Thyroid dysfunction during gestation and gestational diabetes mellitus: a complex relationship

PURPOSE

Gestational diabetes mellitus (GDM) and thyroid dysfunction during gestation (GTD) are the two most prevalent endocrinopathies during pregnancy. The aim of the present review is to provide an overview of the peculiar aspects of GDM and GTD, to highlight the potential interactions and clinical consequences of these two frequent clinical conditions.

METHODS

A literature review regarding GDM and GTD was carried out with particular interest on meta-analyses and human studies dealing with the (i) shared risk factors between GDM and GTD, (ii) the epidemiological link between GTD and GDM, (iii) physiopathologic link between GTD and GDM, (iv) clinical consequences of GDM and GTD, and (v) post-partum implications of GDM and GTD.

RESULTS

The association between GDM and GTD is common and may be explained by the insulin-resistance state due to maternal GTD, to alterations in the placentation process or to the many shared risk factors. Discrepant results of epidemiologic studies can be explained, at least in part, by the changes in diagnostic criteria and screening strategies throughout the years for both conditions. GDM and GTD impact pregnancy outcome and have post-partum long-term consequences, but more studies are needed to prove an additional adverse effect.

CONCLUSIONS

Based on the epidemiological and physio-pathological link between GDM and GTD, it could be suggested that a diagnosis of GTD could lead to screen GDM and the other way round.

Abstract 2950: CD16A shedding facilitates repetitive targeting of tumor cells by AFM13-armed NK cells

Antibody-Dependent Cellular Cytotoxicity (ADCC) is a powerful mechanism of Natural Killer (NK) cells to kill antibody-opsonized target cells. However, ADCC mediated by conventional antibodies has its limitations in killing of tumor cells commonly being characterized by low tumor antigen expression. Several strategies have been implemented to boost ADCC including shedding inhibition of CD16A, a key ADCC-mediating Fc receptor on the plasma membrane of NK cells. However, previous results have shown that genetic engineering of the cleavage site of CD16A leads to decreased serial engagement of target cells. Another approach to boost ADCC is provided by tetravalent-bispecific innate cell engagers (ICE®) cross-linking CD16A and tumor antigens triggering anti-tumoral cytotoxicity.

In the current study, we have investigated whether ICE molecules can induce effective ADCC while maintaining the natural function of CD16A with a particular focus on preserved CD16A shedding. To study cytotoxicity and contact dynamics, we have used an in-house developed live-cell microchip screening with single cell resolution together with a microcontact printing-based assay combined with an ICE®.

Single cell analysis using microchip screening revealed that the CD16A/CD30 targeting ICE® AFM13 induces stronger ADCC of NK cells towards CD30+ target cells when compared to anti-CD30 antibodies. This stronger response was reached through increasing both the overall number of cytotoxic NK cells and the fraction of NK serial killers i.e., NK cells performing three or more kills in sequence. Interestingly, the differences were most prominent towards target cells expressing low levels of CD30.

Combination of AFM13 and inhibition of CD16 shedding increased NK cell conjugation time with target cells, which could potentially limit targeting of additional tumor cells located at a distance from the primary target. To investigate this phenomenon further, we used a microcontact printing assay. Here, a grid of spatially distributed protein patches consisting of AFM13 and anti-LFA-1 was printed on glass surfaces enabling the formation of “artificial immune synapses” when probed by NK cells. On these “artificial immune synapses” we investigated the influence of shedding inhibition on NK cell migration and interaction dynamics.

In conclusion, we show that AFM13 increases both the fraction of tumor-target responsive NK cells and the fraction of serial killing NK cells compared to conventional monoclonal antibodies. Based on our data we hypothesize that CD16A shedding facilitates AFM13 induced ADCC potential of NK cells by allowing potent migration to distantly located tumor cells and serial killing. Especially in the context of AFM13 primary indications, Hodgkin and peripheral T cell lymphoma, migration of NK cells might have a particularly strong impact when treating cancer patients due to the disseminated nature of the disease.

Citation Format: Chiara Zambarda, Karolin Guldevall, Damien Toullec, Susanne Wingert, Christian Breunig, Sheena Pinto, Jacopo Fontana, Joachim Koch, Björn Önfelt. CD16A shedding facilitates repetitive targeting of tumor cells by AFM13-armed NK cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2950.

Wasted leg syndrome: An atypical slowly-progressive form of lower motor neuron disease

We describe four male patients with wasted-leg syndrome, with predominant asymmetric thigh atrophy and weakness that stabilized after a period of slow progression (follow-up 7-18 years). Two patients had an Indian ethnic background and two were Portuguese, without known Indian ancestry. Other mimicking disorders were excluded, but one Indian patient was later diagnosed with CADASIL. Electromyography (EMG) revealed severe chronic neurogenic changes in proximal leg muscles, and mild changes in distal leg muscles, but EMG of the upper limbs was normal. Upper motor neuron signs were absent clinically and on transcranial magnetic stimulation. This seems to represent a variant of the common wasted-leg syndrome presentation.

Reimagining antibody-dependent cellular cytotoxicity in cancer: the potential of natural killer cell engagers

Bi-, tri- and multispecific antibodies have enabled the development of targeted cancer immunotherapies redirecting immune effector cells to eliminate malignantly transformed cells. These antibodies allow for simultaneous binding of surface antigens on malignant cells and activating receptors on innate immune cells, such as natural killer (NK) cells, macrophages, and neutrophils. Significant progress with such antibodies has been achieved, particularly in hematological malignancies. Nevertheless, several major challenges remain, including increasing their immunotherapeutic efficacy in a greater proportion of patients, particularly in those harboring solid tumors, and overcoming dose-limiting toxicities and immunogenicity. Here, we discuss novel antibody-engineering developments designed to maximize the potential of NK cells by NK cell engagers mediating antibody-dependent cellular cytotoxicity (ADCC), thereby expanding the armamentarium for cancer immunotherapy.

Parental perception about the pandemic impact on mental health of children: a cross-sectional study

Background

The pandemic may increase mental issues among children. This study aimed to explore parental perceptions on the pandemic impact on the health status of their children, with a focus on mental health.

Methods

An online nationwide cross-sectional study has been conducted amongst Italian parents (from April 2022-ongoing). The survey included: Strength and Difficulties Questionnaire (SDQ), Kessler-6 (K6) for parent's psychological distress, and pandemic-related items. The outcomes were: child's SDQ above the clinical cut-off and perceived child's worsening of sleep, appetite, physical and mental health during the pandemic. Multivariable regressions were run (p < 0.05 as significant).

