Kutane T-Zell-Lymphome – Update 2021

Kutane T-Zell-Lymphome (CTCL) machen den Großteil aller primären kutanen Lymphome (CL) aus. 80 % aller Fälle von CTCL wiederum entfallen auf Mycosis fungoides (MF) und CD30-positive lymphoproliferative Erkrankungen der Haut. Das klinische Bild der verschiedenen Formen von CTCL zeigt Überschneidungen. Darum ist die klinisch-pathologische Korrelation von großer Bedeutung für die finale Diagnosestellung. Die MF zeigt einen charakteristischen Verlauf mit makuläre Läsionen (Patches), infiltrierte Plaques und, bei einem Teil der Patienten (10–20 %), Tumoren. Die Behandlung erfolgt stadienorientiert mit auf die Haut gerichteten Therapien wie UV-Lichttherapien und Kortikosteroiden in frühen Stadien der Erkrankung (Patch- und begrenztes Plaque-Stadium) und systemischen Therapien (Retinoide bzw. Rexinoide, Interferon, Monochemotherapie, zielgerichtete Therapie) und/oder Strahlentherapie (lokal oder Ganzkörperbestrahlung mit Elektronen) in fortgeschrittenen Stadien. Neuartige Ansätze umfassen zielgerichtete Therapien wie Mogamulizumab (Antikörper gegen CCR4) oder Brentuximab Vedotin (Antikörper gegen CD30) sowie Histon-Deacetylase-Inhibitoren. Angesichts des Impacts von zielgerichteten Therapien sind Biomarker wie CD30 nicht nur für die Diagnosestellung und korrekte Klassifikation eines Lymphoms im Einzelfall von großer Bedeutung, sondern als potenzielle Wirkstoff-Zielmoleküle auch für die Therapie. In der kürzlich überarbeiteten WHO-Klassifikation von 2017 und der aktualisierten WHO-EORTC-Klassifikation der CL von 2018 ist erstmals das CD8-positive akrale T-Zell-Lymphom als eigene, noch provisorische Entität aufgeführt. Diese Form zeigt charakteristische klinische, histologische und phänotypische Merkmale und eine hervorragende Prognose. Zu den seltenen, aber aggressiven CTCL zählen das primär kutane aggressive epidermotrope CD8-positive T-Zell-Lymphom und das kutane Gamma/Delta-T-Zell-Lymphom, die durch rasches Auftreten nekrotischer oder ulzerierender Plaques und Tumoren gekennzeichnet sind. Da bei diesen Formen die Prognose ungünstig ist, umfasst die Behandlung Polychemotherapien und hämatopoetische Stammzelltransplantationen.

Cohort-specific serological recognition of SARS-CoV-2 variant RBD antigens

Background: Estimating the response of different cohorts (e.g. vaccinated or critically ill) to new SARS-CoV-2 variants is important to customize measures of control. Thus, our goal was to evaluate binding of antibodies from sera of infected and vaccinated people to different antigens expressed by SARS-CoV-2 variants. Methods: We compared sera from vaccinated donors with sera from four patient/donor cohorts: critically ill patients admitted to an intensive care unit (split in sera collected between 2 and 7 days after admission and more than ten days later), a NIBSC/WHO reference panel of SARS-CoV-2 positive individuals, and ambulatory or hospitalized (but not critically ill) positive donors. Samples were tested with an anti-SARS-CoV-2 IgG serological assay designed with microplates coated with a SARS-CoV-2 RBD recombinant antigen. The same sample sets were also tested with microplates coated with antigens harbouring RBD mutations present in eleven of the most widespread variants. Results: Sera from vaccinated individuals exhibited higher antibody binding (P<0.001) than sera from infected (but not critically ill) individuals when tested against the WT and each of 11 variants' RBD. The optical density generated by sera from non-critically ill convalescence individuals upon binding to variant's antigens was different (P<0.05) from that of the WT in some variants-noteworthy, Beta, Gamma, Delta, and Delta Plus variants. Conclusions: Understanding differences in binding and neutralizing antibody titers against WT vs variant RBD antigens from different donor cohorts can help design variant-specific immunoassays and complement other diagnostic and clinical data to evaluate the epidemiology of new variants. Key Words: COVID-19; SARS-CoV-2 vaccine; SARS-CoV-2 variants; RBD mutations; antibody specificity; critically ill, immunoassays, serology.

