Biology subjects

Paluch, M.

Publications and source records attributed to Paluch, M..

3 recordsLinked to original sources

bioRxiv2025

A single MHCII neoepitope mRNA vaccine elicits CD4 T- and B- cell responses promoting endogenous CD8 anti-tumor immunity

Recent progress in therapeutic cancer vaccines has shown promising clinical activity, especially when targeting MHC class I (MHCI) neoantigen-specific CD8+ T cell responses in post-surgical patients. To explore the role of CD4+ T cells in vaccine-dependent tumor rejection, we constructed an mRNA lipoplex vaccine encoding a single MHCII-restricted neoantigen. The vaccine elicited Tfh and Th1 cell responses while decreasing Tregs, leading to rejection of established tumors in mice. IL-21 and IFN-{gamma}, crucial for Tfh and Th1 function respectively, contributed to anti-tumor activity. B cells and neoantigen-specific antibodies were also shown to participate in vaccine efficacy. Additionally, conventional type 1 dendritic cells (cDC1s) were essential for eliciting vaccine-induced CD4+ T cells, and both cDC1s and CD4+ T cells were required to enhance endogenous CD8+ responses, which were crucial for tumor control. Our results suggest that immunizing against MHCII neoantigens alone is sufficient to orchestrate a potent and cooperative immune response against cancer.

immunology↗

bioRxiv2024

The effectiveness of two new Metarhizium brunneum formulations against wireworms in potato cultivation

In the absence of officially approved agrochemicals for the use against wireworms (Agriotes spp.) in German potato cultivation, the entomopathogenic fungus genus Metarhizium has been regarded as promising biocontrol agent. However, previous mycoinsecticide formulations of M. brunneum could not achieve consistent effectiveness in field use. Within the scope of the project AgriMet, the effectiveness of two new formulations of M. brunneum was evaluated over three years in the field, greenhouse and laboratory. The application of a soil granule and/or a wettable powder (dry product) of M. brunneum during potato planting aimed to reduce potato tuber damage by controlling wireworms. During field trials in the Lower Saxony (Germany), the combination of both formulations led to an effectiveness between 1 % and 13.6 % compared to the untreated control. The single application of the AgriMet-Granule and the AgriMet-Dry Product was less successful. The standardised greenhouse set-up in pots with A. obscurus indicated that an application rate of at least 300 kg ha-1 of the AgriMet-Granule, respectively 1x1013 conidia ha-1 of the AgriMet-Dry Product was necessary to effectively reduce tuber damage (44-54 %), while surprisingly no larval mortality was recorded. The laboratory experiments showed, that only the AgriMet-Dry Product provided a lethal potential against wireworms, whereas the AgriMet-Granule showed deficits in terms of product quality. However, the effectiveness of the AgriMet-Dry Product against A. obscurus, A. sputator and A. lineatus resulted in significant differences in mortality indicating a species-specific virulence of the M. brunneum isolate used. Additional influencing factors became apparent through analysing multiple soil parameters at the respective field site such as temperature, moisture, colony-forming units of Metarhizium spp. and wireworm density, underlining the complexity of wireworm control using a microbial control agent. Especially the low soil temperatures during spring application pose a serious challenge to the development of an effective control strategy against wireworms.

microbiology↗

bioRxiv2024

Interaction of the wireworm species Agriotes obscurus, A. sputator and A. lineatus with a new granule formulation of Metarhizium brunneum

The attract-and-kill strategy is a promising approach in integrated pest management to increase the efficiency of plant protection products by pushing the required contact between target pest and active ingredient. Within the project AgriMet, a new soil granule of the entomopathogenic fungus Metarhizium brunneum was developed to control wireworms of the genus Agriotes (Coleoptera: Elateridae) in potato cultivation. The formulation is based on autoclaved millet as a substrate to lure the larvae to the infectious conidia on its surface. However, no data existed about the interactions of wireworms with the AgriMet-Granule. Here, I examined the behavioural response of the wireworm species A. obscurus, A. sputator and A. lineatus to the AgriMet-Granule using an olfactometric bioassay in the laboratory. The foraging behaviour of A. obscurus and A. sputator, with regard to the AgriMet-Granule, was tested with a feed-choice-experiment using a horizontal arena set-up. The tested wireworms significantly preferred autoclaved millet compared to the control. Fungal colonisation on the surface of the AgriMet-Granule did not influence their preference in general. However, differences were observed depending on the respective wireworm species and the two Metarhizium spp. isolates used. The feeding bioassay showed that the acceptance of wireworms for the AgriMet-Granule, with a low conidia concentration on its surface, was high. A high conidia concentration on the surface of the AgriMet-Granule led to a decreased acceptance that differed between the wireworm species. However, the survival analysis of wireworms isolated after the feed choice experiment indicated that the wireworms came in contact with the infectious conidia. Overall, the data suggests that autoclaved millet is a suitable substrate for the AgriMet-Granule. It attracts larvae of the genus Agriotes to the biocontrol agent using the formulated M. brunneum isolate.

microbiology↗