Precise determination of time to reach viral load set point after acute HIV-1 infection

Changing roles of CD3 + CD8 low T cells in combating HIV-1 infection

BACKGROUND

Cluster of differentiation 8 (CD8 T) cells play critical roles in eradicating human immunodeficiency virus (HIV)-1 infection, but little is known about the effects of T cells expressing CD8 at low levels (CD8 low ) or high levels (CD8 high ) on HIV-1 replication inhibition after HIV-1 invasion into individual.

METHODS

Nineteen patients who had been acutely infected with HIV-1 (AHI) and 20 patients with chronic infection (CHI) for ≥2 years were enrolled in this study to investigate the dynamics of the quantity, activation, and immune responses of CD3 + CD8 low T cells and their counterpart CD3 + CD8 high T cells at different stages of HIV-1 infection.

RESULTS

Compared with healthy donors, CD3 + CD8 low T cells expanded in HIV-1-infected individuals at different stages of infection. As HIV-1 infection progressed, CD3 + CD8 low T cells gradually decreased. Simultaneously, CD3 + CD8 high T cells was significantly reduced in the first month of AHI and then increased gradually as HIV-1 infection progressed. The classical activation of CD3 + CD8 low T cells was highest in the first month of AHI and then reduced as HIV-1 infection progressed and entered the chronic stage. Meanwhile, activated CD38 - HLA-DR + CD8 low T cells did not increase in the first month of AHI, and the number of these cells was inversely associated with viral load ( r = -0.664, P = 0.004) but positively associated with the CD4 T-cell count ( r = 0.586, P = 0.014). Increased programmed cell death protein 1 (PD-1) abundance on CD3 + CD8 low T cells was observed from the 1st month of AHI but did not continue to be enhanced, while a significant T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif (ITIM) domains (TIGIT) abundance increase was observed in the 12th month of infection. Furthermore, increased PD-1 and TIGIT abundance on CD3 + CD8 low T cells was associated with a low CD4 T-cell count (PD-1: r = -0.456, P = 0.043; TIGIT: r = -0.488, P = 0.029) in CHI. Nonetheless, the nonincrease in PD-1 expression on classically activated CD3 + CD8 low T cells was inversely associated with HIV-1 viremia in the first month of AHI ( r = -0.578, P = 0.015). Notably, in the first month of AHI, few CD3 + CD8 low T cells, but comparable amounts of CD3 + CD8 high T cells, responded to Gag peptides. Then, weaker HIV-1-specific T-cell responses were induced in CD3 + CD8 low T cells than CD3 + CD8 high T cells at the 3rd and 12th months of AHI and in CHI.

CONCLUSIONS

Our findings suggest that CD3 + CD8 low T cells play an anti-HIV role in the first month of infection due to their abundance but induce a weak HIV-1-specific immune response. Subsequently, CD3 + CD8 low T-cell number decreased gradually as infection persisted, and their anti-HIV functions were inferior to those of CD3 + CD8 high T cells.

Increased HBV Coinfection and Decreased IFN-γ-Producing HBV-Specific CD8+ T Cell Numbers During HIV Disease Progression

Objective

To investigate the characteristics and mechanism of the dynamics of HBV infection with the progression of HIV disease and to explore the different responses of T lymphocytes to HBV in HIV patients in different stages of disease.

Methods

We compared the rates and characteristics of HBV coinfection between 372 early HIV-infected and 306 chronically HIV-infected men who have sex with men (MSM) in the Beijing Youan Hospital from October 2006 to November 2014. We further analysed IFN-γ-producing HBV-specific CD8+ T cells in 15 early HIV-infected individuals and 20 chronic HIV-infected individuals with HBV coinfection.

Results

Twenty-three HBsAg-positive cases were detected among the 372 early HIV-infected patients of this cohort, and the coinfection rate was 6.18%, while 35 HBsAg-positive cases were detected among the 306 chronically HIV-infected patients, with a coinfection rate of 11.44%. The coinfection rate of the chronically HIV-infected patients was significantly higher than that of the early-infected patients (p=0.0005). The median CD4+ T cell count in the early HIV infection patients was 445 cells/μL (196-1,030 cells/μL), which was higher than that in the chronic HIV infection patients [358 cells/μL (17-783 cells/μL)] (p<0.001). The proportion of IFN-γ-producing CD8+ T cells in early HIV-infected patients was significantly higher than that in chronically HIV-infected patients.

Conclusion

The coinfection rate of HBV in HIV patients increases with HIV disease progression, which might be related to the decreased IFN-γ-producing HBV-specific CD8+ T cell numbers. The closely monitored HBV serum markers from the early stage of HIV infection are warranted.

