Pharmacological inhibition of TBK1/IKKε blunts immunopathology in a murine model of SARS-CoV-2 infection

TANK-binding kinase 1 (TBK1) is a key signalling component in the production of type-I interferons, which have essential antiviral activities, including against SARS-CoV-2. TBK1, and its homologue IκB kinase-ε (IKKε), can also induce pro-inflammatory responses that contribute to pathogen clearance. While initially protective, sustained engagement of type-I interferons is associated with damaging hyper-inflammation found in severe COVID-19 patients. The contribution of TBK1/IKKε signalling to these responses is unknown. Here we find that the small molecule idronoxil inhibits TBK1/IKKε signalling through destabilisation of TBK1/IKKε protein complexes. Treatment with idronoxil, or the small molecule inhibitor MRT67307, suppresses TBK1/IKKε signalling and attenuates cellular and molecular lung inflammation in SARS-CoV-2-challenged mice. Our findings additionally demonstrate that engagement of STING is not the major driver of these inflammatory responses and establish a critical role for TBK1/IKKε signalling in SARS-CoV-2 hyper-inflammation.

Polymorphic KIR3DL3 expression modulates tissue-resident and innate-like T cells

Most human killer cell immunoglobulin-like receptors (KIR) are expressed by natural killer (NK) cells and recognize HLA class I molecules as ligands. KIR3DL3 is a conserved but polymorphic inhibitory KIR recognizing a B7 family ligand, HHLA2, and is implicated for immune checkpoint targeting. The expression profile and biological function of KIR3DL3 have been somewhat elusive, so we searched extensively for KIR3DL3 transcripts, revealing highly enriched expression in γδ and CD8+ T cells rather than NK cells. These KIR3DL3-expressing cells are rare in the blood and thymus but more common in the lungs and digestive tract. High-resolution flow cytometry and single-cell transcriptomics showed that peripheral blood KIR3DL3+ T cells have an activated transitional memory phenotype and are hypofunctional. The T cell receptor (TCR) usage is biased toward genes from early rearranged TCR-α variable segments or Vδ1 chains. In addition, we show that TCR-mediated stimulation can be inhibited through KIR3DL3 ligation. Whereas we detected no impact of KIR3DL3 polymorphism on ligand binding, variants in the proximal promoter and at residue 86 can reduce expression. Together, we demonstrate that KIR3DL3 is up-regulated alongside unconventional T cell stimulation and that individuals may vary in their ability to express KIR3DL3. These results have implications for the personalized targeting of KIR3DL3/HHLA2 checkpoint inhibition.

Engineering Cell Lines for Specific Human Leukocyte Antigen Presentation

Epitope-specific immunotherapies have enabled the targeted treatment of a variety of diseases, ranging from cancer, infection, and autoimmune disorders. For CD8+ T cell-based therapies, the precise identification of immunogenic peptides presented by human leukocyte antigen (HLA) class I is essential which can be achieved by immunopeptidomics. Here, using lentivirus-mediated transduction and cell sorting approaches, we present a method to engineer a cell line that does not express its native HLA but instead expresses an HLA of interest (in this instance HLA-A*02:01). This technique can be used to elucidate the immunopeptidome of cell lines expressing different HLAs.

Use of a GnRH agonist implant as alternative for surgical neutering in pet ferrets

In the current study, the duration of effectiveness, owner satisfaction and side effects of a gonadotrophin releasing hormone-agonist (deslorelin) implant were investigated during a two-year follow-up study in which 61 male and 69 female entire pet ferrets were given a 4.7 mg deslorelin implant as alternative to surgical neutering. In 27 participating non-oestrous jills, a double-blind placebo controlled study was performed to investigate whether a single low dose of medroxyprogesterone (2 mg orally) four days preceding placement of the implant could prevent oestrus induction. The duration of effectiveness of the implant ranged from 301 days to over 1339 days (mean 1012±38 days), with no sex difference present. Over 90 per cent of owners were pleased with the effects of the implant. Minor local side effects were noted in less than 20 per cent of ferrets, which all resolved within a week without treatment. Oestrus was induced in 77 per cent of jills receiving medroxyprogesterone and 50 per cent of jills receiving the placebo, indicating that administration of a low-dose progestogen cannot prevent postimplant oestrus. Based on the minimum duration of effectiveness, it is advised to place a new implant on a yearly basis to guarantee continuous gonadal suppression, although biannual replacement may be sufficient in the majority of ferrets.