Novel Immune-Related Genetic Expression for Primary Sjögren's Syndrome

Objective: To identify novel immune-related genes expressed in primary Sjögren's syndrome (pSS).Methods: Gene expression profiles were obtained from the Gene Expression Omnibus (GEO) database, and differentially expressed genes (DEGs) were screened. The differences in immune cell proportion between normal and diseased tissues were compared, weighted gene co-expression network analysis was conducted to identify key modules, followed by a protein–protein interaction (PPI) network generation and enrichment analysis. The feature genes were screened and verified using the GEO datasets and quantitative real-time PCR (RT-qPCR).Results: A total of 345 DEGs were identified, and the proportions of gamma delta T cells, memory B cells, regulatory T cells (Tregs), and activated dendritic cells differed significantly between the control and pSS groups. The turquoise module indicated the highest correlation with pSS, and 252 key genes were identified. The PPI network of key genes showed that RPL9, RBX1, and RPL31 had a relatively higher degree. In addition, the key genes were mainly enriched in coronavirus disease-COVID-2019, hepatitis C, and influenza A. Fourteen feature genes were obtained using the support vector machine model, and two subtypes were identified. The genes in the two subtypes were mainly enriched in the JAK-STAT, p53, and toll-like receptor signaling pathways. The majority of the feature genes were upregulated in the pSS group, verified using the GEO datasets and RT-qPCR analysis.Conclusions: Memory B cells, gamma delta T cells, Tregs, activated dendritic cells, RPL9, RBX1, RPL31, and the feature genes possible play vital roles in the development of pSS.

Neutralization of ancestral SARS-CoV-2 and variants Alpha, Beta, Gamma, Delta, Zeta and Omicron by mRNA vaccination and infection-derived immunity through homologous and heterologous variants

Emerging SARS-CoV-2 variants of concern/interest (VOC/VOI) raise questions about effectiveness of neutralizing antibodies derived from infection or vaccination. As the population immunity to SARS-CoV-2 has become more complex due to prior infection and/or vaccination, understanding the antigenic relationship between variants is needed. Here, we have assessed in total 104 blood specimens from convalescent individuals after infection with early-pandemic SARS-CoV-2 (pre-VOC) or with Alpha, Beta, Gamma or Delta, post-vaccination after double-dose mRNA-vaccination and break through infections due to Delta or Omicron. Neutralization against seven authentic SARS-CoV-2 isolates (B.1, Alpha, Beta, Gamma, Delta, Zeta, Omicron) was assessed by plaque-reduction neutralization assay. We found highest neutralization titers against the homologous (previously infecting) variant, with lower neutralization efficiency against heterologous variants. Significant loss of neutralization for Omicron was observed but to a varying degree depending on previously infecting variant (23.0-fold in Beta-convalescence up to 56.1-fold in Alpha-convalescence), suggesting that infection-derived immunity varies, but independent of the infecting variant is only poorly protective against Omicron. Of note, Zeta VOI showed also pronounced escape from neutralization of up to 28.2-fold in Alpha convalescent samples. Antigenic mapping reveals both Zeta and Omicron as separate antigenic clusters. Double dose vaccination showed robust neutralization for Alpha, Beta, Gamma, Delta and Zeta, with fold-change reduction of only 2.8 (for Alpha) up to 6.9 (for Beta). Escape from neutralization for Zeta was largely restored in vaccinated individuals, while Omicron still showed a loss of neutralization of 85.7-fold compared to pre-VOC SARS-CoV-2. Combined immunity from infection followed by vaccination or vaccine breakthrough infection showed highest titers and most robust neutralization for heterologous variants. Breakthrough infection with Delta showed only 12.5-fold reduced neutralization for Omicron, while breakthrough infection with Omicron showed only a 1.5-fold loss for Delta, suggests that infection with antigenically different variants can boost immunity for antigens closer to the vaccine strain. Antigenic cartography showed also a tendency towards broader neutralizing capacity for heterologous variants. We conclude that the complexity of background immunity needs to be taken into account when assessing new VOCs. Development towards separate serotypes such as Zeta was already observed before Omicron emergence, thus other factors than just immune escape must contribute to Omicrons rapid dominance. However, combined infection/vaccination immunity could ultimately lead to broad neutralizing capacity also against non-homologous variants.

