Single-cell landscape of immunological responses in patients with COVID-19.

In coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the relationship between disease severity and the host immune response is not fully understood. Here we performed single-cell RNA sequencing in peripheral blood samples of 5 healthy donors and 13 patients with COVID-19, including moderate, severe and convalescent cases. Through determining the transcriptional profiles of immune cells, coupled with assembled T cell receptor and B cell receptor sequences, we analyzed the functional properties of immune cells. Most cell types in patients with COVID-19 showed a strong interferon-α response and an overall acute inflammatory response. Moreover, intensive expansion of highly cytotoxic effector T cell subsets, such as CD4+ effector-GNLY (granulysin), CD8+ effector-GNLY and NKT CD160, was associated with convalescence in moderate patients. In severe patients, the immune landscape featured a deranged interferon response, profound immune exhaustion with skewed T cell receptor repertoire and broad T cell expansion. These findings illustrate the dynamic nature of immune responses during disease progression.

A human neutralizing antibody targets the receptor-binding site of SARS-CoV-2.

An outbreak of coronavirus disease 2019 (COVID-19)1-3, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)4, has spread globally. Countermeasures are needed to treat and prevent further dissemination of the virus. Here we report the isolation of two specific human monoclonal antibodies (termed CA1 and CB6) from a patient convalescing from COVID-19. CA1 and CB6 demonstrated potent SARS-CoV-2-specific neutralization activity in vitro. In addition, CB6 inhibited infection with SARS-CoV-2 in rhesus monkeys in both prophylactic and treatment settings. We also performed structural studies, which revealed that CB6 recognizes an epitope that overlaps with angiotensin-converting enzyme 2 (ACE2)-binding sites in the SARS-CoV-2 receptor-binding domain, and thereby interferes with virus-receptor interactions by both steric hindrance and direct competition for interface residues. Our results suggest that CB6 deserves further study as a candidate for translation to the clinic.

Prevalence and viral suppression of hepatitis B virus infection among people living with HIV on antiretroviral therapy in Sierra Leone.

OBJECTIVE: Sub-Saharan Africa is one of the regions with the highest burdens of HIV and hepatitis B virus (HBV), but data on the impact of antiretroviral therapy (ART) on HBV DNA suppression is limited. In this study, we aimed to determine the prevalence and associated factors of a positive hepatitis B surface antigen (HBsAg) among people living with HIV, and assess the suppression of ART on HBV replication in people living with HIV in Sierra Leone. METHODS: A cross-sectional study was designed to recruit people living with HIV aged 18 years or older in ten public hospitals in Sierra Leone between August 2022 and January 2023. Statistical analyses were performed using R software. Logistic regression analysis was used to assess factors independently associated with positive HBsAg and HBV DNA suppression. RESULTS: Of the 3106 people living with HIV recruited in this study, 2311 (74.4%) were women. The median age was 36 years, 166 (5.3%) had serological evidence of HBV vaccination. The overall prevalence of HBsAg positivity was 12.0% (95% CI: 10.9% to 13.2%). Male sex (adjusted OR (aOR) 2.11, 95% CI: 1.67 to 2.68; p<0.001) and being separated (aOR 1.83, 95% CI: 1.06 to 3.16, p=0.031; reference group: being married) were independent predictors of HBsAg seropositivity. Among 331 people living with HIV and HBV receiving ART, 242 (73.1%) achieved HBV DNA suppression (below 20 IU/mL). HBV suppression rate was higher in HIV-virally suppressed patients than those with unsuppressed HIV viral load (p<0.001). In addition, the male sex was more likely to have unsuppressed HBV DNA (aOR 1.17, 95% CI: 1.17 to 3.21; p=0.010). CONCLUSIONS: We reported a high prevalence of HBsAg seropositivity and low HBV immunisation coverage in people living with HIV in Sierra Leone. In addition, we observed that ART can efficiently result in a viral suppression rate of HBV infection. Therefore, achieving the global target of eliminating HBV infection by 2030 requires accelerated access to care for people living with HIV and HBV, including HBV testing, antiviral treatment and hepatitis B vaccination.

