Immunodeficiency and Cancer in 3.5 Million People Living With Human Immunodeficiency Virus (HIV): The South African HIV Cancer Match Study.

BACKGROUND: We analyzed associations between immunodeficiency and cancer incidence in a nationwide cohort of people living with human immunodeficiency virus (HIV; PLWH) in South Africa. METHODS: We used data from the South African HIV Cancer Match Study built on HIV-related laboratory measurements from the National Health Laboratory Services and cancer records from the National Cancer Registry. We evaluated associations between time-updated CD4 cell count and cancer incidence rates using Cox proportional hazards models. We reported adjusted hazard ratios (aHRs) over a grid of CD4 values and estimated the aHR per 100 CD4 cells/µL decrease. RESULTS: Of 3 532 266 PLWH, 15 078 developed cancer. The most common cancers were cervical cancer (4150 cases), Kaposi sarcoma (2262 cases), and non-Hodgkin lymphoma (1060 cases). The association between lower CD4 cell count and higher cancer incidence rates was strongest for conjunctival cancer (aHR per 100 CD4 cells/µL decrease: 1.46; 95% confidence interval [CI], 1.38-1.54), Kaposi sarcoma (aHR, 1.23; 95% CI, 1.20-1.26), and non-Hodgkin lymphoma (aHR, 1.18; 95% CI, 1.14-1.22). Among infection-unrelated cancers, lower CD4 cell counts were associated with higher incidence rates of esophageal cancer (aHR, 1.06; 95% CI, 1.00-1.11) but not breast, lung, or prostate cancer. CONCLUSIONS: Lower CD4 cell counts were associated with an increased risk of developing various infection-related cancers among PLWH. Reducing HIV-induced immunodeficiency may be a potent cancer-prevention strategy among PLWH in sub-Saharan Africa, a region heavily burdened by cancers attributable to infections.

Preparation of bispecific antibody-protein adducts by site-specific chemo-enzymatic conjugation.

Historically, bispecific antibodies have been constructed through the genetic fusion of additional binding domains to the constant domains of the antibody heavy- or light chains. We present an alternative method for the introduction of additional functional domains to an antibody: site-specific chemo-enzymatic conjugation. This method relies on the combination of site-specific transpeptidases and bioorthogonal chemistry. Transpeptidases are used to site-specifically introduce chemical handles, which can then be used to couple new functional groups by means of a bioorthogonal chemical reaction. We demonstrate site-specific chemo-enzymatic linkage using the transpeptidase sortase (hereafter: sortase) and either a strain-promoted alkyne-azide cycloaddition (SPAAC) or an inverse-electron demand Diels-Alder reaction. Other transpeptidases and bioorthogonal reactions suitable for this purpose exist. Site-specific chemo-enzymatic linkage is a modular method. After introduction of a chemical handle in the antibody, any functional group of interest may then be attached. The modularity of this conjugation method allows for a 'plug-and-play' approach to prepare new antibody conjugates, thus bypassing the need for (potentially) laborious genetic fusions. Moreover, as sortase is used to specifically modify the exact C-termini of the antibody chains, the final product will be fused in a C-to-C orientation, which is impossible to achieve by genetic manipulations alone. Here we demonstrate the utility of site-specific chemo-enzymatic conjugation to prepare antibody heterodimers, bispecific T-cell engager antibodies, and immunocytokines, discussing purification methods and describing possible pitfalls.

Inducible, Site-Specific Protein Labeling by Tyrosine Oxidation-Strain-Promoted (4 + 2) Cycloaddition.

Genetically encoded tyrosine (Y-tag) can be utilized as a latent anchor for inducible and site-selective conjugation. Upon oxidation of tyrosine with mushroom tyrosinase, strain-promoted cycloaddition (SPOCQ) of the resulting 1,2-quinone with various bicyclo[6.1.0]nonyne (BCN) derivatives led to efficient conjugation. The method was applied for fluorophore labeling of laminarinase A and for the site-specific preparation of an antibody-drug conjugate.

Cancer diagnostic service use in people living with HIV in South Africa: A cross-sectional study.

