Immune response to pertussis vaccine in COPD patients.

Exacerbation triggered by respiratory infection is an important cause of morbidity and mortality in chronic obstructive pulmonary disease (COPD) patients. Strategies aiming to preventing infection may have significant public health impact. Our previous study demonstrated decreased immunological response to seasonal flu vaccination in COPD patients, questioning the efficiency of other vaccines in this group of patients. We performed a prospective, monocenter, longitudinal study that evaluated the humoral and cellular responses upon pertussis vaccination. We included 13 patients with stable COPD and 8 healthy volunteers. No difference in circulating B and T cell subsets at baseline was noted. Both groups presented similar levels of TFH, plasmablasts and pertussis specific antibodies induction after vaccination. Moreover, monitoring T cell immunity after ex-vivo peptide stimulation revealed equivalent induction of functional and specific CD4+ T cells (IFNγ, TNFα and IL-2-expressing T cells) in both groups. Our results highlight the immunological efficiency of pertussis vaccination in this particularly vulnerable population and challenge the concept that COPD patients are less responsive to all immunization strategies. Healthcare providers should stress the necessity of decennial Tdap booster vaccination in COPD patients.

What are the prospects for durable immune control?

During the SARS CoV-2 primary infection, the neutralizing antibodies focused against the spike (S) glycoproteins are responsible for blockage of virus-host cell interaction. The cellular response mediated by CD4+ and CD8+ T-cells is responsible for control of viremia. Immune memory against SARS-CoV-2 depends on virus type, replication kinetics and route of penetration. The formation and persistence of germinal centers are critical for the generation of affinity-matured plasma cells and memory B cells capable of mediating durable immunity. They can persist up to 30 weeks after vaccination and several months after infection. Heterogeneity in the longevity of the vaccination-induced GC response is significant.

A Randomized Placebo-Controlled Efficacy Study of a Prime Boost Therapeutic Vaccination Strategy in HIV-1-Infected Individuals: VRI02 ANRS 149 LIGHT Phase II Trial.

In this placebo-controlled phase II randomized clinical trial, 103 human immunodeficiency virus type 1 (HIV-1)-infected patients under cART (combined antiretroviral treatment) were randomized 2:1 to receive either 3 doses of DNA GTU-MultiHIV B (coding for Rev, Nef, Tat, Gag, and gp160) at week 0 (W0), W4, and W12, followed by 2 doses of LIPO-5 vaccine containing long peptides from Gag, Pol, and Nef at W20 and W24, or placebo. Analytical treatment interruption (ATI) was performed between W36 to W48. At W28, vaccinees experienced an increase in functional CD4+ T-cell responses (P < 0.001 for each cytokine compared to W0) measured, predominantly against Gag and Pol/Env, and an increase in HIV-specific CD8+ T cells producing interleukin 2 (IL-2) and tumor necrosis factor alpha (TNF-α) (P = 0.001 and 0.013, respectively), predominantly against Pol/Env and Nef. However, analysis of T-cell subsets by mass cytometry in a subpopulation showed an increase in the W28/W0 ratio for memory CD8+ T cells coexpressing exhaustion and senescence markers such as PD-1/TIGIT (P = 0.004) and CD27/CD57 (P = 0.044) in vaccinees compared to the placebo group. During ATI, all patients experienced viral rebound, with the maximum observed HIV RNA level at W42 (median, 4.63 log10 copies [cp]/ml; interquartile range [IQR], 4.00 to 5.09), without any difference between arms. No patient resumed cART for CD4 cell count drop. Globally, the vaccine strategy was safe. However, a secondary HIV transmission during ATI was observed. These data show that the prime-boost combination of DNA and LIPO-5 vaccines elicited broad and polyfunctional T cells. The contrast between the quality of immune responses and the lack of potent viral control underscores the need for combined immunomodulatory strategies. (This study has been registered at ClinicalTrials.gov under registration no. NCT01492985.)IMPORTANCE In this placebo-controlled phase II randomized clinical trial, we evaluated the safety and immunogenicity of a therapeutic prime-boost vaccine strategy using a recombinant DNA vaccine (GTU-MultiHIV B clade) followed by a boost vaccination with a lipopeptide vaccine (HIV-LIPO-5) in HIV-infected patients on combined antiretroviral therapy. We show here that this prime-boost strategy is well tolerated, consistently with previous studies in HIV-1-infected individuals and healthy volunteers who received each vaccine component individually. Compared to the placebo group, vaccinees elicited strong and polyfunctional HIV-specific CD4+ and CD8+ T-cell responses. However, these immune responses presented some qualitative defects and were not able to control viremia following antiretroviral treatment interruption, as no difference in HIV viral rebound was observed in the vaccine and placebo groups. Several lessons were learned from these results, pointing out the urgent need to combine vaccine strategies with other immune-based interventions.