Results

Up to date, participants were 333 (88% female). Mean age was 40.7 years (SD = 6.7). Considering their children, 52.9% were female and mean age was 6.62 (SD = 4.3). A total of 12.6% of children passed the SDQ cut-off. Having parents who are healthcare workers (adjOR=4.1), having parents positive for K6 (adjOR=4.0) and having a poor economic situation (adjOR=3.9) were significantly associated with a higher probability of passing the cut-off. Considering the pandemic, 15.4% declared their child had worse sleep, 12.2% lower appetite, 6.6% more physical issues, and 22.9% more mental issues. Using electronic devices more than before the pandemic was significantly associated with worsening of sleep (adjOR=2.9) and appetite (adjOR=6.9). Having parents who are healthcare workers was significantly associated with worsening of sleep (adjOR=2.3) and mental health (adjOR=2.4). Having parents positive for K6 was significantly associated with worsening of mental health (adjOR=5.3).

Conclusions

This study suggested a perceived substantial worsening of children's health, especially considering mental health. Exploring how parents recognize their children's health and how the COVID-19 has changed daily habits should be considered as a public health priority in Europe.

Key messages

Transcriptomic diversity in human medullary thymic epithelial cells

The induction of central T cell tolerance in the thymus depends on the presentation of peripheral self-epitopes by medullary thymic epithelial cells (mTECs). This promiscuous gene expression (pGE) drives mTEC transcriptomic diversity, with non-canonical transcript initiation, alternative splicing, and expression of endogenous retroelements (EREs) representing important but incompletely understood contributors. Here we map the expression of genome-wide transcripts in immature and mature human mTECs using high-throughput 5' cap and RNA sequencing. Both mTEC populations show high splicing entropy, potentially driven by the expression of peripheral splicing factors. During mTEC maturation, rates of global transcript mis-initiation increase and EREs enriched in long terminal repeat retrotransposons are up-regulated, the latter often found in proximity to differentially expressed genes. As a resource, we provide an interactive public interface for exploring mTEC transcriptomic diversity. Our findings therefore help construct a map of transcriptomic diversity in the healthy human thymus and may ultimately facilitate the identification of those epitopes which contribute to autoimmunity and immune recognition of tumor antigens.

SEVERE REFRACTORY HYPOTHYROIDISM IN A 48-YEAR-OLD FEMALE: ROLE OF LOW-DOSE THYROXINE ABSORPTION TEST IN ESTABLISHING DIAGNOSIS OF NONCOMPLIANCE

A 48-year-old female presented with severe chronic hypothyroidism despite progressively increasing doses of levothyroxine. Poor adherence was suspected based on previous laboratory investigations. A low dose thyroxine absorption test using 400 µg of levothyroxine taken orally was performed. FT4 increased by 4.7 pmol/L at 3 hours and 6.6 pmol/L at 5 hours, following ingestion, effectively ruling out malabsorption. Her cardiac hemodynamic profile, measured noninvasively, also improved following levothyroxine intake, further supporting our diagnosis. Poor adherence was successfully managed by implementing twice weekly visits by a registered nurse and an improvement in both thyroid function tests and cardiac parameters was seen at the one-month follow-up visit. We suggest using a lower dose thyroxine absorption test, owing to its efficacy in establishing diagnosis and a safer alternative compared to higher doses in particular in high-risk cardiac patients.

P-064 Clinical outcomes of 127 patients with recurrent implantation failure treated with testicular sperm aspiration (TESA)

Study question

Are the embryological, clinical and newborn outcomes using aspirated testicular sperm improved in cases with recurrent implantation failure previously treated with ejaculated sperm?

Summary answer

Aspirated testicular sperm enabled to obtain significant higher embryological, clinical and newborn outcomes in cases with recurrent implantation failure previously treated with ejaculated sperm.

What is known already

High levels of sperm DNA fragmentation (SDF) were associated to poor clinical outcomes (1-Simon et al., 2017). Testicular sperm display lower SDF than ejaculated sperm (2-Sakas and Alvarez, 2010), improving clinical outcomes in cases with abnormal semen parameters (3-Awaga et al., 2018; 4-Kang et al., 2018), recurrent implantation failure (RIF) and pregnancy loss (RPL) (5-Esteves et al., 2017), and elevated SDF (6-Ambar et al., 2021). As only a few studies are specifically dedicated to RIF, we expanded the number of cases and first provided full demographic, stimulation, embryological, clinical and newborn outcomes.

References

1-(https://doi.org/10.4103/1008-682X.182822);

2-(https://doi.org/10.1016/j.fertnstert.2009.10.046);

3-(https://doi.org/10.1016/j.rbmo.2018.08.017);

4-(https://doi.org/10.1038/s41598-018-26280-0);

5-(https://doi.org/10.1016/j.fertnstert.2017.06.018);

6-(https://doi.org/10.5534/wjmh.200084

Study design, size, duration

We retrospectively evaluated during consecutive years (2010-2020) 63 patients with recurrent implantation failure, which accepted to perform testicular sperm aspiration (TESA) as an alternative treatment. These patients presented a long history of failed treatments (153 cycles) using ejaculated sperm. From these cycles, no pregnancy ensued. The present study compares 127 treatment cycles, 80 with testicular sperm (17 cases repeated TESA) and 47 with ejaculated sperm from the same patients performed at the present IVF clinic.

Participants/materials, setting, methods

Patients were screened for karyotype abnormalities, for Y-chromosome microdeletions (7-Gonçalves et al., 2016), and for SDF with the TUNEL assay (8-Sá et al., 2015). Conventional semen analysis was performed according to World Health Organization guidelines (9-WHO, 2010). Male evaluation and TESA was performed by the same experienced urologist (LF) according to established protocols (10-Madureira et al 2014). The procedure was performed entirely on an outpatient basis, with no complications reported.

References

7-(https://doi.org/10.4103/1008-682X.172827);

8-(https://doi.org/10.1016/j.rbmo.2015.06.019);

9-(https://apps.who.int/iris/handle/10665/44261);

10-(https://doi.org/10.1111/j.2047-2927.2014.00231.x).

Main results and the role of chance

The mean ages were 35.5±3.4 (26-42)-female and 38.1±5.7 (29-59)-male. There were 4 abnormal karyotypes (3-female, 1-male), all without known relevance. Most cases had asthenozoospermia and teratozoospermia (65.1%), or oligoasthenoteratozoospermia (41.8%). Of the 19 cases with &lt;5M/ml, none presented Y-chromosome microdeletions. Although we do not routinely perform SDF testing, 15 patients had previous SDF values (12, &gt;20%; 8, &gt;36%). Female basal characteristics and testicular evaluation were under normal values. The TESA procedure took about 15-20 min, and the time of laboratorial search around 30-60 min. Cases using testicular sperm showed significant higher rates of fertilization (64% vs 73%-p=0.005), blastocyst development (47% vs 62%-p=0.010), implantation (6% vs 27%-p=0.000), clinical pregnancy (10% vs 39%-p=0.001), live birth delivery (5% vs 28%-p=0.005) and newborn (5% vs 32%-p=0.000) than ejaculated sperm. No significant differences were observed regarding the rates of embryo cleavage (95% vs 94.8%) and high quality embryos (89.4% vs 94%), in the mean number of transferred embryos (1.8±0.4 vs 1.9±0.4), or in the abortion rate (2 cases-50% vs 7 cases-25.9%). Cases using testicular sperm had 22 frozen-thawed embryo transfer cycles, enabling per initiated cycle a cumulative pregnancy rate of 45%, live birth delivery rate of 31.3% and newborn rate of 37.5% (32 newborn).

