Genetic diversity of the KIR/HLA system and outcome of patients with metastatic colorectal cancer treated with chemotherapy

Impact of HLA Class I Antigen, Killer Inhibitory Receptor, and FCGR3A Genotypes on Breast Cancer Susceptibility and Tumor Stage

BACKGROUND

The identification in breast cancer (BC) of novel genetic biomarkers regulating natural killer (NK) cell function, including the HLA, KIR, and CD16A (FCGR3A), may be still a challenge.

OBJECTIVE

We aimed to evaluate whether the combined effect of these polymorphisms has an impact on BC susceptibility and progression.

METHODS

47 BC Italian patients and healthy individuals (39 females and 66 males/ females) were genotyped by Sanger sequencing (HLA-C exon 2-4 and FCGR3A- 158V/F, 48L/R/H) and PCR-SSP typing (KIR genes).

RESULTS

HLA-C gene allele analysis showed the group C1, with HLA-C*07:02:01 allele, to be significantly associated with tumor progression (16.7% vs. 4.0%, p=0.04, OR=4.867), and instead, group C2, with HLA-C*05:01:01, was protective against disease susceptibility (0.0% vs. 7.2%, p=0.019, OR=0.087). In addition, we highlighted a significant reduction of the KIR2DS4ins in BC patients (pcorr.=0.022) and an increased combined presence of KIR2DL1 and KIR2DS1 genes in advanced BC patients compared to earlier stages (66.7% vs. 19.2%, p=0.002). The concurrent lack of KIR2DL2 and KIR2DS4 genes in the presence of HLA-C2 alleles was significantly associated with increased susceptibility to BC (p=0.012, OR=5.020) or with lymph node involvement (p=0.008, OR=6.375). Lastly, we identified different combinations of the FCGR3A-48/158 variants and KIR genes in BC patients compared to controls.

CONCLUSION

Our findings suggest that in the development of BC probably exists a disorder of the NK innate immunity influenced by KIR/HLA-C gene content and FCGR3A-158 polymorphisms and that the combined analysis of these biomarkers might help predict genetic risk scores for tailored screening of BC patients in therapy.

Evaluation of KIR3DL1/KIR3DS1 allelic polymorphisms in Kenyan children with endemic Burkitt lymphoma

Endemic Burkitt lymphoma (eBL) is a fast-growing germinal center B cell lymphoma, affecting 5-10 per 100,000 children annually, in the equatorial belt of Africa. We hypothesize that co-infections with Plasmodium falciparum (Pf) malaria and Epstein-Barr virus (EBV) impair host natural killer (NK) and T cell responses to tumor cells, and thus increase the risk of eBL pathogenesis. NK cell education is partially controlled by killer immunoglobulin-like receptors and variable expression of KIR3DL1 has been associated with other malignancies. Here, we investigated whether KIR3D-mediated mechanisms contribute to eBL, by testing for an association of KIR3DL1/KIR3DS1 genotypes with the disease in 108 eBL patients and 99 healthy Kenyan children. KIR3DL1 allelic typing and EBV loads were assessed by PCR. We inferred previously observed phenotypes from the genotypes. The frequencies of KIR3DL1/KIR3DL1 and KIR3DL1/KIR3DS1 did not differ significantly between cases and controls. Additionally, none of the study participants was homozygous for KIR3DS1 alleles. EBV loads did not differ by the KIR3DL1 genotypes nor were they different between eBL survivors and non-survivors. Our results suggest that eBL pathogenesis may not simply involve variations in KIR3DL1 and KIR3DS1 genotypes. However, considering the complexity of the KIR3DL1 locus, this study could not exclude a role for copy number variation in eBL pathogenesis.

HLA/MHC and KIR characterization in humans and non-human primates using Oxford Nanopore Technologies and Pacific Biosciences sequencing platforms

The gene products of the HLA/MHC and KIR multigene families are important modulators of the immune system and are associated with health and disease. Characterization of the genes encoding these receptors has been integrated into different biomedical applications, including transplantation and reproduction biology, immune therapies and in fundamental research into disease susceptibility or resistance. Conventional short-read sequencing strategies have shown their value in high throughput typing, but are insufficient to uncover the entire complexity of the highly polymorphic HLA/MHC and KIR gene systems. The implementation of single-molecule and real-time sequencing platforms, offered by Pacific Biosciences (PacBio) and Oxford Nanopore Technologies (ONT), revolutionized the fields of genomics and transcriptomics. Using fundamentally distinct principles, these platforms generate long-read data that can unwire the plasticity of the HLA/MHC and KIR genes, including high-resolution characterization of genes, alleles, phased haplotypes, transcription levels and epigenetics modification patterns. These insights might have profound clinical relevance, such as improved matching of donors and patients in clinical transplantation, but could also lift disease association studies to a higher level. Even more, a comprehensive characterization may refine animal models in preclinical studies. In this review, the different HLA/MHC and KIR characterization approaches using PacBio and ONT platforms are described and discussed.

Contribution of natural killer cells in innate immunity against colorectal cancer

Natural killer cells are members of the innate immune system and promote cytotoxic activity against tumor or infected cells independently from MHC recognition. NK cells are modulated by the expression of activator/inhibitory receptors. The ratio of this activator/inhibitory receptors is responsible for the cytotoxic activity of NK cells toward the target cells. Owing to the potent anti-tumor properties of NK cells, they are considered as interesting approach in tumor treatment. Colorectal cancer (CRC) is the second most common cause of death in the world and the incidence is about 2 million new cases per year. Metastatic CRC is accompanied by a poor prognosis with less than three years of overall survival. Chemotherapy and surgery are the most adopted treatments. Besides, targeted therapy and immune checkpoint blockade are novel approach to CRC treatment. In these patients, circulating NK cells are a prognostic marker. The main target of CRC immune cell therapy is to improve the tumor cell's recognition and elimination by immune cells. Adaptive NK cell therapy is the milestone to achieve the purpose. Allogeneic NK cell therapy has been widely investigated within clinical trials. In this review, we focus on the NK related approaches including CAR NK cells, cell-based vaccines, monoclonal antibodies and immunomodulatory drugs against CRC tumoral cells.

Association of HLA-G 3'UTR Polymorphisms with Response to First-Line FOLFIRI Treatment in Metastatic Colorectal Cancer

Microenvironmental factors such as non-classical human leukocyte antigen-G (HLA-G) have been associated with cancer invasiveness and metastatic progression. HLA-G expression has been associated with specific single-nucleotide polymorphisms (SNP) in HLA-G 3'untranslated region (UTR) in several diseases. The primary aim was to investigate the predictive role of HLA-G polymorphisms on treatment efficacy in metastatic colorectal cancer (mCRC) patients homogeneously treated with first-line FOLFIRI (irinotecan, 5-fluorouracil, and leucovorin) and their association with soluble HLA-G (sHLA-G) plasma concentration. HLA-G 3'UTR was sequenced in 248 patients. A set of eight polymorphisms and related haplotypes were analyzed for their association with best tumor response, overall survival (OS), and progression-free survival (PFS). sHLA-G was measured by immunoassay in 35 available plasma samples and correlated with HLA-G 3'UTR polymorphisms/haplotypes. Our results showed that carriers of rs371194629 (+2960)-Ins allele were at risk for lack of complete response (hazard ratio (HR):0.29, p_BH = 0.0336), while carriers of rs1710 (+3010)-G allele (rs1063320 (+3142)-C allele in linkage-disequilibrium), and rs9380142 (+3187)-G allele had a higher chance of complete response according to additive models (HR:4.58, p_BH = 0.0245; HR:3.18, p_BH = 0.0336, respectively). The combination of rs371194629-Del, rs1710-G, and rs9380142-G alleles forms the UTR1 haplotype. Patients who were carriers of UTR1/UTR-1 diplotype had a greater chance of complete response to therapy (HR:10.59, p_BH = 0.0294). The same three beneficial alleles showed a trend toward higher pre-treatment sHLA-G plasma levels, supporting a functional role for polymorphisms in protein secretion. In conclusion, genetic variants of HLA-G are associated with treatment efficacy in mCRC patients treated with first-line FOLFIRI. This finding shed light on the combined effect of this immune system factor and chemotherapy in cancer patients.