Planning HIV therapy to prevent future comorbidities: patient years for tenofovir alafenamide.

Since the introduction of suppressive antiretroviral therapy (ART), HIV has become a chronic disease, with infected people in high-income countries approaching similar life expectancy to the general population. As this population ages, an increasing number of people with HIV are living with age-, treatment-, and disease-related comorbidities. Lifestyle factors such as smoking, alcohol abuse, and substance misuse have a role in age-related comorbidity. Some degree of immune dysfunction is suggested by the presence of markers of immune activation/inflammation despite effective suppression of HIV replication. Cumulative exposure to some antiretroviral drugs contributes to HIV-associated comorbidities, with risk increasing with age. Specifically, tenofovir disoproxil fumarate (TDF), ritonavir-boosted atazanavir, and ritonavir-boosted lopinavir are associated with renal impairment, and TDF is known to cause loss of bone mineral density. Tenofovir alafenamide (TAF) was developed to improve on the safety profile of TDF, while maintaining its efficacy. TAF has better stability in plasma, and higher intracellular accumulation of tenofovir diphosphate in target cells, which has resulted in improved antiviral activity at lower doses with improved renal and bone safety. TAF has been studied extensively in randomized clinical trials and real-world studies. TAF-based regimens are recommended over TDF-containing regimens for the improved safety profile.

Low incidence of acute rejection within 6 months of kidney transplantation in HIV-infected recipients treated with raltegravir: the Agence Nationale de Recherche sur le Sida et les Hépatites Virales (ANRS) 153 TREVE trial.

OBJECTIVES: High rates of clinical acute rejection after kidney transplantation have been reported in people living with HIV (PLHIV), probably as a consequence of drug interactions. We therefore investigated the incidence of acute rejection within 6 months of transplantation in HIV-infected recipients treated with a protease-inhibitor-free raltegravir-based regimen. METHODS: The Agence Nationale de Recherche sur le Sida et les Hépatites Virales (ANRS) 153 TREVE (NCT01453192) study was a prospective multicentre single-arm trial in adult PLHIV awaiting kidney transplantation, with viral load < 50 HIV-1 RNA copies/mL, CD4 T-cell count > 200 cells/µL, and HIV-1 strains sensitive to raltegravir, aiming to demonstrate 6-month clinical acute rejection rates < 30%. Time to transplantation was compared with that for uninfected subjects matched for age, sex and registration date. RESULTS: In total, 61 participants were enrolled in the study, and 26 underwent kidney transplantation. Two participants experienced clinical acute rejection, corresponding to an estimated clinical acute rejection rate of 8% [95% confidence interval (CI) 2-24%] at 6 and 12 months post-transplantation. HIV infection remained under control in all but one participant, who temporarily stopped antiretroviral treatment. Median time to transplantation was longer in PLHIV than in controls (4.3 versus 2.8 years, respectively; P = 0.002) and was not influenced by blood group. CONCLUSIONS: Acute rejection rates were low after kidney transplantation in PLHIV treated with a raltegravir-based regimen. However, PLHIV have poorer access to transplantation than HIV-uninfected individuals after registration on the waiting list.

Hospitalization of HIV positive patients: Significant demand affecting all hospital sectors.

BACKGROUND: In a context of the evolution of severe morbidities in patients living with HIV (PLWH), the aim of this study was to describe reasons for hospitalization and the mode of care for the patients requiring hospitalization. METHODS: All admissions (≥24h) of PLWH to 10 hospitals in the south of Paris (COREVIH Ile-de-France Sud) between 1/1/2011 and 12/31/2011 were identified. The hospital database and the file of patients followed in the HIV referral department of each hospital were matched. Detailed clinical and biological data were collected, by returning to the individual medical records, for a random sample (65% of hospitalized patients). RESULTS: A total of 3013 hospitalizations (1489 patients) were recorded in 2011. The estimated rate of hospitalized patients was about 8% among the 10105 PLWH routinely managed in COREVIH Ile-de-France Sud in 2011. The majority (58.5%) of these hospitalizations occurred in a unit other than the HIV referral unit. Non-AIDS-defining infections were the main reason for admission (16.4%), followed by HIV-related diseases (15.6%), hepatic/gastrointestinal diseases (12.0%), and cardiovascular diseases (10.3%). The median length of stay was 5 days overall (IQR: 2-11), it was longer among patients admitted to a referral HIV care unit than to another ward. HIV infection had been diagnosed >10 years previously in 61.4% of these hospitalized patients. They often had associated comorbidities (coinfection HCV/HVB 40.5%, smoking 45.8%; hypertension 33.4%, dyslipidemia 28.8%, diabetes 14.8%). Subjects over 60 years old accounted for 15% of hospitalized patients, most of them were virologically controlled under HIV treatment, and cardiovascular diseases were their leading reason for admission. CONCLUSION: Needs for hospitalization among PLWH remain important, with a wide variety in causes of admission, involving all hospital departments. It is essential to prevent comorbidities to reduce these hospitalizations, and to maintain a link between the management of PLWH, that becomes rightly, increasing ambulatory, and recourse to specialized inpatient services.