Limitations, reasons for caution

Although presenting the higher number of cycles using TESA in the treatment of RIF, this number needs to be increased for drawing more definitive conclusions, as these women present a diversity of conditions, rendering subgrouping difficult. In the future, it would also be important to evaluate SDF in all cases.

Wider implications of the findings

In conclusion, the present results gave further evidence for the superiority of using testicular sperm instead of ejaculated sperm in cases with recurrent implantation failure. Data also evidences the security of using testicular sperm aspiration, as there were no pregnancy or delivery complications, or congenital anomalies among the 32 newborn.

Trial registration number

Not Applicable

CD8+ T Cells Variably Recognize Native Versus Citrullinated GRP78 Epitopes in Type 1 Diabetes

In type 1 diabetes, autoimmune β-cell destruction may be favored by neoantigens harboring posttranslational modifications (PTMs) such as citrullination. We studied the recognition of native and citrullinated glucose-regulated protein (GRP)78 peptides by CD8⁺ T cells. Citrullination modulated T-cell recognition and, to a lesser extent, HLA-A2 binding. GRP78-reactive CD8⁺ T cells circulated at similar frequencies in healthy donors and donors with type 1 diabetes and preferentially recognized either native or citrullinated versions, without cross-reactivity. Rather, the preference for native GRP78 epitopes was associated with CD8⁺ T cells cross-reactive with bacterial mimotopes. In the pancreas, a dominant GRP78 peptide was instead preferentially recognized when citrullinated. To further clarify these recognition patterns, we considered the possibility of citrullination in the thymus. Citrullinating peptidylarginine deiminase (Padi) enzymes were expressed in murine and human medullary epithelial cells (mTECs), with citrullinated proteins detected in murine mTECs. However, Padi2 and Padi4 expression was diminished in mature mTECs from NOD mice versus C57BL/6 mice. We conclude that, on one hand, the CD8⁺ T cell preference for native GRP78 peptides may be shaped by cross-reactivity with bacterial mimotopes. On the other hand, PTMs may not invariably favor loss of tolerance because thymic citrullination, although impaired in NOD mice, may drive deletion of citrulline-reactive T cells.

894 The bispecific innate cell engagers AFM13 (CD30/CD16A) and AFM24 (EGFR/CD16A) increase the fraction of tumor target-responsive NK cells and boost serial killing

Background

The use of bispecific natural killer (NK) cell engagers has emerged as a successful strategy for immune cell activation and killing of tumor cells through antibody-dependent cellular cytotoxicity (ADCC). Among these, tetravalent, bispecific innate cell engagers (ICE®) with specificity for the activating receptor CD16A selectively triggering innate responses from NK cells or macrophages represent the most clinically advanced concept. The CD30/CD16A specific ICE® AFM13, has shown efficacy in patients with CD30+ lymphomas as monotherapy1 and combination therapy with check-point inhibitors2 and most recently in combination with adoptive NK cell therapy.3 The EGFR/CD16A specific ICE® AFM24, targeting a variety of solid tumors like colorectal, or lung cancer with a unique mode of action independent of EGFR signaling inhibition, is currently evaluated in an ongoing Ph1/2a clinical study.

Methods

We used a microchip-based screening with single cell resolution4 to elucidate the dynamic responses of individual NK cells towards tumor target cells upon treatment with AFM13 or AFM24.

Results

We found that AFM13 and AFM24 mediated potent activation of NK cells, leading to increased responsive cytotoxic NK cells and significantly increased the number of NK cells that exerted engagement with multiple target cells rendering these NK cells serial killers. Strikingly, bispecific ICE® molecules triggered stronger cytotoxic responses compared to monoclonal antibodies. One suggested strategy to boost killing by NK cells is to use molecular inhibitors or protein constructs that prevent shedding of CD16.5 However, previous results have shown that this can lead to impaired detachment from target cells, reducing the capacity for an individual NK cell to form serial contacts to target cells.6 We observed that the elevated NK cell killing induced by ICE® molecules was largely conserved when cells were treated with the shedding inhibitor Batimastat. Analysis of the functional dynamics of NK cells revealed that inhibition of CD16 shedding prevented NK cell detachment from target cells, resulting in cell cluster formation. This might strongly impact targeting of distant tumor cells by an individual NK cell thus limiting its anti-tumoral activity.

Conclusions

In conclusion, we show that both AFM13 and AFM24 increase the fraction of tumor-target responsive NK cells and boost serial killing of target cells by individual NK cells. Based on these data, ICE® molecules can be characterized as potent anti-tumoral agents leveraging the enormous potential of NK cells while maintaining crucial features of NK cell biology.

Acknowledgements

We thank members of the Önfelt lab for their valuable help and feedback.

References

Sawas A, Elgedawe H, Vlad G, Lipschitz M, Chen P-H, Rodig SJ, et al. Clinical and biological evaluation of the novel CD30/CD16A tetravalent bispecific antibody (AFM13) in relapsed or refractory CD30-positive lymphoma with cutaneous presentation: a biomarker phase Ib/IIa study (NCT03192202). Blood 2018;132(Supplement 1):2908–2908.

Bartlett NL, Herrera AF, Domingo-Domenech E, Mehta A, Forero-Torres A, Garcia-Sanz R, et al. A phase 1b study of AFM13 in combination with pembrolizumab in patients with relapsed or refractory Hodgkin lymphoma. Blood 2020. Blood 2020;136(21):2401–2409.

Kerbauy LN, Marin ND, Kaplan M, Banerjee PP, Berrien-Elliott MM, Becker-Hapak M, et al. Combining AFM13, a bispecific CD30/CD16 antibody, with cytokine-activated blood and cord blood–derived NK cells facilitates CAR-like responses against CD30 + malignancies. Clin Cancer Res Epub 2021.

Guldevall K, Brandt L, Forslund E, Olofsson K, Frisk TW, Olofsson PE, et al. Microchip screening platform for single cell assessment of NK cell cytotoxicity. Front Immunol 2016;7:119.

Romee R, Foley B, Lenvik T, Wang Y, Zhang B, Ankarlo D, et al. NK cell CD16 surface expression and function is regulated by a disintegrin and metalloprotease-17 (ADAM17). Blood 2013;121(18):3599–608.