THE OMICRON VARIANT BREAKS THE EVOLUTIONARY LINEAGE OF SARS-COV2 VARIANTS

We analyze here 7 very first strains of OMICRON the SARS-CoV2 new variant from South Africa, the USA (California and Minesota), Canada and Belgium. We applied, at the scale of the whole genome and the spike gene, the biomathematics method of Fibonacci meta-structure fractal analysis applied to the UA / CG proportions. We have evidenced the RUPTURE of OMICRON with respect to ALL the previous variants: D614G, ALPHA, BETA, GAMMA, DELTA. Remarkably, it is observed that the density of OMICRON mutations in the SPIKE PRION region is more than 8 times that of the rest of the Spike protein. In particular, we suggest that the mRNA stabilizing secondary structure ("hairpin" conformation) in the spike of all variants is degraded in OMICRON, probably making its mRNA more fragile. The loss of long-range fractal meta-structures in the OMICRON spike gene are in line with common knowledge on the mechanisms of epidemic ending, involving recombination of heavily mutated RNA fragments of the virus, with the possible inference of a distinct helper virus. This would indicate that the SARS-CoV2 is under very strong evolutionary pressure, possibly marking the end of the pandemic. We are studying more particularly the prion-like region of the spike, the mutations rate of which is 8 times higher in OMICRON than that of the whole spike protein.

Comparison of Plaque Size, Thermal Stability, and Replication Rate among SARS-CoV-2 Variants of Concern

SARS-CoV-2, like other RNA viruses, has a propensity for genetic evolution owing to the low fidelity of its viral polymerase. Several recent reports have described a series of novel SARS-CoV-2 variants. Some of these have been identified as variants of concern (VOCs), including alpha (B.1.1.7, Clade GRY), beta (B.1.351, Clade GH), gamma (P.1, Clade GR), and delta (B.1.617.2, Clade G). VOCs are likely to have some effect on transmissibility, antibody evasion, and changes in therapeutic or vaccine effectiveness. However, the physiological and virological understanding of these variants remains poor. We demonstrated that these four VOCs exhibited differences in plaque size, thermal stability at physiological temperature, and replication rates. The mean plaque size of beta was the largest, followed by those of gamma, delta, and alpha. Thermal stability, evaluated by measuring infectivity and half-life after prolonged incubation at physiological temperature, was correlated with plaque size in all variants except alpha. However, despite its relatively high thermal stability, alpha’s small plaque size resulted in lower replication rates and fewer progeny viruses. Our findings may inform further virological studies of SARS-CoV-2 variant characteristics, VOCs, and variants of interest. These studies are important for the effective management of the COVID-19 pandemic.

Vaccine-breakthrough infection by the SARS-CoV-2 Omicron variant elicits broadly cross-reactive immune responses

Highly transmissible SARS-CoV-2 Omicron variant has posted a new crisis for COVID-19 pandemic control. Within a month, Omicron is dominating over Delta variant in several countries probably due to immune evasion. It remains unclear whether vaccine-induced memory responses can be recalled by Omicron infection. Here, we investigated host immune responses in the first vaccine-breakthrough case of Omicron infection in Hong Kong. We found that the breakthrough infection rapidly recruited potent cross-reactive broad neutralizing antibodies (bNAbs) against current VOCs, including Alpha, Beta, Gamma, Delta and Omicron, from unmeasurable IC50 values to mean 1:2929 at around 9-12 days, which were higher than the mean peak IC50 values of BioNTech-vaccinees. Cross-reactive spike- and nucleocapsid-specific CD4 and CD8 T cell responses were detected. Similar results were also obtained in the second vaccine-breakthrough case of Omicron infection. Our preliminary findings may have timely implications to booster vaccine optimization and preventive strategies of pandemic control.