OBJECTIVE: The objective of this study was to map place of cancer diagnosis in relation to Human Immunodeficiency Virus (HIV) care centre among people living with HIV (PLHIV) within South Africa (SA) using national laboratory database. DESIGN: We linked HIV and cancer laboratory data from 2004-2014 using supervised machine-learning algorithms. We performed a cross-sectional analysis comparing province where individuals accessed their HIV care versus where they had their cancer diagnosis. SETTING: We used laboratory test records related to HIV diagnostics and care, such as CD4 cell counts and percentages, rapid tests, qualitative Polymerase Chain Reaction (PCR), antibody and antigen tests for HIV data that was documented as HIV positive and laboratory diagnosed cancer records from SA. STUDY POPULATION: Our study population consisted of HIV records from the National Health Laboratory Service (NHLS) that linked to cancer record at the National Cancer Registry (NCR) between 2004-2014. PRIMARY AND SECONDARY OUTCOMES: We linked HIV records from NHLS to cancer records at NCR in order to study the inherent characteristics of the population with both HIV and cancer. RESULTS: The study population was 68,284 individuals with cancer and documented HIV related laboratory test. The median age at cancer diagnosis was 40 [IQR, 33-48] years for the study population with most cancers in PLHIV diagnosed in females 70.9% [n = 46,313]. Of all the PLHIV and cancer, 25% (n = 16,364 p < 0.001) sought treatment outside their province of residence with 60.7% (n = 10,235) travelling to Gauteng. KZN had 46.6% (n = 4,107) of its PLHIV getting cancer diagnosis in Gauteng. Western Cape had 95% (n = 6,200) of PLHIV getting cancer diagnosis within the province. CONCLUSIONS: Our results showed health systems inequalities across provinces in SA with respect to cancer diagnosis. KZN for example had nearly half of the PLHIV getting cancer diagnosis outside the province while Western Cape is able to offer cancer diagnostic services to most of the PLHIV in the province. Gauteng is getting over burdened with referral for cancer diagnosis from other provinces. More effort is required to ensure equitable access to cancer diagnostic services within the country.

Cancer diagnostic service use in people with HIV in South Africa: a cross-sectional study.

Objective: The objective of this study was to map place of cancer diagnosis in relation to Human Immunodeficiency Virus (HIV) care centre among people with HIV (PWH) within South Africa (SA) using national laboratory database. Design: We linked HIV and cancer laboratory data from 2004-2014 using supervised machine-learning algorithms. We performed a cross-sectional analysis comparing province where individuals accessed their HIV care versus where they had their cancer diagnosis. Setting: We used laboratory test records related to HIV diagnostics and care, such as CD4 cell counts and percentages, rapid tests, qualitative Polymerase Chain Reaction (PCR), antibody and antigen tests for HIV data that was documented as HIV positive and laboratory diagnosed cancer records from SA. Study population: Our study population consisted of HIV records from the National Health Laboratory Service (NHLS) that linked to cancer record at the National Cancer Registry (NCR) between 2004- 2014. Primary and secondary outcomes: We linked HIV records from NHLS to cancer records at NCR in order to study the inherent characteristics of the population with both HIV and cancer. Results: The study population was 68,284 individuals with cancer and documented HIV related laboratory test. The median age at cancer diagnosis was 40 [IQR, 33-48] years for the study population with most cancers in PWH diagnosed in females 70.9% [n=46,313]. Of all the PWH and cancer, 25% (n=16,364 p < 0.001) sought treatment outside their province of residence with 60.7% (n=10,235) travelling to Gauteng. KZN had 46.6% (n=4,107) of its PWH getting cancer diagnosis in Gauteng. Western Cape had 95% (n=6,200) of PWH getting cancer diagnosis within the province. Conclusions: Our results showed health systems inequalities across provinces in South Africa with respect to cancer diagnosis. KZN for example had nearly half of the PWH getting cancer diagnosis outside the province while Western Cape is able to offer cancer diagnostic services to most of the PWH in the province. Gauteng is getting over burdened with referral for cancer diagnosis from other provinces. More effort is required to ensure equitable access to cancer diagnostic services within the country.

Cohort profile: the South African HIV Cancer Match (SAM) Study, a national population-based cohort.

PURPOSE: The South African HIV Cancer Match (SAM) Study is a national cohort of people living with HIV (PLWH). It was created using probabilistic record linkages of routine laboratory records of PLWH retrieved by National Health Laboratory Services (NHLS) and cancer data from the National Cancer Registry. The SAM Study aims to assess the spectrum and risk of cancer in PLWH in the context of the evolving South African HIV epidemic. The SAM Study's overarching goal is to inform cancer prevention and control programmes in PLWH in the era of antiretroviral treatment in South Africa. PARTICIPANTS: PLWH (both adults and children) who accessed HIV care in public sector facilities and had HIV diagnostic or monitoring laboratory tests from NHLS. FINDINGS TO DATE: The SAM cohort currently includes 5 248 648 PLWH for the period 2004 to 2014; 69% of these are women. The median age at cohort entry was 33.0 years (IQR: 26.2-40.9). The overall cancer incidence in males and females was 235.9 (95% CI: 231.5 to 240.5) and 183.7 (181.2-186.2) per 100 000 person-years, respectively.Using data from the SAM Study, we examined national cancer incidence in PLWH and the association of different cancers with immunodeficiency. Cancers with the highest incidence rates were Kaposi sarcoma, cervix, breast, non-Hodgkin's lymphoma and eye cancer. FUTURE PLANS: The SAM Study is a unique, evolving resource for research and surveillance of malignancies in PLWH. The SAM Study will be regularly updated. We plan to enrich the SAM Study through record linkages with other laboratory data within the NHLS (eg, tuberculosis, diabetes and lipid profile data), mortality data and socioeconomic data to facilitate comprehensive epidemiological research of comorbidities among PLWH.