Single-cell RNA sequencing reveals intrahepatic and peripheral immune characteristics related to disease phases in HBV-infected patients.

OBJECTIVE: A comprehensive immune landscape for HBV infection is pivotal to achieve HBV cure. DESIGN: We performed single-cell RNA sequencing of 2 43 000 cells from 46 paired liver and blood samples of 23 individuals, including six immune tolerant, 5 immune active (IA), 3 acute recovery (AR), 3 chronic resolved and 6 HBV-free healthy controls (HCs). Flow cytometry and histological assays were applied in a second HBV cohort for validation. RESULTS: Both IA and AR were characterised by high levels of intrahepatic exhausted CD8+ T (Tex) cells. In IA, Tex cells were mainly derived from liver-resident GZMK+ effector memory T cells and self-expansion. By contrast, peripheral CX3CR1+ effector T cells and GZMK+ effector memory T cells were the main source of Tex cells in AR. In IA but not AR, significant cell-cell interactions were observed between Tex cells and regulatory CD4+ T cells, as well as between Tex and FCGR3A+ macrophages. Such interactions were potentially mediated through human leukocyte antigen class I molecules together with their receptors CANX and LILRBs, respectively, contributing to the dysfunction of antiviral immune responses. By contrast, CX3CR1+GNLY+ central memory CD8+ T cells were concurrently expanded in both liver and blood of AR, providing a potential surrogate marker for viral resolution. In clinic, intrahepatic Tex cells were positively correlated with serum alanine aminotransferase levels and histological grading scores. CONCLUSION: Our study dissects the coordinated immune responses for different HBV infection phases and provides a rich resource for fully understanding immunopathogenesis and developing effective therapeutic strategies.

HIV viral suppression at different thresholds and duration of treatment in the dolutegravir treatment era in Sierra Leone: a nationwide survey.

INTRODUCTION: Viral load assessment for people living with HIV is key for monitoring treatment and achieving the 95-95-95. In this study, we aimed to assess the degree of viral suppression at different thresholds and treatment duration after the introduction of dolutegravir-based therapy in ten public hospitals in Sierra Leone. METHODS: We used a cross-sectional study design to recruits patients aged 18 years or older between August 2022 and January 2023. Statistical analyses were performed using R-software. Logistic regression was used to assess factors independently associated with viral suppression. The level of significance was set at P < 0.05. RESULTS: Of the 2,253 patients recruited, 1,720 (76%) were women and 1,705 (76%) were receiving a fixed dose combination of tenofovir, lamivudine and dolutegravir. The median age and duration of anti-retroviral therapy (ART) was 36.0 (IQR, 28.0-45.0) years and 40.9 (IQR, 14.4-79.6) months, respectively. Using a threshold of HIV RNA < 1000 copies/mL, 1,715 (88.4%) patients on ART for more than 6 months were virally suppressed. Viral suppression rates were higher with dolutegravir-based (1,277, 89.5%) than efavirenz-based (418, 86.2%) ART. HIV RNA was < 200 copies/mL in 1,643 (84.6%) patients or < 50 copies/mL in 1,487 (76.6%) patients or between 50 and 999 copies/mL in 228 (11.7%) patients. Viral suppression rates at different ART durations (months) were as follows: 84.2% (≤ 3), 88.8% (4-6), 90.9% (6-12), and 88.1% (> 12). Viral suppression rates were higher for patients aged 40 or older (40-50 years: aOR 2.05, 95%CI 1.41-3.04, P < 0.01; 50-60 years: aOR 2.51, 95%CI 1.53-4.35, P < 0.01; >60 years: aOR 2.69, 95%CI 1.28-6.63, P = 0.02). Men had 49% lower odds of viral suppression than women (aOR 0.50, 95% CI 0.38-0.67, P < 0.01). CONCLUSION: We report a viral suppression rate of 88.4% among patients on treatment for at least 6 months, with higher rate of suppression with dolutegravir than efavirenz. Factors associated with virological suppression were age and gender, emphasizing the need for innovative differentiated ART delivery models to optimize viral suppression and achieve the 95% target.

