A molecular basis for the control of preimmune escape variants by HIV-specific CD8+ T cells.

The capacity of the immune system to adapt to rapidly evolving viruses is a primary feature of effective immunity, yet its molecular basis is unclear. Here, we investigated protective HIV-1-specific CD8+ T cell responses directed against the immunodominant p24 Gag-derived epitope KK10 (KRWIILGLNK263-272) presented by human leukocyte antigen (HLA)-B∗2705. We found that cross-reactive CD8+ T cell clonotypes were mobilized to counter the rapid emergence of HIV-1 variants that can directly affect T cell receptor (TCR) recognition. These newly recruited clonotypes expressed TCRs that engaged wild-type and mutant KK10 antigens with similar affinities and almost identical docking modes, thereby accounting for their antiviral efficacy in HLA-B∗2705+ individuals. A protective CD8+ T cell repertoire therefore encompasses the capacity to control TCR-accessible mutations, ultimately driving the development of more complex viral escape variants that disrupt antigen presentation.

Long-Term Spontaneous Control of HIV-1 Is Related to Low Frequency of Infected Cells and Inefficient Viral Reactivation.

UNLABELLED: HIV establishes reservoirs of infected cells that persist despite effective antiretroviral therapy (ART). In most patients, the virus begins to replicate soon after treatment interruption. However, a low frequency of infected cells at the time of treatment interruption has been associated with delayed viral rebound. Likewise, individuals who control the infection spontaneously, so-called HIV-1 controllers (HICs), carry particularly low levels of infected cells. It is unclear, however, whether and how this small number of infected cells contributes to durable viral control. Here we compared 38 HICs with 12 patients on effective combined antiretroviral therapy (cART) and found that the low frequency of infected cells in the former subjects was associated both with less efficient viral reactivation in resting CD4(+) T cells and with less efficient virion production ex vivo We also found that a potent HIV-specific CD8(+) T cell response was present only in those HICs whose CD4(+) T cells produced virus ex vivo Long-term spontaneous control of HIV infection in HICs thus appears to be sustained on the basis of the inefficient reactivation of viruses from a limited number of infected cells and the capacity of HICs to activate a potent HIV-specific CD8(+) T cell response to counteract efficient viral reactivation events. IMPORTANCE: There is a strong scientific interest in developing strategies to eradicate the HIV-1 reservoir. Very rare HIV-1-infected patients are able to spontaneously control viremia for long periods of time (HIV-1 controllers [HICs]) and are put forward as a model of HIV-1 remission. Here, we show that the low viral reservoirs found in HICs are a critical part of the mechanisms underlying viral control and result in a lower probability of HIV-1 reactivation events, resulting in limited HIV-1 release and spread. We found that those HICs in whom viral reactivation and spread from CD4(+) T cells in vitro were the most difficult were those with diminished CD8(+) T cell responses. These results suggest that, in some settings, low HIV-1 reservoirs decisively contribute to at least the temporary control of infection without antiretroviral therapy. We believe that this work provides information of relevance in the context of the search for HIV-1 remission.

High Soluble CD14 Levels at Primary HIV-1 Infection Predict More Rapid Disease Progression.

The soluble CD14 (sCD14) level was found associated with mortality during the chronic phase of human immunodeficiency virus (HIV) infection. Here we assessed its prognostic value in 138 patients with primary HIV infection. Higher sCD14 levels were associated with death, from myocardial infarction, but this was based on 3 deaths only. Among 68 untreated patients, those with higher sCD14 levels had more rapid spontaneous CD4 cell decline during the first 18 months following primary infection. This association persisted after adjustment for age, the CD4 cell count, and HIV viral load at diagnosis.

High eomesodermin expression among CD57+ CD8+ T cells identifies a CD8+ T cell subset associated with viral control during chronic human immunodeficiency virus infection.

