Germline genetic regulation of the colorectal tumor immune microenvironment.

OBJECTIVE: To evaluate the contribution of germline genetics to regulating the briskness and diversity of T cell responses in CRC, we conducted a genome-wide association study to examine the associations between germline genetic variation and quantitative measures of T cell landscapes in 2,876 colorectal tumors from participants in the Molecular Epidemiology of Colorectal Cancer Study (MECC). METHODS: Germline DNA samples were genotyped and imputed using genome-wide arrays. Tumor DNA samples were extracted from paraffin blocks, and T cell receptor clonality and abundance were quantified by immunoSEQ (Adaptive Biotechnologies, Seattle, WA). Tumor infiltrating lymphocytes per high powered field (TILs/hpf) were scored by a gastrointestinal pathologist. Regression models were used to evaluate the associations between each variant and the three T-cell features, adjusting for sex, age, genotyping platform, and global ancestry. Three independent datasets were used for replication. RESULTS: We identified a SNP (rs4918567) near RBM20 associated with clonality at a genome-wide significant threshold of 5 × 10- 8, with a consistent direction of association in both discovery and replication datasets. Expression quantitative trait (eQTL) analyses and in silico functional annotation for these loci provided insights into potential functional roles, including a statistically significant eQTL between the T allele at rs4918567 and higher expression of ADRA2A (P = 0.012) in healthy colon mucosa. CONCLUSIONS: Our study suggests that germline genetic variation is associated with the quantity and diversity of adaptive immune responses in CRC. Further studies are warranted to replicate these findings in additional samples and to investigate functional genomic mechanisms.

Examining multilevel influences on parental HPV vaccine hesitancy among multiethnic communities in Los Angeles: a qualitative analysis.

BACKGROUND: Human papillomavirus (HPV) vaccine hesitancy is a growing concern in the United States, yet understudied among racial/ethnic minority parents. We conducted qualitative research to understand parental HPV vaccine hesitancy and inform community-specific, multilevel approaches to improve HPV vaccination among diverse populations in Los Angeles. METHODS: We recruited American Indian/Alaska Native (AI/AN), Hispanic/Latino/a (HL) and Chinese parents of unvaccinated children (9-17 years) from low-HPV vaccine uptake regions in Los Angeles for virtual focus groups (FGs). FGs were conducted in English (2), Mandarin (1), and Spanish (1) between June-August 2021. One English FG was with AI/AN-identifying parents. FGs prompted discussions about vaccine knowledge, sources of information/hesitancy, logistical barriers and interpersonal, healthcare and community interactions regarding HPV vaccination. Guided by the social-ecological model, we identified multilevel emergent themes related to HPV vaccination. RESULTS: Parents (n = 20) in all FGs reported exposure to HPV vaccine information from the internet and other sources, including in-language media (Mandarin) and health care providers (Spanish). All FGs expressed confusion around the vaccine and had encountered HPV vaccine misinformation. FGs experienced challenges navigating relationships with children, providers, and friends/family for HPV vaccine decision-making. At the community-level, historical events contributed to mistrust (e.g., forced community displacement [AI/AN]). At the societal-level, transportation, and work schedules (Spanish, AI/AN) were barriers to vaccination. Medical mistrust contributed to HPV vaccine hesitancy across the analysis levels. CONCLUSION: Our findings highlight the importance of multilevel influences on parental HPV vaccine hesitancy and decision-making and the need for community-specific messaging to combat medical mistrust and other barriers to HPV vaccination among racial/ethnic minority communities.

Understanding medical mistrust and HPV vaccine hesitancy among multiethnic parents in Los Angeles.

