The future of cellular therapy for the treatment of renal cell carcinoma.

INTRODUCTION: Systemic treatment options for renal cell carcinoma (RCC) have expanded considerably in recent years, and both tyrosine kinase inhibitors and immune checkpoint inhibitors, alone or in combination, have entered the clinical arena. Adoptive cell immunotherapies have recently revolutionized the treatment of cancer and hold the promise to further advance the treatment of RCC. AREAS COVERED: In this review, we summarize the latest preclinical and clinical development in the field of adoptive cell immunotherapy for the treatment of RCC, focusing on lymphokine-activated killer (LAK) cells, cytokine induced killer (CIK) cells, tumor-infiltrating T cells (TILs), TCR-engineered T cells, chimeric antigen receptor (CAR) T cells and dendritic cell vaccination strategies. Perspectives on emerging cellular products including CAR NK cells, CAR macrophages as well as γδ T cells are also included. EXPERT OPINION: So far, areas of greater therapeutic success of adoptive cell therapies include the adjuvant administration of CIK cells and the transfer of anti-CD70 CAR T cells in patients with metastatic RCC. Bench to bedside and back research will be needed to overcome current limitations of adoptive cell therapies in RCC, primarily aiming at improving the safety of immune cell products, optimizing their antitumor activity and generating off-the-shelf products ready for clinical use.

The current status of somatostatin analogs in the treatment of neuroendocrine tumors and future perspectives.

INTRODUCTION: Somatostatin analogs (SSAs) were developed as antisecretory agents to palliate hormonal symptoms in patients with functioning neuroendocrine tumors (NETs). Their antiproliferative activity has been established in the phase 3 PROMID and CLARINET trials. SSAs currently represent the standard first-line therapy for the majority of well-differentiated G1/G2 gastroenteropancreatic NETs as well as for pulmonary NETs. AREAS COVERED: An update on the clinical applications of established SSAs for the treatment of NETs is provided. Perspectives on emerging nonpeptide SSAs such as paltusotine and innovative formulations of octreotide (CAM2029) are included. EXPERT OPINION: SSAs represent the cornerstone of treatment for both functioning and nonfunctioning NETs. While standard-dose SSAs have a defined place in the therapeutic algorithm of well-differentiated NETs, uncertainties remain on how to best integrate above-label doses of SSAs in the treatment sequence, particularly when tumor control is the goal. Octreotide and lanreotide appear to be clinically interchangeable, and no signs of superiority of one agent over the other has been observed so far. Whether SSAs may be exploited in the maintenance setting following more aggressive treatments, whether continuing SSAs beyond-progression after first-line therapy could be an effective treatment strategy, and whether new-generation SSAs such as pasireotide could overcome resistance to established SSAs are key areas of investigation.

Cannabidiol modulation of immune cell function: in vitro insights and therapeutic implications for atopic dermatitis.

Introduction: Cannabidiol (CBD) exhibits neuroprotective, anti-inflammatory, and immunomodulatory properties, making it a promising candidate for addressing inflammatory skin disorders like atopic dermatitis. Aim: This study aimed to (i) investigate CBD's impact on lymphocyte proliferation and lymphocyte viability; (ii) assess in vitro cytotoxicity U937 cells (a human promonocytic cell line) of CBD/cytotoxicity of CBD on U937 cells; (iii) provide insights into CBD immunomodulatory potential, and (iv) evaluate suitability of CBD for treating inflammatory skin conditions. Material and methods: To this aim PBMCs from healthy donors were cultured with mitogen and two different CBD doses (0.1 and 1 mg/ml), assessing B and T cell proliferation through flow cytometry. CBD inhibited mitogen-induced lymphocyte proliferation, reducing the percentage of proliferating T and B cells. Notably, both CBD doses did not exhibit cytotoxicity on lymphocytes as revealed by viability assessment. We also analysed the effect of CBD on U937 cells using an optical microscopy approach. Interestingly, the higher dose of CBD exerted a cytotoxic effect on U937 cells, while the lower dose was well tolerated. Results: We analysed the effect of an adjuvant treatment for atopic dermatitis with a CBD-containing cleansing cream in reducing itch. Notably, the treatment with the CBD-containing cleansing cream significantly reduced itch in patients suffering from atopic dermatitis. Conclusions: These findings affirm CBD's immunomodulatory characteristics, emphasizing its potential therapeutic application in inflammatory skin disorders.

Frequency of Euroglyphus maynei sensitization in respiratory allergies: a real-life study with bioinformatic analysis and geographical exploration of allergen prevalence.