Pharmacogenetics Role of Genetic Variants in Immune-Related Factors: A Systematic Review Focusing on mCRC

Pharmacogenetics plays a key role in personalized cancer treatment. Currently, the clinically available pharmacogenetic markers for metastatic colorectal cancer (mCRC) are in genes related to drug metabolism, such as DPYD for fluoropyrimidines and UGT1A1 for irinotecan. Recently, the impact of host variability in inflammatory and immune-response genes on treatment response has gained considerable attention, opening innovative perspectives for optimizing tailored mCRC therapy. A literature review was performed on the predictive role of immune-related germline genetic biomarkers on pharmacological outcomes in patients with mCRC. Particularly, that for efficacy and toxicity was reported and the potential role for clinical management of patients was discussed. Most of the available data regard therapy effectiveness, while the impact on toxicity remains limited. Several studies focused on the effects of polymorphisms in genes related to antibody-dependent cellular cytotoxicity (FCGR2A, FCGR3A) and yielded promising but inconclusive results on cetuximab efficacy. The remaining published data are sparse and mainly hypothesis-generating but suggest potentially interesting topics for future pharmacogenetic studies, including innovative gene-drug interactions in a clinical context. Besides the tumor immune escape pathway, genetic markers belonging to cytokines/interleukins (IL-8 and its receptors) and angiogenic mediators (IGF1) seem to be the best investigated and hopefully most promising to be translated into clinical practice after validation.

Predicting drug response and toxicity in metastatic colorectal cancer: the role of germline markers

INTRODUCTION

Despite the introduction of targeted agents leading to therapeutic advances, clinical management of patients with metastatic colorectal cancer (mCRC) is still challenged by significant interindividual variability in treatment outcomes, both in terms of toxicity and therapy efficacy. The study of germline genetic variants could help to personalize and optimize therapeutic approaches in mCRC.

AREAS COVERED

A systematic review of pharmacogenetic studies in mCRC patients published on PubMed between 2011 and 2021, evaluating the role of germline variants as predictive markers of toxicity and efficacy of drugs currently approved for treatment of mCRC, was perfomed.

EXPERT OPINION

Despite the large amount of pharmacogenetic data published to date, only a few genetic markers (i.e., DPYD and UGT1A1 variants) reached the clinical practice, mainly to prevent the toxic effects of chemotherapy. The large heterogeneity of available studies represents the major limitation in comparing results and identifying potential markers for clinical use, the role of which remains exploratory in most cases. However, the available published findings are an important starting point for future investigations. They highlighted new promising pharmacogenetic markers within the network of inflammatory and immune response signaling. In addition, the emerging role of previously overlooked rare variants has been pointed out.

Correlation Between Immune-Related Genes and Tumor-Infiltrating Immune Cells With the Efficacy of Neoadjuvant Chemotherapy for Breast Cancer

Background: In the absence of targeted therapy or clear clinically relevant biomarkers, neoadjuvant chemotherapy (NAC) is still the standard neoadjuvant systemic therapy for breast cancer. Among the many biomarkers predicting the efficacy of NAC, immune-related biomarkers, such as immune-related genes and tumor-infiltrating lymphocytes (TILs), play a key role.

Methods: We analyzed gene expression from several datasets in the Gene Expression Omnibus (GEO) database and evaluated the relative proportion of immune cells using the CIBERSORT method. In addition, mIHC/IF detection was performed on clinical surgical specimens of triple-negative breast cancer patients after NAC.

Results: We obtained seven immune-related genes, namely, CXCL1, CXCL9, CXCL10, CXCL11, IDO1, IFNG, and ORM1 with higher expression in the pathological complete response (pCR) group than in the non-pCR group. In the pCR group, the levels of M1 and γδT macrophages were higher, while those of the M2 macrophages and mast cells were lower. After NAC, the proportions of M1, γδT cells, and resting CD4 memory T cells were increased, while the proportions of natural killer cells and dendritic cells were decreased with downregulated immune-related genes. The results of mIHC/IF detection and the prognostic information of corresponding clinical surgical specimens showed the correlation of proportions of natural killer cells, CD8-positive T cells, and macrophages with different disease-free survival outcomes.

Conclusion: The immune-related genes and immune cells of different subtypes in the tumor microenvironment are correlated with the response to NAC in breast cancer, and the interaction between TILs and NAC highlights the significance of combining NAC with immunotherapy to achieve better clinical benefits.

KIR-HLA Functional Repertoire Influences Trastuzumab Efficiency in Patients With HER2-Positive Breast Cancer

Trastuzumab induced a high rate of pathological Complete Response (pCR) in patients affected by locally advanced HER2-positive Breast Cancer (HER2-BC), by exploiting immune-mediated mechanisms as Antibody-Dependent Cell Cytotoxicity (ADCC) involving Natural Killer (NK) cells. Host's immune genetics could influence the response to therapy, through the expression of variants that characterize NK receptors involved in ADCC effectiveness. Killer cell immunoglobin-like receptors (KIRs) modulate NK cell activity through their binding to class-I Human Leukocyte Antigens (HLA). The impact of the KIR/HLA repertoire in HER2-BC is under study. We characterized KIR genotypes of 36 patients with locally advanced HER2-BC treated with neoadjuvant chemotherapy including trastuzumab. We monitored pCR achievement before surgery and Disease-Free Survival (DFS) and Overall Survival (OS) after adjuvant therapy. HLA, and Fc gamma receptor IIIa (FcγR3A) and IIa (FcγR2A) were genotyped through targeted PCR and Sanger sequencing in 35/36 patients. The KIR-HLA combinations were then described as functional haplotypes and divided in two main categories as inhibitory tel A and stimulatory tel B. Trastuzumab-dependent ADCC activity was monitored with an in vitro assay using a HER2-BC model and patients' NK cells.We observed a higher frequency of KIR activators in patients who achieved a pCR compared to partial responders. During the study of functional haplotypes, individuals carrying a tel B haplotype showed greater ADCC efficiency than tel A cases. In subjects with the tel A haplotype the presence of the favorite V allele in FcγR3A receptor improved their low ADCC levels. Regardless of the haplotypes detected, the presence of KIR3DL2/HLA-A03 or A11 was always associated with the FcγR3A V allele, and therefore correlated with greater ADCC efficiency. However, this particular KIR receptor appeared to harm DFS and OS. Indeed, patients with tel B haplotype without KIR3DL2/HLA-A03 or A11 showed a better outcome. Our data, although preliminary, suggested a potential predictive role for KIR haplotype tel B, in identifying patients who achieve a pCR after neoadjuvant treatment with trastuzumab, and supported a negative prognostic impact of KIR3DL2/HLA-A03 or A11 in the adjuvant setting.