During HIV infection, increased CD57 expression among CD8(+) T cells has been associated with immune senescence and defective immune responses. Interestingly, CD57-expressing CD8(+) T cells exhibit a dual profile, being simultaneously highly cytotoxic (terminally differentiated effectors) and poorly proliferative (replicative senescent). Recent publications point toward a positive role of CD57-expressing CD8(+) T cell subsets, presumably due to their high cytolytic activity. We further investigated the phenotype of CD57-expressing CD8(+) T cells in healthy donors and during HIV infection combining CD57 expression to Eomesodermin (EOMES), a T box transcription factor which determines, coordinately with T-bet, effector and memory CD8(+) T cell differentiation. We defined in healthy donors two functionally distinct CD57-expressing CD8(+) T cell subsets exhibiting different levels of EOMES expression: EOMES(hi) CD57(+) and EOMES(int) CD57(+) CD8(+) T cells. EOMES(hi) CD57(+) cells exhibited low cytotoxic activity but preserved proliferative capacity and interleukin 7 (IL-7) receptor expression, whereas EOMES(int) CD57(+) cells exhibited obvious cytotoxic functions and a more terminally differentiated phenotype. We next performed a similar analysis in different contexts of HIV infection: primary infected patients, long-term viremic patients, aviremic patients treated with antiretroviral therapy, and HIV controllers; we demonstrated a higher percentage of CD57-expressing cells in all HIV-infected patients regardless of virological status. When heterogeneity in EOMES expression among CD57 cells was taken into account, we detected significantly higher proportions of EOMES(hi) CD57(+) cells among HIV-specific and nonspecific CD8(+) T cells from HIV controllers than in aviremic antiretroviral-treated patients and viremic patients. Importantly, such a peculiar non-terminally differentiated EOMES(hi) CD57(+) phenotypic profile was associated with viral control. Importance: This study demonstrates that functional heterogeneity exists among CD57-expressing CD8 T cells, which include both terminally differentiated, highly cytotoxic EOMES(int) CD57(+) CD8(+) T cells and less differentiated EOMES(hi) CD57(+) CD8 T cells, which do not exhibit immediate cytotoxic functions but present high proliferative capacity. Interestingly, HIV controllers present a high proportion of EOMES(hi) CD57 cells among CD57-expressing HIV-specific CD8 T cells compared to both long-term viremic and aviremic antiretroviral therapy (ART)-treated patients, suggesting a beneficial role for this cell subset in viral control.

Both HLA-B*57 and plasma HIV RNA levels contribute to the HIV-specific CD8+ T cell response in HIV controllers.

CD8(+) T cell responses are thought to play an important role during HIV infection, particularly in HIV controllers (HIC) in whom viral replication is spontaneously controlled without any treatment. We have demonstrated that CD8(+) T cells from these subjects are able to suppress viral replication in vitro. In parallel, HIV-specific CD8(+) responses were shown to be strong and of high quality, with proliferative abilities and cytotoxic capacities, in HIC. The HLA-B*57 allele, which is associated with a better clinical outcome in HIV infection, is overrepresented in HIC. However, we showed that these patients constitute a heterogeneous group that includes subjects who present weak suppression of viral replication in vitro and HIV-specific responses. We performed an extensive study of 101 HIC (49 HLA-B*57(+) and 52 HLA-B*57(-)) to determine the impact of HLA-B*57 on the HIV-specific CD8(+) response. The HLA-B*57-restricted response displayed better qualitative features, such as higher functional avidity, higher proliferation capacity, and a higher level of cytokine production, than responses not restricted by HLA-B*57. However, the highest frequencies of HIV-specific CD8(+) T cells were observed only in a subset of HLA-B*57(+) subjects. They were tightly associated with the ability to suppress viral replication in vitro. In contrast, the subset of HLA-B*57(+) subjects with a weak ability to suppress viral replication had significantly lower ultrasensitive viral loads than all the other groups of controllers. In conclusion, both HLA-B*57 and the amount of ultrasensitive viral load seem to play a role in HIV-specific CD8(+) T cell responses in HIC.

Post-treatment HIV-1 controllers with a long-term virological remission after the interruption of early initiated antiretroviral therapy ANRS VISCONTI Study.

