Biomedical subjects

Christina E Zielinski

Publications and source records attributed to Christina E Zielinski.

3 recordsLinked to original sources

PubMed2026

Pre-treatment T cell features and immune-milieu characteristics shape treatment-induced exhaustion and resistance to Blinatumomab in B-cell acute lymphoblastic leukemia.

BACKGROUND: Blinatumomab (Blina), a CD19×CD3 bispecific T cell engager, is approved for the treatment of B-cell precursor acute lymphoblastic leukemia (BCP-ALL), yet resistance remains a major challenge and the mechanisms driving treatment failure remain poorly understood. METHODS: To define the immunological determinants of resistance, we performed longitudinal profiling of peripheral blood T cells and the immune milieu of 34 patients receiving Blina using flow cytometry (n=19), single-cell CITE-seq (n=13), ex vivo Blina-induced cytotoxicity (n=26) and serum proteomics (n=17). RESULTS: At baseline, Responders (R) were enriched for CD8+ effector memory T cells (TEM) expressing higher levels of cytotoxic genes and their transcriptional regulator ZNF683. Conversely, CD8+ TEM from Non-Responders (NR) displayed transcriptional features of activation without proportionate cytotoxic commitment. Over the course of the first treatment cycle, NR exhibited a progressive expansion of TIM3+CD8+ T cells that correlated with a rapid loss of ex vivo cytotoxic function. Linking baseline state to post-treatment T-cell exhaustion, the magnitude of TIM3+CD8+ expansion correlated inversely with baseline ZNF683 expression in CD8+TEM. Beyond T-cell-intrinsic features, NR harbored an immunosuppressive milieu characterized by higher circulating levels of M2-polarizing factors (CSF-1, HGF) and the TIM-3 ligand Galectin-9, which correlated positively with the magnitude of TIM3+CD8+ T-cell expansion. CONCLUSIONS: These findings indicate that post-Blina CD8+ T-cell exhaustion is associated with resistance and it is shaped by both reduced ZNF683-dependent cytotoxic programming in CD8+ TEM and an immunosuppressive milieu. This provides a rationale for risk stratification based on baseline transcriptional profiling of CD8+ TEM and for combinatorial strategies targeting the suppressive microenvironment.

Humans↗

PubMed2005

Naive CD4+ T cells from lupus-prone Fas-intact MRL mice display TCR-mediated hyperproliferation due to intrinsic threshold defects in activation.

Autoreactive T cell activation is a consistent feature of murine lupus; however, the mechanism of such activation remains unclear. We hypothesized that naive CD4+ T cells in lupus have a lower threshold of activation through their TCR-CD3 complex that renders them more susceptible to stimulation with self-Ags. To test this hypothesis, we compared proliferation, IL-2 production, and single cell calcium signaling of naive CD4+ T cells isolated from Fas-intact MRL/+(Fas-lpr) mice with H-2k-matched B10.BR and CBA/CaJ controls, following anti-CD3 stimulation in the presence or absence of anti-CD28. We also assessed the responsiveness of naive CD4+ T cells isolated from Fas-intact MRL and control mice bearing a rearranged TCR specific for amino acids 88-104 of pigeon cytochrome c to cognate and low affinity peptide Ags presented by bone marrow-matured dendritic cells. TCR transgenic and wild-type CD4+ T cells from MRL mice displayed a lower threshold of activation than control cells, a response that was class II MHC dependent. The rise in intracellular calcium in MRL vs controls was enhanced and prolonged following anti-CD3 triggering, suggestive of proximal defects in TCR-engendered signaling as the mechanism for the observed hyperactivity. These findings were observed as early as 1-2 mo postweaning and, based on analysis of F1 T cells, appeared to be dominantly expressed. This genetically altered threshold for activation of MRL T cells, a consequence of a proximal defect in CD3-mediated signal transduction, may contribute to the abrogation of T cell tolerance to self-Ags in lupus.

Animals↗

PubMed2003

Intrinsic T cell defects in systemic autoimmunity.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by loss of T cell tolerance to nuclear antigens. Studies in mice and humans have demonstrated that T cells from individuals with lupus are abnormal. Here, we review the known T cell defects in lupus and their possible biochemical nature, genetic causes, and significance for lupus pathogenesis.

Animals↗