Overview of Research on Germline Genetic Variation in Immune Genes and Cancer Outcomes

Since the late 19th century, the immune system has been known to play a role in cancer risk, initiation, and progression. Genome-wide association studies (GWAS) have identified hundreds of genetic risk loci for autoimmune and inflammatory diseases, yet the connection between human genetic variation and immune-mediated response to cancer treatments remains less well-explored. Understanding inherited genetic variation, with respect to germline genetic polymorphisms that affect immune system pathways, could lead to greater insights about how these processes may best be harnessed to successfully treat cancer. Our goal in this manuscript was to understand progress and challenges in assessing the role of inherited genetic variation in response to cancer treatments. Overall, the 39 studies reviewed here suggest that germline genetic variation in immune system related genes may potentially affect responses to cancer treatments. Although further research is needed, considering information on germline immune genetic variation may help, in some cases, to optimize cancer treatment.

The importance of immune checkpoints in immune monitoring: A future paradigm shift in the treatment of cancer

The growth and development of cancer are directly correlated to the suppression of the immune system. A major breakthrough in cancer immunotherapy depends on various mechanisms to detect immunosuppressive factors that inhibit anti-tumor immune responses. Immune checkpoints are expressed on many immune cells such as T-cells, regulatory B cells (Bregs), dendritic cells (DCs), natural killer cells (NKs), regulatory T (Tregs), M2-type macrophages, and myeloid-derived suppressor cells (MDSCs). Immune inhibitory molecules, including CTLA-4, TIM-3, TIGIT, PD-1, and LAG-3, normally inhibit immune responses via negatively regulating immune cell signaling pathways to prevent immune injury. However, the up-regulation of inhibitory immune checkpoints during tumor progression on immune cells suppresses anti-tumor immune responses and promotes immune escape in cancer. It has recently been indicated that cancer cells can up-regulate various pathways of the immune checkpoints. Therefore, targeting immune inhibitory molecules through antibodies or miRNAs is a promising therapeutic strategy and shows favorable results. Immune checkpoint inhibitors (ICIs) are introduced as a new immunotherapy strategy that enhance immune cell-induced antitumor responses in many patients. In this review, we highlighted the function of each immune checkpoint on different immune cells and therapeutic strategies aimed at using monoclonal antibodies and miRNAs against inhibitory receptors. We also discussed current challenges and future strategies for maximizing these FDA-approved immunosuppressants' effectiveness and clinical success in cancer treatment.

Improving selection of patients with metastatic colorectal cancer to benefit from cetuximab based on KIR genotypes

AIM

Cetuximab is a standard-of-care treatment for KRAS wild-type metastatic colorectal cancer (mCRC), but it may also be effective in a subgroup of KRAS mutant patients by its immunomodulatory activity. Here, we explore if KIR (killer cell immunoglobulin-like receptor) genotyping can provide a significant added value in the clinical outcome of patients with KRAS mutant mCRC based on cetuximab treatment.

METHODS

We included 69 patients with histologically confirmed mCRC and KRAS mutation, positive EGFR expression, and Eastern Cooperative Oncology Group performance status ≤2. Based on KIR gene content, haplotype (A or B) was defined and genotypes (AA or Bx) were grouped for each patient.

RESULTS

We demonstrated with new evidence the immunomodulatory activity of cetuximab in patients with KRAS mutant mCRC. Patients with homozygous genotypes (AA or BB) showed shorter 12-month progression-free survival (PFS12) and poorer overall survival (OS) than those with heterozygotes (AB). Moreover, multivariate analysis confirmed stratification of patients based on genotype was an independent marker of PFS12 (HR 2.16) and the centromeric and telomeric distribution of KIRs was an independent predictor of both PFS12 (HR 2.26) and OS (HR 1.93) in patients with mCRC with KRAS mutation treated with cetuximab.

CONCLUSIONS

Selection of patients with mCRC based on their KIR genotypes opens a therapeutic opportunity for patients with KRAS mutation, and it should be tested in clinical trials in comparison with other alternatives with scarce benefit.

TRIAL REGISTRATION NUMBER

NCT01450319, EudraCT 2010-023580-18.

Sparse-FCM and Deep Convolutional Neural Network for the segmentation and classification of acute lymphoblastic leukaemia

Leukaemia detection and diagnosis in advance is the trending topic in the medical applications for reducing the death toll of patients with acute lymphoblastic leukaemia (ALL). For the detection of ALL, it is essential to analyse the white blood cells (WBCs) for which the blood smear images are employed. This paper proposes a new technique for the segmentation and classification of the acute lymphoblastic leukaemia. The proposed method of automatic leukaemia detection is based on the Deep Convolutional Neural Network (Deep CNN) that is trained using an optimization algorithm, named Grey wolf-based Jaya Optimization Algorithm (GreyJOA), which is developed using the Grey Wolf Optimizer (GWO) and Jaya Optimization Algorithm (JOA) that improves the global convergence. Initially, the input image is applied to pre-processing and the segmentation is performed using the Sparse Fuzzy C-Means (Sparse FCM) clustering algorithm. Then, the features, such as Local Directional Patterns (LDP) and colour histogram-based features, are extracted from the segments of the pre-processed input image. Finally, the extracted features are applied to the Deep CNN for the classification. The experimentation evaluation of the method using the images of the ALL IDB2 database reveals that the proposed method acquired a maximal accuracy, sensitivity, and specificity of 0.9350, 0.9528, and 0.9389, respectively.

Crucial Gene Identification in Carotid Atherosclerosis Based on Peripheral Blood Mononuclear Cell (PBMC) Data by Weighted (Gene) Correlation Network Analysis (WGCNA)

Background

Many patients are not responsive or tolerant to medical therapies for carotid atherosclerosis. Thus, elucidating the molecular mechanism for the pathogenesis and progression of carotid atherosclerosis and identifying new potential molecular targets for medical therapies that can slow progression of carotid atherosclerosis and prevent ischemic events are quite important.

Material/Methods

We downloaded the expression profiling data of PBMC in Biobank of Karolinska Endarterectomy (BiKE, GSE21545) for GEO. The WGCNA and DEG screening were conducted. The co-expression pattern between patients with ischemic events (the events group) and patients without ischemic events (the no-events group) were compared. Then, we identified hub genes of each module. Finally, the DEG co-expression network was constructed and MCODE was used to identify crucial genes based on this co-expression network.

Results

In the study, 183 DEGs were screened and 8 and 6 modules were assessed in the events group and no-events group, respectively. Compared to the no-events group, genes associated with inflammation and immune response were clustered in the green-yellow module of the events group. The hub gene of the green-yellow module of the events group was KIR2DL5A. We obtained 1 DEG co-expression network, which has 16 nodes and 24 edges, and we detected 5 crucial genes: SIRT1, THRAP3, RBM43, PEX1, and KLHDC2. The upregulated genes (THRAP3 and RBM43) showed potential diagnostic and prognostic value for the occurrence of ischemic events.

