Probes for CD4

Prostate cancer (PCa) does not appear to respond to immune checkpoint therapies where T cell infiltration may be a key limiting factor. Here we report evidence that ablating the growth regulatory kinase Erk5 can increase T cell infiltration in an established Pten-deficient mouse model of human PCa. Mice that were doubly mutant in prostate tissue for Pten and Erk5 (prostate DKO) exhibited a markedly increased median survival with reduced tumor size and proliferation compared to control Pten-mutant mice, the latter of which exhibited increased Erk5 mRNA expression. A comparative transcriptomic analysis revealed upregulation in prostate DKO mice of the chemokines Ccl5 and Cxcl10, two potent chemoattractants for T lymphocytes. Consistent with this effect, we observed a relative increase in a predominantly CD4+ T cell infiltrate in the prostate epithelial and stroma of tumors from DKO mice. Collectively, our results offer a preclinical proof of concept for ERK5 as a target to enhance T cell infiltrates in prostate cancer, with possible implications for leveraging immune therapy in this disease.

The development of increasingly safe and effective antiretroviral treatments for human immunodeficiency virus (HIV) over the past several decades has led to vastly improved patient survival when treatment is available and affordable, an outcome that relies on uninterrupted adherence to combination antiretroviral therapy for life. Looking to the future, the discovery of an elusive 'cure' for HIV will necessitate highly sensitive methods for detecting, understanding, and eliminating viral reservoirs. Next-generation, in situ hybridization (ISH) approaches offer unique and complementary insights into viral reservoirs within their native tissue environments with a high degree of specificity and sensitivity. In this review, we will discuss how modern ISH techniques can be used, either alone or in conjunction with phenotypic characterization, to probe viral reservoir establishment and maintenance. In addition to focusing on how these techniques have already furthered our understanding of HIV reservoirs, we discuss potential avenues for how high-throughput, next-generation ISH may be applied. Finally, we will review how ISH could allow deeper phenotypic and contextual insights into HIV reservoir biology that should prove instrumental in moving the field closer to viral reservoir elimination needed for an 'HIV cure' to be realized.

Sexual transmission of filoviruses was first reported in 1968 after an outbreak of Marburg virus (MARV) disease and recently caused flare-ups of Ebola virus disease in the 2013–2016 outbreak. How filoviruses establish testicular persistence and are shed in semen remain unknown. We discovered that persistent MARV infection of seminiferous tubules, an immune-privileged site that harbors sperm production, is a relatively common event in crab-eating macaques that survived infection after antiviral treatment. Persistence triggers severe testicular damage, including spermatogenic cell depletion and inflammatory cell invasion. MARV mainly persists in Sertoli cells, leading to breakdown of the blood-testis barrier formed by inter-Sertoli cell tight junctions. This disruption is accompanied by local infiltration of immunosuppressive CD4+Foxp3+ regulatory T cells. Our study elucidates cellular events associated with testicular persistence that may promote sexual transmission of filoviruses and suggests that targeting immunosuppression may be warranted to clear filovirus persistence in damaged immune-privileged sites.

Abstract

BACKGROUND & AIMS:

Double-negative (DN) T-cell is a unique regulatory T-cell, which is essential for maintaining immune system homeostasis. However, the role of DN T-cells in the pathogenesis of primary biliary cholangitis (PBC) is still unknown.

METHODS:

We investigated the number and function of DN T-cells in peripheral blood and liver biopsy specimens of PBC patients.

RESULTS:

The number and frequency of DN T-cells significantly decreased in peripheral blood and liver tissue of PBC patients. Furthermore, the frequency of DN T-cells in PBC was negatively correlated with disease severity and positively correlated with UDCA response. In vitro assays showed that perforin expression and the suppressive capability of DN T-cells on the proliferation of CD4+ and CD8+ T-cells were impaired in PBC. Finally, lithocholic acid, the most hydrophobic acid, could downregulate the proliferation and perforin expression of DN T-cells.

CONCLUSIONS:

Decreased quantity and function of DN T-cells in PBC may result in the loss of immune regulations on effector CD4+ and cytotoxic CD8+ T-cells, and thereby may break the immune tolerance and promote the pathogenesis of PBC. 

BACKGROUND:

Children with very early onset inflammatory bowel diseases (VEO-IBD) often have a refractory and severe disease course. A significant number of described VEO-IBD-causing monogenic disorders can be attributed to defects in immune-related genes. The diagnosis of the underlying primary immunodeficiency (PID) often has critical implications for the treatment of patients with IBD-like phenotypes.

METHODS:

To identify the molecular etiology in 5 patients from 3 unrelated kindred with IBD-like symptoms, we conducted whole exome sequencing. Immune workup confirmed an underlying PID.

RESULTS:

Whole exome sequencing revealed 3 novel CARMIL2 loss-of-function mutations in our patients. Immunophenotyping of peripheral blood mononuclear cells showed reduction of regulatory and effector memory T cells and impaired B cell class switching. The T cell proliferation and activation assays confirmed defective responses to CD28 costimulation, consistent with CARMIL2 deficiency.

CONCLUSION:

Our study highlights that human CARMIL2 deficiency can manifest with IBD-like symptoms. This example illustrates that early diagnosis of underlying PID is crucial for the treatment and prognosis of children with VEO-IBD.