Cumulative pregnancy rates and selective drop-out of patients in in-vitro fertilization treatment

The validity of the cumulative pregnancy rate (CPR) calculated by life-table approach, obtained in a transport in-vitro fertilization (IVF) programme, was tested by the determination of possible influence of selective drop-out of patients with a poor treatment prognosis. A cohort of 1211 patients who had a first IVF cycle was followed, and the CPR after three IVF cycles was assessed. First cycles of patients who discontinued treatment after failed IVF, and of those who did not achieve a pregnancy but proceeded to a subsequent cycle, were compared for fertilization rate and for occurrence of prognosticators of poor treatment outcome: oocyte yield < or =2, and replacement of <2 embryos. The CPR after three cycles was 54.9%. No differences were found in the first and second cycles of patients who continued treatment and those who dropped out. Selective drop-out of patients with a poor treatment prognosis was not found. Therefore, although calculations of CPR using life-table analysis generally overestimate the real probability of pregnancy after successive IVF cycles, the calculated CPR after three IVF cycles gives a reliable indication of the chance of occurrence of a pregnancy for the population studied.

Treatment policy after poor fertilization in the first IVF cycle

PURPOSE

The chance of recurrence of poor fertilization in a second in vitro fertilization (IVF) cycle was assessed.

METHODS

Total fertilization failure was defined, and the relationship between the fertilization rate and the number of motile sperm cells per milliliter of semen was assessed. Patients with a total fertilization failure or poor fertilization (20% or less of the oocytes fertilized) were divided into three subgroups with different chances of fertilization and were followed in a subsequent IVF cycle.

RESULTS

The recurrence rate of total fertilization failure was high in all three groups (45-70%), and poor fertilization frequently occurred in the second cycle (50-75%).

CONCLUSIONS

Poor fertilization frequently recurs in the second IVF cycle. The use of intracytoplasmic sperm injection could be considered after fertilization of 20% or less of oocytes in the first cycle, irrespective of the number of motile sperm cells per milliliter of semen.

Transport-in-vitro fertilization/intracellular sperm injection: a prospective randomized study

We performed a prospective randomized clinical trial to investigate whether long distance oocyte transport prior to an intracytoplasmic sperm injection (ICSI) procedure influences fertilization rates, embryo quality and/or embryo implantation rates. After informed consent, 100 infertile couples booked for ICSI treatment were randomized into two groups. In group 1 (n = 50), patients were stimulated and monitored in Rotterdam (The Netherlands), and oocyte retrieval, ICSI procedure and embryo transfer took place in Gent (Belgium). In group 2 (n = 50), patients were stimulated, monitored and punctured in Rotterdam and the oocytes were transported in their follicular fluid in an isothermic transport box to Gent, where the ICSI procedure and the embryo transfer took place. In both groups the stimulation and monitoring regimen, puncture technique, laboratory conditions and transfer policy were identical. In both groups, the number of fertilized oocytes (7.13 +/- 0.65 versus 5.53 +/- 0.60, P = 0.08), the number of transferred embryos (2.36 +/- 0.09 versus 2.40 +/- 0.11, P = 0.87) and the embryo implantation rate [20/113 (17.7%) versus 19/103 (18.4%), P = 0.89] was similar. In group 1, the number of retrieved oocytes was higher (10.83 +/- 0.95 versus 8.44 +/- 0.93, P = 0.05). The total score of the embryos obtained (18.90 +/- 1.73 versus 12.64 +/- 1.26, P = 0.01), the number of good quality embryos (4.63 +/- 0.49 versus 2.98 +/- 0.38, P = 0.02), the mean score of the transferred embryos (3.32 +/- 0.11 versus 2.94 +/- 0.13, P = 0.05) and the number of embryos available for cryopreservation (2.70 +/- 0.45 versus 1.48 +/- 0.38, P = 0.03) were significantly higher in group 1. Therefore, long distance transport of oocytes prior to ICSI does not affect oocyte fertilization and embryo implantation rates, although a negative effect on embryo quality cannot be excluded.

