HLA-Cw group 1 ligands for KIR increase susceptibility to invasive cervical cancer

"HLA-C: evolution, epigenetics, and pathological implications in the major histocompatibility complex"

HLA-C, a gene located within the major histocompatibility complex, has emerged as a prominent target in biomedical research due to its involvement in various diseases, including cancer and autoimmune disorders; even though its recent addition to the MHC, the interaction between HLA-C and KIR is crucial for immune responses, particularly in viral infections. This review provides an overview of the structure, origin, function, and pathological implications of HLA-C in the major histocompatibility complex. In the last decade, we systematically reviewed original publications from Pubmed, ScienceDirect, Scopus, and Google Scholar. Our findings reveal that genetic variations in HLA-C can determine susceptibility or resistance to certain diseases. However, the first four exons of HLA-C are particularly susceptible to epigenetic modifications, which can lead to gene silencing and alterations in immune function. These alterations can manifest in diseases such as alopecia areata and psoriasis and can also impact susceptibility to cancer and the effectiveness of cancer treatments. By comprehending the intricate interplay between genetic and epigenetic factors that regulate HLA-C expression, researchers may develop novel strategies for preventing and treating diseases associated with HLA-C dysregulation.

Dysregulation of DNA Methylation and Epigenetic Clocks in Prostate Cancer among Puerto Rican Men

In 2021, approximately 248,530 new prostate cancer (PCa) cases are estimated in the United States. Hispanic/Latinos (H/L) are the second largest racial/ethnic group in the US. The objective of this study was to assess DNA methylation patterns between aggressive and indolent PCa along with ancestry proportions in 49 H/L men from Puerto Rico (PR). Prostate tumors were classified as aggressive (n = 17) and indolent (n = 32) based on the Gleason score. Genomic DNA samples were extracted by macro-dissection. DNA methylation patterns were assessed using the Illumina EPIC DNA methylation platform. We used ADMIXTURE to estimate global ancestry proportions. We identified 892 differentially methylated genes in prostate tumor tissues as compared with normal tissues. Based on an epigenetic clock model, we observed that the total number of stem cell divisions (TNSC) and stem cell division rate (SCDR) were significantly higher in tumor than adjacent normal tissues. Regarding PCa aggressiveness, 141 differentially methylated genes were identified. Ancestry proportions of PR men were estimated as African, European, and Indigenous American; these were 24.1%, 64.2%, and 11.7%, respectively. The identification of DNA methylation profiles associated with risk and aggressiveness of PCa in PR H/L men will shed light on potential mechanisms contributing to PCa disparities in PR population.

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.

Multi-omics mapping of human papillomavirus integration sites illuminates novel cervical cancer target genes

BACKGROUND

Integration of human papillomavirus (HPV) into the host genome is a dominant feature of invasive cervical cancer (ICC), yet the tumorigenicity of cis genomic changes at integration sites remains largely understudied.

METHODS

Combining multi-omics data from The Cancer Genome Atlas with patient-matched long-read sequencing of HPV integration sites, we developed a strategy for using HPV integration events to identify and prioritise novel candidate ICC target genes (integration-detected genes (IDGs)). Four IDGs were then chosen for in vitro functional studies employing small interfering RNA-mediated knockdown in cell migration, proliferation and colony formation assays.

RESULTS

PacBio data revealed 267 unique human-HPV breakpoints comprising 87 total integration events in eight tumours. Candidate IDGs were filtered based on the following criteria: (1) proximity to integration site, (2) clonal representation of integration event, (3) tumour-specific expression (Z-score) and (4) association with ICC survival. Four candidates prioritised based on their unknown function in ICC (BNC1, RSBN1, USP36 and TAOK3) exhibited oncogenic properties in cervical cancer cell lines. Further, annotation of integration events provided clues regarding potential mechanisms underlying altered IDG expression in both integrated and non-integrated ICC tumours.

CONCLUSIONS

HPV integration events can guide the identification of novel IDGs for further study in cervical carcinogenesis and as putative therapeutic targets.

Lymphocyte activating gene 3 protein expression in nasopharyngeal carcinoma is correlated with programmed cell death-1 and programmed cell death ligand-1, tumor-infiltrating lymphocytes

BACKGROUND

Immunotherapy has shown promising efficacy in patients with nasopharyngeal carcinoma (NPC). Lymphocyte activating 3 gene (LAG-3) represents a significant immune target, however, its relationship with NPC remains unclear. This study aimed to evaluate LAG-3 expression in NPC and its association with CD3+ tumor-infiltrating lymphocytes (TILs), Granzyme B (GZMB), programmed death ligand 1 (PD-L1), and programmed death 1 (PD-1) expression.

