Clinico-biological refinement of BCL11B-related disorder and identification of an episignature: A series of 20 unreported individuals

PURPOSE

BCL11B-related disorder (BCL11B-RD) arises from rare genetic variants within the BCL11B gene, resulting in a distinctive clinical spectrum encompassing syndromic neurodevelopmental disorder, with or without intellectual disability, associated with facial features and impaired immune function. This study presents an in-depth clinico-biological analysis of 20 newly reported individuals with BCL11B-RD, coupled with a characterization of genome-wide DNA methylation patterns of this genetic condition.

METHODS

Through an international collaboration, clinical and molecular data from 20 individuals were systematically gathered, and a comparative analysis was conducted between this series and existing literature. We further scrutinized peripheral blood DNA methylation profile of individuals with BCL11B-RD, contrasting them with healthy controls and other neurodevelopmental disorders marked by established episignature.

RESULTS

Our findings unveil rarely documented clinical manifestations, notably including Rubinstein-Taybi-like facial features, craniosynostosis, and autoimmune disorders, all manifesting within the realm of BCL11B-RD. We refine the intricacies of T cell compartment alterations of BCL11B-RD, revealing decreased levels naive CD4+ T cells and recent thymic emigrants while concurrently observing an elevated proportion of effector-memory expressing CD45RA CD8+ T cells (TEMRA). Finally, a distinct DNA methylation episignature exclusive to BCL11B-RD is unveiled.

CONCLUSION

This study serves to enrich our comprehension of the clinico-biological landscape of BCL11B-RD, potentially furnishing a more precise framework for diagnosis and follow-up of individuals carrying pathogenic BCL11B variant. Moreover, the identification of a unique DNA methylation episignature offers a valuable diagnosis tool for BCL11B-RD, thereby facilitating routine clinical practice by empowering physicians to reevaluate variants of uncertain significance within the BCL11B gene.

Comprehensive analysis of current approaches to inhibit regulatory T cells in cancer

CD4⁺CD25⁺Foxp3⁺ regulatory T cells (Treg) have emerged as a dominant T cell population inhibiting anti-tumor effector T cells. Initial strategies used for Treg-depletion (cyclophosphamide, anti-CD25 mAb…) also targeted activated T cells, as they share many phenotypic markers. Current, ameliorated approaches to inhibit Treg aim to either block their function or their migration to lymph nodes and the tumor microenvironment. Various drugs originally developed for other therapeutic indications (anti-angiogenic molecules, tyrosine kinase inhibitors,etc) have recently been discovered to inhibit Treg. These approaches are expected to be rapidly translated to clinical applications for therapeutic use in combination with immunomodulators.

Induction of resident memory T cells enhances the efficacy of cancer vaccine

Tissue-resident memory T cells (Trm) represent a new subset of long-lived memory T cells that remain in tissue and do not recirculate. Although they are considered as early immune effectors in infectious diseases, their role in cancer immunosurveillance remains unknown. In a preclinical model of head and neck cancer, we show that intranasal vaccination with a mucosal vector, the B subunit of Shiga toxin, induces local Trm and inhibits tumour growth. As Trm do not recirculate, we demonstrate their crucial role in the efficacy of cancer vaccine with parabiosis experiments. Blockade of TFGβ decreases the induction of Trm after mucosal vaccine immunization, resulting in the lower efficacy of cancer vaccine. In order to extrapolate this role of Trm in humans, we show that the number of Trm correlates with a better overall survival in lung cancer in multivariate analysis. The induction of Trm may represent a new surrogate biomarker for the efficacy of cancer vaccine. This study also argues for the development of vaccine strategies designed to elicit them.

Mucosal vaccines: novel strategies and applications for the control of pathogens and tumors at mucosal sites

The mucosal immune system displays several adaptations reflecting the exposure to the external environment. The efficient induction of mucosal immune responses also requires specific approaches, such as the use of appropriate administration routes and specific adjuvants and/or delivery systems. In contrast to vaccines delivered via parenteral routes, experimental, and clinical evidences demonstrated that mucosal vaccines can efficiently induce local immune responses to pathogens or tumors located at mucosal sites as well as systemic response. At least in part, such features can be explained by the compartmentalization of mucosal B and T cell populations that play important roles in the modulation of local immune responses. In the present review, we discuss molecular and cellular features of the mucosal immune system as well as novel immunization approaches that may lead to the development of innovative and efficient vaccines targeting pathogens and tumors at different mucosal sites.