Determinants of parental HPV vaccine hesitancy, including medical mistrust and exposure to negative vaccine information, are understudied in racial/ethnic minority communities where vaccine uptake is low. We conducted a cross-sectional survey (March 2021) among parents of adolescents, ages 9-17 years, from an academic enrichment program serving low-income, first-generation, underrepresented minority families in Los Angeles to understand determinants of parental HPV vaccine hesitancy. Parents completed self-administered surveys, including a 9-item HPV vaccine hesitancy scale, in either English, Spanish, or Chinese. Logistic regression was used to identify individual and interpersonal factors associated with parental hesitancy and adolescent HPV vaccination. One-fifth of parents (n = 357) reported high HPV vaccine hesitancy and > 50% reported concerns about safety or side effects. High medical mistrust was associated with high parental HPV vaccine hesitancy (adjusted-OR 1.69, 95% CI: 1.13, 2.37). Community-tailored and multilevel strategies to increase vaccine confidence are needed to improve HPV and other adolescent vaccinations.

Validity and prognostic significance of sperm protein 17 as a tumor biomarker for epithelial ovarian cancer: a retrospective study.

BACKGROUND: Prior small studies have shown increased expression of sperm protein 17 (Sp17) in epithelial ovarian cancer (EOC) tissue and suggest Sp17 as a potential biomarker for EOC. However, how Sp17 expression varies with histology, grade, and stage of EOC and its expression in other ovarian neoplasms has not been defined. It is unknown whether patients with EOC have elevated serum Sp17 levels or if Sp17 expression is associated with survival outcomes. METHODS: The study included 982 patients with benign, borderline, and malignant ovarian neoplasms and normal ovary. There were 878 patients with tissue only, 39 with serum only, and 65 with matching serum and tissue. Immunohistochemical (IHC) staining with anti-Sp17 antibody was performed on tissue specimens and the intensity scored as weak, moderate, or strong. A sandwich enzyme-linked immunosorbent assay (ELISA) was performed to measure Sp17 sera concentrations. RESULTS: Sp17 expression was most commonly seen in serous cystadenomas (83%) and serous borderline tumors (100%). Of the 773 EOC specimens, 223 (30%) expressed Sp17. Grade and histology were significantly associated with Sp17 expression among EOC specimens (p < 0.001) on both univariate and multivariable analysis, with grade 1 serous adenocarcinomas showing the highest expression (51%). Sp17 expression was limited in other benign and non-epithelial malignant neoplasms. Neither Sp17 tissue expression nor serum concentration correlated with survival outcomes. Serum concentrations were higher in patients with Sp17 tissue expression, and the highest concentrations were noted among patients with serous and clear cell adenocarcinomas. CONCLUSIONS: Sp17 is highly expressed in benign, borderline, and low grade malignant serous ovarian neoplasms and can be quantified in serum. Sp17 expression may have diagnostic significance in this subset of patients.

Cervico-vaginal self-collection in HIV-infected and uninfected women from Tapajós region, Amazon, Brazil: High acceptability, hrHPV diversity and risk factors.

OBJECTIVE: We evaluated acceptability of cervico-vaginal self-collection (CVSC) and prevalence of human papillomavirus (HPV) in Human immunodeficiency virus (HIV)-infected and HIV-uninfected women living in the Tapajós region, Amazon, Brazil. METHODS: Cross-sectional study recruited 153 non-indigenous women (HIV-uninfected, n = 112 and HIV-infected, n = 41) who voluntarily sought assistance in health services. Peripheral blood for HIV screening and cervical scraping (CS) for HPV detection were collected. Women who accepted to perform CVSC received instructions and individual collection kits. Risk factors for high-risk HPV genotypes (hrHPV) were identified by uni- and multivariate analyses. RESULTS: The overall acceptability of CVSC was 87%. Only HIV-infected women had cytological abnormalities (12.2%). Prevalence of any HPV and hrHPV infection was 42.9% and 47.9% for HIV-uninfected and 97.6% and 77.5% for HIV-infected women, respectively. There was significant agreement in the detection of HPV (88%, 0.76, 95% confidence interval [CI], 0.65-0.87) and hrHPV (79.7%, 0.56, 95% CI, 0.41-0.71) between self-collected and clinician-collected samples. The most prevalent hrHPV types were HPV16 and HPV18 in HIV-uninfected and HPV16, HPV51 and HPV59 in HIV-infected women. HIV-infected women with hrHPV infection had multiple hrHPV infections (p = 0.005) and lower CD4 count (p = 0.018). Risk factors for hrHPV infection included being HIV-infected and having five or more sexual partners. CONCLUSIONS: CVSC had high acceptability and high prevalence of hrHPV types in women living in the Tapajós region, Amazon, Brazil.