METHODS

A total of 182 patients with NPC from Sun Yat-sen University Cancer Center, China, were included in this retrospective study. LAG-3 expression in 15 NPC cell lines and LAG-3, CD3+ TILs, GZMB, PD-L1 and PD-1 in clinical samples were estimated using immunohistochemistry. The Chi-square test was used to estimate the association between LAG-3, other biomarkers, and clinical characteristics. Survival analysis was performed using the Kaplan-Meier method and the Cox regression model.

RESULTS

LAG-3 was negatively expressed in all of the 15 NPC cell lines, whereas, 147 patients with NPC (80.8%) exhibited high LAG-3 expression on TILs from tumor tissues. Male patients and those who were EBV-positive presented higher LAG-3 expression. Correlation analyses showed that LAG-3 expression was related to PD-1 expression on TILs, as well as, PD-L1 expression on tumor cells (TCs) and TILs. Both the univariate and multivariate Cox models indicated that pathological type III (P = 0.036), higher LAG-3 on TILs (P < 0.001), higher PD-L1 on TCs (P = 0.027), and higher PD-1 on TILs (P < 0.001) were associated with poorer disease-free survival (DFS). However, lower PD-L1 expression on TILs was related to superior DFS only in the univariate Cox analyses (P = 0.002).

CONCLUSION

Higher LAG-3 and PD-1 on TILs, and higher PD-L1 expression on TCs, and pathological type III were identified as independent risk factors for poorer DFS in NPC patients. Our data demonstrate that LAG-3 is a promising inhibitory receptor that may play an important role in anti-NPC therapy.

HLA and KIR Associations of Cervical Neoplasia

Background

Cervical cancer is the fourth most common cancer in women, and we recently reported human leukocyte antigen (HLA) alleles showing strong associations with cervical neoplasia risk and protection. HLA ligands are recognized by killer immunoglobulin-like receptors (KIRs) expressed on a range of immune cell subsets, governing their proinflammatory activity. We hypothesized that the inheritance of particular HLA-KIR combinations would increase cervical neoplasia risk.

Methods

Here, we used HLA and KIR dosages imputed from single-nucleotide polymorphism genotype data from 2143 cervical neoplasia cases and 13858 healthy controls of European decent.

Results

The following 4 novel HLA alleles were identified in association with cervical neoplasia, owing to their linkage disequilibrium with known cervical neoplasia-associated HLA-DRB1 alleles: HLA-DRB3*9901 (odds ratio [OR], 1.24; P = 2.49 × 10-9), HLA-DRB5*0101 (OR, 1.29; P = 2.26 × 10-8), HLA-DRB5*9901 (OR, 0.77; P = 1.90 × 10-9), and HLA-DRB3*0301 (OR, 0.63; P = 4.06 × 10-5). We also found that homozygosity of HLA-C1 group alleles is a protective factor for human papillomavirus type 16 (HPV16)-related cervical neoplasia (C1/C1; OR, 0.79; P = .005). This protective association was restricted to carriers of either KIR2DL2 (OR, 0.67; P = .00045) or KIR2DS2 (OR, 0.69; P = .0006).

Conclusions

Our findings suggest that HLA-C1 group alleles play a role in protecting against HPV16-related cervical neoplasia, mainly through a KIR-mediated mechanism.

Expression of lymphocyte-activating gene 3 and T-cell immunoreceptor with immunoglobulin and ITIM domains in cutaneous melanoma and their correlation with programmed cell death 1 expression in tumor-infiltrating lymphocytes

BACKGROUND

Lymphocyte-activating gene 3 (LAG-3) and T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif (TIGIT) domains are emerging checkpoint proteins.

OBJECTIVE

We evaluated LAG-3 and TIGIT protein expression patterns, correlated these patterns with programmed cell death 1 (PD-1) protein expression, and determined their effects on clinicopathologic characteristics and biologic responses in melanoma.

METHODS

Diagnostic tissue from 124 patients with melanoma were evaluated for LAG-3, TIGIT, and PD-1 expression by immunohistochemistry. Clinicopathologic features and survival were analyzed according to the expression of LAG-3, TIGIT, and PD-1.