Synergy of Radiotherapy and a Cancer Vaccine for the Treatment of HPV-Associated Head and Neck Cancer

There is growing interest in the association of radiotherapy and immunotherapy for the treatment of solid tumors. Here, we report an extremely effective combination of local irradiation (IR) and Shiga Toxin B (STxB)-based human papillomavirus (HPV) vaccination for the treatment of HPV-associated head and neck squamous cell carcinoma (HNSCC). The efficacy of the irradiation and vaccine association was tested using a model of HNSCC obtained by grafting TC-1/luciferase cells at a submucosal site of the inner lip of immunocompetent mice. Irradiation and the STxB-E7 vaccine acted synergistically with both single and fractionated irradiation schemes, resulting in complete tumor clearance in the majority of the treated mice. A dose threshold of 7.5 Gy was required to elicit the dramatic antitumor response. The combined treatment induced high levels of tumor-infiltrating, antigen-specific CD8(+) T cells, which were required to trigger the antitumor activity. Treatment with STxB-E7 and irradiation induced CD8(+) T-cell memory, which was sufficient to exert complete antitumor responses in both local recurrences and distant metastases. We also report for the first time that a combination therapy based on local irradiation and vaccination induces an increased pericyte coverage (as shown by αSMA and NG2 staining) and ICAM-1 expression on vessels. This was associated with enhanced intratumor vascular permeability that correlated with the antitumor response, suggesting that the combination therapy could also act through an increased accessibility for immune cells. The combination strategy proposed here offers a promising approach that could potentially be transferred into early-phase clinical trials.

VEGF-A modulates expression of inhibitory checkpoints on CD8+ T cells in tumors

Immune escape is a prerequisite for tumor development. To avoid the immune system, tumors develop different mechanisms, including T cell exhaustion, which is characterized by expression of immune inhibitory receptors, such as PD-1, CTLA-4, Tim-3, and a progressive loss of function. The recent development of therapies targeting PD-1 and CTLA-4 have raised great interest since they induced long-lasting objective responses in patients suffering from advanced metastatic tumors. However, the regulation of PD-1 expression, and thereby of exhaustion, is unclear. VEGF-A, a proangiogenic molecule produced by the tumors, plays a key role in the development of an immunosuppressive microenvironment. We report in the present work that VEGF-A produced in the tumor microenvironment enhances expression of PD-1 and other inhibitory checkpoints involved in CD8(+) T cell exhaustion, which could be reverted by anti-angiogenic agents targeting VEGF-A-VEGFR. In view of these results, association of anti-angiogenic molecules with immunomodulators of inhibitory checkpoints may be of particular interest in VEGF-A-producing tumors.

VEGF-A modulates expression of inhibitory checkpoints on CD8+ T cells in tumors

VEGF-A production in the tumor microenvironment enhances expression of PD-1 and other inhibitory checkpoints involved with CD8⁺ T cell exhaustion, which can be reversed with anti-VEGF/VEGFR treatment.

Immune escape is a prerequisite for tumor development. To avoid the immune system, tumors develop different mechanisms, including T cell exhaustion, which is characterized by expression of immune inhibitory receptors, such as PD-1, CTLA-4, Tim-3, and a progressive loss of function. The recent development of therapies targeting PD-1 and CTLA-4 have raised great interest since they induced long-lasting objective responses in patients suffering from advanced metastatic tumors. However, the regulation of PD-1 expression, and thereby of exhaustion, is unclear. VEGF-A, a proangiogenic molecule produced by the tumors, plays a key role in the development of an immunosuppressive microenvironment. We report in the present work that VEGF-A produced in the tumor microenvironment enhances expression of PD-1 and other inhibitory checkpoints involved in CD8⁺ T cell exhaustion, which could be reverted by anti-angiogenic agents targeting VEGF-A–VEGFR. In view of these results, association of anti-angiogenic molecules with immunomodulators of inhibitory checkpoints may be of particular interest in VEGF-A-producing tumors.

