Inborn errors of immunity associated with defects of self-tolerance checkpoints: The CD28 family

Immunogenetic Landscape in Pediatric Common Variable Immunodeficiency

Common variable immunodeficiency (CVID) is the most common symptomatic antibody deficiency, characterized by heterogeneous genetic, immunological, and clinical phenotypes. It is no longer conceived as a sole disease but as an umbrella diagnosis comprising a spectrum of clinical conditions, with defects in antibody biosynthesis as their common denominator and complex pathways determining B and T cell developmental impairments due to genetic defects of many receptors and ligands, activating and co-stimulatory molecules, and intracellular signaling molecules. Consequently, these genetic variants may affect crucial immunological processes of antigen presentation, antibody class switch recombination, antibody affinity maturation, and somatic hypermutation. While infections are the most common features of pediatric CVID, variants in genes linked to antibody production defects play a role in pathomechanisms of immune dysregulation with autoimmunity, allergy, and lymphoproliferation reflecting the diversity of the immunogenetic underpinnings of CVID. Herein, we have reviewed the aspects of genetics in CVID, including the monogenic, digenic, and polygenic models of inheritance exemplified by a spectrum of genes relevant to CVID pathophysiology. We have also briefly discussed the epigenetic mechanisms associated with micro RNA, DNA methylation, chromatin reorganization, and histone protein modification processes as background for CVID development.

CD8+ T cell memory induced by successive SARS-CoV-2 mRNA vaccinations is characterized by shifts in clonal dominance

mRNA vaccines against the spike glycoprotein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) elicit strong T cell responses. However, a clonal-resolution analysis of T cell responses to mRNA vaccination has not been performed. Here, we temporally track the CD8+ T cell repertoire in individuals who received three shots of the BNT162b2 mRNA vaccine through longitudinal T cell receptor sequencing with peptide-human leukocyte antigen (HLA) tetramer analysis. We demonstrate a shift in T cell responses between the clonotypes with different kinetics: from early responders that expand rapidly after the first shot to main responders that greatly expand after the second shot. Although the main responders re-expand after the third shot, their clonal diversity is skewed, and newly elicited third responders partially replace them. Furthermore, this shift in clonal dominance occurs not only between, but also within, clonotypes specific for spike epitopes. Our study will be a valuable resource for understanding vaccine-induced T cell responses in general.

The BTLA-HVEM complex - The future of cancer immunotherapy

The BTLA-HVEM complex plays a pivotal role in cancer and cancer immunotherapy by regulating immune responses. Dysregulation of BTLA and HVEM expression contributes to immunosuppression and tumor progression across various cancer types. Targeting the interaction between BTLA and HVEM holds promise for enhancing anti-tumor immune responses. Disruption of this complex presents a valuable avenue for advancing cancer immunotherapy strategies. Aberrant expression of BTLA and HVEM adversely affects immune cell function, particularly T cells, exacerbating tumor evasion mechanisms. Understanding and modulating the BTLA-HVEM axis represents a crucial aspect of designing effective immunotherapeutic interventions against cancer. Here, we summarize the current knowledge regarding the structure and function of BTLA and HVEM, along with their interaction with each other and various immune partners. Moreover, the expression of soluble and transmembrane forms of BTLA and HVEM in different types of cancer and their impact on the prognosis of patients is also discussed. Additionally, inhibitors of the proteins binding that might be used to block BTLA-HVEM interaction are reviewed. All the presented data highlight the plausible clinical application of BTLA-HVEM targeted therapies in cancer and autoimmune disease management. However, further studies are required to confirm the practical use of this concept. Despite the increasing number of reports on the BTLA-HVEM complex, many aspects of its biology and function still need to be elucidated. This review can be regarded as an encouragement and a guide to follow the path of BTLA-HVEM research.