Conclusions

We detected 8 modules for the events group and 6 modules for the no-events group. The hub genes for modules and crucial genes of the DEG co-expression network were also identified. These genes might serve as potential targets for medical therapies and biomarkers for diagnosis and prognosis. Further experimental and biological studies are needed to elucidate the role of these crucial genes in the progression of carotid atherosclerosis.

Killer Cell Immunoglobulin-Like Receptors (KIRs) Genotype and Haplotype Analysis in Iranians with Non-Melanoma Skin Cancers

Background

The innate immune system against malignancies is mainly orchestrated by natural killer cells, which carry out killing mechanisms by using their receptors, such as killer immunoglobulin-like receptors (KIRs). This study was designed to determine the diversity of KIR genes in non-melanoma skin cancers.

Methods

A total of 160 subjects with skin cancer, including 60 cases of squamous cell carcinoma and 100 cases of basal cell carcinoma (BCC), and 270 healthy subjects formed the study groups. The sequence-specific polymerase chain reaction was carried out to detect the presence or absence of 16 KIR genes.

Results

KIR3DL1 (p = 0.0381, OR = 4.78, 95% CI = 1.108 to 20.62) increased in BCC patients compared to healthy controls.

Conclusion

We concluded that the higher frequency of KIR3DL1 in BCC patients compared with healthy controls may increase the probability of developing BCC in Iranians.

The association of HLA/KIR genes with non-small cell lung cancer (adenocarcinoma) in a Han Chinese population

The host immune system plays a crucial role in the surveillance, recognition and elimination of tumor cells. Recent studies found that Human lymphocyte antigen class I (HLA I) genes, Killer cell immunoglobulin-like receptor (KIR) genes and HLA/KIR combinations play a role in the defense against tumor cells. To evaluated the associations between HLA I genes, KIR genes and HLA/KIR combinations and non-small cell lung cancer (NSCLC) in a Chinese Han population, a total of 229 patients with NSCLC (adenocarcinoma) and 217 healthy individuals were studied. Our results showed that the HLA-C*08:01 allele occurred at a significantly higher frequency in the NSCLCs compared with the controls (P=0.034). The HLA haplotype frequencies bearing HLA-A, -B, and -C loci between the NSCLC and control groups were not different (P>0.05). And there were no differences in the KIR gene, genotype and haplotype frequencies between the NSCLC and control groups (P>0.05). Also, there were no differences between the HLA/KIR combinations in the KIR3D genes and HLA-A3/A11, HLA-Bw4 ligands and KIR2D genes and HLA-C1/C2 ligands between the NSCLC and control groups (P>0.05). Our results indicate that the HLA-C*08:01 allele could be a risk factor for NSCLC (adenocarcinoma) in the Chinese Han population (OR=2.395; 95% CI: 1.359-4.221).

Activating and inhibitory killer cell immunoglobulin like receptors (KIR) genes are involved in an increased susceptibility to colorectal adenocarcinoma and protection against invasion and metastasis

BACKGROUND

A set of activating and inhibitory KIRs (aKIR, iKIR) are involved in NK cell mediated immunity. This study was carried out in order to investigate the KIRs pattern and its association with colorectal carcinoma (CRC) development and clinical outcomes.

METHODS

Sequence-specific primers-polymerase chain reaction (SSP-PCR) for typing of 16 KIR genes was utilized in 165 patients with colorectal adenocarcinoma with 165 age and gender matched healthy controls (CNs).

RESULTS

Possessing KIR2DS1, 2DS5, 3DS1, 2DS4fl, 2DL5, telomeric half KIR genes, ≥ 4 aKIR and CXT4 genotype were associated with an increased susceptibility to colorectal adenocarcinoma while KIR2DS4del and iKIR >aKIR confer resistance to CRC. On the other hand, clinical associations revealed the defensive role of telomeric KIR3DL1, 3DS1, 2DS1, 2DS4, genotypes with ≥ 4 aKIR and more inhibitory KIRs than activating ones (I > A) against metastasis and CXTX genotype in perineural invasion.

CONCLUSION

According to current results it appears that KIRs system play distinctive roles in development and metastasis of colorectal adenocarcinoma.

The use of pharmacogenetics to increase the safety of colorectal cancer patients treated with fluoropyrimidines

Fluoropyrimidines (FP) are given in the combination treatment of the advanced disease or as monotherapy in the neo-adjuvant and adjuvant treatment of colorectal cancerand other solid tumors including breast, head and neck and gastric cancer. FP present a narrow therapeutic index with 10 to 26% of patients experiencing acute severe or life-threatening toxicity. With the high number of patients receiving FP-based therapies, and the significant effects of toxicities on their quality of life, the prevention of FP-related adverse events is of major clinical interest. Host genetic variants in the rate limiting enzyme dihydropyrimidine dehydrogenase (DPYD) gene are related to the occurrence of extremely severe, early onset toxicity in FP treated patients. The pre-treatment diagnostic test of 4 DPYD genetic polymorphisms is suggested by the currently available pharmacogenetic guidelines. Several prospective implementation projects are ongoing to support the introduction of up-front genotyping of the patients in clinical practice. Multiple pharmacogenetic studies tried to assess the predictive role of other polymorphisms in genes involved in the FP pharmacokinetics/pharmacodynamic pathways, TYMS and MTHFR, but no additional clinically validated genetic markers of toxicity are available to date. The development of next-generation sequencing platforms opens new possibilities to highlight previously unreported genetic markers. Moreover, the investigation of the genetic variation in the patients immunological system, a pivotal target in cancer treatment, could bring notable advances in the field. This review will describe the most recent literature on the use of pharmacogenetics to increase the safety of a treatment based on FP administration in colorectal cancer patients.

Combination of KIR2DS4 and FcγRIIa polymorphisms predicts the response to cetuximab in KRAS mutant metastatic colorectal cancer

Cetuximab is a standard-of-care treatment for RAS wild-type metastatic colorectal cancer (mCRC) but not for those harbor a KRAS mutation since MAPK pathway is constitutively activated. Nevertheless, cetuximab also exerts its effect by its immunomodulatory activity despite the presence of RAS mutation. The aim of this study was to determine the impact of polymorphism FcγRIIIa V158F and killer immunoglobulin-like receptor (KIR) genes on the outcome of mCRC patients with KRAS mutations treated with cetuximab. This multicenter Phase II clinical trial included 70 mCRC patients with KRAS mutated. We found KIR2DS4 gene was significantly associated with OS (HR 2.27; 95% CI, 1.08–4.77; P = 0.03). In non-functional receptor homozygotes the median OS was 2.6 months longer than in carriers of one copy of full receptor. Multivariate analysis confirmed KIR2DS4 as a favorable prognostic marker for OS (HR 6.71) in mCRC patients with KRAS mutation treated with cetuximab. These data support the potential therapeutic of cetuximab in KRAS mutated mCRC carrying non-functional receptor KIR2DS4 since these patients significantly prolong their OS even after heavily treatment. KIR2DS4 typing could be used as predictive marker for identifying RAS mutated patients that could benefit from combination approaches of anti-EGFR monoclonal antibodies and other immunotherapies to overcome the resistance mediated by mutation in RAS.