Cancer risk in adolescents and young adults living with HIV in South Africa: a nationwide cohort study.

BACKGROUND: Literature on cancer in adolescents and young adults (AYA; aged 15-24 years) living with HIV is scarce. We studied cancer incidence in AYA living with HIV in South Africa between 2004 and 2014. METHODS: In this nationwide cohort study, we included individuals between 15 and 24 years old who had at least two HIV-related laboratory measurements on separate days between Jan 1, 2004, and Dec 31, 2014, recorded in the National Health Laboratory Service database. We used privacy-preserving probabilistic record linkage methods to identify HIV-related laboratory records that most likely belonged to the same individual and to then link these individuals to cancer diagnoses from the National Cancer Registry. We computed incidence rates for the most common cancers in AYA living with HIV, and we assessed associations between these cancers and sex, age, calendar year, and CD4 cell count using Cox proportional hazards models and adjusted hazard ratios (aHRs). FINDINGS: We included 782 454 AYA living with HIV (698 066 [89·2%] women) with 1 428 114 person-years of follow-up. Of those, 867 developed incident cancer (incidence rate 60·7 per 100 000 person-years), including 429 who developed Kaposi sarcoma (30·0 per 100 000 person-years), 107 non-Hodgkin lymphoma (7·5 per 100 000 person-years), 48 Hodgkin lymphoma (3·4 per 100 000 person-years), 45 cervical cancer (3·4 per 100 000 woman-years), and 32 leukaemia (2·2 per 100 000 person-years). Kaposi sarcoma was more common in the 20-24 year age group than the 15-19 year age group (aHR 1·39, 95% CI 1·03-1·86). Male sex was associated with higher rates of Kaposi sarcoma (2·06, 1·61-2·63), non-Hodgkin lymphoma (3·17, 2·06-4·89), Hodgkin lymphoma (4·83, 2·61-8·93), and leukaemia (unadjusted HR 5·90, 95% CI 2·87-12·12). Cancer rates decreased over the study period, driven by declining Kaposi sarcoma rates. Lower baseline CD4 cell counts were associated with higher rates of Kaposi sarcoma, cervical cancer, non-Hodgkin lymphoma, and Hodgkin lymphoma, but not leukaemia. INTERPRETATION: Infection-related cancers were the most common cancer types in AYA living with HIV in South Africa, and their incidence rates increased with lower CD4 cell counts. Therefore, innovative strategies to maintaining high CD4 cell counts are needed to reduce the cancer burden in this vulnerable population. FUNDING: US National Institutes of Health and Swiss National Science Foundation.

Highly Efficient Mono-Functionalization of Knob-in-Hole Antibodies with Strain-Promoted Click Chemistry.

Knob-in-hole antibodies can be utilized to introduce a single tag for chemo-enzymatic functionalization. By either introducing a single C-terminal sortase tag (sortase-tag expressed protein ligation) or tyrosine tag (G4Y), mono-functionalization of the monoclonal antibody trastuzumab was achieved rapidly and in high yields. This method was applied to selectively and efficiently introduce a single fluorescent tag, cytokine or single-chain variable fragment, as well as produce clean homo dimers of trastuzumab.

mTOR Blockade by Rapamycin in Spondyloarthritis: Impact on Inflammation and New Bone Formation in vitro and in vivo.

