Innate Responses to the Former COVID-19 Vaccine Candidate CVnCoV and Their Relation to Reactogenicity and Adaptive Immunogenicity

Vaccines are highly effective at preventing severe coronavirus disease (COVID-19). With mRNA vaccines, further research is needed to understand the association between immunogenicity and reactogenicity, which is defined as the physical manifestation of an inflammatory response to a vaccination. This study analyzed the immune response and reactogenicity in humans, post immunization, to the former SARS-CoV-2 mRNA investigational vaccine CVnCoV (CV-NCOV-001 and CV-NCOV-002 clinical trials). Immunogenicity was investigated using whole-blood RNA sequencing, serum cytokine levels, and SARS-CoV-2-specific antibodies. The T cell responses in peripheral blood were assessed using intracellular cytokine staining (ICS) and high-dimensional profiling in conjunction with SARS-CoV-2 antigen-specificity testing via mass cytometry. Reactogenicity was graded after participants' first and second doses of CVnCoV using vaccine-related solicited adverse events (AEs). Finally, a Spearman correlation was performed between reactogenicity, humoral immunity, and serum cytokine levels to assess the relationship between reactogenicity and immunogenicity post CVnCoV vaccination. Our findings showed that the gene sets related to innate and inflammatory immune responses were upregulated one day post CVnCoV vaccination, while the gene sets related to adaptive immunity were upregulated predominantly one week after the second dose. The serum levels of IFNα, IFNγ, IP-10, CXCL11, IL-10, and MCP-1 increased transiently, peaking one day post vaccination. CD4+ T cells were induced in all vaccinated participants and low frequencies of CD8+ T cells were detected by ex vivo ICS. Using mass cytometry, SARS-CoV-2 spike-specific CD8+ T cells were induced and were characterized as having an activated effector memory phenotype. Overall, the results demonstrated a positive correlation between vaccine-induced systemic cytokines, reactogenicity, and adaptive immunity, highlighting the importance of the balance between the induction of innate immunity to achieve vaccine efficacy and ensuring low reactogenicity.

Corrigendum to "Safety and immunogenicity of mRNA-LNP COVID-19 vaccine CVnCoV in Latin American adults: A phase 2 randomized study" [Vaccine: X 11 (2022) 100189]

[This corrects the article DOI: 10.1016/j.jvacx.2022.100189.].

Safety and immunogenicity of mRNA-LNP COVID-19 vaccine CVnCoV in Latin American adults: a phase 2 randomized study

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Two 12 µg CVnCoV doses are immunogenic against S-protein in adults.

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Immune responses were lower in > 60 year-olds than 18–60 year-olds.

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Distinct neutralizing antibody and CD4 + T cell responses to S-protein were induced.

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Booster doses increased responses to S-protein showing immune memory was induced.

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Three 12 µg doses are well tolerated with mainly mild to moderate adverse events.

Background

The COVID-19 vaccine candidate CVnCoV comprises sequence-optimized mRNA encoding SARS-CoV-2 S-protein encapsulated in lipid nanoparticles. In this phase 2a study, we assessed reactogenicity and immunogenicity of two or three doses in younger and older adults.

Methods

Younger (18–60 years) and older (>60 years) adults were enrolled in two sites in Panama and Peru to receive either 6 or 12 µg doses of CVnCoV or licensed control vaccines 28 days apart; subsets received a 12 µg booster dose on Day 57 or Day 180. Solicited adverse events (AE) were reported for 7 days and unsolicited AEs for 4 weeks after each vaccination, and serious AEs (SAE) throughout the study. Humoral immunogenicity was measured as neutralizing and receptor binding domain (RBD) IgG antibodies and cellular immunogenicity was assessed as CD4+/CD8 + T cell responses.