A Clinical-Genetic Score to Identify Surgically Resected Colorectal Cancer Patients Benefiting From an Adjuvant Fluoropyrimidine-Based Therapy

There are clinical challenges related to adjuvant treatment in colorectal cancer (CRC) and novel molecular markers are needed for better risk stratification of patients. Our aim was to integrate our previously reported clinical-genetic prognostic score with new immunogenetic markers of 5-year disease-free survival (DFS) to evaluate the recurrence risk stratification before fluoropyrimidine (FL)-based adjuvant therapy. The study population included a total of 270 stage II-III CRC patients treated with adjuvant FL with (FL + OXA, n = 119) or without oxaliplatin (FL, n = 151). Patients were genotyped for a panel of 192 tagging polymorphisms in 34 immune-related genes. The IFNG-rs1861494 polymorphism was associated with worse DFS in the FL + OXA (HR = 2.14, 95%CI 1.13–4.08; P = 0.020, q-value = 0.249) and FL (HR = 1.97, 95%CI 1.00–3.86; P = 0.049) cohorts, according to a dominant model. The integration of IFNG-rs1861494 in our previous clinical genetic multiparametric score of DFS improved the patients’ risk stratification (Log-rank P = 0.0026 in the pooled population). These findings could improve the discrimination of patients who would benefit from adjuvant treatment. In addition, the results may help better elucidate the interplay between the immune system and chemotherapeutics and help determine the efficacy of anti-tumor strategies.

Host genetic profiling to increase drug safety in colorectal cancer from discovery to implementation

Adverse events affect the pharmacological treatment of approximately 90% of colorectal cancer (CRC) patients at any stage of the disease. Chemotherapy including fluoropyrimidines, irinotecan, and oxaliplatin is the cornerstone of the pharmacological treatment of CRC. The introduction of novel targeted agents, as anti-EGFR (i.e. cetuximab, panitumumab) and antiangiogenic (i.e. bevacizumab, ziv-aflibercept, regorafenib, and ramucirumab) molecules, into the oncologist's toolbox has led to significant improvements in the life expectancy of advanced CRC patients, but with a substantial increase in toxicity burden. In this respect, pharmacogenomics has largely been applied to the personalization of CRC chemotherapy, focusing mainly on the study of inhered polymorphisms in genes encoding phase I and II enzymes, ATP-binding cassette (ABC)/solute carrier (SLC) membrane transporters, proteins involved in DNA repair, folate pathway and immune response. These research efforts have led to the identification of some validated genetic markers of chemotherapy toxicity, for fluoropyrimidines and irinotecan. No validated genetic determinants of oxaliplatin-specific toxicity, as peripheral neuropathy, has thus far been established. The contribution of host genetic markers in predicting the toxicity associated with novel targeted agents' administration is still controversial due to the heterogeneity of published data. Pharmacogenomics guidelines have been published by some international scientific consortia such as the Clinical Pharmacogenomics Implementation Consortium (CPIC) and the Dutch Pharmacogenetics Working Group (DPWG) strongly suggesting a pre-treatment dose adjustment of irinotecan based on UGT1A1*28 genotype and of fluoropyrimidines based on some DPYD genetic variants, to increase treatment safety. However, these recommendations are still poorly applied at the patient's bedside. Several ongoing projects in the U.S. and Europe are currently evaluating how pharmacogenomics can be implemented successfully in daily clinical practice. The majority of drug-related adverse events are still unexplained, and a great deal of ongoing research is aimed at improving knowledge of the role of pharmacogenomics in increasing treatment safety. In this review, the issue of pre-treatment identification of CRC patients at risk of toxicity via the analysis of patients' genetic profiles is addressed. Available pharmacogenomics guidelines with ongoing efforts to implement them in clinical practice and new exploratory markers for clinical validation are described.

The combination of anti-KIR monoclonal antibodies with anti-PD-1/PD-L1 monoclonal antibodies could be a critical breakthrough in overcoming tumor immune escape in NSCLC

Background

The anti-programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) monoclonal antibody has a good effect in the treatment of non-small cell lung cancer (NSCLC), but not all PD-1/PD-L1 positive patients can get benefit from it. Compensatory expression of other immune checkpoints may be correlated with the poor efficacy of anti-PD-1/PD-L1 monoclonal antibodies. The inhibitory human leukocyte antigen (HLA)/killer cell Ig-like receptor (KIR) can effectively block the killing effect of natural killer (NK) cells on tumors. Our previous studies have confirmed that high expression of KIR was correlated with poor prognosis of NSCLC. Inhibitory KIR expression was positively correlated with the expression of PD-1.

Methods

The expressions of KIR 2D (L1, L3, L4, S4) (BC032422/ADQ31987/NP_002246/NP_036446, Abcam) and PD-1 (NAT 105, Cell marque) proteins was assessed by immunohistochemistry.

Results

The expression of inhibitory KIR in tumor cells or tumor infiltrating lymphocytes (TILs) is associated with PD-1 expression. Among PD-1 positive patients, 76.3% were KIR 2D (L1, L3, L4, S4) positive on tumor cells, and 74.6% were KIR 2D (L1, L3, L4, S4) positive on TILs. We compared the expression of inhibitory KIR before and after treatment with nivolumab in 11 patients with NSCLC. We found that five (45.5%) patients had positive expression of inhibitory KIR in tumor tissue after being treated with anti-PD-1 monoclonal antibodies, two of whom exhibited a significant increase in expression of inhibitory KIR, and three showed no change.

Conclusions

PD-1 expression was correlated with KIR 2D (L1, L3, L4, S4) on tumor cells or TILs. The resistance to anti-PD-1 monoclonal antibody treatment might be related to KIR. The inhibitory HLA/KIR could combine with the PD-1/PD-L1 signaling pathway negatively regulating NSCLC tumor immunity.

Genotype B of Killer Cell Immunoglobulin-Like Receptor is Related with Gastric Cancer Lesions

NK cells are important in innate immunity for their capacity to kill infected or cancer cells. The killer cell immunoglobulin-like receptors (KIR) are a family of polymorphic genes with inhibitory and activating functions. The main driving force for gastric cancer (GC) development is a chronic response, which causes an increase of NK cells in the gastric mucosa. The aim of this work was to study polymorphisms in KIR genes in patients with either GC or non-atrophic gastritis (NAG). We studied 242 patients (130 with NAG and 112 with GC) and contrasted with 146 asymptomatic individuals. We analyzed diversity in the content and localization of KIR genes in the different clinical groups studied. Four activating and one inhibitory genes were associated with GC: 2DS1 (OR 3.41), 2DS3 (OR 4.66), 2DS5 (OR 2.25), 3DS1 (OR 3.35) and 2DL5 (OR 3.6). The following were also found as risk factors for GC: Bx genotype (OR 4.2), Bx-Bx centromere-telomere (OR 2.55), cA01|cB03 (OR 36.39) and tB01|tB01 (OR 7.55) gene content and three B motifs (OR 10.9). Polymorphisms in KIR genes were associated with GC and suggest that mutated NK cells may contribute to GC development by increasing gastric mucosa inflammation, leading to constant tissue damage.

KIR 2D (L1, L3, L4, S4) and KIR 3DL1 protein expression in non-small cell lung cancer

Background

Nature killer (NK) cells are the immune system's first line of defense against both viral infections and tumors. Killer cell immunoglobulin-like receptors (KIRs) are associated with susceptibility to different types of cancers. We investigated KIR 2D (L1, L3, L4, S4) and KIR 3DL1 protein expression and their association with survival in non-small cell lung cancer (NSCLC).

