Background: The complete response rate of cervical high-grade squamous intraepithelial lesion (cHSIL) patients to imiquimod immunotherapy is approximately 60%. Consequently, many patients are... Show moreBackground: The complete response rate of cervical high-grade squamous intraepithelial lesion (cHSIL) patients to imiquimod immunotherapy is approximately 60%. Consequently, many patients are exposed to unnecessary adverse effects of imiquimod. On the other hand, conventional surgical large loop excision therapy is associated with increased risk of premature births in subsequent pregnancies. An in-depth analysis of the cHSIL immune microenvironment was performed in order to identify and develop a predictive biomarker for response to imiquimod, to maximize therapy efficacy and to avoid adverse effects in patients unlikely to respond. Methods: Biopsies of 35 cHSIL patients, before and 10 weeks on imiquimod treatment, were analyzed by two multispectral seven-color immunofluorescence panels for T cell and myeloid cell composition in relation to treatment response. Based on these results a simplified immunohistochemical detection protocol was developed. Samples were scanned with the Vectra multispectral imaging system and cells were automatically identified using machine learning. Results: The immune microenvironment of complete responders (CR) is characterized by a strong and coordinated infiltration by T helper cells (activated PD1(+)/type 1 Tbet(+)), M1-like macrophages (CD68(+)CD163(-)) and dendritic cells (CD11c(+)) prior to imiquimod. The lesions of non-responders (NRs) displayed a high infiltration by CD3(+)FOXP3(+) regulatory T cells. At 10 weeks on imiquimod, a strong influx of intraepithelial and stromal CD4(+) T cells was observed in CR but not NR patients. A steep decrease in macrophages occurred both in CR and NR patients, leveling the pre-existing differences in myeloid cell composition between the two groups. Based on the pre-existing immune composition differences, the sum of intraepithelial CD4 T cell, macrophage and dendritic cell counts was used to develop a quantitative simplified one color immunohistochemical biomarker, the CHSIL immune biomarker for imiquimod (CIBI), which can be automatically and unbiasedly quantified and has an excellent predictive capacity (receiver operating characteristic area under the curve 0.95, p<0.0001). Conclusion: The capacity of cHSIL patients to respond to imiquimod is associated with a pre-existing coordinated local immune process, fostering an imiquimod-mediated increase in local T cell infiltration. The CIBI immunohistochemical biomarker has strong potential to select cHSIL patients with a high likelihood to experience a complete response to imiquimod immunotherapy. Show less
Abdulrahman, Z.; Santegoets, S.J.; Sturm, G.; Charoentong, P.; Ijsselsteijn, M.E.; Somarakis, A.; ... ; Burg, S.H. van der 2022
Background The composition of the tumor immune microenvironment (TIME) associated with good prognosis generally also predicts the success of immunotherapy, and both entail the presence of pre... Show moreBackground The composition of the tumor immune microenvironment (TIME) associated with good prognosis generally also predicts the success of immunotherapy, and both entail the presence of pre-existing tumor-specific T cells. Here, the blueprint of the TIME associated with such an ongoing tumor-specific T-cell response was dissected in a unique prospective oropharyngeal squamous cell carcinoma (OPSCC) cohort, in which tumor-specific tumor-infiltrating T cells were detected (immune responsiveness (IR+)) or not (lack of immune responsiveness (IR-)). Methods A comprehensive multimodal, high-dimensional strategy was applied to dissect the TIME of treatment-naive IR+ and IR- OPSCC tissue, including bulk RNA sequencing (NanoString), imaging mass cytometry (Hyperion) for phenotyping and spatial interaction analyses of immune cells, and combined single-cell gene expression profiling and T-cell receptor (TCR) sequencing (single-cell RNA sequencing (scRNAseq)) to characterize the transcriptional states of clonally expanded tumor-infiltrating T cells. Results IR+ patients had an