Virion-surface display of a chimeric immunoglobulin Fc domain facilitating uptake by antigen-presenting cells.

Antigen-presenting cells (APCs) play an important role in virus infection control by bridging innate and adaptive immune responses. Macrophages and dendritic cells (DCs) possess various surface receptors to recognize/internalize antigens, and antibody binding can enhance pathogen-opsonizing uptake by these APCs via interaction of antibody fragment crystallizable (Fc) domains with Fc receptors, evoking profound pathogen control in certain settings. Here, we examined phagocytosis-enhancing potential of Fc domains directly oriented on a retroviral virion/virus-like particle (VLP) surface. We generated an expression vector coding a murine Fc fragment fused to the transmembrane region (TM) of a retroviral envelope protein, deriving expression of the Fc-TM fusion protein on the transfected cell surface and production of virions incorporating the chimeric Fc upon co-transfection. Incubation of Fc-displaying simian immunodeficiency virus (SIV) with murine J774 macrophages and bone marrow-derived DCs derived Fc receptor-dependent enhanced uptake, being visualized by imaging cytometry. Alternative preparation of a murine leukemia virus (MLV) backbone-based Fc-displaying VLP loading an influenza virus hemagglutinin (HA) antigen resulted in enhanced HA internalization by macrophages, stating antigen compatibility of the design. Results show that the Fc-TM fusion molecule can be displayed on certain viruses/VLPs and may be utilized as a molecular adjuvant to facilitate APC antigen uptake.

Characterization of proinflammatory cytokines profile during acute SARS-CoV-2 infection in people with human immunodeficiency virus.

Persistent inflammation in chronic HIV infection may affect immune responses against SARS-CoV-2 infection. Plasma levels of multiple proinflammatory cytokines during acute SARS-CoV-2 infection were assessed in people with HIV (PWH) with effective cART. There were no significant differences in any of the tested cytokines between COVID-19 severity in PWH, while most of them were significantly higher in individuals with severe disease in HIV-uninfected individuals, suggesting that excess cytokines release by hyper-inflammatory responses does not occur in severe COVID-19 with HIV infection. The strong associations between the cytokines observed in HIV-uninfected individuals, especially between IFN-α/TNF-α and other cytokines, were lost in PWH. The steady state plasma levels of IP-10, ICAM-1, and CD62E were significantly higher in PWH, indicating that PWH are in an enhanced inflammatory state. Loss of the several inter-cytokine correlations were observed in in vitro LPS stimuli-driven cytokines production in PWH. These data suggest that inflammatory responses during SARS-CoV-2 infection in PWH are distinct from those in HIV-uninfected individuals, partially due to the underlying inflammatory state and/or impairment of innate immune cells.

Prophylactic vaccination inducing anti-Env antibodies can result in protection against HTLV-1 challenge in macaques.

Human T cell leukemia/T-lymphotropic virus type 1 (HTLV-1) infection occurs by cell-to-cell transmission and can induce fatal adult T cell leukemia. Vaccine development is critical for the control of HTLV-1 transmission. However, determining whether vaccine-induced anti-Env antibodies can prevent cell-to-cell HTLV-1 transmission is challenging. Here, we examined the protective efficacy of a vaccine inducing anti-Env antibodies against HTLV-1 challenge in cynomolgus macaques. Eight of 10 vaccinated macaques produced anti-HTLV-1 neutralizing antibodies (NAbs) and were protected from an intravenous challenge with 108 HTLV-1-producing cells. In contrast, the 2 vaccinated macaques without NAb induction and 10 unvaccinated controls showed HTLV-1 infection with detectable proviral load after challenge. Five of the eight protected macaques were administered with an anti-CD8 monoclonal antibody, but proviruses remained undetectable and no increase in anti-HTLV-1 antibodies was observed even after CD8+ cell depletion in three of them. Analysis of Env-specific T cell responses did not suggest involvement of vaccine-induced Env-specific T cell responses in the protection. These results indicate that anti-Env antibody induction by vaccination can result in functionally sterile HTLV-1 protection, implying the rationale for strategies aimed at anti-Env antibody induction in prophylactic HTLV-1 vaccine development.

