Biology subjects

Scholz, A. M.

Publications and source records attributed to Scholz, A. M..

4 recordsLinked to original sources

bioRxiv2024

Making the effect visible - OX40 targeting nanobodies for in vivo imaging of activated T cells

PurposeHuman OX40 (hOX40/CD134), a member of the TNF receptor superfamily, is mainly expressed on activated T lymphocytes. Triggered by its ligand OX40L (CD252), it provides costimulatory signals that support the differentiation, proliferation and long-term survival of T cells. Besides being a relevant therapeutic target, hOX40 is also an important biomarker for monitoring the presence or infiltration of activated T cells within the tumor microenvironment (TME), the inflammatory microenvironment (IME) in immune-mediated diseases (IMIDs) and the lymphatic organs. Here, we developed novel single domain antibodies (nanobodies, Nbs) targeting hOX40 to monitor the activation status of T cells by in vivo molecular imaging. MethodsNbs against hOX40 (hOX40-Nbs) were selected from an immunized Nb-library by phage display. The identified hOX40-Nbs were characterized in vitro, including determination of their specificity, affinity, stability, epitope recognition and their impact on OX40 signaling and T cell function. A lead candidate was site-specifically conjugated with a fluorophore via sortagging and applied for noninvasive in vivo optical imaging (OI) of hOX40-expressing cells in a xenograft mouse model. ResultsOur selection campaign revealed four unique Nbs that exhibit strong binding affinities and high stabilities under physiological conditions. Epitope binning and domain mapping indicated the targeting of at least two different epitopes on hOX40. When analyzing their impact on OX40 signaling, an agonistic effect was excluded for all validated Nbs. Incubation of activated T cells with hOX40-Nbs did not affect cell viability or proliferation patterns, whereas differences in cytokine release were observed. In vivo OI with a fluorophore-conjugated lead candidate in experimental mice with hOX40-expressing xenografts demonstrated its specificity and functionality as an imaging probe. ConclusionConsidering the need for advanced probes for noninvasive in vivo monitoring of T cell activation dynamics, we propose, that our hOX40-Nbs have a great potential as imaging probes for noninvasive and longitudinal in vivo diagnostics. Quantification of OX40+ T cells in TME or IME will provide crucial insights into the activation state of infiltrating T cells, offering a valuable biomarker for assessing immune responses, predicting treatment efficacy, and guiding personalized immunotherapy strategies in patients with cancer or IMIDs.

immunology↗

bioRxiv2023

Two birds with one stone: human SIRPα nanobodies for functional modulation and in vivo imaging of myeloid cells

Signal-regulatory protein (SIRP) expressed by myeloid cells is of particular interest for therapeutic strategies targeting the interaction between SIRP and the "dont eat me" ligand CD47 and as a marker to monitor macrophage infiltration into tumor lesions. To address both approaches, we developed a set of novel human SIRP (hSIRP)-specific nanobodies (Nbs). We identified three high-affinity Nbs targeting the hSIRP/hCD47 interface, thereby enhancing antibody-dependent cellular phagocytosis (ADCP). For non-invasive in vivo imaging, we chose S36 Nb as a non-modulating binder. By quantitative positron emission tomography (PET) in novel hSIRP/hCD47 knock-in (KI) mice, we demonstrated the applicability of 64Cu-hSIRP-S36 Nb to visualize tumor infiltration of myeloid cells. We envision that the hSIRP-Nbs presented in this study have potential as versatile probes, including novel myeloid-specific checkpoint inhibitors for combinatorial treatment approaches and for in vivo stratification and monitoring of individual responses during cancer immunotherapies.

immunology↗

bioRxiv2019

Interplay of primary bovine lymphocytes and Mycobacterium avium subsp. paratuberculosis shows distinctly different proteome changes and immune pathways in host-pathogen interaction

Mycobacterium avium subsp. paratuberculosis (MAP) is a pathogen causing paratuberculosis in cattle and small ruminants. During the long asymptomatic subclinical stage, high numbers of MAP are excreted and can be transmitted to food, where they survive many of the standard techniques of food decontamination. If these MAP are harmful to the consumers is currently under debate. In general, there is a lack of information regarding interaction of the hosts immune system with MAP.\n\nIn this study, we tested the interaction of peripheral blood lymphocytes (PBL) from cattle with MAP in their exoproteomes/secretomes. Because in other mycobacterial infections, the immune phenotype correlates with susceptibility, we additionally tested the interaction of MAP with recently detected immune deviant cows.\n\nIn PBL, different biological pathways were enhanced in response to MAP dependent on the immune phenotype of the host. PBL of control cows activated members of cell activation and chemotaxis of leukocytes pathway as well as IL-12 mediated signaling. In contrast, in ID cows CNOT1 was detected as highly abundant protein, pointing to a different immune response, which could be favorable for MAP. Additionally, MAP reacted different to the hosts. Their exoproteomes differed in either GroEL1 or DnaK abundance, depending on the interacting immune response.\n\nThese findings point to an interdependent, tightly regulated response of MAP and the immune system.

immunology↗

bioRxiv2018

A functional different immune capacity in cattle is associated with higher mastitis incidence

Bovine neonatal pancytopenia (BNP) was a deadly disease transferred by antibodies from 5-10% of cows given a novel BVD vaccine. Disease was lethal in 90% of calves receiving colostrum with BNP antibodies. The cause of BNP is not fully understood to date. We revealed a profound difference in immune capacities between BNP dams and non-responders. Significant differences were detectable in response to in vitro stimulation of peripheral blood derived lymphocytes to several mitogens and IL-2. BNP cows regulated their immune proteomes completely different from controls with other immune response master regulators. Since we detected this response pattern also in 22% of cows that were never vaccinated at all, this immune deviant (ID) phenotype is still present in cattle and probably inherited. Immune response pattern of these cows was stable over an observation period of 38 months. Importantly, ID have a significant increased prevalence of mastitis underscoring the clinical importance.

immunology↗