RESULTS

LAG-3 and TIGIT expression on tumor-infiltrating lymphocytes were significantly correlated with that of PD-1 and was also significantly associated with negative prognostic factors: deeper Breslow thickness, lymph node involvement, and advanced stage of disease. However, PD-1 expression was not associated with clinicopathologic variables of prognostic significance. High expression of either LAG-3 or TIGIT was associated with worse survival. Subgroup analysis on the basis of Breslow thickness showed that both LAG-3 and TIGIT have prognostic significance regardless of tumor thickness. High expression of PD-1 was not predictive of survival.

LIMITATIONS

Retrospective study in a single institution and possibility of type 1 error.

CONCLUSION

Expression of LAG-3 and TIGIT represents an independent unfavorable prognostic factor in cutaneous melanoma.

Genetic variations in human papillomavirus and cervical cancer outcomes

Cervical cancer is driven by persistent infection of human papillomavirus (HPV), which is influenced by HPV type and intratypic variants, yet the impact of HPV type and intratypic variants on patient outcomes is far less understood. Here, we examined the association of cervical cancer stage and survival with HPV type, clade, lineage, and intratypic variants within the HPV E6 locus. Of 1,028 HPV-positive cases recruited through the CerGE study, 301 were in-situ and 727 were invasive cervical cancer (ICC), with an average post-diagnosis follow-up of 4.8 years. HPV sequencing was performed using tumor-isolated DNA to assign HPV type, HPV 16 lineage, clade, and intratypic variants within the HPV 16 E6 locus, of which nonsynonomous variants were functionally annotated by molecular modeling. HPV 18-related types were more prevalent in ICC compared to in-situ disease and associated with significantly worse recurrence-free survival (RFS) compared to HPV 16-related types. The HPV 16 Asian American lineage D3 and Asian lineage A4 associated more frequently with ICC than with in situ disease and women with an intratypic HPV 16 lineage B exhibited a trend toward worse RFS than those with A, C, or D lineages. Participants with intratypic E6 variants predicted to stabilize the E6-E6AP-p53 complex had worse RFS. Variants within the highly immunogenic HPV 16 E6 region (E14-I34) were enriched in ICC compared to in-situ lesions but were not associated with survival. Collectively, our results suggest that cervical cancer outcome is associated with HPV variants that affect virus-host interactions.

Activities of stromal and immune cells in HPV-related cancers

The immune system is composed of immune as well as non-immune cells. As this system is a well-established component of human papillomavirus- (HPV)-related carcinogenesis, high risk human papillomavirus (hrHPV) prevents its routes and mechanisms in order to cause the persistence of infection. Among these mechanisms are those originated from stromal cells, which include the cancer-associated fibroblasts (CAFs), the myeloid-derived suppressor cells (MDSCs) and the host infected cells themselves, i.e. the keratinocytes. These types of cells play central role since they modulate immune cells activities to create a prosperous milieu for cancer development, and the knowledge how such interactions occur are essential for prognostic assessment and development of preventive and therapeutic approaches. Nevertheless, the precise mechanisms are not completely understood, and this lack of knowledge precluded the development of entirely efficient immunotherapeutic strategies for HPV-associated tumors. As a result, an intense work for attaining how host immune response works, and developing of effective therapies has been applied in the last decade. Based on this, this review aims to discuss the major mechanisms of immune and non-immune cells modulated by hrHPV and the potential and existing immunotherapies involving such mechanisms in HPV-related cancers. It is noticed that the combination of immunotherapies has been demonstrated to be essential for obtaining better results, especially because the possibility of increasing the modulating capacity of the HPV-tumor microenvironment has been shown to be central in strengthening the host immune system.

What has GWAS done for HLA and disease associations?