The Cytoskeletal Adaptor Obscurin-Like 1 Interacts with the Human Papillomavirus 16 (HPV16) Capsid Protein L2 and Is Required for HPV16 Endocytosis.

The human papillomavirus (HPV) capsid protein L2 is essential for viral entry. To gain a deeper understanding of the role of L2, we searched for novel cellular L2-interacting proteins. A yeast two-hybrid analysis uncovered the actin-depolymerizing factor gelsolin, the membrane glycoprotein dysadherin, the centrosomal protein 68 (Cep68), and the cytoskeletal adaptor protein obscurin-like 1 protein (OBSL1) as putative L2 binding molecules. Pseudovirus (PsV) infection assays identified OBSL1 as a host factor required for gene transduction by three oncogenic human papillomavirus types, HPV16, HPV18, and HPV31. In addition, we detected OBSL1 expression in cervical tissue sections and noted the involvement of OBSL1 during gene transduction of primary keratinocytes by HPV16 PsV. Complex formation of HPV16 L2 with OBSL1 was demonstrated in coimmunofluorescence and coimmunoprecipitation studies after overexpression of L2 or after PsV exposure. We observed a strong colocalization of OBSL1 with HPV16 PsV and tetraspanin CD151 at the plasma membrane, suggesting a role for OBSL1 in viral endocytosis. Indeed, viral entry assays exhibited a reduction of viral endocytosis in OBSL1-depleted cells. Our results suggest OBSL1 as a novel L2-interacting protein and endocytosis factor in HPV infection. IMPORTANCE: Human papillomaviruses infect mucosal and cutaneous epithelia, and the high-risk HPV types account for 5% of cancer cases worldwide. As recently discovered, HPV entry occurs by a clathrin-, caveolin-, and dynamin-independent endocytosis via tetraspanin-enriched microdomains. At present, the cellular proteins involved in the underlying mechanism of this type of endocytosis are under investigation. In this study, the cytoskeletal adaptor OBSL1 was discovered as a previously unrecognized interaction partner of the minor capsid protein L2 and was identified as a proviral host factor required for HPV16 endocytosis into target cells. The findings of this study advance the understanding of a so far less well-characterized endocytic pathway that is used by oncogenic HPV subtypes.

Annexin A2 antibodies but not inhibitors of the annexin A2 heterotetramer impair productive HIV-1 infection of macrophages in vitro.

During sexual transmission of human immunodeficiency virus (HIV), macrophages are initial targets for HIV infection. Secretory leukocyte protease inhibitor (SLPI) has been shown to protect against HIV infection of macrophages through interactions with annexin A2 (A2), which is found on the macrophage cell surface as a heterotetramer (A2t) consisting of A2 and S100A10. Therefore, we investigated potential protein-protein interactions between A2 and HIV-1 gp120 through a series of co-immunoprecipitation assays and a single molecule pulldown (SiMPull) technique. Additionally, inhibitors of A2t (A2ti) that target the interaction between A2 and S100A10 were tested for their ability to impair productive HIV-1 infection of macrophages. Our data suggest that interactions between HIV-1 gp120 and A2 exist, though this interaction may be indirect. Furthermore, an anti-A2 antibody impaired HIV-1 particle production in macrophages in vitro, whereas A2ti did not indicating that annexin A2 may promote HIV-1 infection of macrophages in its monomeric rather than tetrameric form.

Inhibition of Langerhans cell maturation by human papillomavirus type 16: a novel role for the annexin A2 heterotetramer in immune suppression.