Combination antiretroviral therapy (cART) reduces HIV-associated morbidities and mortalities but cannot cure the infection. Given the difficulty of eradicating HIV-1, a functional cure for HIV-infected patients appears to be a more reachable short-term goal. We identified 14 HIV patients (post-treatment controllers [PTCs]) whose viremia remained controlled for several years after the interruption of prolonged cART initiated during the primary infection. Most PTCs lacked the protective HLA B alleles that are overrepresented in spontaneous HIV controllers (HICs); instead, they carried risk-associated HLA alleles that were largely absent among the HICs. Accordingly, the PTCs had poorer CD8+ T cell responses and more severe primary infections than the HICs did. Moreover, the incidence of viral control after the interruption of early antiretroviral therapy was higher among the PTCs than has been reported for spontaneous control. Off therapy, the PTCs were able to maintain and, in some cases, further reduce an extremely low viral reservoir. We found that long-lived HIV-infected CD4+ T cells contributed poorly to the total resting HIV reservoir in the PTCs because of a low rate of infection of naïve T cells and a skewed distribution of resting memory CD4+ T cell subsets. Our results show that early and prolonged cART may allow some individuals with a rather unfavorable background to achieve long-term infection control and may have important implications in the search for a functional HIV cure.

Pressure from TRIM5α contributes to control of HIV-1 replication by individuals expressing protective HLA-B alleles.

The expression of certain HLA class I alleles, including HLA-B*27 and HLA-B*57, is associated with better control of human immunodeficiency virus type 1 (HIV-1) infection, but the mechanisms responsible are not fully understood. We sought evidence that pressure from the human restriction factor TRIM5α (hTRIM5α) could contribute to viral control. The hTRIM5α sensitivity of viruses from both HLA-B*57-positive (HLA-B*57(+)) and HLA-B*27(+) patients who spontaneously controlled viral replication, but not viruses from viremic patients expressing these alleles, was significantly greater than that of viruses from patients not expressing these protective HLA-B alleles. Overall, a significant negative correlation between hTRIM5α sensitivity and viral load was observed. In HLA-B*57(+) patients, the T242N mutation in the HLA-B*57-restricted TW10 CD8(+) T lymphocyte (CTL) epitope was strongly associated with hTRIM5α sensitivity. In HLA-B*27(+) controllers, hTRIM5α sensitivity was associated with a significant reduction in emergence of key CTL mutations. In several patients, viral evolution to avoid hTRIM5α sensitivity was observed but could be associated with reduced viral replicative capacity. Thus, in individuals expressing protective HLA-B alleles, the combined pressures exerted by CTL, hTRIM5α, and capsid structural constraints can prevent viral escape both by impeding the selection of necessary resistance/compensatory mutations and forcing the selection of escape mutations that increase hTRIM5α sensitivity or impair viral replicative capacity.

Early and long-lasting alteration of effector CD45RA(-)Foxp3(high) regulatory T-cell homeostasis during HIV infection.

Regulatory T-cell (Treg) quantification in human immunodeficiency virus (HIV) infection remains ill defined because of the lack of reliable specific markers to identify human Tregs and the diversity of clinical stages of HIV infection. Using a recently described Treg identification strategy based on CD45RA and Foxp3 expression, we performed an extensive quantification of total, naive (CD45RA(+)Foxp3(low)), and effector (CD45RA(-)Foxp3(high)) Tregs in different contexts of HIV infection: primary HIV infection, long-term viremic patients, aviremic patients treated with highly active antiretroviral therapy, and HIV controllers. We showed that although total Treg percentages were mildly affected by HIV infection, Treg absolute numbers were significantly reduced in all groups studied. We demonstrated that although naive Treg numbers were essentially preserved, effector Tregs were consistently affected during HIV infection. Finally, we demonstrated that effector but not total or naive Treg numbers were negatively correlated with the magnitude of HIV-specific CD8 T-cell responses.

Identification of a particular HIV-specific CD8+ T-cell subset with a CD27+ CD45RO-/RA+ phenotype and memory characteristics after initiation of HAART during acute primary HIV infection.

CD8(+) T cells play an important role in controlling viral infections. Defective CD8(+) T-cell responses during HIV infection could contribute to viral persistence. Early initiation of highly active antiretroviral therapy during acute primary HIV infection helps to preserve HIV-specific immune responses. Here, we describe a particular CD27(+) CD45RO(-)/RA(+) HIV-specific CD8(+) T cell in participants treated early during the primary infection. These cells, which were present at a very low frequency during primary HIV infection, increased markedly after early treatment, whereas their frequency remained unchanged in untreated participants and in participants treated later. These nonnaive antigen-experienced cells are in a resting state and have characteristics of long-lived memory cells. They also possess direct effector capabilities, such as cytokine production, and are able to proliferate and to acquire cytotoxic functions on reactivation. Our results suggest that these HIV-specific CD27(+) CD45RO(-)/RA(+) CD8(+) T cells, observed when early viral replication is inhibited, form a pool of resting cells with memory characteristics.