The major histocompatibility complex (MHC) is located in chromosome 6p21 and contains crucial regulators of immune response, including human leucocyte antigen (HLA) genes, alongside other genes with nonimmunological roles. More recently, a repertoire of noncoding RNA genes, including expressed pseudogenes, has also been identified. The MHC is the most gene dense and most polymorphic part of the human genome. The region exhibits haplotype-specific linkage disequilibrium patterns, contains the strongest cis- and trans-eQTLs/meQTLs in the genome and is known as a hot spot for disease associations. Another layer of complexity is provided to the region by the extreme structural variation and copy number variations. While the HLA-B gene has the highest number of alleles, the HLA-DR/DQ subregion is structurally most variable and shows the highest number of disease associations. Reliance on a single reference sequence has complicated the design, execution and analysis of GWAS for the MHC region and not infrequently, the MHC region has even been excluded from the analysis of GWAS data. Here, we contrast features of the MHC region with the rest of the genome and highlight its complexities, including its functional polymorphisms beyond those determined by single nucleotide polymorphisms or single amino acid residues. One of the several issues with customary GWAS analysis is that it does not address this additional layer of polymorphisms unique to the MHC region. We highlight alternative approaches that may assist with the analysis of GWAS data from the MHC region and unravel associations with all functional polymorphisms beyond single SNPs. We suggest that despite already showing the highest number of disease associations, the true extent of the involvement of the MHC region in disease genetics may not have been uncovered.

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.

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.

LAG-3 Protein Expression in Non-Small Cell Lung Cancer and Its Relationship with PD-1/PD-L1 and Tumor-Infiltrating Lymphocytes

INTRODUCTION

Immunotherapy targeting the programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) checkpoint has shown promising efficacy in patients with NSCLC. Lymphocyte activating 3 gene (LAG-3) is another important checkpoint, and its role in NSCLC is still not clear. In this study we investigated lymphocyte activing 3 (LAG-3) protein expression; its correlation with PD-1, PD-L1, and tumor-infiltrating lymphocytes (TILs); and its association with survival in NSCLC.

METHODS

The expression of LAG-3 (EPR4392 [Abcam, Cambridge, MA]) protein was assessed in 55 NSCLC cell lines by immunohistochemistry. LAG-3, PD-1 (NAT 105 [Cell Marque, Rocklin, CA]), and PD-L1 (22C3 [Dako, Carpenteria, CA]) protein expression was evaluated by immunohistochemistry, and TIL abundance was scored in 139 surgically resected specimens from patients with NSCLC. We also verified results in samples from 62 patients with untreated NSCLC and detected a correlation between LAG-3 expression and EGFR and KRAS mutation and echinoderm microtubule associated protein like 4 gene (EML4)-anaplastic lymphoma receptor tyrosine kinase gene (ALK) rearrangement.

RESULTS

LAG-3 was not expressed on any of the 55 NSCLC cell lines. However, LAG-3 was expressed on the TILs in 36 patients with NSCLC (25.9%). Sixty patient samples (43.2%) were positive for PD-1 on the TILs, and 25 (18.0%) were positive for PD-L1 on tumor cells. Neither LAG-3 nor PD-1 was expressed on the tumor cells. LAG-3 was overexpressed on the TILs in nonadenocarcinoma compared with in adenocarcinoma (p = 0.031). LAG-3 expression on TILs was significantly correlated with that of PD-1 on TILs (p < 0.001) and PD-L1 on tumor cells (p = 0.041) but not with TIL percentage (p = 0.244). With the logistic regression model, the ORs for LAG-3 were 0.320 (95% confidence interval [CI]: 0.110-0.929) and 4.364 (95% CI: 1.898-10.031) when nonadenocarcinoma was compared with adenocarcinoma and TILs that were negative for PD-1 were compared with those positive for PD-1. Recurrence-free survival was significantly different in patients whose TILs were LAG-3-negative as opposed to LAG-3-positive (1.91 years [95% CI: 0.76-3.06] versus 0.87 years [95% CI: 0.27-1.47] [p = 0.025]). Likewise, LAG-3 status of TILs (negative versus positive) did significantly affect overall survival (OS) (3.04 years [95% CI: 2.76-3.32] versus 1.08 years [95% CI: 0.42-1.74] [p = 0.039]). Using Kaplan-Meier analysis, we found that patients with both PD-L1-negative tumor cells and LAG-3-negative TILs have longer recurrence-free survival than patients who are either PD-L1- or LAG-3-positive or both PD-L1- and LAG-3-positive (2.09 years [95% CI: 0.90-3.28] versus 1.42 years [95% CI: 0.46-2.34] versus 0.67 years [95% CI: 0.00-1.45] [p = 0.007]). In the verification stage, high expression of LAG-3 was also significantly correlated with higher expression of PD-1 on TILs (p = 0.016) and PD-L1 on tumor cells (p = 0.014). There was no correlation between LAG-3 expression and EGFR (p = 0.325) and KRAS mutation (p = 1.000) and ALK fusion (p = 0.562).

