The CEPH aging cohort and biobank: a valuable collection of biological samples from exceptionally long-lived French individuals and their offspring for longevity studies

The increasing aging of the human population is currently and for the coming decades a major public health issue in many countries, requiring the implementation of global public health policies promoting healthy and successful aging. Individuals are not equal in the face of aging and some can present exceptional healthspan and/or lifespan, which are notably influenced by both genetic and environmental factors. Research and studies on human aging, healthy aging and longevity should rely in particular on cohorts of long-lived individuals, also including biological samples allowing studies on the biology of aging and longevity. In this manuscript, we provide for the first time a complete description of the CEPH (Centre d'Etude du Polymophisme Humain) Aging cohort, an exceptional cohort recruited during the 90s to 2000s, including more than 1700 French long-lived individuals (≥ 90 years old) born between 1875 and 1916 as well as for some of them their siblings and offspring. Among the participants, 1265 were centenarians, including 255 semi-supercentenarians ([105-110] years old) and 25 supercentenarians (≥ 110 years old). The available anthropometric, epidemiologic and clinical data for the cohort participants are described and especially the collection of blood-derived biological samples associated with the cohort which includes DNA, cryopreserved cells and cell lines, plasma, and serum. This biological collection from the first cohort of centenarians in the world is an inestimable resource for ongoing and future molecular, cellular, and functional studies aimed at deciphering the mechanisms of human (successful) aging and longevity.

Early elevated IFNα is a key mediator of HIV pathogenesis

BACKGROUND

A complete understanding of the different steps of HIV replication and an effective drug combination have led to modern antiretroviral regimens that block HIV replication for decades, but these therapies are not curative and must be taken for life. "Elite controllers" (ECs) is a term for the 0.5% of HIV-infected persons requiring no antiretroviral therapy, whose status may point the way toward a functional HIV cure. Defining the mechanisms of this control may be key to understanding how to replicate this functional cure in others.

METHODS

In ECs and untreated non-EC patients, we compared IFNα serum concentration, distribution of immune cell subsets, and frequency of cell markers associated with immune dysfunction. We also investigated the effect of an elevated dose of IFNα on distinct subsets within dendritic cells, natural killer cells, and CD4+ and CD8 + T cells.

RESULTS

Serum IFNα was undetectable in ECs, but all immune cell subsets from untreated non-EC patients were structurally and functionally impaired. We also show that the altered phenotype and function of these cell subsets in non-EC patients can be recapitulated when cells are stimulated in vitro with high-dose IFNα.

CONCLUSIONS

Elevated IFNα is a key mediator of HIV pathogenesis.

IFNα induces CCR5 in CD4+ T cells of HIV patients causing pathogenic elevation

BACKGROUND

Among people living with HIV, elite controllers (ECs) maintain an undetectable viral load, even without receiving anti-HIV therapy. In non-EC patients, this therapy leads to marked improvement, including in immune parameters, but unlike ECs, non-EC patients still require ongoing treatment and experience co-morbidities. In-depth, comprehensive immune analyses comparing EC and treated non-EC patients may reveal subtle, consistent differences. This comparison could clarify whether elevated circulating interferon-alpha (IFNα) promotes widespread immune cell alterations and persists post-therapy, furthering understanding of why non-EC patients continue to need treatment.

METHODS

Levels of IFNα in HIV-infected EC and treated non-EC patients were compared, along with blood immune cell subset distribution and phenotype, and functional capacities in some cases. In addition, we assessed mechanisms potentially associated with IFNα overload.

RESULTS

Treatment of non-EC patients results in restoration of IFNα control, followed by marked improvement in distribution numbers, phenotypic profiles of blood immune cells, and functional capacity. These changes still do not lead to EC status, however, and IFNα can induce these changes in normal immune cell counterparts in vitro. Hypothesizing that persistent alterations could arise from inalterable effects of IFNα at infection onset, we verified an IFNα-related mechanism. The protein induces the HIV coreceptor CCR5, boosting HIV infection and reducing the effects of anti-HIV therapies. EC patients may avoid elevated IFNα following on infection with a lower inoculum of HIV or because of some unidentified genetic factor.