High-risk human papillomaviruses (HPVs) are sexually transmitted viruses causally associated with several cancers. During its natural life cycle, HPV16, the most common high-risk genotype, infects the epithelial basal cells in a process facilitated through a recently identified receptor, the annexin A2 heterotetramer (A2t). During infection, HPV16 also interacts with Langerhans cells (LC), the APC of the epithelium, inducing immune suppression, which is mediated by the HPV16 L2 minor capsid protein. Despite the importance of these virus-immune cell interactions, the specific mechanisms of HPV16 entry into LC and HPV16-induced immune suppression remain undefined. An N-terminal peptide of HPV16 L2 (aa 108-126) has been shown to specifically interact with A2t. In this study, we show that incubation of human LC with this peptide blocks binding of HPV16. Inhibiting this interaction with an A2t ligand or by small interfering RNA downregulation of A2t significantly decreases HPV16 internalization into LC in an L2-dependent manner. A2t is associated with suppression of LC maturation as demonstrated through attenuated secretion of Th1-associated cytokines and decreased surface expression of MHC class II on LC exposed to A2t. Conversely, small molecule inhibition of A2t prevents HPV16-induced suppression of LC immune function as indicated by significantly increased secretion of inflammatory cytokines and surface expression of CD86 in HPV16 treated LC pre-exposed to A2t inhibitors. These results demonstrate that HPV16 suppresses LC maturation through an interaction with A2t, revealing a novel role for this protein.

Forced LIGHT expression in prostate tumors overcomes Treg mediated immunosuppression and synergizes with a prostate tumor therapeutic vaccine by recruiting effector T lymphocytes.

BACKGROUND: LIGHT, a ligand for lymphotoxin-ß receptor (LTßR) and herpes virus entry mediator, is predominantly expressed on activated immune cells and LTßR signaling leads to the recruitment of lymphocytes. The interaction between LIGHT and LTßR has been previously shown to activate immune cells and result in tumor regression in a virally-induced tumor model, but the role of LIGHT in tumor immunosuppression or in a prostate cancer setting, where self antigens exist, has not been explored. We hypothesized that forced expression of LIGHT in prostate tumors would shift the pattern of immune cell infiltration toward an anti-tumoral milieu, would inhibit T regulatory cells (Tregs) and would induce prostate cancer tumor associated antigen (TAA) specific T cells that would eradicate tumors. METHODS: Real Time PCR was used to evaluate expression of forced LIGHT and other immunoregulatory genes in prostate tumors samples. For in vivo studies, adenovirus encoding murine LIGHT was injected intratumorally into TRAMP-C2 prostate cancer cell tumor bearing mice. Chemokine and cytokine concentrations were determined by multiplex ELISA. Flow cytometry was used to phenotype tumor infiltrating lymphocytes and expression of LIGHT on the tumor cell surface. Tumor-specific lymphocytes were quantified via ELISpot assay. Treg induction and Treg suppression assays determined Treg functionality after LIGHT treatment. RESULTS: LIGHT in combination with a therapeutic vaccine, PSCA TriVax, reduced tumor burden. LIGHT expression peaked within 48 hr of infection, recruited effector T cells that recognized mouse prostate stem cell antigen (PSCA) into the tumor microenvironment, and inhibited infiltration of Tregs. Tregs isolated from tumor draining lymph nodes had impaired suppressive capability after LIGHT treatment. CONCLUSION: Forced LIGHT treatment combined with PSCA TriVax therapeutic vaccination delays prostate cancer progression in mice by recruiting effector T lymphocytes to the tumor and inhibiting Treg mediated immunosuppression. Prostate 75:280-291, 2015. © 2014 Wiley Periodicals, Inc.

Langerhans cells from women with cervical precancerous lesions become functionally responsive against human papillomavirus after activation with stabilized Poly-I:C.