Sero-prevalence of syphilis infection among people living with HIV in Sierra Leone: a cross-sectional nationwide hospital-based study.

BACKGROUND: Globally, there were an estimated 7.1 million new syphilis infections in 2020, with more than 30% of these new infections reported in African countries such as Sierra Leone. Despite this, there is no HIV-specific syphilis screening program in Sierra Leone. Thus, data are needed to inform public health practice. In this study, we aimed to determine the prevalence of syphilis seropositivity and factors associated with syphilis seropositivity among people living with HIV (PLHIV). METHODS: A cross-sectional study was conducted at 10 health facilities in Sierra Leone, among adults with HIV, aged 18 years or older, from September 2022 to January 2023. Parameters of interest were collected including age, sex, marriage, antiretroviral therapy (ART) regimen, HIV viral load, duration of ART treatment, and hospital level of care. The syphilis antibody was detected by a rapid test based on immunochromatography assay. Data were analyzed using R-software version 4.2.3 (R Core Team, Vienna, Austria). Pearson's χ2 test, Fisher's exact test and Kruskal-Wallis H test were applied to assess the differences in syphilis seropositivity between groups as appropriate. Univariate logistic regression and multivariate logistic regression analysis was used to assess factors associated with syphilis seropositivity. The level of statistical significance was set at P < 0.05. RESULTS: Of the 3082 PLHIV individuals in our study, 2294 (74.4%) were female and 2867 (93.0%) were receiving ART. With a median age of 36 years, 211 (6.8%, 95% CI 6.0-7.7) were positive for syphilis. The prevalence of syphilis was highest in people aged 60 years and over (21.1%, 95%CI 14.7-29.2), followed by people aged 50-60 years (15.5%, 95%CI 11.9-19.9) and in the widowed population (11.9%, 95%CI 8.9-15.8). There were no differences in syphilis seropositivity between gender, ART status, ART regimen, duration of ART, HIV viral load and hospital level of care. Older age (50-60 years: adjusted OR 3.49, 95%CI 2.09-5.85 P < 0.001; 60-100 years: adjusted OR 4.28, 95%CI 2.21-8.17, P < 0.001) was an independent predictor of seropositive syphilis. CONCLUSIONS: We observed a high prevalence of syphilis among PLHIV. Older people and widowed population have higher syphilis seropositivity. Older age was an independent predictor of syphilis positivity. Therefore, we call for the integration of syphilis screening, treatment and prevention in HIV services.

Characteristics of blood immune cell profile and their correlation with disease progression in patients infected with HIV-1.

BACKGROUND: Antiretroviral therapy (ART) can reduce viral load in individuals infected with human immunodeficiency virus (HIV); however, some HIV-infected individuals still cannot achieve optimal immune recovery even after ART. Hence, we described the profile of peripheral immune cells and explored the association with disease progression in patients infected with HIV-1. METHODS: Mass cytometry analysis was used to characterize the circulating immune cells of 20 treatment-naïve (TNs), 20 immunological non-responders (INRs), 20 immunological responders (IRs), and 10 healthy controls (HCs). Correlation analysis was conducted between cell subpopulation percentages and indicators including HIV-1 cell-associated (CA)-RNA, DNA, CD4+ T cell count, and CD4/CD8 ratio. RESULTS: Global activation, immunosenescence, and exhaustion phenotypes were observed in myeloid cells and T cells from individuals with HIV-1 infection. We also found that specific subsets or clusters of myeloid, CD4+ T, and CD8+ T cells were significantly lost or increased in TN individuals, which could be partially restored after receiving ART. The percentages of several subpopulations correlated with HIV-1 CA-RNA, DNA, CD4+ T cell count, and CD4/CD8 ratio, suggesting that changes in immune cell composition were associated with therapeutic efficacy. CONCLUSION: These data provide a complete profile of immune cell subpopulations or clusters that are associated with disease progression during chronic HIV-1 infection, which will improve understanding regarding the mechanism of incomplete immune recovery in INRs.

