Immunization with neural derived peptides plus scar removal induces a permissive microenvironment, and improves locomotor recovery after chronic spinal cord injury.

BACKGROUND: Immunization with neural derived peptides (INDP) as well as scar removal-separately-have shown to induce morphological and functional improvement after spinal cord injury (SCI). In the present study, we compared the effect of INDP alone versus INDP with scar removal on motor recovery, regeneration-associated and cytokine gene expression, and axonal regeneration after chronic SCI. Scar removal was conducted through a single incision with a double-bladed scalpel along the stump, and scar renewal was halted by adding α,α'-dipyridyl. RESULTS: During the chronic injury stage, two experiments were undertaken. The first experiment was aimed at testing the therapeutic effect of INDP combined with scar removal. Sixty days after therapeutic intervention, the expression of genes encoding for TNFα, IFNγ, IL4, TGFß, BDNF, IGF1, and GAP43 was evaluated at the site of injury. Tyrosine hydroxylase and 5-hydroxytryptamine positive fibers were also studied. Locomotor evaluations showed a significant recovery in the group treated with scar removal + INDP. Moreover; this group presented a significant increase in IL4, TGFß, BDNF, IGF1, and GAP43 expression, but a decrease of TNFα and IFNγ. Also, the spinal cord of animals receiving both treatments presented a significant increase of serotonergic and catecholaminergic fibers as compared to other the groups. The second experiment compared the results of the combined approach versus INDP alone. Rats receiving INDP likewise showed improved motor recovery, although on a lesser scale than those who received the combined treatment. An increase in inflammation and regeneration-associated gene expression, as well as in the percentage of serotonergic and catecholaminergic fibers was observed in INDP-treated rats to a lesser degree than those in the combined therapy group. CONCLUSIONS: These findings suggest that INDP, both alone and in combination with scar removal, could modify the non-permissive microenvironment prevailing at the chronic phase of SCI, providing the opportunity of improving motor recovery.

A functional identification platform reveals frequent, spontaneous neoantigen-specific T cell responses in patients with cancer.

The clinical impact of tumor-specific neoantigens as both immunotherapeutic targets and biomarkers has been impeded by the lack of efficient methods for their identification and validation from routine samples. We have developed a platform that combines bioinformatic analysis of tumor exomes and transcriptional data with functional testing of autologous peripheral blood mononuclear cells (PBMCs) to simultaneously identify and validate neoantigens recognized by naturally primed CD4+ and CD8+ T cell responses across a range of tumor types and mutational burdens. The method features a human leukocyte antigen (HLA)-agnostic bioinformatic algorithm that prioritizes mutations recognized by patient PBMCs at a greater than 40% positive predictive value followed by a short-term in vitro functional assay, which allows interrogation of 50 to 75 expressed mutations from a single 50-ml blood sample. Neoantigens validated by this method include both driver and passenger mutations, and this method identified neoantigens that would not have been otherwise detected using an in silico prediction approach. These findings reveal an efficient approach to systematically validate clinically actionable neoantigens and the T cell receptors that recognize them and demonstrate that patients across a variety of human cancers have a diverse repertoire of neoantigen-specific T cells.

Use of a Combination Strategy to Improve Morphological and Functional Recovery in Rats With Chronic Spinal Cord Injury.

Immunization with neural derived peptides (INDP), as well as scar removal (SR) and the use of matrices with bone marrow-mesenchymal stem cells (MSCs), have been studied separately and proven to induce a functional and morphological improvement after spinal cord injury (SCI). Herein, we evaluated the therapeutic effects of INDP combined with SR and a fibrin glue matrix (FGM) with MSCs (FGM-MSCs), on motor recovery, axonal regeneration-associated molecules and cytokine expression, axonal regeneration (catecholaminergic and serotonergic fibers), and the induction of neurogenesis after a chronic SCI. For this purpose, female adult Sprague-Dawley rats were subjected to SCI, 60 days after lesion, rats were randomly distributed in four groups: (1) Rats immunized with complete Freund's adjuvant + PBS (vehicle; PBS-I); (2) Rats with SR+ FGM-MSCs; (3) Rats with SR+ INDP + FGM-MSCs; (4) Rats only with INDP. Afterwards, we evaluated motor recovery using the BBB locomotor test. Sixty days after the therapy, protein expression of TNFα, IL-4, IL-10, BDNF, and GAP-43 were evaluated using ELISA assay. The number of catecholaminergic and serotonergic fibers were also determined. Neurogenesis was evaluated through immunofluorescence. The results show that treatment with INDP alone significantly increased motor recovery, anti-inflammatory cytokines, regeneration-associated molecules, axonal regeneration, and neurogenesis when compared to the rest of the groups. Our findings suggest that the combination therapy (SR + INDP + FGM-MSCs) modifies the non-permissive microenvironment post SCI, but it is not capable of inducing an appropriate axonal regeneration or neurogenesis when compared to the treatment with INDP alone.