Analysis of the Characteristics of TIGIT-Expressing CD3-CD56+NK Cells in Controlling Different Stages of HIV-1 Infection

TIGIT expression on natural killer (NK) cells is associated with dysfunction during chronic HIV infection, but the phenotype and biological functions of these cells in the context of acute HIV-1 infection remain poorly understood. Here, 19 acutely infected HIV-1 patients traced at first, third and twelfth month, and age-matched patients with chronic HIV-1 infection were enrolled to investigate the phenotype and functions of TIGIT expression on NK cells. We found that TIGIT-expressing NK cells did not increase in frequency in the first, third and twelfth month of infection until chronic HIV-1 infection lasted over 2 years. The number of TIGIT⁺NK cells in acute infection was positively associated with HIV-1 viral load (r = 0.53, P = 0.0009). CD96 was significantly upregulated on NK cells after acute infection for 1 month and in chronic infection over 2 years, while CD226 was downregulated in chronic infection over 2 years. Further, at different stages of infection, CD96⁻CD226⁺ cells diminished among total NK cells, TIGIT⁺NK and TIGIT⁻NK cells, while CD96⁺CD226⁻ cells expanded. Reduced CD96⁻CD226⁺ cells and elevated CD96⁺CD226⁻ cells among NK cells especially TIGIT⁻NK cells, had opposite associations with viral load in the first month of infection, as well as CD4 T-cell counts in including the twelfth month and more than 2 years of chronic infection. In both HIV-1-infected individuals and healthy donors, TIGIT was predominantly expressed in NKG2A⁻NKG2C⁺NK cells, with a significantly higher proportion than in NKG2A⁺NKG2C⁻NK cells. Moreover, the frequencies of TIGIT⁺NK cells were positively associated with the frequencies of NKG2A⁻NKG2C⁺NK cells in acute infection (r = 0.62, P < 0.0001), chronic infection (r = 0.37, P = 0.023) and healthy donors (r = 0.36, P = 0.020). Enhanced early activation and coexpression of CD38 and HLA-DR in TIGIT⁺NK cells were detected compared to TIGIT⁻NK cells, both of which were inversely associated with the decrease in CD4 T-cell counts in both acute and chronic HIV-1 infection. The ability of TIGIT⁺NK cells to produce TNF-α, IFN-γ and CD107a degranulation substance were consistently weaker than that of TIGIT⁻NK cells in both acute and chronic infection. Moreover, the functionalities of TIGIT⁺NK cells were lower than those of TIGIT⁻NK cells, except for TNF-α⁻CD107a⁺IFN-γ⁻NK cells. These findings highlight the phenotype and functional characteristics of TIGIT-expressing NK cells which have poor capabilities in inhibiting HIV-1 replication and maintaining CD4 T-cell counts.

Engineered Antigen-Specific T Cells Secreting Broadly Neutralizing Antibodies: Combining Innate and Adaptive Immune Response against HIV

While antiretroviral therapy (ART) can completely suppress viremia, it is not a cure for HIV. HIV persists as a latent reservoir of infected cells, able to evade host immunity and re-seed infection following cessation of ART. Two promising immunotherapeutic strategies to eliminate both productively infected cells and reactivated cells of the reservoir are the adoptive transfer of potent HIV-specific T cells and the passive administration of HIV-specific broadly neutralizing antibodies also capable of mediating antibody-dependent cellular cytotoxicity (ADCC). The simultaneous use of both as the basis of a single therapeutic has never been explored. We therefore sought to modify HIV-specific T cells from HIV-naive donors (to allow their use in the context of allotransplant, a promising platform for sterilizing cures) so they are able to secrete a broadly neutralizing antibody (bNAb) directed against the HIV envelope to elicit ADCC. We designed an antibody construct comprising bNAb 10-1074 heavy and light chains, fused to IgG3 Fc to elicit ADCC, with truncated cluster of differentiation 19 (CD19) as a selectable marker. HIV-specific T cells were expanded from HIV-naive donors by priming with antigen-presenting cells expressing overlapping HIV antigens in the presence of cytokines. T cells retained specificity against Gag, Nef, and Pol peptides (218.55 ± 300.14 interferon γ [IFNγ] spot-forming cells [SFC]/1 × 10⁵) following transduction (38.92 ± 25.30) with the 10-1074 antibody constructs. These cells secreted 10-1074 antibodies (139.04 ± 114.42 ng/mL). The HIV-specific T cells maintained T cell function following transduction, and the secreted 10-1074 antibody bound HIV envelope (28.13% ± 19.42%) and displayed ADCC activity (10.47% ± 4.11%). Most critically, the 10-1074 antibody-secreting HIV-specific T cells displayed superior in vitro suppression of HIV replication. In summary, HIV-specific T cells can be engineered to produce antibodies mediating ADCC against HIV envelope-expressing cells. This combined innate/adaptive approach allows for synergy between the two immune arms, broadens the target range of the immune therapy, and provides further insight into what defines an effective anti-HIV response.