CONCLUSIONS

Early control of IFNα is essential for better prognosis of HIV-infected patients.

IFNα induces CCR5 in CD4+ T-cells, causing its anti- HIV inefficiency and its subsequent pathogenic elevation, partially controlled by anti-HIV therapy

Like EC, we find that ART-treated patients control serum IFNα concentration and show few immune cell alterations enabling a healthy but fragile medical status. However, treatment interruption leads to elevated IFNα reflecting virus production indicating that like EC, ART does not achieve a virological cure. The immune system becomes overwhelmed by multiple immune cell abnormalities as found in untreated patients. These are chiefly mediated by elevated IFNα inducing signaling checkpoints abnormalities, including PD1, in cytotoxic immune cells. Importantly, during acute infection, elevated IFNα correlated with HIV load and we found that IFNα enhances CCR5, the HIV coreceptor in CD4+ T-cells, impairing its anti-viral response and accounting for the pathogenic vicious cycle: HIV → IFNα ↗ → infected CD4+ T-cells ↗ →HIV ↗. This study opens immunotherapeutic perspectives showing the need to control IFNα in order to convert ART patients into EC.

Early Elevated IFNα Identified as the Key Mediator of HIV Pathogenesis and its low level a Hallmark of Elite Controllers

Advances in HIV therapy came from understanding its replication. Further progress toward "functional cure" -no therapy needed as found in Elite Controllers (EC)- may come from insights in pathogenesis and avoidance by EC. Here we show that all immune cells from HIV-infected persons are impaired in non-EC, but not in EC. Since HIV infects few cell types, these results suggest an additional mediator of pathogenesis. We identify that mediator as elevated pathogenic IFNα, controlled by EC likely by their preserved potent NK-cells and later by other killer cells. Since the earliest days of infection predict outcome genetic or chance events must be key to EC, and since we found no unique immune parameter at the onset, we suggest a chance infection with a lower HIV inoculum. These results offer an additional approach toward functional cure: a judicious targeting of IFNα for all non-EC patients.

Persistent deficiency of mucosal-associated invariant T cells during dermatomyositis

OBJECTIVES

Mucosal-associated invariant T (MAIT) cells are innate-like lymphocytes that are important for antibacterial immunity and may have regulatory roles. MAIT cells are decreased during SLE. However, their frequencies and phenotype have not been investigated in DM. We studied MAIT cell frequencies and phenotype in DM patients with active and inactive disease (after treatment).

METHODS

Peripheral blood flow cytometry analysis of MAIT cells was compared between DM (n = 22), SLE (n = 10), psoriasis (n = 7) and atopic dermatitis (n = 5) patients, and healthy controls (n = 19).

RESULTS

A dramatic decrease of circulating MAIT cell frequency was observed in active DM and SLE patients compared with healthy controls and other inflammatory skin diseases [active DM: median = 0.25% (interquartile range 0.19-0.6%), P < 0.0001; active SLE: median = 0.61 (0.55-0.77), P < 0.0001 vs healthy controls: 2.32% (1.18-4.45%)]. MAIT cells from active DM patients had an abnormal phenotype including increased expression of CD25 and cytotoxic T-lymphocyte-associated protein 4 that correlated with their low frequency in the blood.

CONCLUSION

In DM, peripheral blood MAIT cells are dramatically reduced and have an activated/exhausted phenotype that may be linked to increased activation-induced cell death.

Purification and immunophenotypic characterization of human B cells with regulatory functions

The analysis of human B cell populations of the blood relies on the expression of surface markers, mainly CD19, CD24, CD38, and CD27. According to these surface markers, three main B cell subsets can be identified in the blood: immature transitional B cells (CD19(+)CD24(high)CD38(high)), naïve B cells (CD19(+)CD24(int)CD38(int)) that have not encountered an antigen, and memory B cells (CD19(+)CD27(+)). To date, human B cells with regulatory functions have been essentially described within the CD24(high)CD38(high) transitional B cell subset. CD24(high)CD38(high) transitional B cells are able to produce interleukin 10 (IL-10) and to regulate in vitro Th1 and Th17 CD4(+) T cell activation. Here, we provide the methods to analyze and purify the CD24(high)CD38(high) transitional B cell subset for further in vitro experiments. We also provide a reliable method to detect B cell IL-10 production using intracellular cytokine staining.