BACKGROUND: Dermatophagoides pteronyssinus and Dermatophagoides farinae belong to the family Pyroglyphidae (subfamily: "Dermatophagoidinae") and have the respective allergenic proteins of Der p1, Der p2, and Der p23 and Der f1 and Der f2. Euroglyphus maynei, belongs to the family Pyroglyphidae (subfamily: "Pyroglyphinae") and its main allergenic protein is Eur m1, a source of sensitization. Sensitization to D. pteronyssinus and D. farinae is assessed through skin tests, while sensitization to E. maynei is assessed less frequently. OBJECTIVE: This experimental work aims to analyze the prevalence of sensitization to E. maynei in patients with respiratory allergies treated at M. Albanesi Allergy and Immunology Unit in Bari, Italy, and the sequence homology of major allergenic proteins of E. maynei with D. farinae and D. pteronyssinus was analyzed. METHODS: In this real-life study, 65 patients were enrolled. In particular, patients with respiratory allergy were subjected to skin prick tests for common respiratory allergens, including Euroglyphus maynei. The sequence homology analysis was performed between the major allergenic proteins of E. maynei and those of D. pteronyssinus and D. farinae. RESULTS: Sensitization to E. maynei accounts for 41.5% of patients. All patients with E. maynei sensitization had concomitant sensitization to D. farinae and D. pteronyssinus. The analysis of sequence homology of Der p1 and Der f1 proteins with the sequence of Eur m1 protein demonstrated an identity of 84.4% and 86%, respectively. CONCLUSIONS: Nearly 50% of house dust mites-sensitized patients have a concomitant sensitization to E. maynei. The cross-sensitization could be due to Der f1, Der p1, and Eur m1 similarity.

Angiogenesis in NENs, with a focus on gastroenteropancreatic NENs: from biology to current and future therapeutic implications.

Neuroendocrine neoplasms (NENs) are highly vascularized malignancies arising from cells of the diffuse neuroendocrine system. An intricated cross-talk exists between NEN cells and the tumor microenvironment, and three main molecular circuits (VEGF/VEGFR pathway, FGF-dependent signaling and PDGF/PDGFR axis) have been shown to regulate angiogenesis in these neoplasms. Multiple randomized trials have investigated antiangiogenic agents over the past two decades, and sunitinib is currently approved for the treatment of advanced, progressive, G1/G2 pancreatic NENs. In recent years, two phase III clinical trials have demonstrated the efficacy and safety of surufatinib, a multi-tyrosine kinase angioimmune inhibitor, in patients with well-differentiated pancreatic and extrapancreatic NENs, and two studies of this agent are currently underway in Europe and US. The HIF-2α inhibitor belzutifan has recently received regulatory approval for the treatment of tumors arising in the context of Von-Hippel Lindau syndrome including pancreatic NENs, and a study of this drug in patients with sporadic tumors is presently ongoing. Combinations of antiangiogenic agents with chemotherapeutics and targeted drugs have been tested, with accumulating toxicities being a matter of concern. The potential of antiangiogenic agents in fine-tuning the immune microenvironment of NENs to enhance the activity of immune checkpoint inhibitors has been only partially elucidated, and further research should be carried out at this regard. Here, we review the current understanding of the biology of angiogenesis in NENs and provide a summary of the latest clinical investigations on antiangiogenic drugs in this malignancy.

Direct and Indirect Effect of TGFß on Treg Transendothelial Recruitment in HCC Tissue Microenvironment.

The balance between anti-tumor and tumor-promoting immune cells, such as CD4+ Th1 and regulatory T cells (Tregs), respectively, is assumed to dictate the progression of hepatocellular carcinoma (HCC). The transforming growth factor beta (TGFß) markedly shapes the HCC microenvironment, regulating the activation state of multiple leukocyte subsets and driving the differentiation of cancer associated fibroblasts (CAFs). The fibrotic (desmoplastic) reaction in HCC tissue strongly depends on CAFs activity. In this study, we attempted to assess the role of TGFß on transendothelial migration of Th1-oriented and Treg-oriented CD4+ T cells via a direct or indirect, CAF-mediated mechanisms, respectively. We found that the blockage of TGFß receptor I-dependent signaling in Tregs resulted in impaired transendothelial migration (TEM) of these cells. Interestingly, the secretome of TGFß-treated CAFs inhibited the TEM of Tregs but not Th1 cells, in comparison to the secretome of untreated CAFs. In addition, we found a significant inverse correlation between alpha-SMA and FoxP3 (marker of Tregs) mRNA expression in a microarray analysis involving 78 HCCs, thus suggesting that TGFß-activated stromal cells may counteract the trafficking of Tregs into the tumor. The apparent dual behavior of TGFß as both pro- and anti-tumorigenic cytokines may add a further level of complexity to the mechanisms that regulate the interactions among cancerous, stromal, and immune cells within HCC, as well as other solid tumors, and contribute to better manipulation of the TGFß signaling as a therapeutic target in HCC patients.