Effects of recombinant human interleukin 7 on T-cell recovery and thymic output in HIV-infected patients receiving antiretroviral therapy: results of a phase I/IIa randomized, placebo-controlled, multicenter study.

BACKGROUND: The immune deficiency of human immunodeficiency virus (HIV) infection is not fully corrected with ARV therapy. Interleukin-7 (IL-7) can boost CD4 T-cell counts, but optimal dosing and mechanisms of cellular increases need to be defined. METHODS: We performed a randomized placebo-controlled dose escalation (10, 20 and 30 µg/kg) trial of 3 weekly doses of recombinant human IL-7 (rhIL-7) in ARV-treated HIV-infected persons with CD4 T-cell counts between 101 and 400 cells/µL and plasma HIV levels <50 copies/mL. Toxicity, activity and the impact of rhIL-7 on immune reconstitution were monitored. RESULTS: Doses of rhIL-7 up to 20 µg/kg were well tolerated. CD4 increases of predominantly naive and central memory T cells were brisk (averaging 323 cells/µL at 12 weeks) and durable (up to 1 year). Increased cell cycling and transient increased bcl-2 expression were noted. Expanded cells did not have the characteristics of regulatory or activated T cells. Transient low-level HIV viremia was seen in 6 of 26 treated patients; modest increases in total levels of intracellular HIV DNA were proportional to CD4 T-cell expansions. IL-7 seemed to increase thymic output and tended to improve the T-cell receptor (TCR) repertoire in persons with low TCR diversity. CONCLUSIONS: Three weekly doses of rhIL-7 at 20 µg/kg are well tolerated and lead to a dose-dependent CD4 T-cell increase and the broadening of TCR diversity in some subjects. These data suggest that this rhIL-7 dose could be advanced in future rhIL-7 clinical studies. CLINICAL TRIALS REGISTRATION: NCT0047732.

A novel mechanism for HIV1-mediated bystander CD4+ T-cell death: neighboring dying cells drive the capacity of HIV1 to kill noncycling primary CD4+ T cells.

CD4+ T-cell death is a crucial feature of AIDS pathogenesis, but the mechanisms involved remain unclear. Here, we present in vitro findings that identify a novel process of HIV1 mediated killing of bystander CD4+ T cells, which does not require productive infection of these cells but depends on the presence of neighboring dying cells. X4-tropic HIV1 strains, which use CD4 and CXCR4 as receptors for cell entry, caused death of unstimulated noncycling primary CD4+ T cells only if the viruses were produced by dying, productively infected T cells, but not by living, chronically infected T cells or by living HIV1-transfected HeLa cells. Inducing cell death in HIV1-transfected HeLa cells was sufficient to obtain viruses that caused CD4+ T-cell death. The addition of supernatants from dying control cells, including primary T cells, allowed viruses produced by living HIV1-transfected cells to cause CD4+ T-cell death. CD4+ T-cell killing required HIV1 fusion and/or entry into these cells, but neither HIV1 envelope-mediated CD4 or CXCR4 signaling nor the presence of the HIV1 Nef protein in the viral particles. Supernatants from dying control cells contained CD95 ligand (CD95L), and antibody-mediated neutralization of CD95L prevented these supernatants from complementing HIV1 in inducing CD4+ T-cell death. Our in vitro findings suggest that the very extent of cell death induced in vivo during HIV1 infection by either virus cytopathic effects or immune activation may by itself provide an amplification loop in AIDS pathogenesis. More generally, they provide a paradigm for pathogen-mediated killing processes in which the extent of cell death occurring in the microenvironment might drive the capacity of the pathogen to induce further cell death.

Caspase-dependent and -independent T-cell death pathways in pathogenic simian immunodeficiency virus infection: relationship to disease progression.