The Genetic Diversity of HIV-1 Quasispecies Within Primary Infected Individuals

HIV has remarkable genetic diversity among populations. The diversity has critical impacts on transmission, immune escape, pathogenesis, and clinical management. HIV-1 diversity originates from frequent mutation and recombination during reverse transcription. This work focuses on the quasispecies genetic dynamics within individuals with primary infections. Eleven men who have sex with men from the Beijing PRIMO Clinical Cohort were identified as primary infection and had three or four series of their anticoagulant blood samples collected. Viral RNA was extracted and amplified using single-genome amplification. Products of the gp120 gene that met single-genome amplification requirements were sequenced. Subtype assortment of all collected sequences was performed using both the jumping profile hidden Markov model (jpHMM) and REGA. Quasispecies diversity at each time was estimated using Mega 6. Intrapatient recombination was analyzed using RDP4. According to the Fiebig classification system, YA-81 belongs to stage III and YA-113 belongs to stage IV. The other samples are all associated with the infection stage of V/VI. YA113 had a dual infection with subtype B and a new unique recombinant form involving CRF01_AE and C. The other eight were infected with CRF01_AE, one was infected with B/C recombinant, and the last one with B. Of the 10 single infections, 8 were caused by 1 founder virus. They all displayed a sharp increase of quasispecies diversity during the sampling times. Two were caused by at least two founder viruses. The diversity of these strains starts at a significantly high level and is followed by a relatively steady trend. Critically, the separate subtypes YA113-B and YA113-CRF01_AE/C both showed a similar trend to those infected by a single founder virus. Recombination analysis revealed that 5 of 11 cases underwent detectable intrapatient recombination. These findings indicate that tracing the dynamics of HIV-1 quasispecies during early infection may be relevant and valuable for understanding pathways of viral diversification and immune escape.

The Mtb-HIV syndemic interaction: why treating M. tuberculosis infection may be crucial for HIV-1 eradication

Accelerated tuberculosis and AIDS progression seen in HIV-1 and Mycobacterium tuberculosis (Mtb)-coinfected individuals indicates the important interaction between these syndemic pathogens. The immunological interaction between HIV-1 and Mtb has been largely defined by how the virus exacerbates tuberculosis disease pathogenesis. Understanding of the mechanisms by which pre-existing or subsequent Mtb infection may favor the replication, persistence and progression of HIV, is less characterized. We present a rationale for the critical consideration of ‘latent’ Mtb infection in HIV-1 prevention and cure strategies. In support of this position, we review evidence of the effect of Mtb infection on HIV-1 acquisition, replication and persistence. We propose that ‘latent’ Mtb infection may have considerable impact on HIV-1 pathogenesis and the continuing HIV-1 epidemic in sub-Saharan Africa.

Efficacy and cost-effectiveness of early antiretroviral therapy and partners' pre-exposure prophylaxis among men who have sex with men in Shenyang, China: a prospective cohort and costing study

BACKGROUND

Biomedical interventions such as antiretroviral therapy (ART) and pre-exposure prophylaxis (PrEP) are highly effective for prevention of human immunodeficiency virus (HIV) infection. However, China has not released national PrEP guidelines, and HIV incidence among men who have sex with men (MSM) is unchanged despite substantial scale-up of ART. We evaluated reductions in HIV transmission that may be achieved through early initiation of ART plus partners' PrEP.

METHODS

Six intervention scenarios were evaluated in terms of their impact on HIV transmission and their cost-effectiveness for 36 months post-infection. Three scenarios were based on observed data: non-ART, standard-ART, and early-ART. Another three scenarios were based on observed and hypothetical data: non-ART plus partners' PrEP, standard-ART plus partners' PrEP, and early-ART plus partners' PrEP. The number of onward transmissions was calculated according to viral load and self-reported sexual behaviors, and calibrated by the prevalence and incidence of HIV among Chinese MSM. Cost-effectiveness outcomes were quality-adjusted life-years (QALYs) and cost-utility ratio (CUR).

RESULTS

The estimated number of onward transmissions by every 100 HIV-positive cases 36 months post-infection was 41.83 (95% credible interval: 30.75-57.69) in the non-ART scenario, 7.95 (5.85-10.95) in the early-ART scenario, and 0.79 (0.58-1.09) in the early-ART plus partners' PrEP scenario. Compared with non-ART, the early-ART and early-ART plus partners' PrEP scenarios were associated with an 81.0 and 98.1% reduction in HIV transmission, and had a CUR of $12,864/QALY and $16,817/QALY, respectively.