Human papillomavirus (HPV)-mediated suppression of Langerhans cell (LC) function can lead to persistent infection and development of cervical intraepithelial neoplasia (CIN). Women with HPV-induced high-grade CIN2/3 have not mounted an effective immune response against HPV, yet it is unknown if LC-mediated T cell activation from such women is functionally impaired against HPV. We investigated the functional activation of in vitro generated LC and their ability to induce HPV16-specific T cells from CIN2/3 patients after exposure to HPV16 followed by treatment with stabilized Poly-I:C (s-Poly-I:C). LC from patients exposed to HPV16 demonstrated a lack of costimulatory molecule expression, inflammatory cytokine secretion, and chemokine-directed migration. Conversely, s-Poly-I:C caused significant phenotypic and functional activation of HPV16-exposed LC, which resulted in de novo generation of HPV16-specific CD8(+) T cells. Our results highlight that LC of women with a history of persistent HPV infection can present HPV antigens and are capable of inducing an adaptive T cell immune response when given the proper stimulus, suggesting that s-Poly-I:C compounds may be attractive immunomodulators for LC-mediated clearance of persistent HPV infection.

A novel murine model for evaluating bovine papillomavirus prophylactics/therapeutics for equine sarcoid-like tumours.

Equine sarcoids are highly recurrent bovine papillomavirus (BPV)-induced fibroblastic neoplasms that are the most common skin tumours in horses. In order to facilitate the study of potential equine sarcoid prophylactics or therapeutics, which can be a slow and costly process in equines, a murine model for BPV-1 protein-expressing equine sarcoid-like tumours was developed in mice through stable transfection of BPV-1 E5 and E6 in a murine fibroblast tumour cell line (K-BALB). Like equine sarcoids, these murine tumour cells (BPV-KB) were of fibroblast origin, were tumorigenic and expressed BPV-1 proteins. As an initial investigation of the preclinical potential of this tumour model for equine sarcoids prophylactics, mice were immunized with BPV-1 E5E6 Venezuelan equine encephalitis virus replicon particles, prior to BPV-KB challenge, which resulted in an increased tumour-free period compared with controls, indicating that the BPV-KB murine model may be a valuable preclinical alternative to equine clinical trials.

Small molecule inhibitors of the annexin A2 heterotetramer prevent human papillomavirus type 16 infection.

OBJECTIVES: High-risk human papillomavirus (HPV) infection leads to the development of several human cancers that cause significant morbidity and mortality worldwide. HPV type 16 (HPV16) is the most common of the cancer-causing genotypes and gains entry to the basal cells of the epithelium through a non-canonical endocytic pathway that involves the annexin A2/S100A10 heterotetramer (A2t). A2t is composed of two annexin A2 monomers bound to an S100A10 dimer and this interaction is a potential target to block HPV16 infection. Here, recently identified small molecule inhibitors of A2t (A2ti) were investigated for their ability to prevent HPV16 infection in vitro. METHODS: A2ti were added to HeLa cells in increasing concentrations prior to the addition of HPV16. Cytotoxicity was evaluated via trypan blue exclusion. HPV16 pseudovirion infection and fluorescently labelled HPV16 capsid internalization was measured with flow cytometry. RESULTS: A2ti blocked HPV16 infection by 100% without substantial cellular toxicity or reduction in cell growth. Furthermore, A2ti blocked HPV16 entry into epithelial cells by 65%, indicating that the observed inhibition of HPV16 infection is in part due to a block in entry and that non-infectious entry may occur in the absence of A2t binding. CONCLUSIONS: These results demonstrate that targeting A2t may be an effective strategy to prevent HPV16 infection.

The evolving field of human papillomavirus receptor research: a review of binding and entry.