Tumor Infiltrating T Cell Cytotoxicity Assay.

Cytotoxicity is the primary function of CD8+ T-cells, also called cytotoxic CD8+ T lymphocytes (or CTLs). Quantification of this capacity is of major importance in diagnostic and research tools. While phenotypic characterization of CTLs is frequent and easily performed, their function is indeed more difficult to assess. CTLs are responsible for the lysis of cells expressing foreign or modified antigen peptides on their MHC class I molecules. Here we describe the detailed protocol used for the in vitro specific lysis of target cells.

Antigen-Specific In Vivo Killing Assay.

The in vivo killing assay allows the quantification of the antigen-specific killing capacity of Cytotoxic CD8+ T Lymphocytes (CTLs) in mice. CTLs are indeed known for the lysis of cells expressing foreign or modified antigen peptides on their MHC class I molecules. Here we describe the detailed protocol used for the in vivo specific lysis of cells expressing the H-2 Kb immunodominant CD8+ T-cell epitope of the OVA protein: an 8 amino acid peptide corresponding to the 257-264 region of OVA (SIINFEKL).

High levels of gut-homing immunoglobulin A+ B lymphocytes support the pathogenic role of intestinal mucosal hyperresponsiveness in immunoglobulin A nephropathy patients.

BACKGROUND: Immunoglobulin A nephropathy (IgAN) is the most frequent primary glomerulonephritis. The role of the microbiota and mucosal immunity in the pathogenesis of IgAN remains a key element. To date, the hypothetical relationship between commensal bacteria, elevated tumour necrosis factor (TNF) superfamily member 13 [also known as B-cell activating factor (BAFF)] levels, perturbed homoeostasis of intestinal-activated B cells and intestinal IgA class switch has not been clearly shown in IgAN patients. METHODS: We studied the intestinal-renal axis connections, analysing levels of BAFF, TNF ligand superfamily member 13 (APRIL) and intestinal-activated B cells in IgAN patients, healthy subjects (HSs) and patients with non-IgA glomerulonephritides. RESULTS: IgAN patients had increased serum levels of BAFF cytokine, correlating with higher amounts of five specific microbiota metabolites, and high APRIL cytokine serum levels. We also found that subjects with IgAN have a higher level of circulating gut-homing (CCR9+ ß7 integrin+) regultory B cells, memory B cells and IgA+ memory B cells compared with HSs. Finally, we found that IgAN patients had high levels of both total plasmablasts (PBs) and intestinal-homing PBs. Interestingly, PBs significantly increased in IgAN but not in patients with other glomerulonephritides. CONCLUSIONS: Our results demonstrate a significant difference in the amount of intestinal-activated B lymphocytes between IgAN patients and HSs, confirming the hypothesis of the pathogenic role of intestinal mucosal hyperresponsiveness in IgAN. The intestinal-renal axis plays a crucial role in IgAN and several factors may contribute to its complex pathogenesis and provide an important area of research for novel targeted therapies to modulate progression of the disease.

Safety of measles, mumps, and rubella vaccine in egg allergy: in vivo and in vitro management.

BACKGROUND: Egg allergy is the second most prevalent form of food allergy in childhood. In spite of the evidence accumulated, inoculating egg allergy children with attenuated vaccines grown on chick embryo cell cultures, such as the measles, mumps, and rubella (MMR) vaccine, is regarded (erroneously) as potentially dangerous or even anaphylactogenic, by many. An issue perceived as particularly conflicting also by Health Professionals. CASE PRESENTATION: A 15-year-old boy, with a history of severe egg allergy in early infancy, who was still sensitized to egg allergens, including baked egg, had never received MMR vaccination, in fear of possible anaphylaxis, in spite of the fact that this vaccination is mandatory in the first year of life, in Italy. Because of that, he was not allowed to attend school, longer, and was referred to us in order to assess the potential risk of MMR vaccination. Upon thorough allergologic workup, sensitization to MMR vaccine components was excluded by an in vivo approach, consisting in skin prick tests, intradermal tests, and subcutaneous injection test, corroborated by vaccine-specific B-lymphocyte proliferation assay, ex vivo. T-cell proliferation in response to MMR vaccine was also excluded. Eventually, the boy was inoculated with MMR vaccine and was readmitted to school. CONCLUSIONS: The diagnostic strategy adopted appears feasible and easy-to-perform and may be adopted in controversial cases (as the one reported), characterized by previous severe allergic reactions to egg. The B-lymphocyte proliferation assay we developed may represent a useful and reliable tool not only in research but also in clinical practice.