Results

A total of 668 participants were vaccinated (332 aged 18–60 years and 336 aged > 60 years) including 75 who received homologous booster doses. Vaccination was well tolerated with no vaccine-related SAEs. Solicited and unsolicited AEs were mainly mild to moderate and resolved spontaneously. Both age groups demonstrated robust immune responses as neutralizing antibodies or RBD-binding IgG, after two doses, with lower titers in the older age group than the younger adults. Neither group achieved levels observed in human convalescent sera (HCS), but did equal or surpass HCS levels following homologous booster doses. Following CVnCoV vaccination, robust SARS-CoV-2 S-protein-specific CD4 + T-cell responses were observed in both age groups with CD8 + T-cell responses in some individuals, consistent with observations in convalescing COVID-19 patients after natural infection.

Conclusions

We confirmed that two 12 µg doses of CVnCoV had an acceptable safety profile, and induced robust immune responses. Marked humoral immune responses to homologous boosters suggest two doses had induced immune memory.

A Third Dose of the COVID-19 Vaccine, CVnCoV, Increased the Neutralizing Activity against the SARS-CoV-2 Wild-Type and Delta Variant

A third dose of CVnCoV, a former candidate mRNA vaccine against SARS-CoV-2, was previously shown to boost neutralizing antibody responses against SARS-CoV-2 wild-type in adults aged 18−60 and >60 years in a phase 2a clinical study. In the present study, we report the neutralizing antibody responses to a wild-type and a variant of concern, Delta, after a third dose of the vaccine on day (D)57 and D180. Neutralization activity was assessed using a microneutralization assay. Comparable levels of neutralizing antibodies against the wild-type and Delta were induced. These were higher than those observed after the first two doses, irrespective of age or pre-SARS-CoV-2-exposure status, indicating that the first two doses induced immune memory. Four weeks after the third dose on D180, the neutralizing titers for wild-type and Delta were two-fold higher in younger participants than in older participants; seroconversion rates were 100% for wild-type and Delta in the younger group and for Delta in the older group. A third CVnCoV dose induced similar levels of neutralizing responses against wild-type virus and the Delta variant in both naïve and pre-exposed participants, aligning with current knowledge from licensed COVID-19 vaccines that a third dose is beneficial against SARS-CoV-2 variants.

Abstract 2161: Identifying GDF-15 as potential novel immunotherapeutic target linked to immune cell exclusion in tumors and resistance to anti-PD-1 treatment

Introduction:

Growth and differentiation factor 15 (GDF-15) is a TGF-β superfamily member mainly expressed in placenta and prostate of healthy individuals. GDF-15 has been linked to feto-maternal tolerance, prevention of excessive immune cell infiltration during tissue damage and to anorexia. In cancer patients, GDF-15 serum levels are frequently elevated and associated with poor prognosis, via so far mostly unknown mechanism(s). A recent study elucidated a mechanism by which GDF-15 inhibits LFA-1 activation on CD8+ T cells, thus interfering with T cell recruitment to tissues [Haake et al. AACR 2020; submitted]. To further delineate the role of GDF-15 in cancer in this study GDF-15 serum and tissue levels were analyzed and correlated with tumoral immune-cell infiltration and clinical anti-PD1 response.

Methods:

In-silico, TCGA-derived mRNA levels of GDF-15 were compared in cancer vs. normal tissue. Two independent melanoma patient cohorts (88 and 34 patients) treated with nivolumab or pembrolizumab were analyzed regarding baseline GDF-15 serum levels, correlation with clinical response and overall survival. Melanoma brain metastases from 80 patients were collected to assess and compare intratumoral GDF-15 levels vs. CD3+, CD8+ and Foxp3+ cell numbers by immunohistochemistry (IHC).

Results:

TCGA-based analyses demonstrated significantly elevated GDF-15 mRNA levels in tumor vs. surrounding normal tissue in various major cancer types such as e.g. colorectal, prostate, head & neck and melanoma. In the two independent, anti-PD1 treated melanoma patient cohorts baseline serum GDF-15 levels were predictive for superior overall survival and clinical response to anti-PD1 treatment (p<0.0001 and p=0.0382, respectively). In melanoma biopsies an inverse correlation of GDF-15 levels (histoscore) with CD3+ (R=-0.26; p=0.016) and CD8+ T cells (R=-0.21; p=0.05), but no correlation with Foxp3+ T cells was shown.