Srpan K, Ambrose A, Karampatzakis A, Saeed M, Cartwright ANR, Guldevall K, et al. Shedding of CD16 disassembles the NK cell immune synapse and boosts serial engagement of target cells. J Cell Biol 2018;217(9):3267–83.

Ethics Approval

This work was performed with NK cells from healthy anonymous blood donors, which requires no ethical permit according to local regulations.

880 Tetravalent, bispecific innate cell engager AFM24 enhances macrophage mediated tumor cell phagocytosis

Background

Enabling innate immunity holds promise to provide a treatment option for patients suffering from various kinds of malignancies. Innate cell engagers (ICE®) derived from the ROCK® (redirected optimized cell killing) platform have demonstrated to induce antibody dependent cellular cytotoxicity (ADCC) and phagocytosis (ADCP) via bivalent targeting of a unique epitope on CD16A of NK cells and macrophages, respectively. Previously published preclinical and clinical data of ICE® molecules show promising efficacy and safety as monotherapy, as a combination therapy with immuno-oncology drugs such as PD-1/PD-L1, and in combination with adoptive NK cell transfer. AFM24 is a tetravalent bispecific epidermal growth factor (EGFR)- and CD16A-binding ICE® for enhanced targeting and killing of EGFR+ tumor cells currently in clinical development. In contrast to approved EGFR-targeting antibodies, AFM24 does not inhibit the signalling pathway of the EGFR but utilizes this receptor merely as an ”anchor” to direct NK cells and macrophages to attack tumor cells via ADCC and ADCP.

Methods

ADCP assays were performed with monocyte-differentiated macrophages from healthy donor PBMCs. Target tumor cells were labelled and co-cultures with macrophages, AFM24 and control antibodies. FACS analysis and live-cell imaging (IncuCyte®) were used to measure ADCP events.

Results

We show that AFM24 enhances macrophage mediated tumor cell phagocytosis i.e., ADCP of tumor cell lines with varying levels of EGFR expression and irrespective of EGFR signaling pathway mutations. The ability of AFM24 to enhance ADCP was further demonstrated in patient-derived xenograft cell lines from various EGFR+ tumor indications. Assays with myeloid-derived suppressor cells, natural killer cells and other immune modulators were designed to address the activity of our ICE® in the context of the suppressive nature of the tumor microenvironment.

Conclusions

We report the ability of our ICE® to enhance ADCP, which might be instrumental to their efficacy, especially in tumors enriched with macrophages. In addition, due to its novel mechanism of action, AFM24 may overcome limitations of existing EGFR-targeting agents, such as dose limiting toxicity, and/or intrinsic or acquired resistance of the tumor. Consequently, AFM24 may be a potential future treatment option for a wide spectrum of patients including those that do not respond or are resistant to current EGFR-directed therapies that inhibit the signaling pathway.

881 Enhanced antibody-mediated phagocytosis and antibody-mediated cell cytotoxicity using tetravalent, bispecific innate cell engagers (ICE®) in 3D spheroids

Background

The redirected optimized cell platform (ROCK®) enables the generation of customizable innate cell engagers (ICE®) of varying valency, affinity, and pharmacokinetic profiles. Preclinical and clinical studies have demonstrated the advantage and unique features of this first-in-class ICE® antibodies across a multitude of cancers and its differentiation to monoclonal antibodies. ICE® are tetravalent, bispecific antibodies that bivalently bind to a unique epitope on CD16A, which is selectively expressed on natural killer (NK) cells and macrophages, while the other domains target a tumor antigen. In addition to promoting antibody-dependent cellular cytotoxicity (ADCC) of NK cells, ICE® can also promote tumor targeting of macrophages eventually inducing antibody-dependent cellular phagocytosis (ADCP).

Methods

ADCP and ADCC assays were performed using monocyte-differentiated macrophages and NK cells derived from healthy donor PBMCs. Target tumor lines and patient-derived xenograft line-derived spheroids were labelled and co-cultured with macrophages or NK cells. Live-cell imaging (IncuCyte®) was used to measure ADCP and ADCC events.

Results

We show that ICE® molecules can enhance ADCP of tumor cells mediated by various functional/phenotypic subsets of macrophages derived from in vitro differentiation of human monocytes. ICE®-induced ADCP of tumor target cells was seen across different macrophage subtypes (M1 and M2). We further investigated the expression of immune-suppressive checkpoint programmed death-ligand 1 (PD-L1) on macrophages upon ICE® treatment that could be a key anti-tumor molecule within the suppressive tumor microenvironment. Based on patient-derived xenograft line-derived spheroids (3D) generated from primary tumor samples of patients suffering from various malignancies, we could demonstrate robust ADCC and ADCP mediated by NK cells and macrophages, respectively.

Conclusions

ICE® molecules are able to mount robust NK cell- and macrophage-mediated anti-tumoral innate immune responses. This combined immune activity has the potential to not only fight tumor cells directly but also to initiate a full immune response comprised of innate and adaptive components of the immune system.

Abstract 1881: AFM24 is a novel, highly potent, tetravalent bispecific EGFR/CD16A-targeting Innate Cell Engager (ICE®) designed for the treatment of EGFR-positive malignancies

AFM24 engages CD16A (FcγRIIIa) on NK cells and macrophages with much higher affinity than monoclonal antibodies (mAbs), triggering NK cell-mediated ADCC and macrophage-mediated ADCP. AFM24's mode of action is highly differentiated from current EGFR-targeting treatment options since it does not rely on inhibition of the EGFR signaling pathway, thus rendering AFM24 insensitive to the mutational status (e.g. KRAS, BRAF) of the tumor. Indeed, the efficacy of currently marketed EGFR inhibitors is limited by i) toxicities arising from blocking of EGFR signaling in healthy tissues and ii) by the occurrence of intrinsic or acquired resistances of the tumor to EGFR-targeting inhibitors. With its distinctive mode of action profile, AFM24 is a novel treatment option for a wide range of EGFR+ patient populations including hard-to-treat patients. In preclinical assays AFM24 added up to 20% more ADCC and up to 6-fold more ADCP towards NSCLC, CRC, HNSCC and ccRCC cell lines with a wide range of EGFR densities when compared to EGFR-targeting mAbs. This superior effect of AFM24 was most pronounced towards target cell lines with low EGFR density or EGFR signaling pathway mutations, such as KRAS. AFM24's efficacy was assessed in a xenograft mouse model using different human EGFR+ cell lines such as the TNBC cell line MDA-MB-231 and an adoptively transferred, cytokine-stimulated and expanded NK cell product. This combination of AFM24 with an NK cell product demonstrated a significant dose-dependent and differentiated reduction in tumor outgrowth as compared to mice treated with NK cell product alone. This model allows for systematic screening of future IO-combination regimens, such as checkpoint inhibitors. Moreover, prevalence and activity of innate and adaptive immune cells were assessed in tumor explants of patients with EGFR+ malignancies. These data will be instrumental to guide the clinical development of AFM24 in monotherapy and combination therapies. In conclusion and considering the previously reported good safety profile in cynomolgus monkeys, the presented data shows AFM24's potential to become a novel treatment option for patients with EGFR+ cancers overcoming limitations of available EGFR-targeting therapies by fully exploiting the potential of the innate immune system. AFM24 is currently being investigated in a phase 1/2a study, NCT04259450, in EGFR+ tumors.