Compromised long-lived memory CD8+ T cells are associated with reduced IL-7 responsiveness in HIV-infected immunological nonresponders.

Immune deficiency is one of the hallmarks of HIV infection and a major cause of adverse outcomes in people living with HIV (PLWH). Long-lived memory CD8+ T cells (LLMCs) are essential executors of long-term protective immunity; however, the generation and maintenance of LLMCs during chronic HIV infection are not well understood. In the present study, we analyzed circulating LLMCs in healthy controls (HCs) and PLWH with different disease statuses, including treatment naïve patients (TNs), complete responders (CRs), and immunological nonresponders (INRs). We found that both TNs and INRs showed severely compromised LLMCs compared with HCs and CRs, respectively. The decrease of LLMCs in TNs correlated positively with the reduction of their precursors, namely memory precursor effector T cells (MPECs), which might be associated with elevated pro-inflammatory cytokines. Strikingly, INRs showed an accumulation of MPECs, which exhibited diminished responsiveness to interleukin 7 (IL-7), thereby indicating abrogated differentiation into LLMCs. Moreover, in vitro studies showed that treatment with dexamethasone could improve the IL7-phosphorylated (p)-signal transducer and activator of transcription (STAT5) response by upregulating the expression of the interleukin 7 receptor (IL-7Rα) on MPECs in INRs. These findings provide insights that will encourage the development of novel therapeutics to improve immune function in PLWH.

α4ß7high CD4+ T cells are prone to be infected by HIV-1 and associated with HIV-1 disease progression.

INTRODUCTION: To investigate the characteristics of ß7high CD4+ T cells during HIV-1 infection and the relationship between ß7high CD4+ T cells and HIV-1 disease progress. METHODS: This study enrolled 124 HIV-1-infected patients, including 80 treatment naïve patients (TNs), 41 patients who underwent antiretroviral therapy (ARTs), and three long-term no progression patients (LTNPs). Nineteen matched healthy subjects were included as controls (HCs). The characteristics and frequency of ß7high CD4+ T cells were analyzed using flow cytometry. An in vitro culture experiment was used to study HIV-1 infection of ß7high CD4+ T cells. Real-time polymerase chain reaction was performed to quantify HIV-1 DNA and CA-RNA levels. RESULTS: The frequency of ß7high CD4+ T in the peripheral blood was significantly decreased and negatively correlated with disease progression during chronic HIV-1 infection. A large proportion of ß7high CD4+ T cells showed Th17 phenotype. Furthermore, ß7high CD4+ T cells were preferentially infected by HIV-1 in vitro and in vivo. There were no significant differences of HIV-1 DNA, and CA-RNA levels between ß7high CD4+ T and ß7low CD4+ T subsets in HIV-1 infected individuals after antiviral treatment. CONCLUSION: The ß7high CD4+ T cells were negatively correlated with disease progression during chronic HIV-1 infection. ß7high CD4+ T cells are susceptible to infection with HIV-1 and HIV-1 latent cells.

Dynamics of HIV reservoir decay and naïve CD4 T-cell recovery between immune non-responders and complete responders on long-term antiretroviral treatment.