Conclusion:

GDF-15 is elevated in serum and tumor tissue of various major cancer types. In melanoma, patients with higher GDF-15 levels have significantly shorter survival and are less likely to respond to anti-PD1 therapy. In addition, intratumoral GDF-15 levels in melanoma brain metastasis correlate inversely with CD3+ and CD8+ T cell infiltration. Consequently, GDF-15 may serve as a predictive biomarker for anti-PD1 response and potentially represent a novel target in the immunotherapy of cancer to improve tumor immune cell infiltration and anti-PD1 response.

Citation Format: Jorg Wischhusen, Kilian Wistuba-Hamprecht, Patrick N. Harter, Phil Cheng, Alexander Martens, Falk Gogolla, Yumi Nonomura, Paula Romer, Sven D. Koch, Markus Haake, Christine Schuberth-Wagner, Manfred Rudiger, Eugen Leo, Michael Mittelbronn, Mitchell P. Levesque, Hubert Hackl, Reinhard Dummer, Benjamin Weide. Identifying GDF-15 as potential novel immunotherapeutic target linked to immune cell exclusion in tumors and resistance to anti-PD-1 treatment [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2161.

A large multicentre, randomized, double-blind, cross-over study in healthy volunteers to compare pharmacokinetics, pharmacodynamics and safety of a pegfilgrastim biosimilar with its US- and EU-reference biologics

Aims

Recombinant PEGylated human granulocyte colony‐stimulating factor (pegfilgrastim) is indicated for the reduction of chemotherapy‐induced neutropenia and prevention of febrile neutropenia. Biosimilar pegfilgrastim is expected to reduce the financial burden of this complication of chemotherapy. The aim of this study was to demonstrate biosimilarity between Sandoz biosimilar pegfilgrastim and its US‐ and EU‐approved reference biologics.

Methods

Phase I, randomized, double‐blind, single‐dose, 3‐period, 6‐sequence cross‐over, multicentre study to evaluate the pharmacokinetics, pharmacodynamics, safety and immunogenicity of Sandoz biosimilar pegfilgrastim with US‐ and EU‐references in healthy adults.

Results

Pharmacokinetic and pharmacodynamic similarity was demonstrated between the 3 biologics, as the 90% confidence interval for all primary pharmacokinetic and pharmacodynamic endpoint comparisons were contained within the predefined similarity margins of 0.80–1.25. Safety, immunogenicity and tolerability were also similar.

Conclusions

Sandoz biosimilar pegfilgrastim demonstrated pharmacokinetic and pharmacodynamic similarity to both US‐ and EU‐reference biologics. No meaningful differences in safety, local tolerability and immunogenicity were identified.

A large multicenter, randomized, double-blind, crossover study in healthy volunteers, comparing pharmacokinetics and pharmacodynamics of Sandoz proposed biosimilar pegfilgrastim with European and United States reference pegfilgrastim

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Background: Similarity of the pharmacokinetic (PK)/pharmacodynamic (PD) profiles of Sandoz proposed biosimilar pegfilgrastim and EU-reference biologic was confirmed in a pivotal Phase I study. In order to confirm PK/PD similarity to the US reference biologic, and to bridge between the two references, a 3-way study was conducted. Methods: A randomized, double-blind, single-dose, 3-treatment, 6-sequence crossover Phase I study was performed in healthy volunteers (HVs) to demonstrate similarity in PK, PD, safety and immunogenicity between Sandoz proposed biosimilar, US reference, and EU reference pegfilgrastim administered subcutaneously (6 mg/0.6 mL) in each treatment period. The primary objective was to demonstrate PK (AUC0-inf, AUC0-last, Cmax) and PD similarity (ANC AUEC0-last, ANC Emax). The study was powered (90%) to achieve confidence intervals (CIs) within biosimilarity margins 0.8─1.25 in pairwise comparisons. Secondary objectives were additional PK/PD parameters, safety and immunogenicity. Results: The study included 577 male and female HVs. PK and PD similarity were demonstrated between Sandoz proposed biosimilar and US reference (Table), as well as EU reference and between both reference biologics since the 90% CIs of the geometric mean ratios were contained within the pre-defined margins of 0.80‒1.25. Safety, immunogenicity and secondary PK/PD parameters were also similar across treatment groups. Conclusions: This large randomized, double-blind, single-dose, 3-treatment, 6-sequence crossover study demonstrated PK and PD similarity between Sandoz proposed biosimilar, US reference and EU reference pegfilgrastim with similar safety, local tolerability and immunogenicity. Clinical trial information: 2016-003549-27. [Table: see text]