Citation Format: Jens Pahl, Gabriele Hintzen, Uwe Reusch, Torsten Haneke, Christian Breunig, Sheena Pinto, Cassandra Choe-Juliak, Andreas Harstrick, Wolfgang Fischer, Arndt Schottelius, Joachim Koch, Erich Rajkovic. AFM24 is a novel, highly potent, tetravalent bispecific EGFR/CD16A-targeting Innate Cell Engager (ICE®) designed for the treatment of EGFR-positive malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1881.

Dynamic cooling strategy based on individual animal response mitigated heat stress in dairy cows

Technological progress enables individual cow's temperatures to be measured in real time, using a bolus sensor inserted into the rumen (reticulorumen). However, current cooling systems often work at a constant schedule based on the ambient temperature and not on monitoring the animal itself. This study hypothesized that tailoring the cooling management to the cow's thermal reaction can mitigate heat stress. We propose a dynamic cooling system based on in vivo temperature sensors (boluses). Thus, cooling can be activated as needed and is thus most efficacious. A total of 30 lactating cows were randomly assigned to one of two groups; the groups received two different evaporative cooling regimes. A control group received cooling sessions on a preset time-based schedule, the method commonly used in farms; and an experimental group, which received the sensor-based (SB) cooling regime. Sensor-based was changed weekly according to the cow's reaction, as reflected in the changes in body temperatures from the previous week, as measured by reticulorumen boluses. The two treatment groups of cows had similar milk yields (44.7 kg/d), but those in the experimental group had higher milk fat (3.65 vs 3.43%), higher milk protein (3.23 vs 3.13%), higher energy corrected milk (ECM, 42.84 vs 41.48 kg/d), higher fat corrected milk 4%; (42.76 vs 41.34 kg/d), and shorter heat stress duration (5.03 vs 9.46 h/day) comparing to the control. Dry matter intake was higher in the experimental group. Daily visits to the feed trough were less frequent, with each visit lasting longer. The sensor-based cooling regime may be an effective tool to detect and ease heat stress in high-producing dairy cows during transitional seasons when heat load can become severe in arid and semi-arid zones.

Peptides Derived From Insulin Granule Proteins Are Targeted by CD8+ T Cells Across MHC Class I Restrictions in Humans and NOD Mice

The antigenic peptides processed by β-cells and presented through surface HLA class I molecules are poorly characterized. Each HLA variant (e.g., the most common being HLA-A2 and HLA-A3) carries some peptide-binding specificity. Hence, features that, despite these specificities, remain shared across variants may reveal factors favoring β-cell immunogenicity. Building on our previous description of the HLA-A2/A3 peptidome of β-cells, we analyzed the HLA-A3-restricted peptides targeted by circulating CD8⁺ T cells. Several peptides were recognized by CD8⁺ T cells within a narrow frequency (1-50/10⁶), which was similar in donors with and without type 1 diabetes and harbored variable effector/memory fractions. These epitopes could be classified as conventional peptides or neoepitopes, generated either via peptide cis-splicing or mRNA splicing (e.g., secretogranin-5 [SCG5]-009). As reported for HLA-A2-restricted peptides, several epitopes originated from β-cell granule proteins (e.g., SCG3, SCG5, and urocortin-3). Similarly, H-2K^d-restricted CD8⁺ T cells recognizing the murine orthologs of SCG5, urocortin-3, and proconvertase-2 infiltrated the islets of NOD mice and transferred diabetes into NOD/scid recipients. The finding of granule proteins targeted in both humans and NOD mice supports their disease relevance and identifies the insulin granule as a rich source of epitopes, possibly reflecting its impaired processing in type 1 diabetes.

How is small bowel permeability in endometriosis patients? a case control pilot study

Endometriosis is a chronic inflammatory disease of women of reproductive age. Small bowel (SB) permeability and lipopolysaccharides (LPS) could play a role in the perduration of low grade inflammation status and the pathogenesis of endometriosis. To clarify this hypothesis, we measured SB permeability through plasma values of LPS and urinary secretion of lactulose (La), mannitol (Ma) and their ratio (L/M) in patients with endometriosis compared with healthy controls (HC). Eight patients and 14 HC entered the study. SB permeability was evaluated by high-performance liquid chromatography of urine concentrations of La and Ma. Plasma levels of LPS were measured in the blood. Moreover, a nutritional, gastroenterological, quality of life evaluation was performed through validates questionnaires and complete gynaecological evaluations. The statistical analysis of the obtained data did not show differences in anthropometric and nutritional characteristics and gastrointestinal functional disease in the two groups. Patients reported higher levels of pelvic chronic pain (3.87 ± 2.99 vs 0.15 ± 0.55; pe = 0.001) and significantly higher LPS plasma levels (0.529 ± 0.11 vs 0.427 ± 0.08; p value = .027) than HC. Our results indicate that intestinal permeability is abnormal in endometriosis patients, and it might play a role in the pathogenesis of this chronic disease.

Compared with classic Hashimoto's thyroiditis, chronic autoimmune serum-negative thyroiditis requires a lower substitution dose of L-thyroxine to correct hypothyroidism

PURPOSE

Serum-negative-chronic-autoimmune-thyroiditis (SN-CAT) is considered a milder variant of classic Hashimoto's thyroiditis (CHT). However, its prevalence remains unknown and it is still unclear whether SN-CAT behaves differently in terms of L-thyroxine (LT4) substitution treatment of hypothyroidism. Aims of this study were to estimate the prevalence of SN-CAT in a large series of hypothyroid patients and to compare LT4 requirements in hypothyroid patients with SN-CAT and CHT.

METHODS

Five-hundred-eighty-one consecutive patients with primary-autoimmune-hypothyroidism were enrolled in a cross-sectional study. LT4 requirements and thyroid-volume changes were longitudinally evaluated in 49 hypothyroid patients with SN-CAT and in 98 sex and age-matched hypothyroid patients with CHT.

RESULTS

In our series the prevalence of SN-CAT was 20.8%. At diagnosis, patients in the CHT and SN-CAT groups had similar male/female ratio, age and BMI, while serum TSH and thyroid-volume were significantly greater in the CHT group. In the longitudinal study, during a follow-up of 8.9 ± 4.6 years, 8 out of 49 (16.3%) SN-CAT patients developed positive tests for of circulating TPO-Ab and/or Tg-Ab. Thyroid-volume significantly decreased in CHT patients, but not in those with SN-CAT. The maximum daily substitution dose of LT4 was smaller in SN-CAT patients as compared with the CHT ones. Multivariate analysis showed that age, BMI, basal TSH and thyroid antibody status independently and significantly predicted the maximum daily substitution dose of LT4.