CONCLUSIONS

Integrated delivery of early ART and sexual partners' PrEP could nearly eliminate HIV transmission and reduce costs during the first 36 months of HIV infection. Our results suggest a feasible and cost-effective strategy for reversing the HIV epidemic among MSM in China.

High polymorphism rates in well-known T cell epitopes restricted by protective HLA alleles during HIV infection are associated with rapid disease progression in early-infected MSM in China

T cell epitopes restricted by several protective HLA alleles, such as B*57, B*5801, B*27, B*51 and B*13, have been very well defined over the past two decades. We investigated 32 well-known T cell epitopes restricted by protective HLA molecules among 54 Chinese men who have sex with men (MSM) at the early stage of HIV-1 infection. Subjects in our cohort carrying protective HLA types did not exhibit slow CD4 T cell count decline (P = 0.489) or low viral load set points (P = 0.500). Variations occurred in 96.88% (31/32) of the known wild-type epitopes (rate 1.85-100%), and the variation rates of the strains of two CRF01_AE lineages were significantly higher than those of non-CRF01_AE strains (76.82% vs. 48.96%, P = 0.004; 71.27% vs. 8.96%, P = 0.025). Subjects infected with CRF01_AE exhibited relatively rapid disease progression (P = 0.035). Therefore, the lack of wild-type protective T cell epitopes restricted by classic protective HLA alleles in CRF01_AE HIV-1 strains may be one of the reasons why rapid disease progression is observed in Chinese MSM with HIV-1 infection.

Harnessing Antibody-Dependent Cellular Cytotoxicity To Control HIV-1 Infection

Passive administration of broadly neutralizing anti-human immunodeficiency virus type 1 (HIV-1) antibodies (bNAbs) has been recently suggested as a promising alternative therapeutic approach for HIV-1 infection. Although the success behind the studies that used this approach has been attributed to the potency and neutralization breadth of anti-HIV-1 antibodies, several lines of evidence support the idea that specific antibody-dependent effector functions, particularly antibody-dependent cellular cytotoxicity (ADCC), play a critical role in controlling HIV-1 infection. In this review, we showed that there is a direct association between the activation of ADCC and better clinical outcomes. This, in turn, suggests that ADCC could be harnessed to control HIV-1 infection. To this end, we addressed the passive administration of bNAbs capable of selectively activating ADCC responses to HIV-1 patients. Finally, we summarized the potential barriers that may impede the optimal activation of ADCC during HIV-1 infection and provided strategic solutions to overcome these barriers.

Plasma HIV RNA level is associated with neurocognitive function among HIV-1-infected patients in Nigeria

Plasma HIV RNA level has been shown to correlate with HIV disease progression, morbidity, and mortality. We examined the association between levels of plasma HIV RNA and cognitive function among patients in Nigeria. A total of 179 HIV-1-infected participants with available plasma HIV RNA results and followed longitudinally for up to 2 years were included in this study. Blood samples from participants were used for the measurement of plasma HIV RNA and CD4+ T cell count. Utilizing demographic and practice effect-adjusted T scores obtained from a seven-domain neuropsychological test battery, cognitive status was determined by the global deficit score (GDS) approach, with a GDS ≥ 0.5 indicating cognitive impairment. In a longitudinal multivariable linear regression analysis, adjusting for CD4 cell count, Beck's Depression Score, age, gender, years of education, and antiretroviral treatment status, global T scores decreased by 0.35 per log10 increase in plasma HIV RNA [p = 0.033]. Adjusting for the same variables in a multivariable logistic regression, the odds of neurocognitive impairment were 28% higher per log10 increase in plasma HIV RNA (OR 1.28 [95% CI 1.08, 1.51]; p = 0.005). There were statistically significant associations for the speed of information processing, executive, and verbal fluency domains in both linear and logistic regression analyses. We found a significant association between plasma HIV RNA levels and cognitive function in both baseline (cross-sectional) and longitudinal analyses. However, the latter was significantly attenuated due to weak association among antiretroviral-treated individuals.

KIR3DL1-Negative CD8 T Cells and KIR3DL1-Negative Natural Killer Cells Contribute to the Advantageous Control of Early Human Immunodeficiency Virus Type 1 Infection in HLA-B Bw4 Homozygous Individuals