BACKGROUND: The dynamics of viral reservoir decay and naïve CD4 T-cell recovery between immunological non-responders (INR) and complete responders (CR) during long-term antiretroviral treatment (ART) are not fully known. METHODS: Twenty-eight chronic HIV-infected individuals on 5-year ART were divided into two groups: INR (CD4 counts ≤350 cells/µL, n = 13) and CR (CD4 counts ≥500 cells/µL, n = 15). The levels of HIV DNA and cell-associated HIV RNA (CA-RNA), CD4 counts, naïve CD4 counts and their correlations were analyzed at baseline, years 1, 3 and 5 of ART between the two groups. Expression of PD-1 on CD4 T-cells was quantified by flow cytometry. Linear mixed effect models were used to estimate the change procession in repeated measurements over 5 years. Slopes of the above-mentioned indicators were estimated using participant-specific linear regressions, respectively. RESULTS: INR maintained higher levels of HIV DNA and CA-RNA with higher percentages of PD-1+CD4 T-cells compared with CR during 5-year ART, concurrent with lower naïve CD4 T-cells. However, the rates of HIV DNA and CA-RNA decay in INR were not different from that in CR over time, and INR had higher rates of naïve CD4 T-cell percentage recovery. The baseline levels of HIV DNA were positively associated with the 5-year levels of HIV DNA, but negatively associated with the 5-year naïve CD4 counts. CONCLUSIONS: INR maintained significantly higher viral reservoir and lower naïve CD4 T-cells compared with CR during 5-year ART, however, the rates of reservoir decay and naïve CD4 T-cell percentage growth within INR were not lower than that in CR over time.

Photonic crystal enabled manipulation of optical and electric field in germanium avalanche photodetectors.

We demonstrate the use of a photonic crystal (PhC) structure to improve the performance of a germanium avalanche photodetector (APD) by simultaneously manipulating the distribution of the optical and electric fields. The PhC is fabricated at the top center of the vertical germanium APD. For a 14 µm diameter device, the 1550 nm responsivity increases from 0.2 to 0.6 A W-1 at unity gain, owing to the resonance-enhanced absorption. Moreover, the structure separates the absorption and multiplication regions of the device, resulting in an increase of the avalanche gain and the gain-bandwidth product. Under -10 dBm input optical power, a 3 dB bandwidth of 34 GHz before avalanche and a clear 40 Gbps eye diagram under avalanche demonstrates good high-speed performance of the device.

Early Detection of Severe Acute Respiratory Syndrome Coronavirus 2 Antibodies as a Serologic Marker of Infection in Patients With Coronavirus Disease 2019.

BACKGROUND: Thousands of medical staff have been infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with hundreds of deaths reported. Such loss could be prevented if there were a serologic assay for SARS-CoV-2-specific antibodies for serological surveillance of its infection at the early stage of disease. METHODS: Using Chinese hamster ovarian (CHO) cell-expressed full-length SARS-CoV-2 S1 protein as capturing antigen, a coronavirus disease 2019 (COVID-19)/SARS-CoV-2 S1 serology enzyme-linked immunosorbent assay (ELISA) kit was developed and validated with negative samples collected prior to the outbreak or during the outbreak and positive samples from patients confirmed with COVID-19. RESULTS: The specificity of the ELISA kit was 97.5%, as examined against total 412 normal human samples. The sensitivity was 97.1% by testing against 69 samples from hospitalized and/or recovered COVID-19 patients. The overall accuracy rate reached 97.3%. The assay was able to detect SARS-CoV-2 antibody on day 1 after the onset of COVID-19 disease. The average antibody levels increased during hospitalization and 14 days after discharge. SARS-CoV-2 antibodies were detected in 28 of 276 asymptomatic medical staff and 1 of 5 nucleic acid test-negative "close contacts" of COVID-19 patients. CONCLUSIONS: With the assays developed here, we can screen medical staff, incoming patients, passengers, and people who are in close contact with the confirmed patients to identify the "innocent viral spreaders," protect the medical staff, and stop further spread of the virus.

Small ordered Ge quantum dots growth on Si (100) hollow nanopillars.