Impaired Anti-Tumor T cell Response in Hepatocellular Carcinoma.

Different subsets of lymphocytes have the capacity to promote or counteract the progression of solid cancers, including hepatocellular carcinoma (HCC). Therefore, to determine the infiltrative ability and functional status of major immune cell subtypes into tumor may lead to novel insights from the perspective of immunotherapy. After obtaining single cell suspensions from freshly collected specimens of HCC tumor, along with paired peritumor tissues and peripheral blood mononuclear cells (PBMCs) from 14 patients, we flow-cytometrically identified and quantified the relative frequencies of lymphocyte subsets within the tissues of origin. We found that the recruitment in the tumor of cytotoxic cells, namely the terminally differentiated CD4+ and CD8+ T cells (TEFF), is impaired, whereas the effector memory CD4+ T cells (TEM) are more attracted in this site. Concerning the other subsets, the frequency of NK CD56hi and NKT CD56hi cells infiltration in the tumor is increased, whereas that of NKT CD56low is reduced. Although CD4+ and CD8+ T cells settled in the tumor show a higher degree of activation than the circulating counterpart, they occur with a more exhausted phenotype. Overall, these data demonstrate the prevalently immunosuppressive nature of HCC microenvironment, and prompt us to search for strategies to enhance the activity of anti-tumor immune cell subsets.

Adult Renal Stem/Progenitor Cells Can Modulate T Regulatory Cells and Double Negative T Cells.

Adult Renal Stem/Progenitor Cells (ARPCs) have been recently identified in the human kidney and several studies show their active role in kidney repair processes during acute or chronic injury. However, little is known about their immunomodulatory properties and their capacity to regulate specific T cell subpopulations. We co-cultured ARPCs activated by triggering Toll-Like Receptor 2 (TLR2) with human peripheral blood mononuclear cells for 5 days and 15 days and studied their immunomodulatory capacity on T cell subpopulations. We found that activated-ARPCs were able to decrease T cell proliferation but did not affect CD8+ and CD4+ T cells. Instead, Tregs and CD3+ CD4- CD8- double-negative (DN) T cells decreased after 5 days and increased after 15 days of co-culture. In addition, we found that PAI1, MCP1, GM-CSF, and CXCL1 were significantly expressed by TLR2-activated ARPCs alone and were up-regulated in T cells co-cultured with activated ARPCs. The exogenous cocktail of cytokines was able to reproduce the immunomodulatory effects of the co-culture with activated ARPCs. These data showed that ARPCs can regulate immune response by inducing Tregs and DN T cells cell modulation, which are involved in the balance between immune tolerance and autoimmunity.

Maintenance-Phase Subcutaneous Immunotherapy with House Dust Mites Induces Cyclic Immunologic Effects.

BACKGROUND: Subcutaneous immunotherapy (SCIT) is an effective treatment of respiratory allergies including house dust mite (HDM) and Hymenoptera venom allergy. During the build-up phase, the allergen is administered weekly at increasing doses, while during the maintenance phase, it is administered at a fixed high dose every 4 weeks. Upon SCIT injection, the allergen is driven to the draining lymph nodes where it most likely induces an immune response. Immunologic changes are thus supposedly induced at each injection. OBJECTIVES: It is now established that SCIT induces tolerance in the long term, but the precise underlying immunologic mechanisms remain unclear. Therefore, we wanted to analyze the immunologic changes induced in both innate and adaptive immune cells at each individual SCIT administration during the maintenance phase in HDM-allergic patients. More specifically, we wondered whether the changes in regulatory T cell (Treg) and IgE+ B cell percentages, which are observed at the end of a 3-year course of SCIT, already occurred during the maintenance phase and whether these possible changes were sustained. METHODS: We enrolled 6 patients suffering from HDM allergic rhinitis and undergoing maintenance HDM SCIT for 18-24 months. The same SCIT extract was used for all patients. We collected blood samples at 5 time points: T1 (immediately before a given SCIT injection), T2 (9 days after T1), T3 (29 days after T1 and right before the successive administration), T4 (39 days after T1), and T5 (61 days after T1 and just before the next injection). Six non-allergic age-matched healthy individuals were used as controls. Using flow cytometry, we assessed the following cell subsets in peripheral blood mononuclear cells: CD4 and CD8 T cells, Tregs, B cells, IgE+ B cells, NK and NKT cells, and total and activated basophils. RESULTS: HDM-allergic patients displayed increased percentages of CD4 and CD8 T cells and NK cells compared to healthy controls. In contrast, NKT cells, total B cells, and basophils were diminished. These differences were maintained throughout the time course and seemed to be independent of the periodical SCIT injections. On the contrary, Treg percentages were significantly reduced in all HDM-allergic patients at T1. However, they increased at T2 and T4 (9 days after each SCIT injection) but decreased again at T3 and T5, just before the next one, resulting in cyclic changes. IgE+ B cells were significantly increased at T1, even more increased after each administration (T2, T4), and went back to their initial levels at T3 and T5, also resulting in a cyclic pattern. CONCLUSIONS: Our data suggest that during the SCIT maintenance phase, cycles of expansion/contraction of Tregs and IgE+ B cells occur at each SCIT injection. Therefore, the sustained induction of immune tolerance by SCIT, through the increase of Tregs, seems to depend on the periodical exposure to the allergen, at least during the early steady state.