excellent survival during >10 years follow-up. The tumors of IR+ patients expressed higher levels of genes strongly related to interferon gamma signaling, T-cell activation, TCR signaling, and mononuclear cell differentiation, as well as genes involved in several immune signaling pathways, than IR- patients. The top differently overexpressed genes included CXCL12 and LTB, involved in ectopic lymphoid structure development. Moreover, scRNAseq not only revealed that CD4(+) T cells were the main producers of LTB but also identified a subset of clonally expanded CD8(+) T cells, dominantly present in IR+ tumors, which secreted the T cell and dendritic cell (DC) attracting chemokine CCL4. Indeed, immune cell infiltration in IR+ tumors is stronger, highly coordinated, and has a distinct spatial phenotypical signature characterized by intratumoral microaggregates of CD8(+)CD103(+) and CD4(+) T cells with DCs. In contrast, the IR- TIME comprised spatial interactions between lymphocytes and various immunosuppressive myeloid cell populations. The impact of these chemokines on local immunity and clinical outcome was confirmed in an independent The Cancer Genome Atlas OPSCC cohort. Conclusion The production of lymphoid cell attracting and organizing chemokines by tumor-specific T cells in IR+ tumors constitutes a positive feedback loop to sustain the formation of the DC-T-cell microaggregates and identifies patients with excellent survival after standard therapy. Show less
Duurland, C.L.; Santegoets, S.J.; Abdulrahman, Z.; Loof, N.M.; Sturm, G.; Wesselink, T.H.; ... ; Burg, S.H. van der 2022
Background Expression of killer cell lectin-like receptor B1 (KLRB1), the gene encoding the cell surface molecule CD161, is associated with favorable prognosis in many cancers. CD161 is expressed... Show moreBackground Expression of killer cell lectin-like receptor B1 (KLRB1), the gene encoding the cell surface molecule CD161, is associated with favorable prognosis in many cancers. CD161 is expressed by several lymphocyte populations, but its role and regulation on tumor-specific CD4+ T cells is unknown. Methods We examined the clinical impact of CD4+CD161+ T cells in human papillomavirus (HPV)16+ oropharyngeal squamous cell carcinoma (OPSCC), analyzed their contribution in a cohort of therapeutically vaccinated patients and used HPV16-specific CD4+CD161+ tumor-infiltrating lymphocytes and T cell clones for in-depth mechanistic studies. Results Central and effector memory CD4+ T cells express CD161, but only CD4+CD161+ effector memory T cells (Tem) are associated with improved survival in OPSCC. Therapeutic vaccination activates and expands type 1 cytokine-producing CD4+CD161+ effector T cells. The expression of CD161 is dynamic and follows a pattern opposite of the checkpoint molecules PD1 and CD39. CD161 did not function as an immune checkpoint molecule as demonstrated using multiple experimental approaches using antibodies to block CD161 and gene editing to knockout CD161 expression. Single-cell transcriptomics revealed KLRB1 expression in many T cell clusters suggesting differences in their activation. Indeed, CD4+CD161+ effector cells specifically expressed the transcriptional transactivator SOX4, known to enhance T cell receptor (TCR) signaling via CD3 epsilon. Consistent with this observation, CD4+CD161+ cells respond more vigorously to limiting amounts of cognate antigen in presence of interleukin (IL)-12 and IL-18 compared to their CD161- counterparts. The expression of CD161/KLRB1 and SOX4 was downregulated upon TCR stimulation and this effect was boosted by transforming growth factor (TGF)beta 1. Conclusion High levels of CD4+CD161+ Tem are associated with improved survival and our data show that CD161 is dynamically regulated by cell intrinsic and extrinsic factors. CD161 expressing CD4+ T cells rapidly respond to suboptimal antigen stimulation suggesting that CD161, similar to SOX4, is involved in the amplification of TCR signals in CD4+ T cells. Show less