A phase I/IIa study of the mRNA-based cancer immunotherapy CV9201 in patients with stage IIIB/IV non-small cell lung cancer

CV9201 is an RNActive®-based cancer immunotherapy encoding five non-small cell lung cancer-antigens: New York esophageal squamous cell carcinoma-1, melanoma antigen family C1/C2, survivin, and trophoblast glycoprotein. In a phase I/IIa dose-escalation trial, 46 patients with locally advanced (n = 7) or metastatic (n = 39) NSCLC and at least stable disease after first-line treatment received five intradermal CV9201 injections (400-1600 µg of mRNA). The primary objective of the trial was to assess safety. Secondary objectives included assessment of antibody and ex vivo T cell responses against the five antigens, and changes in immune cell populations. All CV9201 dose levels were well-tolerated and the recommended dose for phase IIa was 1600 µg. Most AEs were mild-to-moderate injection site reactions and flu-like symptoms. Three (7%) patients had grade 3 related AEs. No related grade 4/5 or related serious AEs occurred. In phase IIa, antigen-specific immune responses against ≥ 1 antigen were detected in 63% of evaluable patients after treatment. The frequency of activated IgD+CD38hi B cells increased > twofold in 18/30 (60%) evaluable patients. 9/29 (31%) evaluable patients in phase IIa had stable disease and 20/29 (69%) had progressive disease. Median progression-free and overall survival were 5.0 months (95% CI 1.8-6.3) and 10.8 months (8.1-16.7) from first administration, respectively. Two- and 3-year survival rates were 26.7% and 20.7%, respectively. CV9201 was well-tolerated and immune responses could be detected after treatment supporting further clinical investigation.

Phase Ib evaluation of a self-adjuvanted protamine formulated mRNA-based active cancer immunotherapy, BI1361849 (CV9202), combined with local radiation treatment in patients with stage IV non-small cell lung cancer

BACKGROUND

Preclinical studies demonstrate synergism between cancer immunotherapy and local radiation, enhancing anti-tumor effects and promoting immune responses. BI1361849 (CV9202) is an active cancer immunotherapeutic comprising protamine-formulated, sequence-optimized mRNA encoding six non-small cell lung cancer (NSCLC)-associated antigens (NY-ESO-1, MAGE-C1, MAGE-C2, survivin, 5T4, and MUC-1), intended to induce targeted immune responses.

METHODS

We describe a phase Ib clinical trial evaluating treatment with BI1361849 combined with local radiation in 26 stage IV NSCLC patients with partial response (PR)/stable disease (SD) after standard first-line therapy. Patients were stratified into three strata (1: non-squamous NSCLC, no epidermal growth factor receptor (EGFR) mutation, PR/SD after ≥4 cycles of platinum- and pemetrexed-based treatment [n = 16]; 2: squamous NSCLC, PR/SD after ≥4 cycles of platinum-based and non-platinum compound treatment [n = 8]; 3: non-squamous NSCLC, EGFR mutation, PR/SD after ≥3 and ≤ 6 months EGFR-tyrosine kinase inhibitor (TKI) treatment [n = 2]). Patients received intradermal BI1361849, local radiation (4 × 5 Gy), then BI1361849 until disease progression. Strata 1 and 3 also had maintenance pemetrexed or continued EGFR-TKI therapy, respectively. The primary endpoint was evaluation of safety; secondary objectives included assessment of clinical efficacy (every 6 weeks during treatment) and of immune response (on Days 1 [baseline], 19 and 61).

