Checkpoint inhibitor-expressing lentiviral vaccine suppresses tumor growth in preclinical cancer models.

BACKGROUND: While immunotherapy has been highly successful for the treatment of some cancers, for others, the immune response to tumor antigens is weak leading to treatment failure. The resistance of tumors to checkpoint inhibitor therapy may be caused by T cell exhaustion resulting from checkpoint activation. METHODS: In this study, lentiviral vectors that expressed T cell epitopes of an experimentally introduced tumor antigen, ovalbumin, or the endogenous tumor antigen, Trp1 were developed. The vectors coexpressed CD40 ligand (CD40L), which served to mature the dendritic cells (DCs), and a soluble programmed cell death protein 1 (PD-1) microbody to prevent checkpoint activation. Vaccination of mice bearing B16.OVA melanomas with vector-transduced DCs induced the proliferation and activation of functional, antigen-specific, cytolytic CD8 T cells. RESULTS: Vaccination induced the expansion of CD8 T cells that infiltrated the tumors to suppress tumor growth. Vector-encoded CD40L and PD-1 microbody increased the extent of tumor growth suppression. Adoptive transfer demonstrated that the effect was mediated by CD8 T cells. Direct injection of the vector, without the need for ex vivo transduction of DCs, was also effective. CONCLUSIONS: This study suggests that therapeutic vaccination that induces tumor antigen-specific CD8 T cells coupled with a vector-expressed checkpoint inhibitor can be an effective means to suppress the growth of tumors that are resistant to conventional immunotherapy.

Comparing Clinical Outcomes of Steroid-Sparing Therapy With Rituximab Versus Rituximab Alone in Pemphigus.

BACKGROUND: Previous clinical trials have demonstrated that rituximab therapy combined with conventional steroid-sparing therapy (SST) has increased rates of disease control for mucous membrane pemphigoid compared with rituximab alone. However, limited data is available regarding the role of SST with rituximab therapy in pemphigus. OBJECTIVE: This study aimed to examine clinical outcomes in pemphigus patients treated with rituximab with SST versus without the addition of SST. METHODS: A retrospective chart review was performed for adult pemphigus patients in the Southeastern US at Emory between January 1, 2011, and December 31, 2021. Primary outcomes, including time to remission, time to prednisone dose of 10 mg or less, time to cessation of prednisone therapy, and time to relapse after a rituximab cycle, were compared between patients on SST and patients without SST.  Results: Following rituximab therapy, there was no difference in time to remission, time to prednisone dose of 10 mg or less, time to cessation of prednisone therapy, or time to relapse for patients with or without SST. LIMITATIONS: Our study is limited by its retrospective decline, setting at a single academic center, and inclusion of a high proportion of patients with moderate disease. CONCLUSIONS: The use of SST with rituximab dosing did not improve clinical outcomes related to time to remission, reduction in prednisone dosing, or relapse. These data provide further evidence for the use of rituximab in the majority of pemphigus patients without the need for SST. J Drugs Dermatol. 2024;23(3):e97-e99    doi:10.36849/JDD.7949e.

Dermatologic Conditions of the External Ear: Basics, Updates, and Pearls.

Cutaneous diseases of the ear encompass a wide range of symptoms, complaints, and factors that negatively impact patients' well-being. These observations are frequently encountered by otolaryngologists and other physicians who treat individuals with ear-related issues. In this document, we aim to offer up-to-date information on diagnosing, predicting outcomes, and treating commonly occurring ear diseases.

Directly injected lentiviral vector-based T cell vaccine protects mice against acute and chronic viral infection.