CONCLUSIONS

SN-CAT accounts for a significant proportion of patients with autoimmune hypothyroidism. Compared with hypothyroid patients diagnosed with CHT, the SN-CAT ones require smaller doses of LT4 to correct their hypothyroidism.

Discovery of Hydroxyamidine Based Inhibitors of IDO1 for Cancer Immunotherapy with Reduced Potential for Glucuronidation

Following the impressive success of checkpoint inhibitors in the treatment of cancer, combinations of IDO1 inhibitors with PD-1/PD-L1 antibodies are in clinical development aiming to increase response rates. Using the hydroxyamidine pharmacophore of the IDO1 inhibitor INCB14943 as a starting point for the design of new inhibitors, the potential shortcomings of extensive hydroxyamidine glucuronidation in humans was addressed. Compounds were optimized using a stability assay with recombinant UGT1A9 enzyme together with the measurement of glucuronide formation in human hepatocytes. Optimized analog 24 showed cellular and biochemical IDO1 IC₅₀ values in the low nanomolar range, a suitable in vitro ADME/PK profile, and efficacy in an animal model of cancer. In a humanized liver mouse model the lead compound exhibited significantly reduced glucuronidation compared to epacadostat (2).

The clinical phenotype of Graves' disease occurring as an isolated condition or in association with other autoimmune diseases

PURPOSE

Graves' disease (GD) can present as an isolated disease (iGD) or in association with other autoimmune diseases (aGD). The aim of this study, performed in two Endocrine referral centers settled in different geographical areas of Italy, was to compare the anthropometric, clinical, and biochemical phenotype of iGD patients with that of the aGD ones.

METHODS

Clinical history, physical examination data, serum levels of TSH, FT4, FT3, thyroglobulin (TgAb), thyroid-peroxidase (TPOAb) and TSH-receptor (TRAb) antibody, presence of Graves' orbitopathy (GO), and thyroid ultrasound examination at disease diagnosis were recorded.

RESULTS

68 aGD and 136 iGD patients were consecutively recruited. At diagnosis, aGD and iGD patients did not differ for F/M ratio, age at presentation, thyroid function parameters, serum levels of TRAb, TgAb, TPOAb, presence of GO, and thyroid volume. The serum levels of TRAb were strongly correlated with the circulating concentrations of both FT3 (ρ = 0.667; p < 0.0001) and FT4 (ρ = 0.628; p < 0.001) in iGD patient, but not in the aGD ones (FT3: ρ = 0.231; p = 0.058; FT4: ρ = 0.096; p = 0.435). Compared with iGD patients, the aGD ones displayed a higher rate of transition from the previous hypothyroidism to hyperthyroidism (χ² = 6.375; p = 0.012).

CONCLUSION

Despite similar anthropometric, clinical, and biochemical features at diagnosis, aGD patients display a higher rate of transition from a thyroid functional status to the other as compared with iGD patients.

French adaptation of the "Frenchay Dysarthria Assessment 2" speech intelligibility test

OBJECTIVES

Speech intelligibility can be defined as "the degree to which a speaker's intended message is recovered by a listener". Loss of intelligibility is one of the most frequent complaints in patients suffering from speech disorder, impairing communication. Measurement of intelligibility is therefore an important parameter in follow-up. We developed a French version of the "Frenchay Dysarthria Assessment, 2nd edition" (FDA-2), an intelligibility test recognized internationally in its English version. The present study details the construction of the test and its preliminary validation.

MATERIALS AND METHODS

We first compiled a set of words and phrases in French, based on the criteria defined in FDA-2. In a second step, we validated the test in healthy subjects in normal and noisy conditions, to check sensitivity to speech signal degradation.

RESULTS

The test proved valid and sensitive, as scores were significantly lower for noise-degraded stimuli.

CONCLUSION

This French-language intelligibility test can be used to evaluate speech disorder: for example, in dysarthria, head and neck cancer or after cochlear implantation.

Employment two years after breast cancer diagnosis: role of household characteristics, CANTO cohort

Background

Breast cancer is associated with a high 5-year survival rate and more than half women are still of working age at diagnosis. Many studies evaluated the clinical determinants of return to work (RTW) but few investigated RTW in relation to family factors. Our objective was to study the role of household characteristics in non-RTW two years after breast cancerdiagnosis.

Methods

We used data of a French prospective cohort of women diagnosed with stage I-III, primary breast cancer (CANTO, NCT01993498). Patients had to be under 57 and have a job at diagnosis. We performed logistic regressions to model non-RTW two years after diagnosis in relation to household characteristics at diagnosis (marital status, children, support from partner), adjusting for tumor characteristics, health status at baseline and one year after diagnosis, and household income at diagnosis. In a second step, we conducted analyses stratified for household income at diagnosis.

Results

In total, 1874 women were eligible. Being in a relationship did not impact non-RTW (OR = 1.43 [95% CI 0.95-2.16]). Among the 1566 women in a relationship, being married was associated with elevated odds of non-RTW(OR = 1.37 [0.96-1.94]). Having children(OR = 1.17 [0.81-1.69]) or receiving support from their partner (OR = 1.17 [0.77-1.78]) was not associated with non-RTW. However, the situation differed in low-income households(&lt;2500€) among whom being married was associated with more elevated odds of non-RTW(OR = 1.94 [0.97-3.88]). No clear association was observed between having children (OR = 1.85 [0.85-4.03]) and non-RTW, but living with at least two children (OR = 2.76 [1.14-6.70]) and receiving support from their partner (OR = 2.28 [1.01-5.17]) was associated with increased odds of non-RTW.

Conclusions

The family environment is associated with non-RTW among the poorest women but not the others.

Key messages

Among the poorest women, the family environment is associated with non-RTW. Among all women, the family environment is not associated with non-RTW.

Identifying binge-eating disorders in obese young people living in vulnerable areas of Marseille

Background

While anxiety, depression and self-esteem have been identified as contributors to obesity, binge-eating disorder (BED) also requires attention to avoid worsening obesity. However, handling obese young people living in vulnerable neighbourhoods is rather difficult both in terms of psychosocial representations of obesity and the poor care offer. The objective of our exploratory research is to study the impact of a dedicated multidisciplinary management program on anxiety and depression of obese young adolescents presenting with, or not, a binge-eating disorder.