RESULTS

Study treatment was well tolerated; injection site reactions and flu-like symptoms were the most common BI1361849-related adverse events. Three patients had grade 3 BI1361849-related adverse events (fatigue, pyrexia); there was one grade 3 radiation-related event (dysphagia). In comparison to baseline, immunomonitoring revealed increased BI1361849 antigen-specific immune responses in the majority of patients (84%), whereby antigen-specific antibody levels were increased in 80% and functional T cells in 40% of patients, and involvement of multiple antigen specificities was evident in 52% of patients. One patient had a partial response in combination with pemetrexed maintenance, and 46.2% achieved stable disease as best overall response. Best overall response was SD in 57.7% for target lesions.

CONCLUSION

The results support further investigation of mRNA-based immunotherapy in NSCLC including combinations with immune checkpoint inhibitors.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01915524 .

RNAdjuvant®, a novel, highly-potent RNA-based adjuvant, combines strong immunostimulatory capacities with a favorable safety profile

Purified recombinant proteins and peptides, which are currently under development in various anti-cancer vaccination approaches, lack sufficient immunogenicity. Therefore, potent adjuvants are needed to induce strong and persistent anti-tumor immunity. However, currently only few adjuvants are licensed, most of which primarily enhance antibody, but not T cell responses.

Here, we demonstrate that a novel, well defined, and thoroughly characterized RNA-based adjuvant mediates balanced and long-lasting humoral and cellular immune responses. Our adjuvant significantly enhances anti-tumor immunity, and even complete tumor rejection can be achieved as shown for the syngeneic TC-1 tumor model, a murine model of human HPV-induced cervical cancer.

Our adjuvant acts locally, promoting strong but transient up-regulation of anti-viral and pro-inflammatory cytokines, CXCR3-ligands and cytoplasmic RNA sensors at the injection site, avoiding any systemic cytokine release. A phase I first in man clinical trial testing different doses of RNAdjuvant® alone and in combination with reduced doses of the licensed rabies vaccine Rabipur® was successfully conducted in 43 subjects. Healthy volunteers received 2 intramuscular injections of RNAdjuvant® on days 0 and 21, either alone or in combination with 1/20 or 1/10 of the licensed Rabipur® dose. Virus neutralizing antibody titers (VNTs) measured on days 14 and 28 revealed a significant increase in median VNTs in subjects with RNAdjuvant® compared to their respective control group with 1/10 dose Rabipur® alone.

In summary, our data suggest that RNAdjuvant® represents a novel, highly efficacious adjuvant candidate that can enhance cellular and humoral immune responses.

Distinct transcriptional changes in non-small cell lung cancer patients associated with multi-antigenic RNActive® CV9201 immunotherapy

We recently completed a phase I/IIa trial of RNActive® CV9201, a novel mRNA-based therapeutic vaccine targeting five tumor-associated antigens in non-small cell lung cancer (NSCLC) patients. The aim of the study presented here was to comprehensively analyze changes in peripheral blood during the vaccination period and to generate hypotheses facilitating the identification of potential biomarkers correlating with differential clinical outcomes post RNActive® immunotherapy. We performed whole-genome expression profiling in a subgroup of 22 stage IV NSCLC patients before and after initiation of treatment with CV9201. Utilizing an analytic approach based on blood transcriptional modules (BTMs), a previously described, sensitive tool for blood transcriptome data analysis, patients segregated into two major clusters based on transcriptional changes post RNActive® treatment. The first group of patients was characterized by the upregulation of an expression signature associated with myeloid cells and inflammation, whereas the other group exhibited an expression signature associated with T and NK cells. Patients with an enrichment of T and NK cell modules after treatment compared to baseline exhibited significantly longer progression-free and overall survival compared to patients with an upregulation of myeloid cell and inflammatory modules. Notably, these gene expression signatures were mutually exclusive and inversely correlated. Furthermore, our findings correlated with phenotypic data derived by flow cytometry as well as the neutrophil-to-lymphocyte ratio. Our study thus demonstrates non-overlapping, distinct transcriptional profiles correlating with survival warranting further validation for the development of biomarker candidates for mRNA-based immunotherapy.