Mucosal imprinting of vaccine-induced CD8⁺ T cells is crucial to inhibit the growth of mucosal tumors

Although many human cancers are located in mucosal sites, most cancer vaccines are tested against subcutaneous tumors in preclinical models. We therefore wondered whether mucosa-specific homing instructions to the immune system might influence mucosal tumor outgrowth. We showed that the growth of orthotopic head and neck or lung cancers was inhibited when a cancer vaccine was delivered by the intranasal mucosal route but not the intramuscular route. This antitumor effect was dependent on CD8⁺ T cells. Indeed, only intranasal vaccination elicited mucosal-specific CD8⁺ T cells expressing the mucosal integrin CD49a. Blockade of CD49a decreased intratumoral CD8⁺ T cell infiltration and the efficacy of cancer vaccine on mucosal tumor. We then showed that after intranasal vaccination, dendritic cells from lung parenchyma, but not those from spleen, induced the expression of CD49a on cocultured specific CD8⁺ T cells. Tumor-infiltrating lymphocytes from human mucosal lung cancer also expressed CD49a, which supports the relevance and possible extrapolation of these results in humans. We thus identified a link between the route of vaccination and the induction of a mucosal homing program on induced CD8⁺ T cells that controlled their trafficking. Immunization route directly affected the efficacy of the cancer vaccine to control mucosal tumors.

Immunotherapy of HPV-associated head and neck cancer: Critical parameters

Various arguments support the development of a vaccine targeting human papillomavirus (HPV) for the treatment of HPV-associated head and neck cancer. However, the mucosal localization of this tumor, the HPV-driven downregulation of MHC Class I molecules and various other immunosuppressive mechanisms must be carefully considered to improve the clinical efficacy of such an immunotherapeutic strategy.

Abstract 2830: Mucosal imprinting of vaccine induced-CD8+T cells is crucial to inhibit mucosal tumors

Although many human cancers are located in mucosal sites, most cancer vaccines are tested against subcutaneous tumors in preclinical models. The utility of preferentially inducing an anti-tumor immune response in the mucosal anatomic site of tumors has never been addressed. We therefore wondered whether mucosa-specific homing instructions to the immune system might influence mucosal tumor outgrowth. For this purpose, we set up original orthotopic models of head and neck and lung cancers monitored by magnetic resonance imaging or luciferase based in vivo optical imaging and vaccine based on a non replicative delivery system, the B subunit of Shiga toxin (STxB) as mucosal vector which has previously been shown to target antigen to dendritic cells. We showed that the growth of orthotopic head and neck or lung cancers expressing the E7 protein from HPV16 was only inhibited, when a cancer vaccine was delivered by the intranasal (i.n) mucosal and not the intramuscular (i.m) route. This anti-tumor effect was dependent on mucosal CD8+T cells as : i) Only a vaccine composed of STxB coupled to an E7 derived polypeptide (STxB-E7), but not the free E7 polypeptide elicited mucosal CD8+T cells. This mucosal induction of anti-E7 CD8+T cells, but not the systemic (spleen) specific anti-E7 CD8+T cells correlated with mucosal tumor protection. ii) A greater mucosal tumor infiltration of CD8+T cells was detected 7 days after tumor graft in mice that had been previously intranasally immunized with STxB-E7, than in mice vaccinated by the i.m. route. iii) CD8+T cell-depleted mice vaccinated with STxB-E7 by the i.n. route died before 20 days, whereas mice survived more than 6 months without CD8 depletion. As control, both routes of vaccine administration controlled the growth of subcutaneous tumors and elicited anti-E7 specific CD8+T cells in the spleen. To explain this finding, we demonstrated that only i.n. vaccination elicited mucosal specific CD8+T cells expressing the mucosal integrin CD49a. Blockade of CD49a decreased intratumoral CD8+T cell infiltration and the efficacy of cancer vaccine on mucosal tumor. We then showed that after intranasal vaccination, only dendritic cell from lung parenchyma, but not from spleen induced the expression of CD49a on co-cultured specific CD8+T cells. Tumor-infiltrating lymphocytes from human mucosal lung cancer also expressed CD49a at higher levels than TIL from non mucosal tumors, supporting the relevance and possible extrapolation of these results in humans. We thus identified a link between the route of vaccination and the induction of a mucosal homing program on induced CD8+T cells controlling their trafficking with a direct application on the efficacy of cancer vaccine to control mucosal tumors.