Human papillomaviruses (HPVs) infect epithelia and can lead to the development of lesions, some of which have malignant potential. HPV type 16 (HPV16) is the most oncogenic genotype and causes various types of cancer, including cervical, anal, and head and neck cancers. However, despite significant research, our understanding of the mechanism by which HPV16 binds to and enters host cells remains fragmented. Over several decades, many HPV receptors and entry pathways have been described. This review puts those studies into context and offers a model of HPV16 binding and entry as a framework for future research. Our model suggests that HPV16 binds to heparin sulfate proteoglycans (HSPGs) on either the epithelial cell surface or basement membrane through interactions with the L1 major capsid protein. Growth factor receptors may also become activated through HSPG/growth factor/HPV16 complexes that initiate signaling cascades during early virion-host cell interactions. After binding to HSPGs, the virion undergoes conformational changes, leading to isomerization by cyclophilin B and proprotein convertase-mediated L2 minor capsid protein cleavage that increases L2 N terminus exposure. Along with binding to HSPGs, HPV16 binds to α6 integrins, which initiate further intracellular signaling events. Following these primary binding events, HPV16 binds to a newly identified L2-specific receptor, the annexin A2 heterotetramer. Subsequently, clathrin-, caveolin-, lipid raft-, flotillin-, cholesterol-, and dynamin-independent endocytosis of HPV16 occurs.

Identifying the intersection of parental HPV and COVID-19 vaccine hesitancy to inform health messaging interventions in community-based settings.

PURPOSE: Parental human papillomavirus (HPV) vaccine hesitancy contributes to delays or refusals in adolescent uptake. It is unclear if COVID-19 vaccine hesitancy has further impacted the low HPV vaccine uptake trends among underrepresented minorities. This study examines the relationship between COVID-19 vaccine intent and HPV vaccine hesitancy among parents for their adolescents in communities with low vaccine uptake in Los Angeles County. METHODS: Parents from a school-based academic enrichment program serving low-income, first-generation immigrant families completed an online cross-sectional survey to understand parental HPV vaccine hesitancy, adolescent HPV vaccine behavior, and attitudes towards other vaccines, including intent to receive COVID-19 vaccines. In March 2021, parents with children ages 9-17 years completed online surveys. Using multivariate logistic regression models, we examined whether low parent intent to vaccinate their adolescent against COVID-19 was associated with hesitancy to vaccinate against HPV. RESULTS: A total of 291 surveys were completed. Among parents with high HPV vaccine hesitancy for their adolescent, 33 % did not intend to vaccinate their adolescent against COVID-19 compared to 7 % among parents with low HPV vaccine hesitancy. Low parent intention to vaccinate adolescent against COVID-19 was associated with higher HPV vaccine hesitancy (p < 0.01) after controlling for parent nativity status, medical mistrust, receiving the flu vaccination and negative HPV information. DISCUSSION: Our findings indicate associations between low parental COVID-19 vaccine intent and higher HPV vaccine hesitancy for their adolescent. Identifying community-relevant health interventions to address parental vaccine hesitancy across multiple child and adolescent vaccines may help to achieve equitable vaccine uptake.

Notch1 regulates chemotaxis and proliferation by controlling the CC-chemokine receptors 5 and 9 in T cell acute lymphoblastic leukaemia.

Tumour cells often express deregulated profiles of chemokine receptors that regulate cancer cell migration and proliferation. Notch1 pathway activation is seen in T cell acute lymphoblastic leukaemia (T-ALL) due to the high frequency of Notch1 mutations affecting approximately 60% of patients, causing ligand-independent signalling and/or prolonging Notch1 half-life. We have investigated the possible regulative role of Notch1 on the expression and function of chemokine receptors CCR5, CCR9 and CXCR4 that play a role in determining blast malignant properties and localization of extramedullary infiltrations in leukaemia. We inhibited the pathway through γ-Secretase inhibitor and Notch1 RNA interference and analysed the effect on the expression and function of chemokine receptors. Our results indicate that γ-Secretase inhibitor negatively regulates the transcription level of the CC chemokine receptors 5 and 9 in T-ALL cell lines and patients' primary leukaemia cells, leaving CXCR4 expression unaltered. The Notch pathway also controls CCR5- and CCR9-mediated biological effects, ie chemotaxis and proliferation. Furthermore, engaging CCR9 through CCL25 administration rescues proliferation inhibition associated with abrogation of Notch activity. Finally, through RNA interference we demonstrated that the oncogenic isoform in T-ALL, Notch1, plays a role in controlling CCR5 and CCR9 expression and functions. These findings suggest that Notch1, acting in concert with chemokine receptors pathways, may provide leukaemia cells with proliferative advantage and specific chemotactic abilities, therefore influencing tumour cell progression and localization.