Immunotherapy of vulvar high-grade squamous intraepithelial lesion (vHSIL) is investigated as an alternative for surgery, because of high comorbidity and risk of recurrence. Limited evidence exists... Show moreImmunotherapy of vulvar high-grade squamous intraepithelial lesion (vHSIL) is investigated as an alternative for surgery, because of high comorbidity and risk of recurrence. Limited evidence exists on the role and composition of the immune microenvironment in current immunotherapeutic approaches for vHSIL. The vHSIL of 29 patients biopsied before treatment with imiquimod were analyzed by two multiplex seven-color immunofluorescence panels to investigate the pre-existing T-cell and myeloid cell composition in relation to treatment response. The samples were scanned with the Vectra multispectral imaging system. Cells were automatically phenotyped and counted with inForm advanced image analysis software. Cell counts and composition were compared to that of vHSIL patients before therapeutic vaccination (n = 29) and to healthy vulva (n = 27). Our data show that the immune microenvironment of complete responders (CR) to imiquimod resembled the coordinated infiltration with type 1 CD4(+)and CD8(+)T cells and CD14(+)inflammatory myeloid cells also found in healthy vulva. However, more CD8(+)T cells and FoxP3(+)regulatory T cells were present in CR. The lesions of partial responders (PR) lacked such a coordinated response and displayed an impaired influx of CD14(+)inflammatory myeloid cells. Importantly, complete responses after imiquimod or therapeutic vaccination showed the same dependency on a pre-existing coordinated type 1 T-cell and CD14(+)myeloid cell infiltration. In conclusion, a good clinical outcome after two different forms of immunotherapy for vHSIL is associated with the presence of a primary inflammatory process resulting in the coordinated influx of several types of immune cells which is then amplified. Show less
Nejad, E.B.; Labrie, C.; Abdulrahman, Z.; Elsas, M.J. van; Rademaker, E.; Kleinovink, J.W.; ... ; Burg, S.H. van der 2020
Background Immunotherapy of cancer is successful but tumor regression often is incomplete and followed by escape. Understanding the mechanisms underlying this acquired resistance will aid the... Show moreBackground Immunotherapy of cancer is successful but tumor regression often is incomplete and followed by escape. Understanding the mechanisms underlying this acquired resistance will aid the development of more effective treatments. Methods We exploited a mouse model where tumor-specific therapeutic vaccination results in tumor regression, followed by local recurrence and resistance. In depth studies on systemic, local and tumor intrinsic changes were performed with flow and mass cytometry, immunohistochemistry, transcriptomics and several perturbation studies with inhibitors or agonistic antibodies in mice. Main findings were recapitulated in vaccinated patients. Results Full tumor regression and cure of tumor-bearing mice is dependent on the magnitude of the vaccine-induced T-cell response. Recurrence of tumors did not involve classical immune escape mechanisms, such as antigen-presentation alterations, immune checkpoint expression, resistance to killing or local immune suppression. However, the recurrent tumors displayed a changed transcriptome with alterations in p53, tumor necrosis factor-alpha and transforming growth factor-beta signaling pathways and they became immunologically cold. Remarkably, ex vivo cell-sorted recurrent tumors, directly reinjected in naive hosts retained their resistance to vaccination despite a strong infiltration with tumor-specific CD8(+)T cells, similar to that of vaccine-responsive tumors. The influx of inflammatory mature myeloid effector cells in the resistant tumors, however, was impaired and this turned out to be the underlying mechanisms as restoration of inflammatory myeloid cell infiltration reinstated the sensitivity of these refractory tumors to vaccination. Notably, impaired myeloid cell infiltration after vaccination was also associated with vaccine resistance in patients. Conclusion An immunotherapy-induced disability of tumor cells to attract innate myeloid effector cells formed a major mechanism underlying immune escape and acquired resistance. These data not only stresses the importance of myeloid effector cells during immunotherapy but also demands for new studies to harness their tumoricidal activities. Show less