Citation Format: Federico Sandoval, Mevyn Nizard, Magali Terme, Cecile Badoual, Michel-Francis Bureau, Olivier Clement, Elie Marcheteau, Alain Gey, Estelle Dransart, Françoise Quintin-Colonna, Gwenhael Autret, Tzyy-Choou Wu, Wolf H. Fridman, Ludger Johannes, Eric Tartour. Mucosal imprinting of vaccine induced-CD8+T cells is crucial to inhibit mucosal tumors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2830. doi:10.1158/1538-7445.AM2013-2830

PD-1-expressing tumor-infiltrating T cells are a favorable prognostic biomarker in HPV-associated head and neck cancer

Head and neck cancers positive for human papillomavirus (HPV) have a more favorable clinical outcome than HPV-negative cancers, but it is unknown why this is the case. We hypothesized that prognosis was affected by intrinsic features of HPV-infected tumor cells or differences in host immune response. In this study, we focused on a comparison of regulatory Foxp3(+) T cells and programmed death-1 (PD-1)(+) T cells in the microenvironment of tumors that were positive or negative for HPV, in two groups that were matched for various clinical and biologic parameters. HPV-positive head and neck cancers were more heavily infiltrated by regulatory T cells and PD-1(+) T cells and the levels of PD-1(+) cells were positively correlated with a favorable clinical outcome. In explaining this paradoxical result, we showed that these PD-1(+) T cells expressed activation markers and were functional after blockade of the PD-1-PD-L1 axis in vitro. Approximately 50% of PD-1(+) tumor-infiltrating T cells lacked Tim-3 expression and may indeed represent activated T cells. In mice, administration of a cancer vaccine increased PD-1 on T cells with concomitant tumor regression. In this setting, PD-1 blockade synergized with vaccine in eliciting antitumor efficacy. Our findings prompt a need to revisit the significance of PD-1-infiltrating T cells in cancer, where we suggest that PD-1 detection may reflect a previous immune response against tumors that might be reactivated by PD-1/PD-L1 blockade.

Abstract 5388: Local mucosal CD8+T cell response is required to inhibit the growth of orthotopic head and neck and lung cancers

Tumors may be located at mucosal or non-mucosal sites. However, the clinical benefit of preferentially inducing an anti-tumor immune response in the anatomic site of tumors has never been addressed. We set up orthotopic models of head and neck and lung cancers to compare the systemic and local anti-tumor immune response after administration of a cancer vaccine by mucosal and systemic routes. We also selected a non replicative delivery system, the B subunit of Shiga toxin (STxB), as a mucosal vector able to target dendritic cells. We show that intranasal immunization of mice with STxB based vaccine is the best route to elicit polyfunctional specific CD8+T cells in cervical and mediastinal lymph node than the use of non vectorized antigen or the intramuscular route. In line with these results, nasal mucosal administration of a model tumor antigen (E7 polypeptide from HPV 16) targeted to dendritic cells by STxB is more efficient to inhibit the growth of established orthotopic head and neck and lung cancers expressing the E7 antigen, than the administration of non vectorized antigen or the use of intramuscular route. A higher infiltration of CD8+T cells was detected 7 days after tumor graft, when mice were previously intranasally immunized with STxB-E7, than in mice vaccinated by the intramuscular route. Specific anti-E7 CD8+T cell tumor infiltration, was only observed after nasal immunization. Indeed, depletion of CD8+T cells inhibited the clinical efficiency of tumor vaccine demonstrating their role in tumor protection. In contrast, both routes completely controlled the growth of a subcutaneously E7 expressing tumor, which correlated with a similar induction of anti-E7 CD8+T cells in the spleen. Analysis of Integrin and chemokine receptor expression on tetramere positive cells showed that intranasal immunization induced higher levels of CD103 on T cells in bronchoalveolar lavage than intramuscular immunization with the same vaccine. This study emphasizes the need to elicit a potent anti-tumor response at the anatomic site of tumor and not just in the systemic compartment to induce tumor regression. This was achieved by i) administration of the vaccine by the intranasal route which was efficient in inducing CD8+T cells response at both locoregional and systemic sites allowing the control of both mucosal and non mucosal tumors. ii) The targeting of antigen to dendritic cells by STxB. This study is relevant to humans, as 30% of head and neck cancers express HPV16. Our results support the development of STxB-E7 vaccine administered by the i.n. route for the treatment of these HPV associated head and neck cancers. More generally, this study provides direct evidence for the compartmentalization of tumor immunity, a critical finding for the design of better cancer vaccines.