A triplet pregnancy after in vitro fertilization is a procedure-related complication that should be prevented by replacement of two embryos only

OBJECTIVE

To investigate whether the incidence and obstetric outcome of triplet pregnancies after IVF treatment justify strict limitation of the number of embryos to be replaced to two.

DESIGN

Retrospective analysis.

SETTING

A transport IVF program.

PATIENT(S)

All patients who had more than one embryo replaced.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Obstetric outcome, pregnancy.

RESULT(S)

High-order pregnancies occurred in 24 cases (23 triplets and 1 quadruplet). Three patients opted for selective embryo reduction (12.5%). Three triplet pregnancies spontaneously reduced to twins. Comparison of 18 triplets, reaching at least 20 weeks' gestation, with 54 twin pregnancies shows a higher perinatal mortality in the triplet group, causing 6 out of 18 patients to be confronted with at least one perinatal death. Triplets were born at a lower gestational age, had a lower birth weight, and a higher hospital admission rate of longer duration. Replacement of two, three, or four embryos did not lead to differences in pregnancy rates in the population studied. When a pregnancy occurred after replacement of three embryos, the risk of having a triplet pregnancy was 7.5%.

CONCLUSION(S)

The obstetric outcome of triplet pregnancies in our population indicates that triplet pregnancies after IVF treatment have to be prevented. Selective embryo reduction is acceptable for few patients only and can therefore not be seen as a solution. Replacement of three embryos results in triplet pregnancy in an unacceptably high percentage. Replacement of two embryos only gives acceptable IVF results and is the method chosen in the IVF program in Rotterdam to prevent triplet pregnancies.

The ovarian response as a predictor for successful in vitro fertilization treatment after the age of 40 years

OBJECTIVE

To determine whether age or response to controlled ovarian hyperstimulation (COH) is a better predictor of IVF outcome in women > or = 40 years.

DESIGN

Retrospective analysis.

SETTING

A transport IVF program.

PATIENT(S)

For patients undergoing IVF treatment the correlation between treatment outcome and age and response to COH was analyzed using the data of 2,588 consecutive cycles.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Pregnancy.

RESULT(S)

The incidence of poor ovarian response rises significantly with increasing age. Analysis of all cycles showed a significant decrease in clinical and ongoing pregnancy rate for women > or = 40 years. Analysis of cycles with a good ovarian response showed no statistically significant differences for these parameters between women > or = 40 years and those younger. A logistic regression analysis on pregnancy showed that ovarian response contributes more to the prediction of pregnancy than age.

CONCLUSION(S)

Patients aged > or = 40 years with a good response to COH have a good prognosis for IVF treatment. The age limit for acceptance of patients should not be set at 40 years. Instead, the response to COH can be used to predict candidates likely to have a successful IVF outcome.

The incidence of major clinical complications in a Dutch transport IVF programme

Four different major clinical complications were identified in a retrospective analysis of 2495 in-vitro fertilization (IVF) cycles resulting in oocyte retrieval. The severe form of ovarian hyperstimulation syndrome (OHSS) occurred in 18 patients, giving a prevalence for this complication of 0.7%. Seven (39%) of these 18 patients had previously been diagnosed as having polycystic ovaries. Eleven patients were admitted with moderate OHSS. Adnexal torsion was diagnosed in two patients. Ovariectomy was considered necessary in both cases. Complications of the transvaginal procedure occurred in seven cases (0.3%): one patient had an acute appendicitis with puncture holes in the appendix, six patients were admitted shortly after oocyte retrieval with a pelvic inflammatory disease. Of the 624 pregnancies obtained, 13 were ectopic, giving an ectopic pregnancy rate of 2.1%. It is concluded that serious clinical complications of IVF treatment are rare. However, patients should be counselled for the occurrence of serious procedure-related complications before entering an IVF programme.