Bw4 homozygosity in human leukocyte antigen class B alleles has been associated with a delayed acquired immunodeficiency syndrome (AIDS) development and better control of human immunodeficiency virus type 1 (HIV-1) viral load (VL) than Bw6 homozygosity. Efficient CD8 T cell and natural killer (NK) cell functions have been described to restrain HIV-1 replication. However, the role of KIR3DL1 expression on these cells was not assessed in Bw4-homozygous participants infected with HIV-1 CRF01_A/E subtype, currently the most prevalent subtype in China. Here, we found that the frequency of KIR3DL1-expressing CD8 T cells of individuals homozygous for Bw6 [1.53% (0–4.56%)] was associated with a higher VL set point (Spearman r_s = 0.59, P = 0.019), but this frequency of KIR3DL1⁺CD8⁺ T cells [1.37% (0.04–6.14%)] was inversely correlated with CD4 T-cell count in individuals homozygous for Bw4 (r_s = −0.59, P = 0.011). Moreover, CD69 and Ki67 were more frequently expressed in KIR3DL1⁻CD8⁺ T cells in individuals homozygous for Bw4 than Bw6 (P = 0.046 for CD69; P = 0.044 for Ki67), although these molecules were less frequently expressed in KIR3DL1⁺CD8⁺ T cells than in KIR3DL1⁻CD8⁺ T cells in both groups (all P < 0.05). KIR3DL1⁻CD8⁺ T cells have stronger p24-specific CD8⁺ T-cell responses secreting IFN-γ and CD107a than KIR3DL1⁺CD8⁺ T cells in both groups (all P < 0.05). Thus, KIR3DL1 expression on CD8 T cells were associated with the loss of multiple functions. Interestingly, CD69⁺NK cells lacking KIR3DL1 expression were inversely correlated with HIV-1 VL set point in Bw4-homozygous individuals (r_s = −0.52, P = 0.035). Therefore, KIR3DL1⁻CD8⁺ T cells with strong early activation and proliferation may, together with KIR3DL1⁻CD69⁺NK cells, play a protective role during acute/early HIV infection in individuals homozygous for Bw4. These findings highlight the superior functions of KIR3DL1⁻CD8⁺ T cells and KIR3DL1⁻CD69⁺NK cells being a potential factor contributing to delayed disease progression in the early stages of HIV-1 infection.

Differences in Risk Behavior and Demographic Factors Between Men Who Have Sex With Men With Acute and Nonacute Human Immunodeficiency Virus Infection in a Community-Based Testing Program in Los Angeles

INTRODUCTION

High viremia combined with HIV-infection status unawareness and increased sexual risk behavior contributes to a disproportionate amount of new HIV infections.

METHODS

From August 2011 to July 2015, the Los Angeles Lesbian, Gay, Bisexual, and Transgender Center conducted 66,546 HIV tests. We compared factors, including the presence of concomitant sexually transmitted infections, number of recent sex partners and reported condomless anal intercourse between men who have sex with men (MSM) diagnosed with an acute HIV infection and a nonacute HIV infection using multivariable logistic regression.

RESULTS

Of 1082 unique MSM who tested HIV-infected for the first time, 165 (15%) had an acute infection and 917 had a nonacute infection. HIV rapid antibody testing was 84.8% sensitive for detecting HIV infection (95% confidence interval (CI): 82.9% to 87.1%). Median HIV viral load among acutely infected MSM was 842,000 copies per milliliter (interquartile range = 98,200-4,897,318). MSM with acute infection had twice the number of sex partners in the prior 30 days (median = 2) and prior 3 months (median = 4) before diagnosis compared with those diagnosed with nonacute infection (P ≤ 0.0001). The odds of acute HIV infection were increased with the numbers of recent sex partners after controlling for age and race/ethnicity (adjusted odds ratio (aOR) >5 partners in past 30 days = 2.74; 95% CI: 1.46 to 5.14; aOR >10 partners in past 3 months = 2.41; 95% CI: 1.36 to 4.25). Non-African American MSM had almost double the odds of being diagnosed with an acute HIV infection compared with African American MSM (aOR = 1.97; 95% CI: 1.10 to 3.52).

CONCLUSIONS

MSM with acute HIV infection had nearly twice as many sex partners in the past 30 days and 3 months compared with MSM with newly diagnosed nonacute HIV infection. Those diagnosed with acute HIV infection had decreased odds of being African American MSM.

Broadly neutralizing antibodies: An approach to control HIV-1 infection

Although available antiretroviral therapy (ART) has changed human immunodeficiency virus (HIV)-1 infection to a non-fatal chronic disease, the economic burden of lifelong therapy, severe adverse ART effects, daily ART adherence, and emergence of ART-resistant HIV-1 mutants require prospecting for alternative therapeutic modalities. Indeed, a growing body of evidence suggests that broadly neutralizing anti-HIV-1 antibodies (BNAbs) may offer one such feasible alternative. To evaluate their therapeutic potential in established HIV-1 infection, we sought to address recent advances in pre-clinical and clinical investigations in this area of HIV-1 research. In addition, we addressed the obstacles that may impede the success of such immunotherapeutic approach, suggested strategic solutions, and briefly compared this approach with the currently used ART to open new insights for potential future passive immunotherapy for HIV-1 infection.