Diversity of Anal HPV and Non-HPV Sexually Transmitted Infections and Concordance with Genital Infections in HIV-Infected and HIV-Uninfected Women in the Tapajós Region, Amazon, Brazil.

The aim of this study was to classify the diversity of anal HPV and non-HPV sexually transmitted infections (STIs) and compare the concordance between anal and genital infections in HIV-infected and uninfected women living in the Tapajós region, Amazon, Brazil. A cross-sectional study was performed with 112 HIV-uninfected and 41 HIV-infected nonindigenous women. Anal and cervical scrapings were collected and analyzed for HPV, Chlamydia trachomatis (CT), Neisseria gonorrheae (NG), Trichomonas vaginalis (TV), Mycoplasma genitalium (MG), and Human alphaherpesvirus 2 (HSV-2). The Kappa test evaluated the concordance between anal and genital infections. The overall prevalence of anal HPV infection was 31.3% in HIV-uninfected and 97.6% in HIV-infected women. The most frequent anal high-risk HPV (hrHPV) types were HPV18 and HPV16 in HIV-uninfected women and HPV51, HPV59, HPV31, and HPV58 in HIV-infected women. Anal HPV75 Betapapillomavirus was also identified. Anal non-HPV STIs were identified in 13.0% of all participants. The concordance analysis was fair for CT, MG, and HSV-2, almost perfect agreement for NG, moderate for HPV, and variable for the most frequent anal hrHPV types. Thus, a high prevalence of anal HPV infection with moderate and fair concordance between anal and genital HPV and non-HPV STIs was observed in our study.

Heterozygote advantage at HLA class I and II loci and reduced risk of colorectal cancer.

Objective: Reduced diversity at Human Leukocyte Antigen (HLA) loci may adversely affect the host's ability to recognize tumor neoantigens and subsequently increase disease burden. We hypothesized that increased heterozygosity at HLA loci is associated with a reduced risk of developing colorectal cancer (CRC). Methods: We imputed HLA class I and II four-digit alleles using genotype data from a population-based study of 5,406 cases and 4,635 controls from the Molecular Epidemiology of Colorectal Cancer Study (MECC). Heterozygosity at each HLA locus and the number of heterozygous genotypes at HLA class -I (A, B, and C) and HLA class -II loci (DQB1, DRB1, and DPB1) were quantified. Logistic regression analysis was used to estimate the risk of CRC associated with HLA heterozygosity. Individuals with homozygous genotypes for all loci served as the reference category, and the analyses were adjusted for sex, age, genotyping platform, and ancestry. Further, we investigated associations between HLA diversity and tumor-associated T cell repertoire features, as measured by tumor infiltrating lymphocytes (TILs; N=2,839) and immunosequencing (N=2,357). Results: Individuals with all heterozygous genotypes at all three class I genes had a reduced odds of CRC (OR: 0.74; 95% CI: 0.56-0.97, p= 0.031). A similar association was observed for class II loci, with an OR of 0.75 (95% CI: 0.60-0.95, p= 0.016). For class-I and class-II combined, individuals with all heterozygous genotypes had significantly lower odds of developing CRC (OR: 0.66, 95% CI: 0.49-0.87, p= 0.004) than those with 0 or one heterozygous genotype. HLA class I and/or II diversity was associated with higher T cell receptor (TCR) abundance and lower TCR clonality, but results were not statistically significant. Conclusion: Our findings support a heterozygote advantage for the HLA class-I and -II loci, indicating an important role for HLA genetic variability in the etiology of CRC.

Identification of AKAP-4 as a new cancer/testis antigen for detection and immunotherapy of prostate cancer.