Heterogeneity in HIV suppression by CD8 T cells from HIV controllers: association with Gag-specific CD8 T cell responses.

"HIV controllers" (HICs) are rare individuals in whom HIV-1 plasma viral load remains undetectable without antiretroviral treatment. This spontaneous viral control in HICs is usually associated to strong functional HIV-specific CD8(+) T cell responses. Accordingly, we have recently shown that CD8(+) T cells from HICs strongly suppress ex vivo HIV-1 infection of autologous CD4(+) T cells, suggesting a crucial role of this response in vivo. Knowledge of the mechanisms underlying the CD8(+) T cell antiviral activity might help to develop effective T cell-based vaccines. In the present work, we further characterized the HIV-suppressive capacity of CD8(+) T cells in 19 HICs. CD8(+) T cells from 14 of the 19 HICs showed strong HIV-suppressive capacity ex vivo. This capacity was stable over time and was partially effective even on other primate lentiviruses. HIV-suppressive capacity of CD8(+) T cells correlated strongly with the frequency of HIV-specific CD8(+) T cells, and in particular of Gag-specific CD8(+) T cells. We also identified five HICs who had weak HIV-suppressive CD8(+) T cell capacities and HIV-specific CD8(+) T cell responses. Among these five HICs, at least three had highly in vitro replicative viruses, suggesting that the control of viremia in these patients is not due to replication-defective viruses. These results, on the one hand, suggest the importance of Gag responses in the antiviral potency of CD8(+) T cells from HICs and, on the other hand, propose that other host mechanisms may contribute to restraining HIV infection in HICs.

Spontaneous control of viral replication during primary HIV infection: when is "HIV controller" status established?

Eight patients in the ANRS PRIMO cohort experienced early spontaneous viral control. Viral control was established a median of 6.2 months after primary human immunodeficiency virus type 1 infection and lasted a median of 4.1 years. Seven of the patients initially had detectable viral replication. For 4 patients, viral control was lost during follow-up.

Stimulation of the primary anti-HIV antibody response by IFN-alpha in patients with acute HIV-1 infection.

Type I IFNs are needed for the production of antiviral antibodies in mice; whether they also stimulate primary antibody responses in vivo during human viral infections is unknown. This was assessed in patients acutely infected with HIV-1 and treated with IFN-alpha2b. Patients with acute HIV-1 infection were randomized to receive antiretroviral therapy alone (Group A, n=60) or combined for 14 weeks with pegylated-IFN-alpha2b (Group B, n=30). Emergence of anti-HIV antibodies was monitored during 32 weeks by Western blot (WB) analyses of serum samples. IFN-alpha2b treatment stimulated the production of anti-HIV antibodies. On Week 32, 19 weeks after the last IFN-alpha2b administration, there were 8.5 (6.5-10.0) HIV WB bands (median, interquartile range) in Group B and 7.0 (5.0-10.0) bands in Group A (P=0.054), and band intensities were stronger in Group B (P<0.05 for p18, p24, p34, p40, and p55 HIV antigens). IFN-alpha2b treatment also increased circulating concentrations of the B cell-activating factor of the TNF family (P<0.001) and ex vivo production of IL-12 (P<0.05), reflecting its effect on innate immune cells. Withdrawal of antiretroviral treatment on Week 36 resulted in a lower rebound of HIV replication in Group B than in Group A (P<0.05). Therefore, type I IFNs stimulate the emerging anti-HIV immune response in patients with acute HIV-1 infection, resulting in an improved control of HIV replication. Type I IFNs are thus critical in the development of efficient antiviral immune responses in humans, including the production of antiviral antibodies.

Preserved central memory and activated effector memory CD4+ T-cell subsets in human immunodeficiency virus controllers: an ANRS EP36 study.