Methods

Twelve patients (7 girls, 5 boys; mean age: 12.8 +/-1.3 years, range: 11-17) participated so far in this ongoing study. The mean body mass index was 36.5 +/- 7.2 (range: 27-53.4) for the group. They were all residents of vulnerable neighbourhoods of Marseille (France). They were evaluated at inclusion and 3 months after the 6-weeks program with the following self-questionnaires: Adolescent Binge Eating Disorder scale (ADO-BEDS), Hospital Anxiety Depression (HAD), 6-item Kutcher Adolescent Depression Scale (KADS-6), Self-esteem Measurement Scale for Adolescent (EMESA).

Results

So far, only 3 patients were evaluated pre- and post-management. For two patients with ADO-BEDS scores at inclusion and post-management showing the presence of a BED, the KADS-6 and EMESA (general and physical appearance items) scores improved at 3 months. The remaining patient, without any depression signs at both inclusion and after 3 months, experienced a decreased self-esteem while a BED, not assessed at inclusion, was clearly revealed at 3 months. BMI did not change from pre- to post-management.

Conclusions

Our clinical impression is that participating to the management program failed, at least for our first patients, to make them engage in a psychiatric/psychological therapy. Nevertheless, the program contributed to provide a motivating support system allowing them and their parents to become involved in their care.

Key messages

A multidisciplinary management program could potentially have a beneficial impact on depression and self-esteem in obese young adolescents presenting with a binge-eating disorder. The management program seemed to provide a motivating support system allowing obese young adolescents living in vulnerable neighbourhoods, and their parents, to become involved in their care.

Characterization of CCDC103 expression profiles: further insights in primary ciliary dyskinesia and in human reproduction

PROPOSE

To study CCDC103 expression profiles and understand how pathogenic variants in CCDC103 affect its expression profile at mRNA and protein level.

METHODS

To increase the knowledge about the CCDC103, we attempted genotype-phenotype correlations in two patients carrying novel homozygous (missense and frameshift) CCDC103 variants. Whole-exome sequencing, quantitative PCR, Western blot, electron microscopy, immunohistochemistry, immunocytochemistry, and immunogold labelling were performed to characterize CCDC103 expression profiles in reproductive and somatic cells.

RESULTS

Our data demonstrate that pathogenic variants in CCDC103 gene negatively affect gene and protein expression in both patients who presented absence of DA on their axonemes. Further, we firstly report that CCDC103 is expressed at different levels in reproductive tissues and somatic cells and described that CCDC103 protein forms oligomers with tissue-specific sizes, which suggests that CCDC103 possibly undergoes post-translational modifications. Moreover, we reported that CCDC103 was restricted to the midpiece of sperm and is present at the cytoplasm of the other cells.

CONCLUSIONS

Overall, our data support the CCDC103 involvement in PCD and suggest that CCDC103 may have different assemblies and roles in cilia and sperm flagella biology that are still unexplored.

Peripheral Biomarkers of Inflammation in Depression: Evidence from Animal Models and Clinical Studies

Depression is a highly prevalent psychiatric condition, with over 300 million sufferers, and is an important comorbidity for other conditions, like cardiovascular disorders or diabetes. Therapy is largely based on psychotherapy and/or pharmacological intervention, particularly aimed at altering neurotransmitter levels in the central nervous system, but inadequate response to treatment remains a significant clinical problem. Herein, evidence supporting a molecular link between inflammation and depression will be discussed, particularly the increased prevalence of depression in chronic inflammatory diseases and the evidence on the use of anti-inflammatory drugs to treat depression. Moreover, the potential for the levels of peripheral inflammatory molecules to act as depression biomarkers, in the diagnosis and monitoring of depression will be examined, considering clinical- and animal model-based evidence.

Islet-reactive CD8+ T cell frequencies in the pancreas, but not in blood, distinguish type 1 diabetic patients from healthy donors

The human leukocyte antigen-A2 (HLA-A2)-restricted zinc transporter 8_186-194 (ZnT8_186-194) and other islet epitopes elicit interferon-γ secretion by CD8⁺ T cells preferentially in type 1 diabetes (T1D) patients compared with controls. We show that clonal ZnT8_186-194-reactive CD8⁺ T cells express private T cell receptors and display equivalent functional properties in T1D and healthy individuals. Ex vivo analyses further revealed that CD8⁺ T cells reactive to ZnT8_186-194 and other islet epitopes circulate at similar frequencies and exhibit a predominantly naïve phenotype in age-matched T1D and healthy donors. Higher frequencies of ZnT8_186-194-reactive CD8⁺ T cells with a more antigen-experienced phenotype were detected in children versus adults, irrespective of disease status. Moreover, some ZnT8_186-194-reactive CD8⁺ T cell clonotypes were found to cross-recognize a Bacteroides stercoris mimotope. Whereas ZnT8 was poorly expressed in thymic medullary epithelial cells, variable thymic expression levels of islet antigens did not modulate the peripheral frequency of their cognate CD8⁺ T cells. In contrast, ZnT8_186-194-reactive cells were enriched in the pancreata of T1D patients versus nondiabetic and type 2 diabetic individuals. Thus, islet-reactive CD8⁺ T cells circulate in most individuals but home to the pancreas preferentially in T1D patients. We conclude that the activation of this common islet-reactive T cell repertoire and progression to T1D likely require defective peripheral immunoregulation and/or a proinflammatory islet microenvironment.

Conventional and Neo-antigenic Peptides Presented by β Cells Are Targeted by Circulating Naïve CD8+ T Cells in Type 1 Diabetic and Healthy Donors

Although CD8⁺ T-cell-mediated autoimmune β cell destruction occurs in type 1 diabetes (T1D), the target epitopes processed and presented by β cells are unknown. To identify them, we combined peptidomics and transcriptomics strategies. Inflammatory cytokines increased peptide presentation in vitro, paralleling upregulation of human leukocyte antigen (HLA) class I expression. Peptide sources featured several insulin granule proteins and all known β cell antigens, barring islet-specific glucose-6-phosphatase catalytic subunit-related protein. Preproinsulin yielded HLA-A2-restricted epitopes previously described. Secretogranin V and its mRNA splice isoform SCG5-009, proconvertase-2, urocortin-3, the insulin gene enhancer protein ISL-1, and an islet amyloid polypeptide transpeptidation product emerged as antigens processed into HLA-A2-restricted epitopes, which, as those already described, were recognized by circulating naive CD8⁺ T cells in T1D and healthy donors and by pancreas-infiltrating cells in T1D donors. This peptidome opens new avenues to understand antigen processing by β cells and for the development of T cell biomarkers and tolerogenic vaccination strategies.

Plasma level of club-cell (CC-16) predicts outcome in amyotrophic lateral sclerosis

OBJECTIVES

The club cell protein (CC-16) is a biomarker associated with respiratory distress and pulmonary inflammation. We evaluated CC-16 as a candidate biomarker for respiratory failure in amyotrophic lateral sclerosis (ALS).