The application of ordered Ge quantum dots (QDs) is limited by the indirect bandgap and the large size. Here, a structure of hollow nanopillars (HNPs) is proposed to grow small ordered Ge QDs using molecular beam epitaxy by suppressing the expansion of the central holes (CHs) during degassing and inhibiting the lateral growth of Ge QDs, the growth mechanisms are explained by the evolution of surface morphology and the surface chemical potential distribution. The width of Ge QDs in CHs mainly depends on the diameter of HNPs and has little relationship to the diameter of CHs. The small ordered Ge QDs with a mean base diameter of 47.1 nm and a period of 1 µm are grown under high growth temperature (580 °C). The size, shape, height, and period of HNPs are all shown to affect the growth of Ge QDs in CHs. Hence, HNPs provide us with more controllable parameters than pits to control the shape, location, and size of Ge QDs.

Precisely ordered Ge quantum dots on a patterned Si microring for enhanced light-emission.

Semiconductor microcavities can greatly enhance the light-emission of embedded quantum dots (QDs). Here, a new route toward the microcavity-QD system by fabricating microcavities followed by growing ordered QDs on a patterned microresonator is proposed, which keeps QDs from being etched. Self-assembled Ge QDs prefer to form at the rims of Si microrings or microdisks. The Ge QDs on the pit- or groove-patterned microring resonator (MRR) show better size uniformity and position accuracy. These features are explained by the evolutions of surface morphology and surface chemical potential distribution. Sharp photoluminescence peaks in the telecommunication band with the quality factors in the range of 450-850 from groove-patterned MRR are observed at 295 K due to efficient overlap between Ge QDs and resonant modes. Our schemes shed light on the exactly site-controlled growth of QDs on micro- and nano-structures, which further facilitates the investigation of light-matter interactions.

Transforming growth factor-ß promotes the function of HIV-specific CXCR5+ CD8 T cells.

HIV replication can be inhibited by CXCR5+ CD8 T cells (follicular cytotoxic T cell [TFC]) which transfer into B-cell follicles where latent HIV infection persists. However, how cytokines affect TFC remain unclear. Understanding which cytokines show the ability to affect TFC could be a key strategy toward curing HIV. Similar mechanisms could be used for the growth and transfer of TFCs and follicular helper T (TFH) cells; as a result, we hypothesized that cytokines IL-6, IL-21, and transforming growth factor-ß (TGF-ß), which are necessary for the differentiation of TFH cells, could also dictate the development of TFCs. In this work, lymph node mononuclear cells and peripheral blood mononuclear cells from HIV-infected individuals were cocultured with IL-6, IL-21, and TGF-ß. We then carried out T-cell receptor (TCR) repertoire analysis to compare the differences between CXCR5- and CXCR5+ CD8 T cells. Our results showed that the percentage and function of TFC can be enhanced by stimulation with TGF-ß. Besides, TGF-ß stimulation enhanced the diversity of TCR and complementarity-determining region 3 sequences. HIV DNA showed a negative correlation with TFC. The use of TGF-ß to promote the expression of CXCR5+ CD8 T cells could become a new treatment approach for curing HIV.

Design of pH-sensitive peptides from natural antimicrobial peptides for enhancing polyethylenimine-mediated gene transfection.

BACKGROUND: Poor endosomal release is a major barrier of polyplex-mediated gene transfection. Antimicrobial peptides (AMPs) are commonly used to improve polyethylenimine (PEI)-mediated gene transfection by increasing endosomal release. In the present study, we designed novel pH-sensitive peptides that highly enhance transfection efficiency compared to their parent peptides. METHODS: Two analogues of melittin (Mel) and RV-23 (RV) were synthesized by replacing the positively-charged residues in their sequences with glutamic acid residues. The pH-sensitive lysis ability of the peptides, the effect of the peptides on physicochemical characteristics, the intracellular trafficking, the transfection efficiency, and the cytotoxicity of the polyplexes were determined. RESULTS: The acidic peptides showed pH-sensitive lytic activity. The hemolytic activity of acidic peptides at pH 5.0 was higher than that at pH 7.4. The incorporation of acidic peptides did not affect the DNA binding ability of PEI but affected the physicochemical characteristics of the PEI/DNA polyplexes, which may be beneficial for endosomal release and gene transfection. The incorporation of acidic peptides into PEI/DNA polyplexes enhanced the PEI-mediated transfection efficiency corresponding to up to 42-fold higher luciferase activity compared to that of PEI alone. CONCLUSIONS: The results of the present study indicate that replacement of positively-charged residues with glutamic acid residues in the AMP sequence yields pH-sensitive peptides, which enhance the transfection efficiency of PEI/DNA polyplexes in various cell lines.