A tetravalent dengue virus-like particle vaccine induces high levels of neutralizing antibodies and reduces dengue replication in non-human primates.

Dengue virus (DENV) represents a significant global health burden, with 50% of the world's population at risk of infection, and there is an urgent need for next-generation vaccines. Virus-like particle (VLP)-based vaccines, which mimic the antigenic structure of the virus but lack the viral genome, are an attractive approach. Here, we describe a dengue VLP (DENVLP) vaccine which generates a neutralizing antibody response against all four DENV serotypes in 100% of immunized non-human primates for up to 1 year. Additionally, DENVLP vaccination produced no ADE response against any of four DENV serotypes in vitro. DENVLP vaccination reduces viral replication in a non-human primate challenge model. We also show that transfer of purified IgG from immunized monkeys into immunodeficient mice protects against subsequent lethal DENV challenge, indicating a humoral mechanism of protection. These results indicate that this DENVLP vaccine is immunogenic and can be considered for clinical evaluation. Immunization of non-human primates with a tetravalent DENVLP vaccine induces high levels of neutralizing antibodies and reduces the severity of infection for all four dengue serotypes.IMPORTANCEDengue is a viral disease that infects nearly 400 million people worldwide and causes dengue hemorrhagic fever, which is responsible for 10,000 deaths each year. Currently, there is no therapeutic drug licensed to treat dengue infection, which makes the development of an effective vaccine essential. Virus-like particles (VLPs) are a safe and highly immunogenic platform that can be used in young children, immunocompromised individuals, as well as healthy adults. In this study, we describe the development of a dengue VLP vaccine and demonstrate that it induces a robust immune response against the dengue virus for over 1 year in monkeys. The immunity induced by this vaccine reduced live dengue infection in both murine and non-human primate models. These results indicate that our dengue VLP vaccine is a promising vaccine candidate.

Longitudinal analysis of microbiome composition in Ghanaians living with HIV-1.

Human immunodeficiency virus (HIV) 1 infection is known to cause gut microbiota dysbiosis. Among the causes is the direct infection of HIV-1 in gut-resident CD4+ T cells, causing a cascade of phenomena resulting in the instability of the gut mucosa. The effect of HIV infection on gut microbiome dysbiosis remains unresolved despite antiretroviral therapy. Here, we show the results of a longitudinal study of microbiome analysis of people living with HIV (PLWH). We contrasted the diversity and composition of the microbiome of patients with HIV at the first and second time points (baseline_case and six months later follow-up_case, respectively) with those of healthy individuals (baseline_control). We found that despite low diversity indices in the follow-up_case, the abundance of some genera was recovered but not completely, similar to baseline_control. Some genera were consistently in high abundance in PLWH. Furthermore, we found that the CD4+ T-cell count and soluble CD14 level were significantly related to high and low diversity indices, respectively. We also found that the abundance of some genera was highly correlated with clinical features, especially with antiretroviral duration. This includes genera known to be correlated with worse HIV-1 progression (Achromobacter and Stenotrophomonas) and a genus associated with gut protection (Akkermansia). The fact that a protector of the gut and genera linked to a worse progression of HIV-1 are both enriched may signify that despite the improvement of clinical features, the gut mucosa remains compromised.

Mpox Neutralizing Antibody Response to LC16m8 Vaccine in Healthy Adults.