CONCLUSIONS

LAG-3 is expressed on TILs in tumor tissues of some patients with NSCLC. Its expression was higher in nonadenocarcinoma and correlated with PD-1/PD-L1 expression. LAG-3 positivity or both LAG-3 and PD-L1 positivity was correlated with early postoperative recurrence. LAG-3 was related to poor prognosis.

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.

The Influence of HLA and KIR Genes on Malignant Melanoma Development and Progression

Many studies have described the role of killer immunoglobulin-like receptors (KIRs) and their cognate human leukocyte antigen (HLA) class I ligands in the immune protection against melanoma, but the effect of these markers on intra-individual variations in tumor development and progression has remained less clear. We performed KIR, HLA, and KIR/ligand analysis in 283 patients with malignant melanoma in order to evaluate their integrated influence on disease stage and progression. The patients were grouped according to AJCC staging, histological type of the primary tumor, progression, and survival rate. Analysis of HLA class I alleles revealed positive association of HLA-C*14 (Pc = 0.026, OR = 5.99) and negative association of HLA-C*02 (Pc = 0.026, OR = 0.43) with the disease. Decreased frequency of KIR2DS5 was observed in patients with rapid progression, as compared to those with slow progression. KIR BB genotype was prevalent in patients with metastasis (p = 0.004, OR = 0.025). KIR AA genotype was nearly twice as frequent in rapidly progressive cases, but without statistical relevance (p = 0.055, OR = 2.6). Significantly increased frequency of KIR2DL2 in the presence of C1 ligand (strong inhibition) was found in patients with AJCC III and IV, as compared to individuals with AJCC I stage (p = 0.045, OR = 1.93). In summary, our data imply that KIR/ligand gene content in patients could modulate the disease course towards unfavorable tumor behavior.

Association of the genetic diversity of killer cell immunoglobulin-like receptor genes and HLA-C ligand in Saudi women with breast cancer

Breast cancer (BC) progression and metastases have been linked to antitumor immunity inefficiency and particularly to natural killer (NK) cells. Killer cell immunoglobulin-like receptors (KIRs) are the most polymorphic receptors of NK cells. Through their interactions with human leukocyte antigen (HLA)-C ligands, they modulate NK and T cell actions against target cells. Therefore, we studied the combinatorial effect of KIR genes and their HLA-C ligands on the susceptibility to development of BC in Saudi women. The presence of KIR genes and HLA-C1 and HLA-C2 groups was typed in 50 Saudi patients living in Riyadh and 65 healthy controls using polymerase chain reaction with sequence-specific primers. Our results indicated a protective effect by the KIR2DS2, 2DS3, and 2DL5A genes against BC (OR = 0.25, 0.21, and 0.27, respectively, and p < 0.01). The synergistic action of the three genes was observed when they occurred together, and the absence of the three genes increased BC occurrence by 6.5-fold. Distribution of the HLA-C1/C2 ligand between patients and controls showed an increase in the risk of BC occurrence for the heterozygote C1/C2 (OR = 2.33; 95 % CI = 1.08-5.02; p = 0.037) and a protective effect of the homozygote C2C2 (OR = 0.03; 95 % CI = 0.009-0.098; p < 0.001). Combinatory analyses of KIR genes and their HLA-C ligands showed protective effects of KIR2DL2 and 2DL3 in the absence of their HLA-C1 ligand. These results suggested that KIR-gene content combined with their ligand could influence the risk of BC development in women in Saudi Arabia.

Killer cell immunoglobulin-like receptor and human leukocyte antigen gene profiles in a cohort of HIV-infected Mexican Mestizos

Killer cell immunoglobulin-like receptors (KIRs) represent the most polymorphic genes responsible for natural killer cell function, while human leukocyte antigen (HLA) class I molecules define and restrict cytotoxic T lymphocyte responses. Specific KIR, HLA, or KIR-HLA combinations have been implicated in the outcome of human immunodeficiency virus (HIV) disease. The remarkable polymorphism of KIR and HLA genes warrants descriptive gene frequency studies in different populations, as well as their impact on HIV disease progression in different immunogenetic contexts. We report KIR and HLA class I gene profiles of 511 unrelated HIV-infected Mexican Mestizo individuals from 18 states for whom genetic ancestry proportions were assessed. KIR and HLA gene profiles were compared between individuals from the north and central-south regions of the country and between individuals with higher European (EUR) or Amerindian (AMI) genetic ancestry component. A total of 65 KIR genotypes were observed, 11 harboring novel KIR gene combinations. A total of 164 HLA alleles were observed: 43 HLA-A, 87 HLA-B, and 34 HLA-C. Differences in the distribution of 12 HLA alleles were observed between individuals with higher AMI or EUR ancestry components (p < 0.05, q < 0.2). After correcting for genetic ancestry, only individual HLA alleles were associated with HIV disease progression, including a novel association with A*02:06, an Amerindian HLA allele associated with lower CD4+ T cell counts. No KIR effects were significant. Our results highlight the advantages of considering a detailed genetic stratification within populations when studying genetic profiles that could be implicated in disease-association studies.