BACKGROUND: Prostate cancer (PC) is the second most common cancer in older men, after skin cancer. PC is difficult to diagnose because the prostate-specific antigen screening method is associated with many false positives. In addition there is a need to develop new and more effective treatments. Among presently available new treatments, immunotherapy is a promising approach. We investigated the expression of the cancer/testis antigen, AKAP-4, in PC patients to evaluate the possibility of exploiting AKAP-4 as a target for immunotherapy. METHODS: We analyzed normal prostate tissues, 15 patients with PC and the LnCAP PC cell line by immunohistochemistry. We tested AKAP-4 immunogenicity through indirect ELISA on sera from patients and healthy subjects, and we generated in vitro AKAP-4-specific cytotoxic lymphocytes from peripheral blood mononuclear cells. RESULTS: AKAP-4 was shown both at the cytoplasmic and surface levels of the LnCAP PC cell line. AKAP-4 was also highly expressed in PC cells from patients. We detected specific anti-AKAP-4 circulating immunoglobulins in AKAP-4 positive subjects. Using recombinant AKAP-4 loaded autologous dendritic cells, we generated AKAP-4-specific and HLA-I-restricted cytotoxic T lymphocytes able to kill PC cells in vitro. Further characterization indicated a Th-1 skewing in the cytokine secretion profile of these cells. CONCLUSIONS: We demonstrate the aberrant expression of AKAP-4 in PC, which will potentially be developed as a biomarker in PC. We provide evidence that AKAP-4 is a potential target for PC adoptive immunotherapy or anti-tumor vaccination.

A novel series of conferences tackling the hurdles confronting the translation of novel cancer immunotherapies.

While there has been significant progress in advancing novel immune therapies to the bedside, much more needs to be done to fully tap into the potential of the immune system. It has become increasingly clear that besides practical and operational challenges, the heterogeneity of cancer and the limited efficacy profile of current immunotherapy platforms are the two main hurdles. Nevertheless, the promising clinical data of several approaches point to a roadmap that carries the promise to significantly advance cancer immunotherapy. A new annual series sponsored by Arrowhead Publishers and Conferences aims at bringing together scientific and business leadership from academia and industry, to identify, share and discuss most current priorities in research and translation of novel immune interventions. This Editorial provides highlights of the first event held earlier this year and outlines the focus of the second meeting to be held in 2013 that will be dedicated to stem cells and immunotherapy.

A paradigm shift in therapeutic vaccination of cancer patients: the need to apply therapeutic vaccination strategies in the preventive setting.

An extraordinary variety of potential therapeutic vaccine strategies directed against a wide variety of tumor antigens has been explored in clinical trials. To date, none of these cancer immunotherapies have been approved by the Food and Drug Administration for use in humans. A significant problem is that the vast majority of such clinical trials are carried out in patients with advanced or metastatic cancer. The immune systems of these patients are considerably compromised as a result of tumor- and treatment-mediated immunosuppression. Even in cases where patients are immunized in the adjuvant setting, where there is minimal residual disease, vaccines directed against tumor-associated antigens have failed to mediate eradication of tumors in the overwhelming majority of cases. Recently, we and others have experimented with administering therapeutic cancer vaccines in the preventive setting. This is achieved by vaccinating at the earliest possible stage of carcinogenesis. These studies have demonstrated that early vaccination is extremely effective in eliciting an anti-tumor immune response that leads to unprecedented improvements in the survival of mice that spontaneously develop cancer. Certain human cancers, notably prostate adenocarcinoma and cervical cancer, can currently be detected at very early stages of carcinogenesis. Therapeutic vaccines are available for these diseases, opening up the possibility of administering vaccinations early to patients diagnosed with pre-malignant lesions to halt disease progression. In addition, new technologies have become available in the past decade that will soon yield very sensitive and specific diagnostic tests for a plethora of other cancers. Earlier detection of these cancers, combined with existing vaccines directed against them, will soon make them targets for therapeutic vaccination in the preventive setting. The ability to immunize patients at the very earliest stages of carcinogenesis, when they have fully competent immune systems, has the potential to cause a paradigm shift in how therapeutic cancer vaccines are tested and used clinically.