Phase Ib study evaluating a self-adjuvanted mRNA cancer vaccine (RNActive®) combined with local radiation as consolidation and maintenance treatment for patients with stage IV non-small cell lung cancer

BACKGROUND

Advanced non-small cell lung cancer (NSCLC) represents a significant unmet medical need. Despite advances with targeted therapies in a small subset of patients, fewer than 20% of patients survive for more than two years after diagnosis. Cancer vaccines are a promising therapeutic approach that offers the potential for durable responses through the engagement of the patient's own immune system. CV9202 is a self-adjuvanting mRNA vaccine that targets six antigens commonly expressed in NSCLC (NY-ESO-1, MAGEC1, MAGEC2, 5 T4, survivin, and MUC1).

METHODS/DESIGN

The trial will assess the safety and tolerability of CV9202 vaccination combined with local radiation designed to enhance immune responses and will include patients with stage IV NSCLC and a response or stable disease after first-line chemotherapy or therapy with an EGFR tyrosine kinase inhibitor. Three histological and molecular subtypes of NSCLC will be investigated (squamous and non-squamous cell with/without EGFR mutations). All patients will receive two initial vaccinations with CV9202 prior to local radiotherapy (5 GY per day for four successive days) followed by further vaccinations until disease progression. The primary endpoint of the study is the number of patients experiencing Grade >3 treatment-related adverse events. Pharmacodynamic analyses include the assessment of immune responses to the antigens encoded by CV9202 and others not included in the panel (antigen spreading) and standard efficacy assessments.

DISCUSSION

RNActive self-adjuvanted mRNA vaccines offer the potential for simultaneously inducing immune responses to a wide panel of antigens commonly expressed in tumors. This trial will assess the feasibility of this approach in combination with local radiotherapy in NSCLC patients.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT01915524/EudraCT No.: 2012-004230-41.

A novel, disruptive vaccination technology: self-adjuvanted RNActive(®) vaccines

Nucleotide based vaccines represent an enticing, novel approach to vaccination. We have developed a novel immunization technology, RNActive^® vaccines, that have two important characteristics: mRNA molecules are used whose protein expression capacity has been enhanced by 4 to 5 orders of magnitude by modifications of the nucleotide sequence with the naturally occurring nucleotides A (adenosine), G (guanosine), C (cytosine), U (uridine) that do not affect the primary amino acid sequence. Second, they are complexed with protamine and thus activate the immune system by involvement of toll-like receptor (TLR) 7. Essentially, this bestows self-adjuvant activity on RNActive^® vaccines. RNActive^® vaccines induce strong, balanced immune responses comprising humoral and cellular responses, effector and memory responses as well as activation of important subpopulations of immune cells, such as Th1 and Th2 cells. Pre-germinal center and germinal center B cells were detected in human patients upon vaccination. RNActive^® vaccines successfully protect against lethal challenges with a variety of different influenza strains in preclinical models. Anti-tumor activity was observed preclinically under therapeutic as well as prophylactic conditions. Initial clinical experiences suggest that the preclinical immunogenicity of RNActive^® could be successfully translated to humans.

Analysis of stem-cell-like properties of human CD161++IL-18Rα+ memory CD8+ T cells