Multiple T-cell responses are associated with better control of acute HIV-1 infection: An observational study

Cytotoxic T lymphocyte (CTL) responses play pivotal roles in controlling the replication of human immunodeficiency virus type 1 (HIV-1), but the correlation between CTL responses and the progression of HIV-1 infection are controversial on account of HIV immune escape mutations driven by CTL pressure were reported.The acute HIV-1-infected patients from Beijing were incorporated into our study to investigate the effects of CTL response on the progression of HIV-1 infection.A longitudinal study was performed on acute HIV-1-infected patients to clarify the kinetic of T-cell responses, the dynamic of escape mutations, as well as the correlation between effective T-cell response and the progression of HIV infection.Seven human leukocyte antigen-B51+ (HLA-B51+) individuals were screened from 105 acute HIV-1 infectors. The detailed kinetic of HLA-B51-restricted CTL responses was described through blood sampling time points including seroconversion, 3 and 6 months after HIV-1 infection in the 7 HLA-B51+ individuals, by using 16 known HLA-B51 restricted epitopes. Pol743-751 (LPPVVAKEI, LI9), Pol283-289 (TAFTIPSI, TI8), and Gag327-3459 (NANPDCKTI, NI9) were identified as 3 dominant epitopes, and ranked as starting with LI9, followed by TI8 and NI9 in the ability to induce T-cell responses. The dynamics of escape mutations in the 3 epitopes were also found with the same order as T-cell response, by using sequencing for viral clones on blood sampling at seroconversion, 3 and 6 months after HIV-1 infection.We use solid evidence to demonstrate the correlation between T-cell response and HIV-1 mutation, and postulate that multiple T-cell responses might benefit the control of HIV-1 infection, especially in acute infection phase.

Targeting HIV Prevention Based on Molecular Epidemiology Among Deeply Sampled Subnetworks of Men Who Have Sex With Men

BACKGROUND

Molecular epidemiology can be useful in identifying clusters of human immunodeficiency virus (HIV) transmission that can be targeted for prevention.

METHODS

Regular screening of 2000 men who have sex with men (MSM) in Beijing, China, for HIV infection every 2 months identified 179 primary infections (2007-2010). HIV-1 pol sequences were obtained and used to infer the transmission network and identify transmitted drug resistance (TDR) among these individuals. We evaluated the use of clinical and network information to target prevention efforts. Prevention efficiency was calculated as the number of infections saved per number of interventions.

RESULTS

This cohort was infected with HIV-1 subtype B (28%), circulating recombinant form (CRF)_01 AE (53%), and CRF_07 BC (16%). The overall rate of TDR was low (5%), but the rate of clustering was high (64%), suggesting deep sampling of the subnetwork. Provision of a theoretically high-efficacy intervention like antiretroviral therapy to all participants had a prevention efficiency of 23%. The efficiency of targeting prevention based on lower CD4 counts (<200 cells/mL, <350 cells/mL, or <500 cells/mL) and higher viral loads (>100 000 copies/mL and >50 000 copies/mL) was between 10% and 18%. The efficiency of targeting prevention based on number of network connections was much higher (30%-42%). For example, treating the 33 participants with ≥5 connections in 2009 would have theoretically prevented 14 infections in 2010 (42% prevention efficiency).

CONCLUSIONS

Regular HIV testing of MSM in Beijing can deeply sample the local transmission subnetwork, and targeting prevention efforts based on network connectivity may be an efficient way to deliver prevention interventions.

Interferon-induced transmembrane protein-3 rs12252-C is associated with rapid progression of acute HIV-1 infection in Chinese MSM cohort

Background:

The interferon-inducible transmembrane protein-3 (IFITM3) is a protein that restricts multiple pathogenic viruses such as influenza virus. The single-nucleotide polymorphism rs12252-C, which is rare in Caucasian populations, but much more common in the Han Chinese population, has been found in much higher homozygous frequency in patients with severe acute influenza. Until now, there has been no study on the effect of this genetic variant on the clinical control of other viral infections.

Objectives:

To investigate the impact of IFITM3-rs12252 genotypes on primary HIV-1 infection progression in an acute HIV-1-infected cohort in Beijing (PRIMO), China.

Design and methods:

We identified IFITM3-rs12252 genotypes of 178 acute HIV-1-infected patients and 196 HIV-negative candidates from the PRIMO cohort. HIV-1 viral load and CD4⁺ T-cell counts were monitored at multiple time points during the first year of infection, and the association between IFITM3-rs12252 genotype and disease progression was evaluated.