MATERIALS AND METHODS

We studied 81 ALS patients and 30 matched controls. We used an ALS-related measure of functional capacity, and tested forced vital capacity (FVC) and the amplitude of the diaphragmatic response by phrenic nerve stimulation (PhrenAmpl). Plasma CC-16 levels were measured in venous blood. Kaplan-Meier survival curves were plotted to evaluate risk to non-invasive ventilation and death in patients with abnormal CC-16 levels.

RESULTS

CC-16 levels were significantly raised in ALS patients (10.56 ng/mL ± 6.84 vs 8.34 ng/mL ± 3.10, P = .02), and in 17% of them, CC-16 level was above the upper cutoff value (mean + 2.5SD). CC-16 levels did not correlate with age, onset region, disease duration, functional status, FVC, and PhrenAmpl. In patients with increased CC-16 level, the risk of non-invasive was greater in the following 6 months (P = .01) and tended to have higher mortality in the following 30 months (P = .07).

CONCLUSIONS

We propose that increased CC-16 levels is a marker of lung inflammatory response that associated with ventilatory insufficiency are related to impending respiratory failure, not fully predicted by conventional respiratory tests. The latter are limited by the moment of testing.

Revisiting the Road Map of Medullary Thymic Epithelial Cell Differentiation

The basic two-step terminal differentiation model of the medullary thymic epithelial cell (mTEC) lineage from immature MHC class II (MHCII)lo to mature MHCIIhi mTECs has recently been extended to include a third stage, namely the post-Aire MHCIIlo subset as identified by lineage-tracing models. However, a suitable surface marker distinguishing the phenotypically overlapping pre- from the post-Aire MHCIIlo stage has been lacking. In this study, we introduce the lectin Tetragonolobus purpureas agglutinin (TPA) as a novel cell surface marker that allows for such delineation. Based on our data, we derived the following sequence of mTEC differentiation: TPAloMHCIIlo → TPAloMHCIIhi → TPAhiMHCIIhi → TPAhiMHCIIlo Surprisingly, in the steady-state postnatal thymus TPAloMHCIIlo pre-Aire rather than terminally differentiated post-Aire TPAhiMHCIIlo mTECs were marked for apoptosis at an exceptionally high rate of ∼70%. Hence, only the minor cycling fraction of the MHCIIlo subset (<20%) potentially qualified as mTEC precursors. FoxN1 expression inversely correlated with the fraction of slow cycling and apoptotic cells within the four TPA subsets. TPA also further subdivided human mTECs, although with different subset distribution. Our revised road map emphazises close parallels of terminal mTEC development with that of skin, undergoing an alternative route of cell death, namely cornification rather than apoptosis. The high rate of apoptosis in pre-Aire MHCIIlo mTECs points to a "quality control" step during early mTEC differentiation.

Gestural praxis in young adults with mild to moderate intellectual disabilities

BACKGROUND

Praxis functioning in the population with intellectual disabilities (ID) has been poorly studied. The goal of this research was to look for a starting point to study the praxic functioning in young adults with mild to moderate ID.

METHOD

Thirty young adults with ID and 30 young adults without ID, between the ages of 18 and 35 years, participated in this study. All participants completed tests that assessed gestural praxis.

RESULTS

It was possible to observe similar praxis behaviour in the group with ID in almost all domains studied, albeit showing statistical values lower than those of the group without ID.

DISCUSSIONS

Despite the high number of errors committed, the sample of participants with ID was able to reach the goal of praxic tasks performed; such errors may be associated with a deficit in the development of various brain functions and not only with praxis functioning, mainly related to a lower yield in terms of planning, monitoring and correcting intentional movement.

Thymic expression of tissue-restricted self-antigens is a highly coordinated and evolutionary conserved process

Promiscuous gene expression (pGE) of tissue-restricted antigens (TRAs) in medullary thymic epithelial cells (mTECs) is essential for tolerance imposition in the thymus. PGE is characterized on the one hand by inclusion of a broad range of TRAs and on the other hand by its mosaic patterns, whereby each antigen is only expressed in 1–3% of mTECs at a given point in time. Yet, this mosaic pattern at the single cell level faithfully adds up to the full repertoire of self-antigens at the population level.

In order to analyze the regulatory mechanisms underlying this transcriptional heterogeneity among mTECs, we applied two complementing approaches, the isolation of minor mTEC subsets as defined by TRA-selected gene co-expression groups in conjunction with single cell mRNA sequencing.

Different TRA-selected mTEC subfractions, each expressing distinct sets of genes in a mutually overlapping fashion, mapped to distinct stages of mTEC development. These co-expression patterns were evolutionary conserved between mouse and human (Rattay et al., J. Autoimmunity 2015).

Applying an unbiased single cell mRNA sequencing approach, we extended these findings to the single cell level and showed that the mouse mTEC population essentially represents a composite of multiple co-expression groups (Brennecke et al., Nat. Immunology 2015).

These co-expression groups may represent only snapshots of a continuum of changing co-expression groups along the lifetime of an individual mTEC, as captured in the model of “sliding co-expression groups” (Pinto et al., PNAS 2013). Continuous genome scanning would potentially enlarge the overall diversity of self-antigens displayed by a single mTEC.

The role of bone marrow promiscuous gene expression in peripheral tolerance

For the negative selection of autoreactive T cells, peripheral tissue-restricted antigens (TRAs) are ectopically expressed and presented by medullary thymic epithelial cells (mTECs). This physiological property of mTECs, termed promiscuous gene expression (pGE), is predominantly regulated by the transcription factor, autoimmune regulator (AIRE). In the periphery, pGE was also found in secondary lymphoid organs and can induce peripheral immune tolerance. Bone marrow is an important organ known to prime naïve conventional T cells, as well as being a reservoir of regulatory T cells. However, the occurrence of pGE in the bone marrow is hitherto unknown. We hypothesize that a repertoire of auto-antigens is ectopically expressed and presented in the bone marrow, which maintains the peripheral tolerance of T cells. We investigated the presence of AIRE-expressing cells in bone marrow using a transgenic reporter mouse model in which GFP is expressed under the control of the AIRE promoter. AIRE expression was detected at both the RNA and protein levels. The bone marrow-resident AIRE-expressing cells (BMACs) anatomically locate adjacent to clusters of CD4+ T cells and express high levels of CD45, MHC-II and EpCAM. Their tolerogenic characteristic was conferred by the expression of PD-L1 and lack of costimulatory molecules CD80 and CD86. Gene expression analysis showed the AIRE-dependent TRA genes expressed in BMACs differ from those expressed in mTECs. BMACs were also detected at various frequencies in patients carrying different tumor entities. Our result demonstrates that the AIRE-expressing cells which ectopically express TRAs in the bone marrow could comprise the cellular basis for the induction of peripheral T-cell tolerance.