Thermo-Sensitive Liposome co-Loaded of Vincristine and Doxorubicin Based on Their Similar Physicochemical Properties had Synergism on Tumor Treatment.

PURPOSE: To develop vincristine (VCR) and doxorubicin (DOX) co-encapsulated thermo-sensitive liposomes (VD-TSL) against drug resistance, with increased tumor inhibition rate and decreased system toxicity, improving drug targeting efficiency upon mild hyperthermia (HT) in solid tumor. METHODS: Based on similar physicochemical properties, VCR and DOX were co-loaded in TSL with pH gradient active loading method and characterized. The time-dependent drug release profiles at 37 and 42°C were assessed by HPLC. Then we analysed the phospholipids in filtrate after ultrafiltration and studied VD-TSL stability in mimic in vivo conditions and long-time storage conditions (4°C and -20°C). Cytotoxic effect was studied on PANC and sw-620 using MTT. Intracellular drug delivery was studied by confocal microscopy on HT-1080. In vivo imaging of TSL pharmacokinetic and biodistribution was performed on MCF-7 tumor-bearing nude mice. And therapeutic efficacy on these xenograft models were followed under HT. RESULTS: VD-TSL had excellent particle distribution (about 90 nm), high entrapment efficiency (>95%), obvious thermo-sensitive property, and good stability. MTT proved VD-TSL had strongest cell lethality compared with other formulations. Confocal microscopy demonstrated specific accumulation of drugs in tumor cells. In vivo imaging proved the targeting efficiency of TSL under hyperthermia. Then therapeutic efficacy revealed synergism of VCR and DOX co-loaded in TSL, together with HT. CONCLUSION: VD-TSL could increase drug efficacy and decrease system toxicity, by making good use of synergism of VCR and DOX, as well as high targeting efficiency of TSL.

T-Cell Epitope Mapping of SARS-CoV-2 Reveals Coordinated IFN-γ Production and Clonal Expansion of T Cells Facilitates Recovery from COVID-19.

BACKGROUND: T-cell responses can be protective or detrimental during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection; however, the underlying mechanism is poorly understood. METHODS: In this study, we screened 144 15-mer peptides spanning the SARS-CoV-2 spike, nucleocapsid (NP), M, ORF8, ORF10, and ORF3a proteins and 39 reported SARS-CoV-1 peptides in peripheral blood mononuclear cells (PBMCs) from nine laboratory-confirmed coronavirus disease 2019 (COVID-19) patients (five moderate and four severe cases) and nine healthy donors (HDs) collected before the COVID-19 pandemic. T-cell responses were monitored by IFN-γ and IL-17A production using ELISA, and the positive samples were sequenced for the T cell receptor (TCR) ß chain. The positive T-cell responses to individual SARS-CoV-2 peptides were validated by flow cytometry. RESULTS: COVID-19 patients with moderate disease produced more IFN-γ than HDs and patients with severe disease (moderate vs. HDs, p < 0.0001; moderate vs. severe, p < 0.0001) but less IL-17A than those with severe disease (p < 0.0001). A positive correlation was observed between IFN-γ production and T-cell clonal expansion in patients with moderate COVID-19 (r = 0.3370, p = 0.0214) but not in those with severe COVID-19 (r = -0.1700, p = 0.2480). Using flow cytometry, we identified that a conserved peptide of the M protein (Peptide-120, P120) was a dominant epitope recognized by CD8+ T cells in patients with moderate disease. CONCLUSION: Coordinated IFN-γ production and clonal expansion of SARS-CoV-2-specific T cells are associated with disease resolution in COVID-19. Our findings contribute to a better understanding of T-cell-mediated immunity in COVID-19 and may inform future strategies for managing and preventing severe outcomes of SARS-CoV-2 infection.

