DECTIN-1: A modifier protein in CTLA-4 haploinsufficiency

Cancer-associated fungi: An emerging powerful player in cancer immunotherapy

The role of the human microbiome in cancer has been extensively studied, focusing mainly on bacteria-host interactions and their impact on tumor development and treatment response. However, fungi, an immune-active component of the human microbiome, have received less attention regarding their roles in cancer. Recent studies have identified the widespread and specific colonization and distribution of fungi in multiple sites in patients across various cancer types. Importantly, host-fungal immune interactions significantly influence immune regulation within the tumor microenvironment. The rapid advancement of immune-checkpoint blockade (ICB)-based cancer immunotherapy creates an urgent need for effective biomarkers and synergistic therapeutic targets. Cancer-associated fungi and their associated antifungal immunity demonstrate significant potential and efficacy in enhancing cancer immunotherapy. This review summarizes and discusses the growing evidence of the functions and mechanisms of commensal and pathogenic cancer-associated fungi in cancer immunotherapy. Additionally, we emphasize the potential of fungi as predictive biomarkers and therapeutic targets in cancer immunotherapy.

The effect of HLA genotype on disease onset and severity in CTLA-4 insufficiency

Introduction

Human Cytotoxic-T-lymphocyte-antigen-4 (CTLA-4) insufficiency caused by heterozygous germline mutations in CTLA4 is a complex immune dysregulation and immunodeficiency syndrome presenting with reduced penetrance and variable disease expressivity, suggesting the presence of disease modifiers that trigger the disease onset and severity. Various genetic and non-genetic potential triggers have been analyzed in CTLA-4 insufficiency cohorts, however, none of them have revealed a clear association to the disease. Multiple HLA haplotypes have been positively or negatively associated with various autoimmune diseases and inborn errors of immunity (IEI) due to the relevance of MHC in the strength of the T cell responses.

Methods

In this exploratory study, we investigated the association of disease onset, severity and clinical manifestations of CTLA-4 insufficiency with specific HLA class I (A, B and C) and class II (DRB1 and DQB1) alleles in forty-three individuals harboring heterozygous mutations in CTLA4. Twenty-six out of the 43 recruited individuals presented moderate or severe clinical symptoms whereas 17 were completely healthy. HLA frequency analysis, odds ratio analysis and genetic linkage analysis were used.

Results

The principal statistical analyses showed no positive association between the HLA genotypes analyzed with the disease onset or the disease severity. We found potential risk associations of HLA-DQB1*05:01 and HLA-DRB1*01:02 with respiratory tract involvement and HLA-C*05:01 with affection of the neurological system in the CTLA-4-insufficient patients. Additionally, we found a potential protective association of HLA-DRB1*01:01 with gastrointestinal symptoms.

Discussion

Even though, our findings suggest that HLA-A, -B, -C, DRB1, and DQB1 do not contribute to the onset or severity of disease in CTLA-4 insufficiency, certain HLA-alleles may influence the manifestation of specific symptoms. We advocate for further investigation of specific class I and class II HLA alleles as potential disease modifiers in larger clinical cohorts of CTLA-4 insufficiency.

Long non‑coding RNA SNHG1 promotes autophagy in vascular smooth muscle cells induced by facilitating CLEC7A

Long non‑coding RNAs serve a crucial role in autophagy of vascular smooth muscle cells (VSMCs). The present study aimed to investigate the effect of small nucleolar RNA host gene 1 (SNHG1) on autophagy in VSMCs and the associated underlying mechanisms. Rapamycin was used to induce autophagy in VSMCs and the effects of SNHG1 on the proliferation and migration of VSMCs and the change in phenotype were tested following overexpression and silencing of SNHG1. The target gene of SNHG1 was predicted and validated. SNHG1‑regulated autophagy of VSMCs via C‑type lectin domain family 7 member A (CLEC7A) was determined by combined silencing of SNHG1 and overexpression of CLEC7A. Rapamycin‑induced autophagy in VSMCs changed the cell phenotype from contractile to synthetic, with decreased expression of α‑smooth muscle actin and smooth muscle protein 22a and increased expression of osteopontin. Overexpression of SNHG1 caused the same change in phenotype while the opposite change was observed following SNHG1 silencing. Overexpression of SNHG1 promoted the proliferation and migration of VSMCs. CLEC7A was identified as a target gene of SNHG1 and a direct binding relationship between them was confirmed by RNA immunoprecipitation and RNA pull‑down assays. Overexpression of SNHG1 increased the expression of CLEC7A. The expression of both SNHG1 and CLEC7A was increased during autophagy of VSMCs. Overexpression of SNHG1 promoted autophagy of VSMCs and silencing of CLEC7A reduced this effect of SNHG1. In conclusion, SNHG1 and CLEC7A were increased in VSMCs following autophagy. SNHG1 promotes the conversion of VSMCs from a contractile phenotype to a synthetic phenotype by facilitating CLEC7A expression.

Myeloid C-type lectin receptors in innate immune recognition

C-type lectin receptors (CLRs) expressed by myeloid cells constitute a versatile family of receptors that play a key role in innate immune recognition. Myeloid CLRs exhibit a remarkable ability to recognize an extensive array of ligands, from carbohydrates and beyond, and encompass pattern-associated molecular patterns (PAMPs), damage-associated molecular patterns (DAMPs), and markers of altered self. These receptors, classified into distinct subgroups, play pivotal roles in immune recognition and modulation of immune responses. Their intricate signaling pathways orchestrate a spectrum of cellular responses, influencing processes such as phagocytosis, cytokine production, and antigen presentation. Beyond their contributions to host defense in viral, bacterial, fungal, and parasitic infections, myeloid CLRs have been implicated in non-infectious diseases such as cancer, allergies, and autoimmunity. A nuanced understanding of myeloid CLR interactions with endogenous and microbial triggers is starting to uncover the context-dependent nature of their roles in innate immunity, with implications for therapeutic intervention.