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 5388. doi:1538-7445.AM2012-5388

[Herniation of a lumbar disk in the elderly. Results of chemonucleolysis]

The purpose of this study was to evaluate the outcome after chymopapain chemonucleolysis in elderly patients with low back pain and sciatica due to lumbar disc herniation without concomitant stenosis, unresponsive to conservative therapy. In the 42 study patients, aged 60 years or older, clinical manifestations were similar to those usually seen in younger patients. Evidence of nerve root tension, including a positive straight-leg raising test seen in 67% of our patients, proved valuable for outruling sciatica due to bony impingement. Outcome was favorable in 78% of cases after a mean follow-up of 2.5 years. This findings is consistent with previous studies performed without age restrictions. Chemonucleolysis had no adverse effects. Despite the biochemical changes which occur in the aging disc, chemonucleolysis is an effective tool for the treatment of sciatica due to disc herniation in elderly patients.

[Results of treatment of habitual laxation of the shoulder with modified surgical technique (author's transl)]

The article describes a modification of the original surgical technique employed by M. Lange in the treatment of habitual laxation of the shoulder. This consists mainly of opening the joint with bone chip implantation under visual control, and turning the spongy side towards the head of the humerus and interpositioning the capsula while tightening the same. In addition, however, the point of insertion of the subscapular tendon is shifted while drawing it tighter also. The article describes the advantages, as seen from the case histories of 57 operations, about one-half being subjected to follow-up examinations over a period of at least 3 years, on the average 9 years. In all patients, excellent to good stabilisation of the shoulder was achieved.

[Technique and results of arthrodesis of the ankle joint with autocompression plates (author's transl)]

The article describes the technique of arthrodesis of the ankle joint, introduced in 1973 by Mittelmeier, with suitable preparation (freshening) of the joint, resection of syndesmoses and internal osteosynthesis with autocompression angle plates, as well as additional fastening by screwing the fibula against tibia and talus. This method imparts high biomechanical stability to the joint thanks to the internal bracing of the frame; compared with external fixation, this method offers the advantage of avoiding the risk of subsequent infection of the borehole, as well as the possibility of early impaired wearing of trousers and of being able to bathe after superficial wound healing. Treatment results achieved in 14 patients showed (despite 1 reinfection following osteomyelitis caused by a fracture due to a bullet wound) regular, rapid and stable osseous reconstruction of the joint in which arthrodesis had been performed. Hence, this technique seems to be superior to external compression arthrodesis in aseptical cases.

[Experiences and results of replacement of the fibulo-talar ligaments in relatively old ankle-joint traumas (author's transl)]

This is a report about the experiences and results of replacement of the fibulo-talar-ligaments by using the peronaeus brevis tendon. The typical anatomic and biomechanic findings are shown as well as the typical traumatisms. The importance of a good primary diagnosis and a good primary treatment is shown. In case of persisting of older instabilities we have the possibility of operative reconstruction. This is a report about 18 patients operated by the technique of Watson-Jones by using the peronaeus brevis tendon. Our results can demonstrate the big values of this technique for operative treatment of chronical fibulo-talar instabilities.

[An original surgical procedure for the treatment of valgus flat foot in children (author's transl)]

A surgical procedure associating a translocation of the peroneus brevis on the tendon of the tibialis posterior and a tightening of the capsule of the Chopart joint is described, for the treatment of valgus flat feet. 38 children (65 feet) have been operated on. The results seem to be favorable.

[Indications, technic and complications of intramedullary nailing in orthopedic view (author's transl)]

After short statement of the present indication and short illustrations of the technics of intramedullary nailing, 41 cases of failure (with the necessity of reoperation) are investigated with demonstrating the observed complications and their causes. Especially were seen malunions, shortening of legs, pseudarthrosis and osteomyelitis and some secondary anchylosis after fractures of metaphysis or comminuted fractures. These results were caused by use of nails with too small diameter and deficient reaming with following insufficient solidity.