CD4⁺ follicular helper T cell infiltration predicts breast cancer survival

CD4⁺ T cells are critical regulators of immune responses, but their functional role in human breast cancer is relatively unknown. The goal of this study was to produce an image of CD4⁺ T cells infiltrating breast tumors using limited ex vivo manipulation to better understand the in vivo differences associated with patient prognosis. We performed comprehensive molecular profiling of infiltrating CD4⁺ T cells isolated from untreated invasive primary tumors and found that the infiltrating T cell subpopulations included follicular helper T (Tfh) cells, which have not previously been found in solid tumors, as well as Th1, Th2, and Th17 effector memory cells and Tregs. T cell signaling pathway alterations included a mixture of activation and suppression characterized by restricted cytokine/chemokine production, which inversely paralleled lymphoid infiltration levels and could be reproduced in activated donor CD4⁺ T cells treated with primary tumor supernatant. A comparison of extensively versus minimally infiltrated tumors showed that CXCL13-producing CD4⁺ Tfh cells distinguish extensive immune infiltrates, principally located in tertiary lymphoid structure germinal centers. An 8-gene Tfh signature, signifying organized antitumor immunity, robustly predicted survival or preoperative response to chemotherapy. Our identification of CD4⁺ Tfh cells in breast cancer suggests that they are an important immune element whose presence in the tumor is a prognostic factor.

Active and passive anticytokine immune therapies: current status and development

Anticytokine (AC) immune therapies derived from vaccine procedures aim at enhancing natural immune defense mechanisms ineffective to contain abnormally produced cytokines and counteract their pathogenic effects. Given their short half-life, cytokines, the production of which by effector immune cells (T and B lymphocytes, antigen-presenting cells (APCs), natural killer (NK) and endothelial cells) is inducible and controlled by negative feedback regulation, (1) exert locally their signaling to paracrine/autocrine target responder cells carrying high-affinity membrane receptors and (2) are commonly present at minimal concentration in the body fluid (lymph, serum). Aberrant signaling triggered by cytokines, uncontrolly released by effector immune cells or produced by cancer and other pathologic cells, contribute to the pathogenesis of chronic diseases including cancer, viral infections, allergy, and autoimmunity. To block these ectopic cytokine signaling and prevent their pathogenic effects, AC Abs supplied either by injections (passive AC immune therapy) or elicited by immunization with cytokine-derived immunogenes called Kinoids (active AC immune therapy) proved to be experimentally effective and safe. In this review, we detailed the rationale and the requirements for the use of AC immunotherapies in humans, the proof of efficacy of these medications in animal disease models, and their current clinical development and outcome, including adverse side effects they may generate. We particularly show that, to date, the benefit:risk ratio of AC immune therapies is highly positive.

Control of allergic reactions in mice by an active anti-murine IL-4 immunization

Pathogenesis of allergic inflammatory disorders is characterized by allergen-induced IgE stimulated by Th2 cytokines including mainly IL-4 overproduction. To counteract IL-4 effects in sensitized-BALB/c mice, we prepared an IL-4 derivative immunogen, made of KLH and murine IL-4 heterocomplex, termed mIL-4 kinoid. Murine IL-4 kinoid immunized mice produced high titer of anti-IL-4 neutralizing Abs. In contrast to KLH control immunization kinoid immunization reversed the allergic IgE:IgG ratio hallmark in rBet v 1a sensitized mice and reduced pulmonary eosinophil recruitment and bronchial hyperreactivity in Ova-sensitized mice. These data pave the way to alternative therapies to combat allergic conditions.