Lack of MHC class II molecules favors CD8+ T-cell infiltration into tumors associated with an increased control of tumor growth.

Regulatory T-cells (Tregs) are crucial for the maintenance of immune tolerance and homeostasis as well as for preventing autoimmune diseases, but their impact on the survival of cancer patients remains controversial. In the TC-1 mouse model of human papillomavirus (HPV)-related carcinoma, we have previously demonstrated that the therapeutic efficacy of the CyaA-E7-vaccine, targeting the HPV-E7 antigen, progressively declines with tumor growth, in correlation with increased intratumoral recruitment of Tregs. In the present study, we demonstrated that these TC-1 tumor-infiltrating Tregs were highly activated, with increased expression of immunosuppressive molecules. Both intratumoral effector CD4+ T-cells (Teffs) and Tregs expressed high levels of PD-1, but anti-PD-1 antibody treatment did not impact the growth of the TC-1 tumor nor restore the therapeutic effect of the CyaA-E7 vaccine. To analyze the mechanisms by which Tregs are recruited to the tumor site, we used MHC-II KO mice with drastically reduced numbers of CD4+ effector T-cells. We demonstrated that these mice still had significant numbers of Tregs in their lymphoid organs which were recruited to the tumor. In MHC-II KO mice, the growth of the TC-1 tumor was delayed in correlation with a strong increase in the intratumoral recruitment of CD8+ T-cells. In addition, in mice that spontaneously rejected their tumors, the infiltration of E7-specific CD8+ T-cells was significantly higher than in MHC-II KO mice with a growing tumor. These results demonstrate that tumor-specific CD8+ T-cells can be efficiently activated and recruited in the absence of MHC class II molecules and of CD4+ T-cell help.

Inflammation induces osteoclast differentiation from peripheral mononuclear cells in chronic kidney disease patients: crosstalk between the immune and bone systems.

Background: Inflammation and immune system alterations contribute to bone damage in many pathologies by inducing the differentiation of osteoclasts (OCs), the bone resorbing cells. This link is largely unexplored in chronic kidney disease (CKD) and haemodialysis (HD) patients, in which reduced renal function is accompanied by an increased inflammatory state and skeletal abnormality. Methods: We used ex vivo culture experiments to investigate the osteoclastogenic potential of peripheral blood mononuclear cells (PBMCs) of CKD and HD patients, focusing on immune cell subsets and inflammatory cytokines such as LIGHT and receptor activator of nuclear factor κB ligand (RANKL). Results: We observed spontaneous osteoclastogenesis with a significant increase in OC formation and bone resorbing activity in late-stage CKD and HD patients when compared with early-stage CKD patients and healthy donors, likely due to an increased expression of RANKL and LIGHT (homologous to Lymphotoxins exhibiting Inducible expression and competing with herpes simplex virus Glycoprotein D for herpes virus entry mediator [HVEM], a receptor expressed by T lymphocytes) in PBMCs. Specific inhibition of these cytokines in PBMCs isolated from CKD stages 3b-5 and HD patients induced the reduction of OC formation in vitro. The phenotypic characterization of peripheral blood cells revealed a significant increase of OC precursors (CD14+CD11b+CD51/61+) and CD14+CD16+ monocytes in advanced CKD and HD patients compared with the control group. Conclusions: Our results suggest that circulating inflammatory monocytes from advanced CKD or HD patients trans differentiate into OCs in vitro and play a relevant role in mineral bone disorders and that LIGHT and RANKL represent new potential therapeutic targets in these settings.