SARS-CoV-2 seroprevalence and associated factors among people living with HIV in Sierra Leone.

BACKGROUND: Human immunodeficiency virus (HIV) infection is an important risk factor for Coronavirus Disease 2019 (COVID-19), but data on the prevalence of COVID-19 among people living with HIV (PLWH) is limited in low-income countries. Our aim was to assess the seroprevalence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) specific antibodies and associated factors among PLWH in Sierra Leone. METHODS: We conducted a cross-sectional survey of PLWH aged 18 years or older in Sierra Leone between August 2022 and January 2023. Participants were tested for SARS-CoV-2 antibodies using a rapid SARS-CoV-2 antibody (immunoglobulin M/immunoglobulin G [IgG]) kits. Stepwise logistic regression was used to explore factors associated with SARS-CoV-2 antibody seroprevalence with a significance level of p < .05. RESULTS: In our study, 33.4% (1031/3085) participants had received a COVID-19 vaccine, and 75.7% were SARS-CoV-2 IgG positive. Higher IgG seroprevalence was observed in females (77.2% vs. 71.4%, p = .001), adults over 60 years (88.2%), those with suppressed HIV RNA (80.7% vs. 51.7%, p < .001), antiretroviral therapy (ART)-experienced individuals (77.9% vs. 44.6%, p < .001), and vaccinated participants (80.7% vs. 73.2%, p < .001). Patients 60 years or older had the highest odds of IgG seroprevalence (adjusted odds ratio [aOR] = 2.73, 95% CI = 1.68-4.65). Female sex (aOR = 1.28, 95%CI = 1.05-1.56), COVID-19 vaccination (aOR = 1.54, 95% CI = 1.27-1.86), and ART (aOR = 2.20, 95% CI = 1.56-3.11) increased the odds, whereas HIV RNA ≥ 1000 copies/mL (aOR = 0.32, 95% CI = 0.26-0.40) reduced the odds of IgG seroprevalence. CONCLUSIONS: We observed a high seroprevalence of SARS-CoV-2 antibody among PLWH in Sierra Leone. We recommend the introduction of targeted vaccination for PLWH with a high risk of severe COVID-19, especially those with an unsuppressed HIV viral load.

Implications of Accumulation of Clonally Expanded and Senescent CD4 + GNLY+ T Cells in Immunological Non-responders of HIV-1 infection.

Increased CD4 + GNLY+ T cells have been confirmed to be inversely associated with CD4+ T cell count in immunological non-responders (INRs), however, the underlying mechanisms are unknown. This study aimed to elucidate the characteristics of CD4 + GNLY+ T cells and their relationship with immune restoration. Single-cell RNA sequencing, single-cell TCR sequencing, and flow cytometry were used to analyze the frequency, phenotypes, and function of CD4 + GNLY+ T cells. Moreover, Enzyme linked immunosorbent assay was performed to detect plasma cytokines production in patients. CD4 + GNLY+ T cells were found to be highly clonally expanded, characterized by higher levels of cytotoxicity, senescence, P24, and HIV-1 DNA than CD4 + GNLY- T cells. Additionally, the frequency of CD4 + GNLY+ T cells increased after ART, and further increased in INRs, and were positively associated with the antiretroviral therapy duration in INR. Furthermore, increased IL-15 levels in INRs positively correlated with the frequency and senescence of CD4 + GNLY+ T cells, suggesting that CD4 + GNLY+ T cells may provide new insights for understanding the poor immune reconstitution of INRs. In conclusion, increased, highly clonally expanded, and senescent CD4 + GNLY+ T cells may contribute to poor immune reconstitution in HIV-1 infection.