Risk of Classic Kaposi Sarcoma With Combinations of Killer Immunoglobulin-Like Receptor and Human Leukocyte Antigen Loci: A Population-Based Case-control Study

BACKGROUND

Kaposi sarcoma (KS) is a complication of KS-associated herpesvirus (KSHV) infection. Other oncogenic viral infections and malignancies are associated with certain HLA alleles and their natural killer (NK) cell immunoglobulin-like receptor (KIR) ligands. We tested whether HLA-KIR influences the risk of KSHV infection or KS.

METHODS

In population-based case-control studies, we compared HLA class I and KIR gene frequencies in 250 classic (non-AIDS) KS cases, 280 KSHV-seropositive controls, and 576 KSHV-seronegative controls composing discovery and validation cohorts. Logistic regression was used to calculate sex- and age-adjusted odds ratios (ORs) and 95% confidence intervals.

RESULTS

In both the discovery and validation cohorts, KS was associated with HLA-A*11:01 (adjusted OR for the combined cohorts, 0.4; P = .002) and HLA-C*07:01 (adjusted OR, 1.6; P = .002). Consistent associations across cohorts were also observed with activating KIR3DS1 plus HLA-B Bw4-80I and homozygosity for HLA-C group 1. With KIR3DS1 plus HLA-B Bw4-80I, the KSHV seroprevalence was 40% lower (adjusted OR for the combined cohorts, 0.6; P = .01), but the KS risk was 2-fold higher (adjusted OR, 2.1; P = .002). Similarly, the KSHV seroprevalence was 40% lower (adjusted OR, 0.6; P = .01) but the KS risk 80% higher with HLA-C group 1 homozygosity (adjusted OR, 1.8; P = .005).

CONCLUSIONS

KIR-mediated NK cell activation may decrease then risk of KSHV infection but enhance KSHV dissemination and progression to KS if infection occurs.

Polymorphisms in immune mediators associate with risk of cervical cancer

OBJECTIVE

The immune system is critical for controlling the progression of HPV cervical disease and the development of cancer. This study aimed to identify cervical cancer susceptibility alleles in candidate immune-modulating genes.

METHODS

Our family-based study involved a cohort of 641 probands (women with ICC/CIN III) and their biologic parents or siblings (641 trios). In the discovery phase (stage 1), involving 288 of the trios, 80 tag single nucleotide polymorphisms (SNPs) in 11 immune-modulating genes (IFNG, IFNGR1, IFNGR2, JAK1, JAK2, STAT1, STAT6, IL12A, TNF, LTA and LTB) were evaluated on the GoldenGate platform. We used the combined dataset for a total of 641 trios (stage 2) and the Taqman platform to validate the SNPs that had proved significant in the discovery dataset. The transmission disequilibrium test was used to detect significant shifts in allelic transmissions in the datasets.

RESULTS

Two SNPs in JAK2 and one SNP in STAT6 showed significant allelic association with cervical cancer in the stage 1 discovery dataset and were replicated in the larger joint analysis stage 2 dataset (JAK2 rs10815144, P=0.0029 and rs12349785, P=0.0058; and STAT6 rs3024971, P=0.0127). An additional SNP in exon 19 of JAK2 (rs2230724) was also examined in the combined dataset due to its strong linkage disequilibrium (LD) with rs10815144. It was also significant (P=0.0335).

CONCLUSIONS

Our results suggest an association of SNPs in JAK2 and STAT6 with cervical cancer. This association should be investigated in additional cervical cancer populations.