Studies of human immunodeficiency virus (HIV) and nonhuman primate models of pathogenic and nonpathogenic simian immunodeficiency virus (SIV) infections have suggested that enhanced ex vivo CD4 T-cell death is a feature of pathogenic infection in vivo. However, the relative contributions of the extrinsic and intrinsic pathways to programmed T-cell death in SIV infection have not been studied. We report here that the spontaneous death rate of CD4+ T cells from pathogenic SIVmac251-infected rhesus macaques ex vivo is correlated with CD4 T-cell depletion and plasma viral load in vivo. CD4+ T cells from SIVmac251-infected macaques showed upregulation of the death ligand (CD95L) and of the proapoptotic proteins Bim and Bak, but not of Bax. Both CD4+ and CD8+ T cells from SIVmac251-infected macaques underwent caspase-dependent death following CD95 ligation. The spontaneous death of CD4+ and CD8+ T cells was not prevented by a decoy CD95 receptor or by a broad-spectrum caspase inhibitor (zVAD-fmk), suggesting that this form of cell death is independent of CD95/CD95L interaction and caspase activation. IL-2 and IL-15 prevented the spontaneous death of CD4+ and CD8+ T cells, whereas IL-10 prevented only CD8 T-cell death and IL-7 had no effect on T-cell death. Our results indicate that caspase-dependent and caspase-independent pathways are involved in the death of T cells in pathogenic SIVmac251-infected primates.

[HIV1-associated CD4 T lymphocyte apoptosis]. / Infection par le VIH1 et apoptose lymphocytaire T CD4.

PURPOSE: Apoptosis during HIV infection has been evoked for ten years. The role of apoptosis during HIV infection have be confirmed by several authors but the exact relationships between viral replication, apoptosis and lymphocyte depletion remain to be clarified. CURRENT KNOWLEDGE AND KEY POINTS: HIV may induce apoptosis of infected but also of uninfected bystander CD4+ lymphocytes. Those two types of HIV induced apoptosis lie on different pathways. While Fas and FasL are involved in apoptosis of bystander cells, mitochondrial pathway is required for apoptosis of infected cells. Cytokines but also anti HIV drugs may modulate HIV-induced lymphocyte apoptosis. Morever while protease inhibitor influence HIV replication and then secondary apotosis of infected cells, they can also interfere with spontaneous apoptosis of lymphocyte beside the context of HIV infection. FUTURES AND PROJECTS: Apoptosis is thought to be one of the mechanism involved in CD4 T lymphocyte cell death during HIV infection. However relationships between apoptosis and HIV replication may be more complex. In fact it has been recently reported that while HIV replication induced lymphocyte apoptosis, apoptosis may in turn induced HIV replication in a loop amplification pathway

Role of CD95-activated caspase-1 processing of IL-1beta in TCR-mediated proliferation of HIV-infected CD4(+) T cells.

CD95 plays a critical role in the homeostasis of the immune system, and has been reported to participate in T cell death during HIV infection. Here we report that the response to CD3-TCR stimulation of CD4(+) T cells from HIV-infected individuals and CD4(+) T cells from healthy donors incubated in vitro with HIV-1(Lai) depends on the manner the CD3-TCR complex is engaged. While stimulation by anti-CD3 antibodies in solution induced CD4 T cell apoptosis both in the absence or presence of anti-CD95 antibodies, stimulation by immobilized anti-CD3 antibodies rendered CD4(+) T cells resistant to CD95-mediated death and led to increased CD4 T cell proliferation in response to CD95 ligation. CD95 ligation of CD4(+) T cells led to the activation of caspases, while costimulation induced by anti-CD3 and anti-CD95 mAb prevented the full processing of caspase-3 and caspase-8. Proliferation of CD4(+) T cells induced by CD3-TCR and CD95 costimulation was decreased by treatments with a caspase-1 inhibitor or with neutralizing antibodies to IL-1ss, indicating a requirement for caspase-1-mediated IL-1beta processing and secretion. Our findings suggest a novel mechanism whereby in addition to its role in inducing T cell apoptosis, CD95 signaling during HIV infection may also provide a costimulatory signal leading to an enhancement of CD4 T cell proliferation in response to CD3-TCR complex engagement.

Possible mechanism of toxicity of zidovudine by induction of apoptosis of CD4+ and CD8+ T-cells in vivo.

Some HIV-infected patients have a discordant response to highly active antiretroviral therapy with a low virus load and an incomplete restoration of CD4+ T-cell counts. Zidovudine may limit CD4+ restoration by a hematotoxic mechanism. Apoptosis and T-cell counts were assessed in two patients before and after they switched from zidovudine to stavudine. Whereas CD4+ T-cell apoptosis fell from 52% and 66% before the zidovudine switch to 7% and 12%, respectively, after the switch, the patients' CD4+ counts rose gradually to +183 and +150 cells, respectively. It was therefore hypothesized that zidovudine directly induced apoptosis. Zidovudine withdrawal could be tested before immunological interventions such as interleukin-2 therapy are considered.