CD161(++)IL-18Rα(+)CD8(+) human T cells have recently been identified as a new subset of memory cells but their exact role remains unclear. CD161(++)IL-18Rα(+)CD8(+), mucosal-associated invariant T cells express a semi-invariant TCR Vα7.2-Jα33, which recognizes the MHC-related protein 1. On the basis of properties including the expression of the ABC-B1 transporter, cKit expression and survival after chemotherapy, CD161(++)IL-18Rα(+)CD8(+) T cells have been designated as 'stem' cells. Here we analyse location and functional properties of CD161(++)IL-18Rα(+) CD8(+) T cells and question whether they have other traits that would mark them as genuine 'stem' cells. CD161(++)IL-18Rα(+)CD8(+) T cells were found in peripheral blood, spleen and bone marrow but interestingly hardly at all in lymph nodes (LNs), which may possibly be explained by the finding that these cells express a specific set of chemokine receptors that allows migration to inflamed tissue rather than to LNs. In addition to TCR ligation and co-stimulation, CD161(++)IL-18Rα(+) CD8(+) T cells require cytokines for proliferation. The CD161(++)IL-18Rα(+) CD8(+) pool contains cells reactive towards peptides, derived from both persisting and cleared viruses. Although CD161(++)IL-18Rα(+) CD8(+) T cells express the ABC-B1 transporter, they have shorter telomeres and less telomerase activity and do not express aldehyde dehydrogenase. Finally, CD161(++)IL-18Rα(+) CD8(+) T cells show similarities to terminally differentiated T cells, expressing IFNγ, KLRG1 and the transcription factor Blimp-1. In conclusion, CD161(++)IL-18Rα(+) CD8(+) T cells lack many features of typical 'stem' cells, but appear rather to be a subset of effector-type cells.

Characteristics of alloreactive T cells measured before renal transplantation

Several assays to measure pre-existing allospecific T cell immunity in renal transplant candidates have been developed in the past years. In 46 patients, we used flow cytometry-based mixed lymphocyte culture to measure the precursor frequency and phenotype of alloreactive T cells before renal transplantation, using donor-specific or third-party cells for allostimulation. Allostimulation induced up-regulation of co-stimulatory molecules, chemokine receptors relevant for migration of T cells into the graft and effector proteins. Recipients prone for acute rejection had a higher precursor frequency of alloreactive CD8(+) T cells and a lower percentage of interleukin (IL)-7Rα expressing alloreactive CD8(+) T cells than non-rejectors. These data point to quantitative and qualitative differences between T cells of patients who will experience acute cellular rejection episodes from those who will not.

Messenger RNA vaccination and B-cell responses in NSCLC patients

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Background: Vaccination with mRNA is a novel technology in cancer immunotherapy. CV9201 consists of self-adjuvanted mRNA molecules (RNActive) coding for five non small cell lung cancer (NSCLC)-associated tumor antigens (MAGE-C1, MAGE-C2, NY-ESO-1, BIRC5, 5T4). We report final results of a phase I/IIa trial of CV9201 in patients (pts.) with NSCLC. Methods: Pts. with stage IIIB/IV NSCLC with a response or stable disease after first-line chemotherapy or chemoradiation were eligible. Cohorts of 3 pts. were treated at three dose levels (400µg, 800µg and 1600µg CV9201) and observed for DLTs to select the highest tolerated dose for phase IIa. Primary endpoint was safety and tolerability; secondary endpoints were immune response, clinical efficacy and survival. Pts. received up to five vaccinations of CV9201 within 15 weeks. Antigen-specific immune responses against each of the 5 antigens were measured at baseline, and two weeks after the 3rd and 5th vaccination. Frequency of lymphocyte subsets and expression of activation and maturation markers were measured and retrospectively correlated with immunological and clinical parameters. Results: 46 pts. were included (9 phase I; 37 phase IIa); No DLTs occurred, and the 1600 µg dose was investigated in phase IIa. The most frequent related adverse events were mild to moderate injection site reactions and flu-like symptoms. 3 patients (7%) had potentially related grade 3 AEs (fatigue, injection site granuloma, asthma attack) and no related SAEs were reported. There were no objective responses. Data on PFS and survival will be presented. Antigen specific immune responses against at least one antigen were induced in 65% of pts. (39% cellular and 49% humoral). Consistently, a significant ≥2 fold increase of pre germinal center B cells (pGCB) was observed in 61% of pts. This increase of pGCB correlated significantly (p=0.0028) with increase of total CD4 effector T cells. Frequency of CD 4 T Reg cells did not increase during treatment. Conclusions: Vaccination with CV9201 has a favorable safety profile and induces T and B cell responses against all included antigens. Vaccine-induced increase of pGCB is a new finding and might be used as a biomarker in cancer immunotherapy.