Human immunodeficiency virus (HIV) controllers are rare individuals who spontaneously control HIV type 1 replication for 10 years or more in the absence of antiretroviral treatment. In the present study, HIV controllers (n = 11) maintained potent HIV-specific CD4 responses in spite of very low antigenic loads. Their CD4+ central memory T (T(CM)) cells were characterized by near-normal numbers and preserved interleukin-2 (IL-2) secretion in response to HIV antigens and uniformly high expression of the survival receptor IL-7 receptor alpha (IL-7Ralpha). Controllers expressed CCR7 at higher levels than uninfected controls, suggesting differences in T(CM)-cell homing patterns. CD4+ effector memory T (T(EM))-cell responses were polyfunctional in HIV controllers, while IL-2 secretion was lost in viremic patients. Cytokine production was three times higher in controllers than in treated patients with undetectable viral loads, suggesting an intrinsically more efficient response in the former group. The total CD4+ T(EM)-cell pool underwent immune activation in controllers, as indicated by increased HLA-DR expression, decreased IL-7Ralpha expression, a bias towards gamma interferon production upon polyclonal stimulation, and increased macrophage inflammatory protein 1beta secretion associated with chronic CCR5 down-regulation. Thus, HIV controllers showed a preserved CD4+ T(CM)-cell compartment and signs of potent functional activation in the CD4+ T(EM)-cell compartment. While controllers did not show the generalized immune activation pattern associated with disease progression, they had signs of immune activation restricted to the effector compartment. These findings suggest the induction of an efficient, nondetrimental type of immune activation in patients who spontaneously control HIV.

Interruption of antiretroviral therapy initiated during primary HIV-1 infection: impact of a therapeutic vaccination strategy combined with interleukin (IL)-2 compared with IL-2 alone in the ANRS 095 Randomized Study.

HIV-specific T cell responses play a critical role in the control of infection. We evaluated the impact of immune-based interventions in patients first treated during primary HIV-1 infection (PHI). Forty-three patients were randomized within three groups, to receive either interleukin-2 (IL-2 group), or boosts of ALVAC-HIV (vCP1433) and LIPO-6T followed by interleukin-2 (Vac-IL2 group), compared with no immune intervention (control group), and were monitored for T cell responses. Impact of strategies on viral replication was subsequently assessed during long-term treatment interruption. HIV-specific CD4(+) T cell responses did not change during the study period in immunized patients relative to controls, and vaccination had only a transient effect on interferon-gamma-producing CD8 responses. Viral rebound after treatment interruption was similar in immunized patients and controls. Forty percent of patients had HIV RNA values <10,000 copies/ml 12 weeks after interruption. The cumulative time off treatment represented almost half the total follow-up period. Immunological and virological status during PHI and HIV DNA load at interruption were predictive of the level of viral rebound after treatment interruption, whereas HIV RNA level during PHI and HIV DNA level at interruption were predictive of the time off treatment. Treatment interruption is safe in patients treated early after primary HIV infection. On the basis of this pilot study, HIV immunizations and interleukin-2 appear to have no supplementary benefit.

CD4 cell count and HIV DNA level are independent predictors of disease progression after primary HIV type 1 infection in untreated patients.

BACKGROUND: Treatment initiation at the time of primary human immunodeficiency virus (HIV) type 1 (HIV-1) infection has become less frequent in recent years. METHODS: In the French prospective PRIMO Cohort, in which patients are enrolled at the time of primary HIV-1 infection, 30% of the 552 patients recruited during 1996-2004 did not start receiving antiretroviral treatment during the first 3 months after diagnosis. We analyzed the patients' clinical and immunological outcomes and examined potential predictors of disease progression. Progression was defined as the occurrence of an acquired immunodeficiency syndrome (AIDS)-related clinical event or a CD4 cell count <350 cells/mm3. RESULTS: Fifty-six (34%) of the untreated patients experienced immunological progression during a median duration of follow-up of 24 months, and 1 of these patients had an AIDS-related event. The estimated risks of progression were 25%, 34%, and 42% at 1, 2, and 3 years after enrollment, respectively. Compared with patients who did not have progression, those with progression had significantly lower CD4 cell counts at diagnosis (455 vs. 738 cells/mm3), higher plasma HIV RNA levels (4.9 vs. 4.5 log10 copies/mL), and higher HIV DNA levels (3.3 vs. 3.0 log(10) copies/10(6) peripheral blood mononuclear cells [PBMCs]). All 3 parameters were significantly associated with progression in univariate analysis. In multivariate analysis, only the CD4 cell count and HIV DNA level were independently predictive of disease progression (relative hazard for CD4 cell count, 1.84 per decrease of 100 cells/mm3; relative hazard for HIV DNA level, 2.73 per increase of 1 log(10) copies/10(6) PBMCs). CONCLUSIONS: Both a low initial CD4 cell count and a high HIV DNA level are predictive of rapid progression of untreated primary HIV-1 infection. Affected patients may therefore benefit from close clinical and laboratory monitoring and/or early administration of treatment.