Lentiviral vector-based dendritic cell vaccines induce protective T cell responses against viral infection and cancer in animal models. In this study, we tested whether preventative and therapeutic vaccination could be achieved by direct injection of antigen-expressing lentiviral vector, obviating the need for ex vivo transduction of dendritic cells. Injected lentiviral vector preferentially transduced splenic dendritic cells and resulted in long-term expression. Injection of a lentiviral vector encoding an MHC class I-restricted T cell epitope of lymphocytic choriomeningitis virus (LCMV) and CD40 ligand induced an antigen-specific cytolytic CD8+ T lymphocyte response that protected the mice from infection. The injection of chronically infected mice with a lentiviral vector encoding LCMV MHC class I and II T cell epitopes and a soluble programmed cell death 1 microbody rapidly cleared the virus. Vaccination by direct injection of lentiviral vector was more effective in sterile alpha motif and HD-domain containing protein 1-knockout (SAMHD1-knockout) mice, suggesting that lentiviral vectors containing Vpx, a lentiviral protein that increases the efficiency of dendritic cell transduction by inducing the degradation of SAMHD1, would be an effective strategy for the treatment of chronic disease in humans.

Lentiviral-Vector-Based Dendritic Cell Vaccine Synergizes with Checkpoint Blockade to Clear Chronic Viral Infection.

Dendritic cell vaccines are a promising strategy for the treatment of cancer and infectious diseases but have met with mixed success. We report on a lentiviral vector-based dendritic cell vaccine strategy that generates a cluster of differentiation 8 (CD8) T cell response that is much stronger than that achieved by standard peptide-pulsing approaches. The strategy was tested in the mouse lymphocytic choriomeningitis virus (LCMV) model. Bone marrow-derived dendritic cells from SAMHD1 knockout mice were transduced with a lentiviral vector expressing the GP33 major-histocompatibility-complex (MHC)-class-I-restricted peptide epitope and CD40 ligand (CD40L) and injected into wild-type mice. The mice were highly protected against acute and chronic variant CL-13 LCMVs, resulting in a 100-fold greater decrease than that achieved with peptide epitope-pulsed dendritic cells. Inclusion of an MHC-class-II-restricted epitope in the lentiviral vector further increased the CD8 T cell response and resulted in antigen-specific CD8 T cells that exhibited a phenotype associated with functional cytotoxic T cells. The vaccination synergized with checkpoint blockade to reduce the viral load of mice chronically infected with CL-13 to an undetectable level. The strategy improves upon current dendritic cell vaccine strategies; is applicable to the treatment of disease, including AIDS and cancer; and supports the utility of Vpx-containing vectors.

Transcriptional down-regulation of ccr5 in a subset of HIV+ controllers and their family members.

HIV +Elite and Viremic controllers (EC/VCs) are able to control virus infection, perhaps because of host genetic determinants. We identified 16% (21 of 131) EC/VCs with CD4 +T cells with resistance specific to R5-tropic HIV, reversed after introduction of ccr5. R5 resistance was not observed in macrophages and depended upon the method of T cell activation. CD4 +T cells of these EC/VCs had lower ccr2 and ccr5 RNA levels, reduced CCR2 and CCR5 cell-surface expression, and decreased levels of secreted chemokines. T cells had no changes in chemokine receptor mRNA half-life but instead had lower levels of active transcription of ccr2 and ccr5, despite having more accessible chromatin by ATAC-seq. Other nearby genes were also down-regulated, over a region of ~500 kb on chromosome 3p21. This same R5 resistance phenotype was observed in family members of an index VC, also associated with ccr2/ccr5 down-regulation, suggesting that the phenotype is heritable.

Degeneration of the costovertebral articulation: a cause of pulmonary pseudolesion.

The objective was to report examples of degeneration of the costovertebral articulation producing a pulmonary pseudolesion. Three cases in which a nodular opacity seen on plain radiograph was determined to be secondary to degeneration of the costovertebral articulation were compiled, one of which was confirmed by CT. Pseudolesions produced by degenerative osteophytes of the vertebral spine and anomalous articulations between transverse processes are more commonly identified, but less well described is the pseudolesion produced by degeneration of the costovertebral articulation. Recognition of this etiology may prevent misconstruing the lesion as a significant finding.