using large-animal long-term circulatory models for our novel combined anticalcification protocol including immunological modification, which had been proven effective in small animal experiments. Bovine/porcine xenografts were treated with decellularization, immunological modification with α-galactosidase, GA fixation with organic solvent, and detoxification with glycine. Valve conduits made of these xenografts were transplanted into the pulmonary root of goats, and hemodynamic, radiological, immunohistopathological, and biochemical results were obtained for 12 months after implantation. Evaluation of echocardiography and cardiac catheterization demonstrated good hemodynamic status and function of the pulmonary xenograft valves. Durability of the xenografts was well preserved without calcification by specimen radiography and immunohistopathological examination. The calcium concentrations of the explanted xenografts were lower than the control xenografts. This preclinical study using large-animal long-term circulatory models demonstrated that our synergistic and simultaneous employment of multiple anticalcification therapies and novel tissue treatments, including immunological modifications, have promising safety and efficacy and should be examined further in future clinical studies.

Invivo efficacy for novel combined anticalcification treatment of glutaraldehyde-fixed cardiac xenograft using humanized mice.

The animal immune response against Galα1,3-Galβ1-4GlcNAc-R(α-Gal) epitopes gives an important cause for the failure of glutaraldehyde(GA)-fixed cardiac xenografts. This study aimed to assess the invivo effect of our novel combined anticalcification treatment, which includes immunologic modification, using α1,3-galactosyltransferase knock-out mice to mimic human immunologic environment. Bovine pericardia were cross-linked with GA and treated with decellularization, immunologic modification with α-galactosidase, space-filler with polyethylene glycol, organic solvent, and detoxification. The bovine pericardia were subcutaneously implanted into humanized and wild type mice, and titers of anti α-Gal IgM and IgG were evaluated at various time intervals. Invivo calcification and immunohistochemistry staining was assessed for the explanted xenografts several months after implantation. In humanized mice, titers for anti α-Gal IgM and IgG increased as the period of implantation increased, and reduced with our anticalcification treatments. The humanized mice had more invivo calcification in GA-fixed xenografts treated with our anticalcification protocol compared with wild type mice. In humanized mice, invivo calcification reduced with our combined anticalcification treatment, and the immunohistochemistry of the harvested xenografts proved the compatible findings with the results of invivo immunogenicity and calcification. Humanized mice are effective model for the assessment of invivo calcification, and our combined anticalcification treatments reduced invivo calcification as well as invivo immunogenicity in humanized mice group, suggesting that the animal immune reaction is the cause for calcification. Our novel combined anticalcification strategies of decellularization, immunologic modification, space-filler, organic solvent, and detoxification have possible promise to prolong the lifespan of cardiac xenograft.

Genital warts and other HPV infections: Established and novel therapies

Wart therapies involve methods of targeted lesion destruction, as well as selective immunologic modification. While there are several therapeutic options, no treatment has been proven to be superior in terms of clinical clearance or recurrence. Controlled trials comparing treatments are currently lacking. Many factors are used in the selection of treatment. Variables that should be taken into account include but are not limited to the morphology of the lesions such as thickness and size, quantity, anatomic location, human papilloma virus (HPV) classification, immunocompromized or immune competent status, as well as the preferences of the patient and the provider, cost and availability. No current treatment completely eradicates the human papillomavirus virus. The availability of vaccinations against HPV infection is contributing to the decreasing incidence of this disease. This contribution highlights conventional therapies, off-label treatment strategies including combination therapies, and prophylaxis for condylomata acuminata.

Immune Mechanisms of Allergen-Specific Immunotherapy

Allergen immunotherapy (AIT) has the exclusive ability to modify the natural history of allergy and to maintain its clinical efficacy also after stopping the treatment. This occurs because of the AIT mechanism of action, mainly consisting in a specific induction of tolerance to the causative allergen. Such tolerance takes place as a result of a complex interaction of innate and adaptive immunity processes, that involve inflammatory cells, cytokines and chemokines. The first response to allergens is provided by the antigen-presenting cells, and particularly by dendritic cells (Dcs) that, following activation, acquire chemokine receptors (CCRs), useful for migration to lymphoid organs, where adaptive immune response is induced. DCs act by presenting the antigen(s) to effectors T cells (T helper CD4 + and T suppressor CD8 +) derived from naïve T cells. The development of different cell subtypes from naïve T cells (Th0) may follow various pathways and depends on both individual genetic background (atopic/non atopic) and environmental factors. The T cell response in atopic subjects is influenced by the Th2 polarization promoting the production of cytokines such as IL-4 and IL- 5. On the contrary, the expression of CD80 may determine a Th1 cytokines production, and ICOS-L supports the Tregulatory cells activation that significantly reduce allergic inflammation. The suppressive effect of Treg is due to the expression of high level of the transcription factor Foxp3 on their surface, to the production of IL-10 and TGF-ß and to the expression of membrane molecules as CTL-4 PD-1 and BTLA. Recent advances highlighted a role also for Th9 and Th17 lymphocytes. Such immunologic modification leads to the long noted events in studies on mechanisms of action, such as the decrease of specific IgE and the increase of specific IgG1 and IgG4, and ultimately on the inhibition of inflammatory cells such as mast cells, basophils and eosinophils and on the control of clinical symptoms.

Phase I study of MVE-2 evaluating toxicity and biologic response modification capability.

A total of 21 patients were treated in a phase I trial using the biological response modifier MVE-2, a low molecular weight component of pyran copolymer. All patients received weekly IV MVE-2 infused over 2 h. Proteinuria, sometimes of nephrotic proportions, was the dose limiting toxicity, and was seen with increasing incidence as the cumulative dose of MVE-2 exceeded 2500 mg. Other toxicity with MVE-2 was minimal. Biologic response modification at tolerable doses was inconsistent, although several assays, particularly natural cell-mediated cytotoxicity, indicated enhanced activity at higher dosages of MVE-2. No objective tumor responses were observed. MVE-2 is not useful as a biological response modifier using our initial method of administration, since the dose limiting toxicity occurred at lower levels than were necessary to induce consistent biologic response modification. Following completion of the phase I study, we administered MVE-2 by 30-min infusion to 8 additional patients and did not detect proteinuria, in spite of large cumulative doses. It is possible that alternate schedules of MVE-2 administration could minimize proteinuria and allow the administration of dosages necessary for immunologic modification.

Immunologic modification: a basic survival mechanism.

Immunologic modification: a basic survival mechanism.

DRUGS EMPLOYED FOR THE SUPPRESSION OF IMMUNOLOGIC RESPONSIVENESS.

SCINCE the grafting of organs between genetically nonidentical individuals uniformly leads to immunologic reaction against the graft and its subsequent death and rejection, successful homotransplantation requires immunologic modification of the recipient. At the time of writing such suppression of immunologic reactivity has been most readily obtained with drugs. It should be remarked at the outset that immunologic suppression either with drugs or by any other means is not a simple or well understood event. The complexity arises from the phenomenon of tolerance1 originally observed in neonatal animals by Medawar, but now recognized as occurring under a variety of circumstances in . . .