Methods

The expression of KIR 2D (L1, L3, L4, S4) (BC032422/ ADQ31987/ NP_002246/ NP_036446, ABCAM) and KIR 3DL1 (AA 1-444, ABCAM) protein was assessed by immunohistochemistry (IHC) in 62 NSCLC patients.

Results

KIR 2D (L1, L3, L4, S4) and KIR 3DL1 were expressed both on NSCLC tumor cells and tumor infiltrating lymphocytes (TILs). Fourteen samples (22.6%) stained positive for KIR 2D (L1, L3, L4, S4) on the tumor cells, and 10 (16.1%) had positive expression on the TILs. Thirty-three samples (53.2%) stained positive for KIR 3DL1 on the tumor cells, and 31 (50.0%) had positive expression on the TILs. Patients with negative KIR 2D (L1, L3, L4, S4) expression on tumor cells or TILs had longer overall survival (OS) than patients who are KIR 2D (L1, L3, L4, S4) positive on tumor cells (40.70 weeks, 95% CI 24.76-56.65 vs. 7.10 weeks, 95% CI 0.00-19.38, P = 0.014) or TILs (40.70 weeks, 95% CI 24.05-57.35 vs. 3.90 weeks, 95% CI 0.00-9.17, P < 0.001). Likewise, longer OS was significantly correlated with negative expression of KIR 3DL1 on tumor cells (62.30 weeks, 95% CI 0.00-177.37 vs. 13.10 weeks, 95% CI 3.42-22.78, P < 0.001) or TILs (62.30 weeks, 95% CI 0.00-152.05 vs. 12.10 weeks, 95% CI 2.61-21.59, P < 0.001). Cox regression analysis showed that KIR 2D (L1, L3, L4, S4) on TILs was correlated with OS (P = 0.032, Odds Ratio 2.628 95%CI 1.089-6.340).

Conclusions

KIR 2D (L1, L3, L4, S4) and KIR 3DL1 expression was correlated with poor prognosis in NSCLC patients.

HLA-Bw4 80(T) and multiple HLA-Bw4 copies combined with KIR3DL1 associate with spontaneous clearance of HCV infection in people who inject drugs

BACKGROUND & AIMS

Natural killer (NK) cell function is regulated by inhibitory and activating receptors including killer cell immunoglobulin-like receptors (KIRs). Here, we analyzed the impact of different KIR/KIR-ligand genotypes on the outcome of hepatitis C virus (HCV) infection in people who inject drugs (PWID).

METHODS

KIR/KIR-ligand genotypes associated with spontaneous clearance of HCV infection were identified in a cohort of PWID from Germany (n=266) and further validated in a second anti-HCV positive cohort of PWID recruited in North America (n=342). NK cells of PWID and healthy donors were functionally characterized according to their KIR/KIR-ligand genotype by flow cytometry.

RESULTS

Multivariate logistic regression analysis revealed that KIR3DL1/HLA-Bw4 80(T) was associated with spontaneous clearance of HCV infection in PWID, which was confirmed in the PWID cohort from North America. Compared with PWID with detectable HCV RNA, the frequency of individuals with multiple HLA-Bw4 alleles was significantly higher in anti-HCV positive PWID with resolved HCV infection (29.7% vs. 15.2%; p=0.0229) and in anti-HCV seronegative PWID (39.2%; p=0.0006). KIR3DL1+ NK cells from HLA-Bw4 80(T)-positive PWID showed superior functionality compared to HLA-Bw4 80(I)-positive PWID. This differential impact was not observed in healthy donors; however, the HLA-Bw4 copy number strongly correlated with the functionality of KIR3DL1+ NK cells.

CONCLUSIONS

HLA-Bw4-80(T) and multiple HLA-Bw4 copies in combination with KIR3DL1 are associated with protection against chronic hepatitis C in PWID by distinct mechanisms. Better licensing of KIR3DL1+ NK cells in the presence of multiple HLA-Bw4 copies is beneficial prior to seroconversion whereas HLA-Bw4 80(T) may be beneficial during acute hepatitis C. Lay summary: Natural killer (NK) cells are part of the innate immune system and are regulated by a complex network of activating and inhibiting receptors. The regulating receptor-ligand pairs of an individual are genetically determined. Here, we identified a particular set of ligand and receptor genes that are associated with better functionality of NK cells and better outcome upon exposure to HCV in a high-risk group.

Influence of HLA class I, HLA class II and KIRs on vertical transmission and chronicity of hepatitis C virus in children

Background & aim

There is evidence that maternal viral load of HCV during delivery influences the risk for Mother-to-child transmission (MTCT), but this does not explain all cases. We study the role of the immunogenetic profile (HLA, KIRs and KIR-ligand binding) of mothers and children in HCV-MTCT and in chronicity in the children.

Methodology

79 HCV-RNA (+) mothers and their 98 children were included. 24 children were infected, becoming chronic in 8 cases and clearing in 16. HLA-class-I and II and KIRs were determined by Luminex.

Results

MTCT study: The presence of HLA-C1-ligand in mothers and/or their children reduces the risk of transmission (mothers: Pc = 0.011, children: P = 0.033), whereas the presence of HLA-C2C2-ligand in mothers increases it (Pc = 0.011). In children KIR2DL3-HLA-C1 is a protector factor (Pc = 0.011). Chronicity in children study: Maternal DQA1*01 allele (Pc = 0.027), KIR2DS1 (Pc = 0.011) or KIR3DS1 (Pc = 0.011) favours chronicity in the child. The presence of the DQB1*03 allele (Pc = 0.027) and KIR2DS3 (P = 0.056) in the child and homozygosity for KIR3DL1/3DL1 (Pc = 0.011) and for the HLA-Bw4/Bw4 ligand (P = 0.027) is associated with viral clearance, whereas the presence of HLA-Bw6 ligand (P = 0.027), the binding of KIR3DS1-HLA-Bw4 (P = 0.037) and heterozygosity for KIR3DL1/3DS1 (Pc = 0.011) favour viral chronicity. Mother/child allele matching: In the joint HLA analysis, matching was greater between mothers and children with chronic infection vs those who had cleared the virus (67%±4.1 vs 57%±1.2, P = 0.003).

Conclusions

The HLA-C1 ligand in the mother is related to MTCT, while several genetic factors of the mother or child are involved in the chronification or clearance of infection in the child. Matching allelic data is considered to be an indicator of HCV chronicity in the child and can be used as a potential prognostic test. This implies that NK cells may play a previously undocumented role in protecting against MTCT and that both NK cell immunity and adaptive T-cell responses may influence viral clearance in infected children.

Cancer treatment and the KIR-HLA system: an overview

Accumulating evidence indicates that the success of cancer therapy depends not only on a combination of adequate procedures (surgery, chemotherapy and radiotherapy) that aim to eliminate all tumor cells, but also on the functional state of the host immune system. HLA and KIR molecules, in particular, are critical to the interactions between tumor cells and both innate and adaptive immune cells such as NK cells and T cells. Different KIR-HLA gene combinations as well as different HLA expression levels on tumor cells associate with variable tumor prognosis and response to treatment. On the other hand, different therapies have different effects on HLA molecules and immune cell functions regulated by these molecules. Here, we provide an overview of the KIR-HLA system, a description of its alterations with clinical relevance in diverse tumor types, and an analysis of the consequences that conventional cancer therapies may have on it. We also discuss how this knowledge can be exploited to identify potential immunological biomarkers that can help to select patients for tailored therapy.