Maintenance immunosuppressive therapy with everolimus preserves humoral immune responses

While the guidelines for vaccination in renal transplant recipients recommend the use of pneumococcal polysaccharide (PPS) and tetanus toxoid (TT), their efficacy in immunocompromised renal transplant recipients is not known. Here we tested the effect of everolimus on immune responses after vaccination by measuring the capacity of 36 stable renal transplant recipients to mount cellular and humoral responses after vaccination. Twelve patients in each treatment arm received immunosuppressive therapy consisting of prednisolone (P) plus cyclosporine (CsA), mycophenolate sodium (MPA), or everolimus. Patients were vaccinated with the T-cell-dependent antigens immunocyanin and TT, and the T-cell-independent PPS. Treatment with CsA partially inhibited and MPA completely abolished the capacity to mount a primary humoral response, whereas everolimus left this largely intact. Recall responses were inhibited by MPA only. All drug combinations inhibited cellular responses against TT. In patients treated with MPA, B-cell numbers were severely reduced. Thus, combined with P, treatment with MPA completely disturbed primary and secondary humoral responses. Everolimus or CsA allowed the boosting of T-cell-dependent and -independent secondary humoral responses. Treatment with everolimus allowed a primary response.

Simultaneous infiltration of polyfunctional effector and suppressor T cells into renal cell carcinomas

Renal cell carcinoma is frequently infiltrated by cells of the immune system. This makes it important to understand interactions between cancer cells and immune cells so they can be manipulated to bring clinical benefit. Here, we analyze subsets and functions of T lymphocytes infiltrating renal cell tumors directly ex vivo following mechanical disaggregation and without any culture step. Subpopulations of memory and effector CD4(+) Th1, Th2, and Th17 and CD8(+) Tc1 cells were identified based on surface phenotype, activation potential, and multicytokine production. Compared with the same patient's peripheral blood, T lymphocytes present inside tumors were found to be enriched in functional CD4(+) cells of the Th1 lineage and in effector memory CD8(+) cells. Additionally, several populations of CD4(+) and CD8(+) regulatory T cells were identified that may synergize to locally dampen antitumor T-cell responses.

Alloantigen-induced regulatory CD8+CD103+ T cells

Regulatory T cells (Tregs) appear of great importance in the balance between alloreactivity and tolerance and subsets of both CD4(+) and CD8(+) T cells have been recognized to function as regulatory T cells after allogenic transplantation. Among the CD8(+) T-cell subsets, the CD103(+) cells were most recently identified as regulatory. In this review, we describe their phenotypical and functional properties, as well as their relevance for the alloimmune response in vivo. These CD8(+)CD103(+) Tregs are generated within mixed lymphocyte cultures (MLCs) and are elevated by additional transforming growth factor-beta. Interestingly, myeloid dendritic cells are the responsible cell type for induction of CD103(+) Tregs. Allostimulated CD8(+)CD103(+) Tregs display an antigen-experienced effector phenotype with limited effector functions such as cytotoxicity and interferon-gamma production and show a reduced proliferation capacity after restimulation. Beside this anergic phenotype, CD8(+)CD103(+) Tregs are able to suppress alloreactive effector T cells. Through intracellular cytokine staining and transwell assays, we showed that the mechanism of suppression is cytokine independent, but close cell-cell contact is required for suppression.

Keyless data capture: emerging technologies in health information processing

As middle managers, medical record practitioners will be involved in justification of auto ID technology to upper management. To prepare a good justification, one must have a thorough knowledge of the technology and its advantages and disadvantages. One must also be familiar with the payback period and the installation process. This article has attempted to introduce the reader to some emerging technologies in health care, and answer some of the questions that are key to justifying their acquisition. By most estimates, these technologies are finding their way into health care, however slowly, and hold much promise for improvement in productivity and accuracy in data collection.