Introduction: Spondyloarthritis (SpA) is characterized by inflammation, articular bone erosions and pathologic new bone formation. Targeting TNFα or IL-17A with current available therapies reduces inflammation in SpA, however, treatment of the bone pathology in SpA remains an unmet clinical need. Activation of the mammalian target Of rapamycin (mTOR) promotes IL-17A expression and osteogenesis. Therefore, the inhibition of mTOR (with rapamycin) could be a promising therapeutic avenue in SpA. Objectives: To investigate the effect of blocking mTOR on inflammation, bone erosions and new bone formation in SpA. Methods: Peripheral blood mononuclear cells (PBMCs) from patients with SpA were stimulated with anti-CD3/CD28 in the presence or absence of rapamycin and the resulting cytokine expression was assessed. Fibroblast-like synoviocytes (FLS) from SpA patients were assessed for osteogenic differentiation potential in conditions with TNFα, IL-17A, or TNFα plus IL-17A, in the presence or absence of rapamycin. HLA-B27/Huß2m transgenic rats were immunized with low dose heat-inactivated Mycobacterium tuberculosis (M. tub), treated with 1.5 mg/kg rapamycin prophylactically or therapeutically and monitored for arthritis and spondylitis. Histology and mRNA analysis were performed after 5 weeks of treatment to assess inflammation and bone pathology. Results:In vitro TNFα and IL-17A protein production by SpA PBMCs was inhibited in the presence of rapamycin. Rapamycin also inhibited osteogenic differentiation of human SpA FLS. Ex vivo analysis of SpA synovial biopsies indicated activation of the mTOR pathway in the synovial tissue of SpA patients. In vivo, prophylactic treatment of HLA-B27/Huß2m transgenic rats with rapamycin significantly inhibited the development and severity of inflammation in peripheral joints and spine (arthritis and spondylitis), with histological evidence of reduced bone erosions and new bone formation around peripheral joints. In addition, therapeutic treatment with rapamycin significantly decreased severity of arthritis and spondylitis, with peripheral joint histology showing reduced inflammation, bone erosions and new bone formation. IL-17A mRNA expression was decreased in the metacarpophalangeal joints after rapamycin treatment. Conclusion: mTOR blockade inhibits IL-17A and TNFα production by PBMCs, and osteogenic differentiation of FLS from patients with SpA in vitro. In the HLA-B27 transgenic rat model of SpA, rapamycin inhibits arthritis and spondylitis development and severity, reduces articular bone erosions, decreases pathologic new bone formation and suppresses IL-17A expression. These results may support efforts to evaluate the efficacy of targeting the mTOR pathway in SpA patients.

A Chemo-enzymatically Linked Bispecific Antibody Retargets T Cells to a Sialylated Epitope on CD43 in Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) is a high-risk disease with a poor prognosis, particularly in elderly patients. Because current AML treatment relies primarily on untargeted therapies with severe side effects that limit patient eligibility, identification of novel therapeutic AML targets is highly desired. We recently described AT1413, an antibody produced by donor B cells of a patient with AML cured after allogeneic hematopoietic stem cell transplantation. AT1413 binds CD43s, a unique sialylated epitope on CD43, which is weakly expressed on normal myeloid cells and overexpressed on AML cells. Because of its selectivity for AML cells, we considered CD43s as a target for a bispecific T-cell-engaging antibody (bTCE) and generated a bTCE by coupling AT1413 to two T-cell-targeting fragments using chemo-enzymatic linkage. In vitro, AT1413 bTCE efficiently induced T-cell-mediated cytotoxicity toward different AML cell lines and patient-derived AML blasts, whereas endothelial cells with low binding capacity for AT1413 remained unaffected. In the presence of AML cells, AT1413 bTCE induced upregulation of T-cell activation markers, cytokine release, and T-cell proliferation. AT1413 bTCE was also effective in vivo. Mice either coinjected with human peripheral blood mononuclear cells or engrafted with human hematopoietic stem cells [human immune system (HIS) mice] were inoculated with an AML cell line or patient-derived primary AML blasts. AT1413 bTCE treatment strongly inhibited tumor growth and, in HIS mice, had minimal effects on normal human hematopoietic cells. Taken together, our results indicate that CD43s is a promising target for T-cell-engaging antibodies and that AT1413 holds therapeutic potential in a bTCE-format. SIGNIFICANCE: These findings offer preclinical evidence for the therapeutic potential of a bTCE antibody that targets a sialylated epitope on CD43 in AML.

Site-Specific Phosphorylation of PSD-95 PDZ Domains Reveals Fine-Tuned Regulation of Protein-Protein Interactions.

The postsynaptic density protein of 95 kDa (PSD-95) is a key scaffolding protein that controls signaling at synapses in the brain through interactions of its PDZ domains with the C-termini of receptors, ion channels, and enzymes. PSD-95 is highly regulated by phosphorylation. To explore the effect of phosphorylation on PSD-95, we used semisynthetic strategies to introduce phosphorylated amino acids at four positions within the PDZ domains and examined the effects on interactions with a large set of binding partners. We observed complex effects on affinity. Most notably, phosphorylation at Y397 induced a significant increase in affinity for stargazin, as confirmed by NMR and single molecule FRET. Additionally, we compared the effects of phosphorylation to phosphomimetic mutations, which revealed that phosphomimetics are ineffective substitutes for tyrosine phosphorylation. Our strategy to generate site-specifically phosphorylated PDZ domains provides a detailed understanding of the role of phosphorylation in the regulation of PSD-95 interactions.