Results:

The current study shows that the IFITM3-rs12252 genetic variant affects the progression of HIV-1 infection, but not the acquisition. A significantly higher frequency of the CC/CT genotypes was found in rapid progressors compared to nonprogressors. Patients with CC/CT genotypes showed an elevated peak viremia level and significantly lower CD4⁺ T-cell count at multiple time points during the first year of primary infection, and a significantly higher risk of rapid decline of the CD4⁺ T-cell count to below 350 cells/μl.

Conclusion:

A novel association between IFITM3 gene polymorphism and rapid disease progression is reported in an acute HIV-1-infected MSM cohort in China.

Longitudinal changes in plasma Caspase-1 and Caspase-3 during the first 2 years of HIV-1 infection in CD4Low and CD4High patient groups

Over 95% of CD4 cell death occurs by Caspase-1-mediated pyroptosis during HIV infection. Caspase-3-mediated apoptosis accounts for the death in a small proportion of infected CD4 cells. To date, there have been no reports on the dynamics of Caspase-1 and Caspase-3 and their relationship with disease progression in acute HIV-1 infection. In this study, two distinct HIV-1 patient groups were enrolled. The CD4_High group maintained a CD4 level above450 cells/μl while CD4 levels in the CD4_Low group dropped below 250 cells/μl within 2 years after infection. Blood samples were collected at 1, 2, 3, 4, 6, 12 and 24 months after HIV infection. Plasma Caspase-1 and Caspase-3 levels in the two patients groups were determined by a single-step ELISA using commercially available monoclonal antibodies. The results showed that Caspase-1 and Caspase-3 levels in the CD4_High group increased rapidly and then decreased within a short time during early HIV-1 infection. In contrast, Caspase-1 and Caspase-3 levels in the CD4_Low group were obviously increased after 1 year of HIV-1 infection.

Knowledge and awareness of acute human immunodeficiency virus infection among mobile app-using men who have sex with men: a missed public health opportunity

In a national online survey, we assessed awareness and knowledge of acute human immunodeficiency virus (HIV) infection manifestation among 1748 men who have sex with men (MSM). Only 39% of respondents were aware that acute HIV infection may be accompanied by symptoms. Education and increased access to acute HIV testing may facilitate MSM to appropriately seek acute HIV testing.

Short communication: Longitudinal changes in peripheral blood NK cells during the first year of HIV-1 Infection in CD4Low and CD4High patient groups

Natural killer (NK) cells may modulate the pathogenesis of primary HIV-1 infection. However, the relationship between the number and function of NK cells during an acute HIV-1 infection and HIV-1 disease progression remains to be elucidated. In this study, we enrolled two distinct patient groups. One group progressed to where their CD4 cell counts fell below 200 cells/μl within 2 years (CD4Low group), while the CD4 cell counts of the other group remained above 500 cells/μl for over 2 years (CD4High group). We compared the number and function of NK cells during the first year of HIV-1 infection between the two distinct groups. We found that the number of total NK cells and the number of cells in the CD56(dim)CD16(pos) subset rapidly decreased in both groups during early HIV-1 infection. The absolute number of total NK cells and CD56(dim)CD16(pos) NK cells was significantly higher in the CD4High group when compared to the CD4Low group during the first month of infection. No significant difference between the numbers of CD56(bright)CD16(neg) NK cells of the two groups was observed. However, more CD56(neg)CD16(pos) NK cells were found in the CD4Low group than in the CD4High group. We also found that NK cell function increased within the first 3 months of HIV-1 infection in the CD4High group and then exhibited a decreasing trend. However, in the CD4Low group, NK cell function did not increase significantly within the first 3 months of HIV-1 infection but then gradually increased. We concluded, therefore, that robust NK functioning cells that are present during an acute HIV-1 infection might be beneficial in controlling HIV-1 disease progression.

Distortion of memory Vδ2 γδ T cells contributes to immune dysfunction in chronic HIV infection

γδ T cells play important roles in innate immunity as the first-line of defense against infectious diseases. Human immunodeficiency virus (HIV) infection disrupts the balance between Vδ(1) T cells and Vδ(2) T cells and causes dysfunction among γδ T cells. However, the biological mechanisms and clinical consequences of this disruption require further investigation. In this study, we performed a comprehensive analysis of phenotype and function of memory γδ T cells in cohorts of Chinese individuals with HIV infection. We found a dynamic change in memory Vδ(2) γδ T cells, skewed toward an activated and terminally differentiated effector memory phenotype T(EMRA) Vδ(2) γδ T cell, which may account for the dysfunction of Vδ(2) γδ T cells in HIV disease. In addition, we found that IL-17-producing γδ T cells were significantly increased in HIV-infected patients with fast disease progression and positively correlated with HLA-DR(+) γδ T cells and CD38(+)HLA-DR(+) γδ T cells. This suggests the IL-17 signaling pathway is involved in γδ T-cell activation and HIV pathogenesis. Our findings provide novel insights into the role of Vδ(2) T cells during HIV pathogenesis and represent a sound basis on which to consider immune therapies with these cells.