Typing of killer-cell immunoglobulin-like receptors and their cognate human leukocyte antigen class I ligands predicts survival of Chinese Han patients with metastatic non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) may establish an immunosuppressive tumor microenvironment that is conducive to tumor growth. Natural killer (NK) cells play a pivotal role in immunological surveillance. Activation of NK cells partially depends on the interactions between killer-cell immunoglobulin-like receptors (KIRs) and human leukocyte antigen (HLA) class I ligands. We herein investigated the association of KIRs and HLA ligands with survival in metastatic NSCLC (mNSCLC) patients treated with chemotherapy in a Chinese Han population. Polymerase chain reaction with sequence-specific primers was used to type 15 KIRs at the DNA and mRNA level and 6 HLA ligands in 70 mNSCLC patients. Survival curves were estimated using the Kaplan-Meier method and compared with the log-rank test. Cox proportional hazard regression model was applied for multivariate survival analysis, with the stepwise selection, to determine independent predictors of survival. It was observed that patients with KIR2DS4del gene expression at the mRNA level or HLA-Bw4T80 exhibited poor overall survival (OS). The multivariate analysis revealed that HLA-Bw4T80 and KIR2DS4del expression were independent predictors of OS. This observation indicated that the KIR/HLA ligand is a promising predictor of survival in mNSCLC and may also provide a strategy for treatment stratification and patient management.

KIR Genes and Their Ligands Predict the Response to Anti-EGFR Monoclonal Antibodies in Solid Tumors

Killer-cell immunoglobulin-like receptors (KIRs) regulate the killing function of natural killer cells, which play an important role in the antibody-dependent cell-mediated cytotoxicity response exerted by therapeutic monoclonal antibodies (mAbs). However, it is unknown whether the extensive genetic variability of KIR genes and/or their human leukocyte antigen (HLA) ligands might influence the response to these treatments. This study aimed to explore whether the variability in KIR/HLA genes may be associated with the variable response observed to mAbs based anti-epidermal growth factor receptor (EGFR) therapies. Thirty-nine patients treated with anti-EGFR mAbs (trastuzumab for advanced breast cancer, or cetuximab for advanced colorectal or advanced head and neck cancer) were included in the study. All the patients had progressed to mAbs therapy and were grouped into two categories taking into account time to treatment failure (TTF ≤6 and ≥10 months). KIR genotyping (16 genetic variability) was performed in genomic DNA from peripheral blood by PCR sequence-specific primer technique, and HLA ligand typing was performed for HLA-B and -C loci by reverse polymerase chain reaction sequence-specific oligonucleotide methodology. Subjects carrying the KIR/HLA ligand combinations KIR2DS1/HLAC2C2-C1C2 and KIR3DS1/HLABw4w4-w4w6 showed longer TTF than non-carriers counterparts (14.76 vs. 3.73 months, p < 0.001 and 14.93 vs. 4.6 months, p = 0.005, respectively). No other significant differences were observed. Two activating KIR/HLA ligand combinations predict better response of patients to anti-EGFR therapy. These findings increase the overall knowledge on the role of specific gene variants related to responsiveness to anti-EGFR treatment in solid tumors and highlight the importance of assessing gene polymorphisms related to cancer medications.

Colorectal cancer and the KIR genes in the human genome: A meta-analysis

Colorectal cancer is one of the most common types of inflammation-based cancers and is occurred due to growth and spread of cancer cells in colon and/or rectum. Previously genetic association of cell cycle genes, both proto-oncogenes and the tumor suppressors has been proved. But there were few studies about association of immune related genes such as killer-cell immunoglobulin-like receptors (KIRs). Thus we intend to perform a meta-analysis to find the association of different genes of KIR and susceptibility to be affected by colorectal cancer. The overall population of the four studies investigated in our meta-analysis was 953 individuals (470 individuals with colorectal cancer and 483 individuals in control groups). After the analyses, we concluded that colorectal cancer is affected by KIR2DS5 and also there were no protecting gene. This result shows the inflammatory basis of this cancer. In other words, in contrast to leukemia and blood cancers, colorectal cancers seem to be affected by hyper activity of natural killer-cells (NKs). Whys and therefore of this paradox, is suggested to be investigated further.

Role of KIR and CD16A genotypes in colorectal carcinoma genetic risk and clinical stage

Background

NK cell cytotoxicity is regulated by the types of the interaction between killer immunoglobulin-like receptors (KIRs) and human leukocyte antigen (HLA) class I ligands on target cells and the different binding affinity of the Fcγ receptor IIIA (CD16A) for IgG-coated tumor cells. Thus, it is conceivable that KIR and CD16A gene contents may contribute to the function of NK cells by modulating an immune response in the colorectal carcinoma (CRC) microenvironment. This hypothesis is supported by recent evidence suggesting that NK cells improve the clinical course of CRC patients by enhancing the anti-CRC effect of CD8 + T cells. This information provides the rationale to test the hypothesis whether the independent KIR segregation and specificity, as well as CD16A gene polymorphisms, have an impact on CRC.

Methods

Using polymerase chain reaction-sequence-specific primers (PCR-SSP) and sequence-based typing (SBT), we investigated KIR/HLA-C complex and CD16A (48H/R/L,158V/F) gene polymorphisms in 52 CRC patients and 61 local healthy controls (LCTRs).

Results

The allele frequency (AF) of at least five activating KIR (aKIRs) of the B haplotype (p = 0.036, OR 0.204), KIR2DL2 (p = 0.047, OR 0.2616), and KIR2DS2 genes (5.8 vs LCTR 13.8 % and vs. Fasano’s CTR 16.3 %, p = 0.05, OR 0.3145), in the absence of their cognate HLA-C1 ligands, were significantly associated with a reduced genetic risk of CRC. In contrast, CD16A-48H polymorphism was positively associated with an increased genetic risk of CRC (p = 0.05, OR 2.761). The latter was also found to be correlated with advanced stages of disease [III and IV (p = 0.03, OR 3.625)].

Conclusions

Our data suggest that the analysis of aKIRs and KIR2DL2 gene and CD16A-48H may be of interest for the identification of individuals at reduced and increased genetic risk of CRC, respectively.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-1001-y) contains supplementary material, which is available to authorized users.

Co-evolution of the MHC class I and KIR gene families in rhesus macaques: ancestry and plasticity

Researchers dealing with the human leukocyte antigen (HLA) class I and killer immunoglobulin receptor (KIR) multi‐gene families in humans are often wary of the complex and seemingly different situation that is encountered regarding these gene families in Old World monkeys. For the sake of comparison, the well‐defined and thoroughly studied situation in humans has been taken as a reference. In macaques, both the major histocompatibility complex class I and KIR gene families are plastic entities that have experienced various rounds of expansion, contraction, and subsequent recombination processes. As a consequence, haplotypes in macaques display substantial diversity with regard to gene copy number variation. Additionally, for both multi‐gene families, differential levels of polymorphism (allelic variation), and expression are observed as well. A comparative genetic approach has allowed us to answer questions related to ancestry, to shed light on unique adaptations of the species’ immune system, and to provide insights into the genetic events and selective pressures that have shaped the range of these gene families.