Abdulrahman, Z.; Miranda, N. de; Esch, E.M.G. van; Steenwijk, P.J.D. van; Nijman, H.W.; Welters, M.J.P.; ... ; Burg, S.H. van der 2020
BackgroundVulvar high-grade squamous intraepithelial lesion (vHSIL) is predominantly induced by high-risk human papilloma virus type 16 (HPV16). In two independent trials, therapeutic vaccination... Show moreBackgroundVulvar high-grade squamous intraepithelial lesion (vHSIL) is predominantly induced by high-risk human papilloma virus type 16 (HPV16). In two independent trials, therapeutic vaccination against the HPV16 E6 and E7 oncoproteins resulted in objective partial and complete responses (PRs/CRs) in half of the patients with HPV16(+) vHSIL at 12-month follow-up. Here, the prevaccination and postvaccination vHSIL immune microenvironment in relation to the vaccine-induced clinical response was investigated.MethodsTwo novel seven-color multiplex immunofluorescence panels to identify T cells (CD3, CD8, Foxp3, Tim3, Tbet, PD-1, DAPI) and myeloid cells (CD14, CD33, CD68, CD163, CD11c, PD-L1, DAPI) were designed and fully optimized for formalin-fixed paraffin-embedded tissue. 29 prevaccination and 24 postvaccination biopsies of patients with vHSIL, and 27 healthy vulva excisions, were stained, scanned with the Vectra multispectral imaging system, and automatically phenotyped and counted using inForm advanced image analysis software.ResultsHealthy vulvar tissue is strongly infiltrated by CD4 and CD8 T cells expressing Tbet and/or PD-1 and CD14(+)HLA-DR+ inflammatory myeloid cells. The presence of such a coordinated pre-existing proinflammatory microenvironment in HPV16(+) vHSIL is associated with CR after vaccination. In partial responders, a disconnection between T cell and CD14(+) myeloid cell infiltration was observed, whereas clinical non-responders displayed overall lower immune cell infiltration. Vaccination improved the coordination of local immunity, reflected by increased numbers of CD4(+)Tbet(+) T cells and HLA-DR(+)CD14(+) expressing myeloid cells in patients with a PR or CR, but not in patients with no response. CD8(+) T cell infiltration was not increased after vaccination.ConclusionA prevaccination inflamed type 1 immune contexture is required for stronger vaccine-induced immune infiltration and is associated with better clinical response. Therapeutic vaccination did not overtly increase immune infiltration of cold lesions. Show less
Kortekaas, K.E.; Santegoets, S.J.; Abdulrahman, Z.; Ham, V.J. van; Tol, M. van der; Ehsan, I.; ... ; Burg, S.H. van der 2019
Checkpoint blockade immunotherapies have revolutionised cancer treatment in the last decade. Nevertheless, these are only beneficial for a small proportion of cancer patients. Important... Show moreCheckpoint blockade immunotherapies have revolutionised cancer treatment in the last decade. Nevertheless, these are only beneficial for a small proportion of cancer patients. Important prognosticators for response to immunotherapy are the mutation burden of tumours as well as the quality and quantity of tumour-infiltrating immune cells. High-throughput multiplex immunophenotyping technologies have a central role in deciphering the complexity of anti-tumour immune responses. Current techniques for the immunophenotyping of solid tumours are held back by the lack of spatial context, limitations in the number of targets that can be visualised simultaneously, and/or cumbersome protocols. We developed a tyramide signal amplification-free method for the simultaneous detection of seven cellular targets by immunofluorescence. This method overcomes limitations posed by most widespread techniques and provides a unique tool for extensive phenotyping by multispectral fluorescence microscopy. Furthermore, it can be easily implemented as a high-throughput technology for validation of discovery sets generated by RNA sequencing or mass cytometry and may serve in the future as a complementary diagnostic tool. Show less
Abdulrahman, Z.; Kortekaas, K.E.; Steenwijk, P.J.D. van; Burg, S.H. van der; Poelgeest, M.I.E. van 2018