Implication of HLA-C and KIR alleles in human papillomavirus infection and associated cervical lesions

Human papillomavirus (HPV) regulation of host immune response leads to cervical lesions. In particular, natural killer (NK) cells are crucial for HPV control. Since specific HLA-I/KIR interactions modify NK cell activation, we analyzed HLA-C and KIR alleles in HPV infection and lesion development in 150 controls, 33 condyloma acuminatum, and 111 invasive cervical cancer (ICC) patients. We showed an increase in HLA-C1/KIR2DL2 and HLA-C1/KIR2DL3 pairs in HPV high-risk infected patients (OR 3.05, 3.24) with ICC (OR 1.33, 3.68). These data suggest HLA-C and KIR typing as risk marker for HPV infection and lesion evolution.

The association of the immune response genes to human papillomavirus-related cervical disease in a Brazilian population

The genetic variability of the host contributes to the risk of human papillomavirus (HPV)-related cervical disease. Immune response genes to HPV must be investigated to define patients with the highest risk of developing malignant disease. The aim of this study was to investigate the association of polymorphic immune response genes, namely KIR, HLA class I and II, and single-nucleotide polymorphisms (SNPs) of cytokines with HPV-related cervical disease. We selected 79 non-related, admixed Brazilian women from the state of Paraná, southern region of Brazil, who were infected with high carcinogenic risk HPV and present cervical intraepithelial neoplasia grade 3 (CIN3), and 150 HPV-negative women from the same region matched for ethnicity. KIR genes were genotyped using an in-house PCR-SSP. HLA alleles were typed using a reverse sequence-specific oligonucleotide technique. SNPs of TNF −308G>A, IL6 −174G>C, IFNG +874T>A, TGFB1 +869T>C +915G>C, and IL10 −592C>A −819C>T −1082G>A were evaluated using PCR-SSP. The KIR genes were not associated with HPV, although some pairs of i(inhibitory)KIR-ligands occurred more frequently in patients, supporting a role for NK in detrimental chronic inflammatory and carcinogenesis. Some HLA haplotypes were associated with HPV. The associations of INFG and IL10 SNPs potentially reflect impaired or invalid responses in advanced lesions.

Analysis of KIR gene frequencies and HLA class I genotypes in breast cancer and control group

Breast cancer is the main cause of cancer-related death among women, with a 0.5% increase in incidence per year. Natural killer cells (NK) are part of the innate immune system recognizing class I HLA molecules on target cells through their membrane receptors, called killer cell immunoglobulin-like receptors (KIR). The aim of our study was to evaluate the association between the KIR genes and HLA alleles in patients with breast cancer and healthy controls. Two hundred thirty patients with breast cancer and 272 healthy controls were typed for HLA class I and KIR genes by PCR-SSO. When both groups were compared, the presence of inhibitory KIR2DL2 receptors was significantly higher in breast cancer patients than in healthy controls. No significant differences were found for HLA-C2 and HLA-Bw4. However, a higher frequency of HLA-C1 in breast cancer patients was observed. These findings suggest a potential role for the KIR gene system in breast cancer. Further studies to confirm this observation are warranted.

KIR gene variability in cutaneous malignant melanoma: influence of KIR2D/HLA-C pairings on disease susceptibility and prognosis

Natural killer and CD8(+) T cells are believed to be involved in the immune protection against melanoma. Their function may be regulated by a group of receptors defined as killer immunoglobulin-like receptors (KIRs) and their cognate HLA class I ligands. In this study, we analyzed the influence of KIR genes and KIR/HLA-I combinations on melanoma susceptibility and/or prognosis in a Spanish Caucasian population. For this purpose, KIR genotyping by PCR-SSP and HLA-C genotyping by reverse PCR-SSO were performed in 187 melanoma patients and 200 matched controls. We found a significantly low frequency of KIR2DL3 in nodular melanoma (NM) patients (P = 0.001) and in ulcerated melanoma patients (P < 0.0001). Similarly, the KIR2DL3/C1 combination was significantly decreased in melanoma patients (Pc = 0.008) and in patients with sentinel lymph node (SLN) melanoma metastasis (Pc = 0.002). Multivariate logistic regression models showed that KIR2DL3 behaves as a protective marker for NM and ulcerated melanoma (P = 0.02, odds ratio (OR) = 0.14 and P = 0.04, OR = 0.28, respectively), whereas the KIR2DL3/C1 pair acts as a protective marker for melanoma (P = 0.017, OR = 0.54), particularly superficial spreading melanoma (P = 0.02, OR = 0.52), and SLN metastasis (P = 0.0004, OR = 0.14). In contrast, the KIR2DL3(-)/C1C2 genotype seems to be correlated with NM and ulceration. We also report that the KIR2DL1(+)/S1(-)/C2C2 genotype is associated with susceptibility to melanoma and SLN metastasis. Altogether, the study of KIR2D genes and HLA-C ligands may help in assessing cutaneous melanoma risk and prognosis.