Minimal monitoring of ovarian hyperstimulation: a useful simplification of the clinical phase of in vitro fertilization treatment

OBJECTIVE

To investigate the feasibility of IVF treatment with minimal monitoring during ovarian hyperstimulation.

DESIGN

Retrospective analysis and prospective study with real-time control group.

SETTING

Transport IVF program with transport clinic and satellite clinics.

PATIENTS

One hundred consecutive IVF cycles monitored at a transport clinic and 100 concurrent consecutive cycles monitored at satellite clinics, using the same stimulation-monitoring protocol and resulting in oocyte aspiration, are compared retrospectively for the number of ultrasound (US) measurements carried out during monitoring and for results of IVF treatment. No patient selection took place. After introduction of a minimal monitoring protocol at a transport clinic, a prospective study was started comparing 100 minimal monitoring cycles at a transport clinic with 100 concurrent conventional monitoring cycles at satellite clinics, all resulting in oocyte aspiration. Patients entered the retrospective or prospective study only once. In all cases the same laboratory facility was used. Monitoring of ovarian hyperstimulation was done with US measurements only. Cycles were canceled for impending ovarian hyperstimulation syndrome (OHSS) when > 35 follicles were seen to develop during hyperstimulation.

RESULTS

Retrospective analysis shows no difference for the average number of US measurements at transport and satellite clinics (2.8 +/- 0.9 and 3.0 +/- 1.0; mean +/- SD). No differences were found in the number of ongoing pregnancies obtained in the two groups: 22 and 18, respectively. One case of severe OHSS occurred in the satellite clinic group. Introduction of minimal monitoring at the transport clinic gives a significant reduction of the average number of US measurements at the transport clinic compared with satellite clinics, where conventional monitoring continued to be used (1.5 +/- 0.8 versus 2.8 +/- 0.9). Ongoing pregnancies at transport and satellite clinics numbered 33 and 26, respectively. In both groups one patient developed severe OHSS. Sixty-two percent of cycles at the transport clinic were monitored with one US measurement only. No cancellations for impending OHSS occurred during the study period.

CONCLUSION

A large group of patients need only one US measurement during monitoring of ovarian hyperstimulation. Minimal monitoring gives a useful further simplification of the clinical phase of IVF treatment, without adverse effects on treatment outcome and incidence of OHSS.

Results of decentralized in-vitro fertilization treatment with transport and satellite clinics

The results of in-vitro fertilization (IVF) treatments carried out in a university IVF centre are compared with those obtained following 15-40 min transportation of oocytes from a transport IVF clinic to the central IVF laboratory of the university centre. Moreover, treatment results following monitoring of ovarian stimulation in satellite clinics, combined with ovum retrieval at the transport clinic and transport of oocytes to the central IVF laboratory, are described. In a total of 5540 IVF treatment cycles, 24-26% of viable pregnancies per embryo transfer were found in the three groups. Comparison of results, obtained with the three different treatment modalities, showed no negative influences of transporting oocytes from transport clinic to IVF laboratory and of monitoring ovarian stimulation in satellite clinics. It is concluded that decentralization of the clinical phase of IVF treatment is possible. This leads to a more optimal use of existing laboratory facilities in large urban areas. It is stressed that good communication between satellite clinic, transport clinic and IVF laboratory is necessary for a decentralized IVF programme. To obtain good quality assurance, both the satellite clinic and the transport clinic must adhere to the same protocol.