Acute HIV infection is beneficial for controlling chronic hepatitis B

BACKGROUND

Coinfection with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) is common. Most studies have concentrated on the effects of chronic HIV infection on HBV infection; however, studies on the effects of acute HIV infection on HBV infection are especially important to elucidate the potential mechanisms leading to complications from HIV/HBV coinfection.

METHODS

We evaluated the HBV DNA, hepatitis B surface antigen (HBsAg), and hepatitis B "e" antigen (HBeAg) in stored serum samples from 25 men with chronic hepatitis B who had acquired acute HIV infection.

RESULTS

All of the 25 men had decreased HBV DNA levels during acute HIV infection. Three men converted from HBsAg positive before HIV infection to HBsAg negative during acute HIV infection, and 10 men converted from HBeAg positive before HIV infection to HBeAg negative during acute HIV infection.

CONCLUSIONS

These data suggest that the early effects of HIV infection improve the immune response against HBV.

Transmitted antiretroviral drug resistance in the men who have sex with men HIV patient cohort, Beijing, China, 2008-2011

Transmitted drug resistance (TDR) is an ongoing public health problem in HIV disease treatment. However, little is known about TDR among men who have sex with men (MSM) patients in China. In addition, TDR prevalence among patients with acute HIV infection (AHI) or early HIV infection (EHI) was believed higher than that of patients with chronic HIV infection (CHI), but as AHI is typically either unidentified or crudely defined in large populations, very few direct comparisons have been made. We did a retrospective analysis of TDR in 536 antiretroviral-naive MSM patients from our immunodeficiency clinics at You'an Hospital, Capital Medical University (CMU), in Beijing, China, 2008-2011. The cohort included 266 patients with AHI/EHI and 270 patients with CHI. We analyzed the subtype, estimated the TDR prevalence, and characterized the model of TDR and the predicted drug sensitivity. Additionally, we made a comparison of TDR between the patients with AHI/EHI and patients with CHI. Our results indicated that among the 536 patients, HIV-1 subtype CRF01_AE accounted for 52.1%, subtype B accounted for 24.8%, CRF07_BC/ CRF08_BC accounted for 21.6% (116/536), and 1.3% were denoted as unique recombinant forms (URFs). A total of 7.8% patients had one or more transmitted HIV-1 drug resistance mutations, representing 6.2% for PI-related mutations, 0.9% for NRTI-related mutations, and 1.7% for NNRTI-related mutations. Although patients with AHI/EHI had a higher TDR prevalence as compared to that of patients with CHI, the difference was not statistically significant. There was no significant difference in TDR model and predicted drug susceptibility between the two groups of patients either. This study provides important strategic information for public health planning by healthcare officials in China and warrants a comprehensive study with larger patient cohorts from various healthcare centers within China.

Identification of 3 distinct HIV-1 founding strains responsible for expanding epidemic among men who have sex with men in 9 Chinese cities

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Objectives:

To investigate the epidemiological relationships between HIV-1 strains that are spread among the men who have sex with men (MSM) populations of 9 cities across China and to analyze the origins and divergence times of the major epidemic strains found in the MSM population.

Methods:

A total of 583 HIV-1-positive subjects were recruited from high-risk MSM populations in 9 cities across China between 2009 and 2011. Nucleotide sequences of 1.0-kb pro-RT regions were amplified and sequenced. Phylogenetic and Bayesian molecular clock analyses were performed.

Results:

The overall distribution of HIV-1 genotypes was as follows: CRF01_AE, 62.1%; CRF07_BC, 18.2%; subtype B (United States–European), 15.9%; subtype B', 0.7%; other recombinants, 3.1%. In addition to the 2 distinct CRF01_AE clusters [cluster 1 (n = 157, 26.9%) and cluster 2 (n = 196, 33.6%)] previously reported by our group, we identified a novel CRF07_BC cluster (cluster 3) (n = 94, 16.1%) unique to China's MSM population whose strains were homologous and could be detected in all 9 cities. These 3 lineages of HIV-1 strains (clusters 1–3) accounted for 76.7% (447 of 583) of infections among MSM in China as a whole. Clusters 1, 2, and 3 were estimated to have been introduced into the MSM population in 1999, 2001, and 2001, respectively, indicating that the newly identified CRF07_BC cluster 3 is not a young lineage. However, it spread quickly in recent years.

Conclusions:

We identified 3 distinct HIV-1 lineages (clusters 1–3) responsible for the recent upsurge of the AIDS epidemic among MSM in China. These 3 HIV-1 variants are spread widely among MSM throughout China, demonstrating remarkable founding effects.