HIV controllers: a homogeneous group of HIV-1-infected patients with spontaneous control of viral replication.

We identified a total 15 patients who have maintained undetectable plasma HIV RNA loads without antiretroviral treatment for >10 years from cohorts of 1300 and 1551 patients infected with human immunodeficiency virus (HIV). These 15 patients, whom we have referred to as "HIV controllers," are characterized by a low HIV DNA load in peripheral blood mononuclear cells and by a strong HIV-specific immune response.

Immunologic and Virologic Progression in HIV Controllers: The Role of Viral "Blips" and Immune Activation in the ANRS CO21 CODEX Study.

Some HIV controllers (HICs) experience CD4+T cell count loss and/or lose their ability to control HIV. In this study, we investigated the rate of immunologic and/or virologic progression (ImmP/VirP) and its determinants in the ANRS CO21/CODEX cohort. Immunologic progression was defined as a lasting fall in CD4+T cell count below 350/mm(3) or more than 200/mm(3) with a baseline count below 600/mm(3). Virologic progression was defined as a HIV viral load (VL) above 2000 copies/mL on two consecutive determinations. Clinical characteristics, immune activation, ultrasensitive HIV VL and total HIV DNA were analyzed. Disease progression was observed in 15 of the 217 patients followed up between 2009 and 2013 (ImmP, n = 10; VirP, n = 5). Progressors had higher ultrasensitive HIV RNA levels at inclusion (i.e. 1-2 years before progression) than non-progressors. ImmP had also lower CD4+T cell nadir and CD4+T cell count at inclusion, and VirP had higher HIV DNA levels in blood. T cell activation and IP10 levels at inclusion were significantly higher in ImmP than in non-progressors. In summary, the lasting loss of CD4+T cells, residual HIV replication and basal levels of immune activation appear to be major determinants of progression in HICs. These factors should be considered for adjusting their follow-up.

Intensive five-drug antiretroviral therapy regimen versus standard triple-drug therapy during primary HIV-1 infection (OPTIPRIM-ANRS 147): a randomised, open-label, phase 3 trial.

BACKGROUND: Early combination antiretroviral therapy (cART) initiation at the time of primary HIV-1 infection could restrict the establishment of HIV reservoirs. We aimed to assess the effect of a cART regimen intensified with raltegravir and maraviroc, compared with standard triple-drug cART, on HIV-DNA load. METHODS: In this randomised, open-label, phase 3 trial, we recruited patients from hospitals across France. Inclusion criteria were primary HIV-1 infection (an incomplete HIV-1 western blot and detectable plasma HIV-RNA), with either symptoms or a CD4+ cell count below 500 cells per µL. Patients were randomly assigned (1:1) to an intensive, five-drug cART regimen (raltegravir 400 mg and maraviroc 150 mg twice daily, and a fixed-dose combination of tenofovir disoproxil fumarate 300 g plus emtricitabine 200 g, darunavir 800 g, and ritonavir 100 g once daily) or a standard triple-drug cART regimen (tenofovir disoproxil fumarate 300 g plus emtricitabine 200 g, darunavir 800 g, and ritonavir 100 g once daily) using a predefined randomised list generated by randomly selected variable block sizes. The primary endpoint was the median number of HIV-DNA copies per 10(6) peripheral blood mononuclear cells (PBMC) at month 24, analysed in the modified intention-to-treat population, defined as all patients who started their assigned treatment. This study is registered with ClinicalTrials.gov, number NCT01033760. FINDINGS: Between April 26, 2010, and July 13, 2011, 110 patients were enrolled, of whom 92 were randomly assigned and 90 started treatment (45 in each treatment group). Six (13%) patients in the intensive cART group and two (4%) in the standard cART group discontinued before month 24. At month 24, HIV-DNA loads were similar between groups (2·35 [IQR 2·05-2·50] log10 per 10(6) PBMC in the intensive cART group vs 2·25 [1·71-2·55] in the standard cART group; p=0·21). Eight grade 3-4 clinical adverse events were reported in seven patients in the intensive cART group and seven grade 3-4 clinical adverse events were reported in seven patients in the standard cART group. Three serious clinical adverse events occurred: two (pancreatitis and lipodystrophy) in the standard cART group, which were regarded as treatment related, and one event (suicide attempt) in the intensive cART group that was unrelated to treatment. INTERPRETATION: After 24 months, cART intensified with raltegravir and maraviroc did not have a greater effect on HIV blood reservoirs than did standard cART. These results should help to design future trials of treatments aiming to decrease the HIV reservoir in patients with primary HIV-1 infection. FUNDING: Inserm-ANRS, Gilead Sciences, Janssen Pharmaceuticals, Merck, and ViiV Laboratories.