VEGF kinoid vaccine, a therapeutic approach against tumor angiogenesis and metastases

Tumor growth depends on blood supply, requiring the development of new vessels, and vascular endothelial growth factor (VEGF) plays a central role in neoangiogenic processes. For this reason, VEGF represents a target for the development of new therapeutic antiangiogenic molecules. Clinical trials using anti-VEGF mAbs such as bevacizumab have validated the efficacy of this therapeutic approach but have also revealed adverse effects. Here we report that a VEGF-derived immunogen, consisting of a heterocomplex of a murine (m)VEGF and keyhole limpet hemocyanin, called "mVEGF kinoid," triggered a strong Ab immune response in mice. The anti-VEGF Abs inhibited both the proliferation of human umbilical vein endothelial cells cultured in the presence of mVEGF and the binding of mVEGF to its receptor-2 Flk-1. In mVEGF kinoid-immunized BALB/c mice challenged with syngeneic CT26 colorectal tumor cells, the number and size of lung metastases were significantly decreased. In human (h)VEGF kinoid-immunized BALB/c mice, high levels of serum Abs to hVEGF were present, and purified IgG from these mice decreased by > or =50% the tumor growth of human A673 rhabdomyosarcoma cells and HT29 colon carcinoma xenografted in Swiss nude and NOD/SCID mice, respectively. Tumor cell growth inhibition was similar to that observed in mice receiving therapeutic doses of bevacizumab. These experiments suggest that a therapeutic vaccine containing VEGF kinoid may represent a strategy for safely combating VEGF-dependent neovascularization and metastases occurring in malignant tumors.

TNFalpha kinoid vaccination-induced neutralizing antibodies to TNFalpha protect mice from autologous TNFalpha-driven chronic and acute inflammation

The proinflammatory cytokine TNFalpha is a potent mediator of septic shock and a therapeutic target for chronic inflammatory pathologies including rheumatoid arthritis and Crohn's disease. As an alternative to anti-human TNFalpha (hTNFalpha) mAbs and other hTNFalpha blocker approved drugs, we developed an active anti-hTNFalpha immunotherapy, based on a vaccine comprised of a keyhole limpet hemocyanin-hTNFalpha heterocomplex immunogen (hTNFalpha kinoid) adjuvanted in incomplete Freund's adjuvant. In mice transgenic for hTNFalpha (TTg mice), hTNFalpha kinoid vaccination elicited high titers of Abs that neutralized hTNFalpha bioactivities but did not result in a cellular response to hTNFalpha. The vaccine was safe and effective in two experimental models. Kinoid-immunized but not control TTg mice resisted hTNFalpha-driven shock in one model and were prevented from spontaneous arthritis, inflammatory synovitis, and articular destruction in a second model. These data demonstrate an anti-cytokine induction of autoimmune protection against both acute and chronic hTNFalpha exposure. They show that active vaccination against a human cytokine can be achieved, and that the immune response can be effective and safe.

Identification of immunodominant epitopes in inactivated Tat-vaccinated healthy and HIV-1-infected volunteers

We analyzed the epitopes and the molecular forms of Tat recognized by the antibodies raised by Tat-toxoid vaccination in both healthy and HIV-infected volunteers. Tat-toxoid-vaccinated healthy volunteer sera reacted predominantly with peptides covering amino acids 1 through 24 and 46 through 60, corresponding to the N-terminus and basic domains of Tat. In contrast, whereas all sera from vaccinated HIV-1-positive patients reacted with the N-terminus and (with a single exception) with the basic domain, most of these sera also recognized peptides encompassing distinct domains of Tat, particularly the C-terminus (79-86). The sera of vaccinated individuals recognized both monomeric and oligomeric forms of Tat 1 through 86 or of Tat 1 through 101 and also blocked the ability of cell-released extracellular Tat to transactivate the HIV-1 LTR promoter. Synthetic Tat preincubated with sera from vaccinated individuals lost its functional activity as well. This is probably because of its inability to enter the cells as a result of immune complex formation with anti-Tat IgG. These data demonstrate that Tat-toxoid vaccination induces an efficient antibody response blocking the functional activity of Tat.