The distribution of genetic diversity of KIR genes in the Chinese Mongolian population

Killer cell immunoglobulin-like receptors (KIRs) are expressed on natural killer cells and as such regulate their response against infection and malignancy. KIR genes are variable in gene content and type, which results in different KIR haplotypes, and can be used to discriminate individuals and populations from different regions or ethnic groups. In the present study, we represent the first report on the KIR gene frequency and content diversities of 14 KIR genes (KIR2DL1, 2DL2, 2DL3, 2DL4, 2DL5, 2DS1, 2DS2, 2DS3, 2DS4, 2DS5, 3DL1, 3DL2, 3DL3, 3DS1) and 2 pseudogenes (KIR3DP1 and 2DP1) in the Chinese Mongolian population. The 16 detected KIR genes were all observed. All the individuals were typed positive for the four framework genes KIR3DL3, 3DL2, 2DL4 and the pseudogene KIR3DP1, as well as for the pseudogene KIR2DP1. The observed carrier gene frequencies (OF) of the other KIR genes ranged from 16% at the KIR2DL2 locus to 93% at the KIR3DL1 locus. Over all, 48 different gene profiles were found in the study population and the most commonly observed KIR gene profile with a frequency of 14% consisted of KIR2DL4, 3DL2, 3DL3, 2DP1, 3DP1, 2DL1, 2DL3 and 3DL1 which belongs to the AA genotype. Principal component analysis (PCA) and the dendrogram illustrated the genetic distances between our study population and previously published populations from other ethnic groups or regions. The results of the present study show that the KIR gene family is highly polymorphic and can be a valuable tool for enriching the Chinese ethnical gene information resources, for anthropological studies, as well as for KIR gene related disease research.

Activating KIR/HLA complexes in classic Kaposi's Sarcoma

BACKGROUND

Classic Kaposi's Sarcoma (cKS) is a rare vascular tumor associated with Human Herpesvirus 8 (KSHV) infection, nevertheless not all KSHV-infected individuals have cKS.

OBJECTIVE

We investigated whether particular KIR/HLA receptor/ligand genotypes would be preferentially present in KSHV-infected and uninfected individuals who have or have not developed cKS.

METHODS

KIR/HLA genotypes were analyzed by molecular genotyping in 50 KSHV-infected individuals who did or did not have cKS and in 33 age-and sex-matched KSHV seronegative individuals.

RESULTS

There was no association of individual KIR, HLA or receptor ligand combinations with KSHV infection. However, activating KIR and KIR/HLA genotypes were significantly more frequent in cKS cases, specifically KIR3DS1, KIR2DS1, and KIR2DS1 with its HLA-C2 ligand.

CONCLUSION

A nonspecific inflammatory response triggered by activation of NK cells upon KIR-HLA interaction could be associated with the pathogenesis of KS.

The emerging role of HLA-C in HIV-1 infection

Recently, genome-wide association studies have identified the major histocompatibility complex class I protein HLA-C as an important molecule that affects HIV disease progression. The association between HLA-C and HIV disease outcome was originally determined through a single nucleotide polymorphism (SNP) 35 kb upstream of the HLA-C locus. More recent work has focused on elucidating the functional significance of the -35 SNP, and several groups now have demonstrated HLA-C surface expression to be a key element in control of HIV viral load, with higher surface expression associating with slower disease progression. Most recently, control of HLA-C surface expression has been correlated with the presence of microRNA binding sites that affect HLA-C expression and control of HIV disease. This review highlights these results and explores the ways in which HLA-C surface expression could affect immune system function in the setting of HIV disease.

HLA-C as a mediator of natural killer and T-cell activation: spectator or key player?

The biochemical properties of the HLA-C antigen differ substantially from those of HLA-A and -B molecules. For this reason, HLA-C diversity and expression at the cell surface are much lower than its counterparts and in consequence HLA-C-restricted responses have been infrequently detected and described. In this review we summarise the key differences between HLA-C and other class I molecules and provide an update on natural killer and T-cell responses restricted by HLA-C. We also discuss the different clinical settings associated with HLA-C alleles which mainly consist of autoimmune disorders, cancers and chronic infections.