Heterogeneity of the simian immunodeficiency virus (SIV) specific CD8(+) T-cell response in mucosal tissues during SIV primary infection.

Virus-specific CD8(+) T cells play an important role in controlling viral replication during acute primary infection. At this early stage, mucosal tissues represent a major site of viral replication. Therefore, the presence of functional virus-specific CD8(+) effector T cells in the mucosa during primary infection is a key issue in the pathogenesis of infection. In order to evaluate the extent of this response, six rhesus macaques were infected with simian immunodeficiency virus (SIV)mac251 and sacrificed on day 28 following infection. The functional activity of SIV-effector CD8(+) T cells was evaluated by means of a gamma-IFN ELISpot assay with autologous cells expressing SIV env, gag, pol and nef genes as antigen-presenting cells. This evaluation was performed on PBMCs, spleen, peripheral lymph node, gut-associated lymph node and lamina propria lymphocytes isolated from different mucosal sites. In parallel, the cell-associated viral load was quantified in all these tissues. Five macaques had gamma-IFN SIV-specific CD8(+) T cells in PBMCs and/or lymph nodes. However, in these macaques, these CD8(+) T cells were only present in seven mucosal sites out of 24 tested (the lamina propria lymphocytes of the duodenum, jejunum, ileum and colon were evaluated separately for each animal), whereas they were detected in all corresponding gut-associated lymph nodes. In addition, the mean frequency of SIV-specific gamma-IFN-secreting CD8(+) T cells was 117 +/- 228 per 10(6) cells in the lamina propria vs. 958 +/- 1184 in gut associated lymph nodes (P = 0.001). No overall correlation was observed between the CD8(+) T-cell activity and the viral load: among the 17 mucosal sites in which the virus was isolated, no specific activity was detected in 13 sites. In conclusion, these data indicate that the frequencies of SIV-specific gamma-IFN-secreting CD8(+) T cells are low in the mucosa during early primary infection. This may be of importance with regard to the intense viral replication observed in the mucosa at this stage.

Potential role for HIV-specific CD38-/HLA-DR+ CD8+ T cells in viral suppression and cytotoxicity in HIV controllers.

BACKGROUND: HIV controllers (HIC) are rare HIV-1-infected patients who exhibit spontaneous viral control. HIC have high frequency of CD38-/HLA-DR+ HIV-specific CD8+ T cells. Here we examined the role of this subset in HIC status. MATERIALS AND METHODS: We compared CD38-/HLA-DR+ CD8+ T cells with the classical CD38+/HLA-DR+ activated phenotype in terms of 1) their activation status, reflected by CD69, CD25, CD71, CD40 and Ki67 expression, 2) functional parameters: Bcl-2 expression, proliferative capacity, and IFN-γ and IL-2 production, and 3) cytotoxic activity. We also investigated how this particular profile is generated. RESULTS: Compared to CD38+/HLA-DR+ cells, CD38-/HLA-DR+ cells exhibited lower expression of several activation markers, better survival capacity (Bcl-2 MFI, 367 [134-462] vs 638 [307-747], P = 0.001), higher frequency of polyfunctional cells (15% [7%-33%] vs 21% [16%-43%], P = 0.0003), greater proliferative capacity (0-fold [0-2] vs 3-fold [2]-[11], P = 0.007), and higher cytotoxicity in vitro (7% [3%-11%] vs 13% [6%-22%], P = 0.02). The CD38-/HLA-DR+ profile was preferentially generated in response to low viral antigen concentrations. CONCLUSIONS: These data highlight the role of CD38-/HLA-DR+ HIV-specific CD8+ T cell cytotoxicity in HIC status and provide insights into the mechanism by which they are generated. Induction of this protective CD8+ subset may be important for vaccine strategies.