Impact of "Killer Immunoglobulin-Like Receptor /Ligand" Genotypes on Outcome following Surgery among Patients with Colorectal Cancer: Activating KIRs Are Associated with Long-Term Disease Free Survival

Approximately 30 % of patients with stage II/III colorectal cancer develop recurrence following surgery. How individual regulation of host mediated anti-tumor cytotoxicity is modified by the killer-cell immunoglobulin-like receptor (KIRs) genotype is essential for prediction of outcome. We analyzed the frequency of KIR and KIR ligand Human Leukocyte Antigen Class I genotypes, and their effects on recurrence and disease-free survival (DFS). Out of randomly selected 87 colorectal cancer patients who underwent R0 resection operations between 2005 and 2008, 29 patients whose cancers progressed within a median five-year follow-up period were compared with 58 patients with no recurrence within the same time period. Recurrent cases shared similar tumor stages with non-recurrent cases, but had different localizations. We used DNA isolated from pathological archival lymphoid and tumor tissues for KIR and KIR ligand (HLA-C, group C1, group C2, and HLA-A-Bw4) genotyping. Among cases with recurrence, KIR2DL1 (inhibitory KIR) and A-Bw4 (ligand for inhibitory KIR3DL1) were observed more frequently (p=0.017 and p=0.024); and KIR2DS2 and KIR2DS3 (both activating KIRs) were observed less frequently (p=0.005 and p=0.043). Similarly, in the non-recurrent group, inhibitory KIR-ligand combinations 2DL1-C2 and 2DL3-C1 were less frequent, while the activating combination 2DS2-C1 was more frequent. The lack of KIR2DL1, 2DL1-C2, and 2DL3-C1 improved disease-free survival (DFS) (100% vs. 62.3%, p=0.05; 93.8% vs. 60.0%, p=0.035; 73.6% vs. 55.9%, p=0.07). The presence of KIR2DS2, 2DS3, and 2DS2-C1 improved DFS (77.8% vs. 48.5%, p=0.01; 79.4% vs. 58.5%, p=0.003; 76.9% vs. 51.4%, p=0.023). KIR2DS3 reduced the risk of recurrence (HR=0.263, 95% CI = 0.080-0.863, p=0.028). The number of activating KIRs are correlated strongly with DFS, none/ one/ two KIR : 54/77/98 months (p=0.004). In conclusion the inheritance of increasing numbers of activating KIRs and lack of inhibitory KIRs, independent of tumor localization or stage, is associated with long-term DFS.

Killer Cell Immunoglobulin-like Receptors and Their HLA Ligands are Related with the Immunopathology of Chagas Disease

The aim of this study was to investigate the influence of killer cell immunoglobulin-like receptor (KIR) genes and their human leucocyte antigen (HLA) ligands in the susceptibility of chronic Chagas disease. This case-control study enrolled 131 serologically-diagnosed Chagas disease patients (59 men and 72 women, mean age of 60.4 ± 9.8 years) treated at the University Hospital of Londrina and the Chagas Disease Laboratory of the State University of Maringa. A control group was formed of 165 healthy individuals - spouses of patients or blood donors from the Regional Blood Bank in Maringa (84 men and 81 women, with a mean age of 59.0 ± 11.4 years). Genotyping of HLA and KIR was performed by PCR-SSOP. KIR2DS2-C1 in the absence of KIR2DL2 (KIR2DS2⁺/2DL2^-/C1⁺) was more frequent in Chagas patients (P = 0.020; Pc = 0.040; OR = 2.14) and, in particular, those who manifested chronic chagasic cardiopathy—CCC (P = 0.0002; Pc = 0.0004; OR = 6.64; 95% CI = 2.30–18.60) when compared to the control group, and when CCC group was compared to the patients without heart involvement (P = 0.010; Pc = 0.020; OR = 3.97). The combination pair KIR2DS2⁺/2DL2^-/KIR2DL3⁺/C1⁺ was also positively associated with chronic chagasic cardiopathy. KIR2DL2 and KIR2DS2 were related to immunopathogenesis in Chagas disease. The combination of KIR2DS2 activating receptor with C1 ligand, in the absence of KIR2DL2, may be related to a risk factor in the chronic Chagas disease and chronic chagasic cardiopathy.

Chagas disease is an infection caused by the haemoflagellate protozoan Trypanosoma cruzi. It is one of the most important public health problems in Latin America, and was first described by Carlos Justiniano Ribeiro das Chagas, a Brazilian physician and scientist, in 1909. It is mostly vector-borne transmitted to humans by contact with faeces of triatomine bugs. The World Health Organization estimates that about 6 to 7 million people are currently infected with T. cruzi worldwide. The disease is characterised by acute and chronic phases. The immune response during disease development is crucial for protection because immunological imbalances can lead to heart and digestive tract lesions in chagasic patients. In this work we analysed the role of receptors of immune cells known as Natural Killer cells (killer cell immunoglobulin-like receptor—KIR) and their ligands (Human leukocyte antigens—HLA) in chagasic patients compared to healthy individuals. The uncontrolled activation of NK cells can lead to tissue damage, which, in turn, leads to the development of serious chronic illness. We found that KIR-HLA complex may be related to a risk factor in the chronic Chagas disease and chronic chagasic cardiopathy.

Genetic diversity of the KIR/HLA system and susceptibility to hepatitis C virus-related diseases

Background

The variability in the association of host innate immune response to Hepatitis C virus (HCV) infection requires ruling out the possible role of host KIR and HLA genotypes in HCV-related disorders: therefore, we therefore explored the relationships between KIR/HLA genotypes and chronic HCV infection (CHC) as they relate to the risk of HCV-related hepatocarcinoma (HCC) or lymphoproliferative disease progression.

Methods and Findings

We analyzed data from 396 HCV-positive patients with CHC (n = 125), HCC (118), and lymphoproliferative diseases (153), and 501 HCV-negative patients. All were HIV and HBV negative. KIR-SSO was used to determine the KIR typing. KIR2DL5 and KIR2DS4 variants were performed using PCR and GeneScan analysis. HLA/class-I genotyping was performed using PCR-sequence-based typing. The interaction between the KIR gene and ligand HLA molecules was investigated. Differences in frequencies were estimated using Fisher’s exact test, and Cochran-Armitage trend test. The non-random association of KIR alleles was estimated using the linkage disequilibrium test. We found an association of KIR2DS2/KIR2DL2 genes, with the HCV-related lymphoproliferative disorders. Furthermore, individuals with a HLA-Bw6 KIR3DL1+ combination of genes showed higher risk of developing lymphoma than cryoglobulinemia. KIR2DS3 gene was found to be the principal gene associated with chronic HCV infection, while a reduction of HLA-Bw4 + KIR3DS1+ was associated with an increased risk of developing HCC.

Conclusions

Our data highlight a role of the innate-system in developing HCV-related disorders and specifically KIR2DS3 and KIR2D genes demonstrated an ability to direct HCV disease progression, and mainly towards lymphoproliferative disorders. Moreover the determination of KIR3D/HLA combination of genes direct the HCV progression towards a lymphoma rather than an hepatic disease. In this contest IFN-α therapy, a standard therapy for HCV-infection and lymphoproliferative diseases, known to be able to transiently enhance the cytotoxicity of NK-cells support the role of NK cells to counterstain HCV-related and lymphoproliferative diseases.