KIR copy number variations in dengue-infected patients from northeastern Thailand

Identification of HLA ligands in dengue patients by multiplex PCR-SSP method

BACKGROUND

High-throughput DNA sequencing technologies have revolutionized genetic studies of populations and diseases. These methods provide deeper insights into gene structure and variation, offering more comprehensive immunogenetic data with stronger relevance to protein function and biological impact. However, the widespread adoption of high-resolution sequencing is hindered by factors such as cost and limited accessibility. Furthermore, successful implementation requires high-quality and sufficient quantities of genomic DNA.

METHODS AND RESULTS

This study addresses the challenges of limited DNA yields, a common issue in clinical samples, by employing whole-genome amplification (WGA) with isothermal multiple displacement amplification (IMDA). We investigated HLA ligands in 253 dengue samples with low DNA quantity. A multiplex PCR-SSP method was developed to determine HLA ligands in population, including HLA-C1, HLA-C2, HLA-A (Bw4), HLA-Bw4 (I80), HLA-Bw4 (T80), and HLA-A*11. The study successfully demonstrates the applicability of a multiplex PCR-SSP method for HLA genotyping in a large cohort of dengue patients. Our findings highlight the high prevalence of HLA-C1 (92.1%) and HLA-A*11:03 (78.3%) in dengue patients, providing valuable data for further investigations into the role of HLA polymorphisms in diseases.

CONCLUSIONS

This study demonstrates the utility of our approach for investigating HLA ligands in clinical samples with limited DNA. WGA-IMDA effectively overcomes the challenge of low DNA availability, making this approach suitable for resource-constrained settings. The multiplex PCR-SSP method provides a simple and cost-effective solution for immunogenetic studies.

Diversity of major histocompatibility complex (MHC) and natural killer cell receptor (NKR) genes and their interactions in domestic horses

The immunogenome is the part of the genome that underlies immune mechanisms and evolves under various selective pressures. Two complex regions of the immunogenome, major histocompatibility complex (MHC) and natural killer cell receptor (NKR) genes, play an important role in the response to selective pressures of pathogens. Their importance is expressed by their genetic polymorphism at the molecular level, and their diversity associated with different types of diseases at the population level. Findings of associations between specific combinations of MHC/NKR haplotypes with different diseases in model species suggest that these gene complexes did not evolve independently. No such associations have been described in horses so far. The aim of the study was to detect associations between MHC and NKR gene/microsatellite haplotypes in three horse breed groups (Camargue, African, and Romanian) by statistical methods; chi-square test, Fisher's exact test, Pearson's goodness-of-fit test and logistic regression. Associations were detected for both MHC/NKR genes and microsatellites; the most significant associations were found between the most variable KLRA3 gene and the EQCA-1 or EQCA-2 genes. This finding supports the assumption that the KLRA3 is an important receptor for MHC I and that interactions of these molecules play important roles in the horse immunity and reproduction. Despite some limitations of the study such as low numbers of horses or lack of knowledge of the selected genes functions, the results were consistent across different statistical methods and remained significant even after overconservative Bonferroni corrections. We therefore consider them biologically plausible.

Immunogenomics of Killer Cell Immunoglobulin-Like Receptor (KIR) and HLA Class I: Coevolution and Consequences for Human Health

Interactions of killer cell immunoglobin-like receptors (KIR) with human leukocyte antigens (HLA) class I regulate effector functions of key cytotoxic cells of innate and adaptive immunity. The extreme diversity of this interaction is genetically determined, having evolved in the ever-changing environment of pathogen exposure. Diversity of KIR and HLA genes is further facilitated by their independent segregation on separate chromosomes. That fetal implantation relies on many of the same types of immune cells as infection control places certain constraints on the evolution of KIR interactions with HLA. Consequently, specific inherited combinations of receptors and ligands may predispose to specific immune-mediated diseases, including autoimmunity. Combinatorial diversity of KIR and HLA class I can also differentiate success rates of immunotherapy directed to these diseases. Progress toward both etiopathology and predicting response to therapy is being achieved through detailed characterization of the extent and consequences of the combinatorial diversity of KIR and HLA. Achieving these goals is more tractable with the development of integrated analyses of molecular evolution, function, and pathology that will establish guidelines for understanding and managing risks. Here, we present what is known about the coevolution of KIR with HLA class I and the impact of their complexity on immune function and homeostasis.