CD40L modulates transcriptional signatures of neutrophils in the bone marrow associated with development and trafficking

Exploring the role of EBV in multiple sclerosis pathogenesis through EBV interactome

Background

Epstein-Barr virus (EBV) is a known risk factor for multiple sclerosis (MS), even though the underlying molecular mechanisms are unclear and engage multiple immune pathways. Furthermore, the ultimate role of EBV in MS pathogenesis is still elusive. In contrast, Cytomegalovirus (CMV) has been identified as a protective factor for MS.

Objectives

This study aims to identify MS-associated genes that overlap with EBV interactome and to examine their expression in immune and glial cell subtypes.

Methods

We used P-HIPSTer, GWAS, and the Human Protein Atlas (HPA) to derive data on the EBV interactome, MS-associated genes and single-cell gene expression in immune and glial cells. The geneOverlap and dplyr R packages identified overlapping genes. A similar analysis was done for CMV and Adenovirus as negative control. Metascape and GTEx analyzed biological pathways and brain-level gene expression; transcriptomic analysis was performed on glial cells and peripheral blood in MS and controls. All the analyses performed in this study were generated using publicly available data sets.

Results

We identified a "core" group of 21 genes shared across EBV interactome, MS genes, and immune and glial cells (p<0.001). Pathway analysis revealed expected associations, such as immune system activation, and unforeseen results, like the prolactin signaling pathway. BCL2 in astrocytes, MINK1 in microglia were significantly upregulated while AHI1 was downregulated in MS compared to controls.

Conclusions

Our findings offer novel insights into EBV and CMV interaction with immune and glial cells in MS, that may shed light on mechanisms involved in disease pathophysiology.

CD40 Ligand Potentiates Immunogenecity of Mycoplasma pneumoniae Subunit Vaccine Candidate in a Murine Model

Mycoplasma hyopneumoniae (Mhp) infection severely affects the daily weight gain and feed-to-meat ratio of pigs, while secondary infections with other pathogens can further lead to increased mortality, causing significant economic losses to the pig industry. CD40L is a molecular adjuvant that enhances the cellular and humoral immune responses to vaccines. In this study, the CD40L peptide was fused to the C-terminus of the chimeric P97R1P46P42 protein by genetic engineering using the pFastBac Dual vector. The recombinant chimeric protein P97R1P46P42 and its fusion P97R1P46P42-CD40L were expressed in Sf9 cells and purified. Mice were immunized with P97R1P46P42 or its fusion protein. Seppic ISA 201 emulsified protein, conventional Mhp vaccine and PBS control groups were included. Immunogenecity was assessed by specific IgG antibody response, splenic lymphocyte proliferation, and cytokine IL-4 and IFN-γ levels. We found that CD40L fusion significantly enhanced specific antibody response, lymphocyte proliferation and IL-4 level in the immunized mouse sera as compared to the P97R1P46P42 or conventional vaccine group. This study provides clear evidence that CD40L potentiates the humoral and cellular immune responses to the Mhp chimeric protein P97R1P46P42 in the mouse model. This CD40L-fused chimeric protein could be a MPS subunit vaccine candidate to be tested for its efficacy in pigs in response to challenges with pathogenic Mycoplasma hyopneumoniae strain(s).

Neuroimmunology of rabies: New insights into an ancient disease

Rabies is an ancient neuroinvasive viral (genus Lyssavirus, family Rhabdoviridae) disease affecting approximately 59,000 people worldwide. The central nervous system (CNS) is targeted, and rabies has a case fatality rate of almost 100% in humans and animals. Rabies is entirely preventable through proper vaccination, and thus, the highest incidence is typically observed in developing countries, mainly in Africa and Asia. However, there are still cases in European countries and the United States. Recently, demographic, increasing income levels, and the coronavirus disease 2019 (COVID-19) pandemic have caused a massive raising in the animal population, enhancing the need for preventive measures (e.g., vaccination, surveillance, and animal control programs), postexposure prophylaxis, and a better understanding of rabies pathophysiology to identify therapeutic targets, since there is no effective treatment after the onset of clinical manifestations. Here, we review the neuroimmune biology and mechanisms of rabies. Its pathogenesis involves a complex and poorly understood modulation of immune and brain functions associated with metabolic, synaptic, and neuronal impairments, resulting in fatal outcomes without significant histopathological lesions in the CNS. In this context, the neuroimmunological and neurochemical aspects of excitatory/inhibitory signaling (e.g., GABA/glutamate crosstalk) are likely related to the clinical manifestations of rabies infection. Uncovering new links between immunopathological mechanisms and neurochemical imbalance will be essential to identify novel potential therapeutic targets to reduce rabies morbidity and mortality.

CD40 Ligand Deficiency in Latin America: Clinical, Immunological, and Genetic Characteristics

CD40 ligand (CD40L) deficiency is a rare inborn error of immunity presenting with heterogeneous clinical manifestations. While a detailed characterization of patients affected by CD40L deficiency is essential to an accurate diagnosis and management, information about this disorder in Latin American patients is limited. We retrospectively analyzed data from 50 patients collected by the Latin American Society for Immunodeficiencies registry or provided by affiliated physicians to characterize the clinical, laboratory, and molecular features of Latin American patients with CD40L deficiency. The median age at disease onset and diagnosis was 7 months and 17 months, respectively, with a median diagnosis delay of 1 year. Forty-seven patients were genetically characterized revealing 6 novel mutations in the CD40LG gene. Pneumonia was the most common first symptom reported (66%). Initial immunoglobulin levels were variable among patients. Pneumonia (86%), upper respiratory tract infections (70%), neutropenia (70%), and gastrointestinal manifestations (60%) were the most prevalent clinical symptoms throughout life. Thirty-five infectious agents were reported, five of which were not previously described in CD40L deficient patients, representing the largest number of pathogens reported to date in a cohort of CD40L deficient patients. The characterization of the largest cohort of Latin American patients with CD40L deficiency adds novel insights to the recognition of this disorder, helping to fulfill unmet needs and gaps in the diagnosis and management of patients with CD40L deficiency.