BACKGROUND: Vaccination against mpox (formerly known as monkeypox), an infectious disease caused by the monkeypox virus (MPXV), is needed to prevent outbreaks and consequent public health concerns. The LC16m8 vaccine, a dried cell-cultured proliferative live attenuated vaccinia virus­based vaccine, was approved in Japan against smallpox and mpox. However, its immunogenicity and efficacy against MPXV have not been fully assessed. We assessed the safety and immunogenicity of LC16m8 against MPXV in healthy adults. METHODS: We conducted a single-arm study that included 50 participants who were followed up for 168 days postvaccination. The primary end point was the neutralizing antibody seroconversion rate against MPXVs, including the Zr599 and Liberia strains, on day 28. The secondary end points included the vaccine "take" (major cutaneous reaction) rate, neutralizing titer kinetics against MPXV and vaccinia virus (LC16m8) strains, and safety outcomes. RESULTS: Seroconversion rates on day 28 were 72% (36 of 50), 70% (35 of 50), and 88% (44 of 50) against the Zr599 strain, the Liberia strain, and LC16m8, respectively. On day 168, seroconversion rates decreased to 30% (15 of 50) against the Zr599 and Liberia strains and to 76% (38 of 50) against LC16m8. The vaccine "take" (broad definition) rate on day 14 was 94% (46 of 49). Adverse events (AEs), including common solicited cutaneous reactions, occurred in 98% (45 of 48) of participants; grade 3 severity AEs occurred in 16% (8 of 50). No deaths, serious AEs, or mpox onset incidences were observed up to day 168. CONCLUSIONS: The LC16m8 vaccine generated neutralizing antibody responses against MPXV in healthy adults. No serious safety concerns occurred with LC16m8 use. (Funded by the Ministry of Health, Labour and Welfare of Japan; Japan Registry of Clinical Trials number, jRCTs031220171.)

HIV-1 RNAs whose transcription initiates from the third deoxyguanosine of GGG tract in the 5' long terminal repeat serve as a dominant genome for efficient provirus DNA formation.

Unspliced HIV-1 RNAs function as messenger RNAs for Gag or Gag-Pol polyproteins and progeny genomes packaged into virus particles. Recently, it has been reported that fate of the RNAs might be primarily determined, depending on transcriptional initiation sites among three consecutive deoxyguanosine residues (GGG tract) downstream of TATA-box in the 5' long terminal repeat (LTR). Although HIV-1 RNA transcription starts mostly from the first deoxyguanosine of the GGG tract and often from the second or third deoxyguanosine, RNAs beginning with one guanosine (G1-form RNAs), whose transcription initiates from the third deoxyguanosine, were predominant in HIV-1 particles. Despite selective packaging of G1-form RNAs into virus particles, its biological impact during viral replication remains to be determined. In this study, we revealed that G1-form RNAs are primarily selected as a template for provirus DNA rather than other RNAs. In competitions between HIV-1 and lentiviral vector transcripts in virus-producing cells, approximately 80% of infectious particles were found to generate provirus using HIV-1 transcripts, while lentiviral vector transcripts were conversely selected when we used HIV-1 mutants in which the third deoxyguanosine in the GGG tract was replaced with deoxythymidine or deoxycytidine (GGT or GGC mutants, respectively). In the other analyses of proviral sequences after infection with an HIV-1 mutant in which the GGG tract in 3' LTR was replaced with TTT, most proviral sequences of the GGG-tract region in 5' LTR were found to be TTG, which is reasonably generated using the G1-form transcripts. Our results indicate that the G1-form RNAs serve as a dominant genome to establish provirus DNA.IMPORTANCESince the promoter for transcribing HIV-1 RNA is unique, all viral elements including genomic RNA and viral proteins have to be generated by the unique transcripts through ingenious mechanisms including RNA splicing and frameshifting during protein translation. Previous studies suggested a new mechanism for diversification of HIV-1 RNA functions by heterogeneous transcriptional initiation site usage; HIV-1 RNAs whose transcription initiates from a certain nucleotide were predominant in virus particles. In this study, we established two methods to analyze heterogenous transcriptional initiation site usage by HIV-1 during viral infection and showed that RNAs beginning with one guanosine (G1-form RNAs), whose transcription initiates from the third deoxyguanosine of the GGG tract in 5' LTR, were primarily selected as viral genome in infectious particles and thus are used as a template to generate provirus for continuous replication. This study provides insights into the mechanism for diversification of unspliced RNA functions and requisites of lentivirus infectivity.

Development of a partnership between academia, community, and government in response to the 2022 mpox outbreak in Japan.

Objectives　In response to the steady rise in the number of cases of mpox in nonendemic countries, starting with an outbreak in the United Kingdom in May 2022, the World Health Organization declared a public health emergency of international concern on July 23, 2022. As of November 13, 2022, seven cases of mpox have been reported in Japan.Methods　A community engagement approach was applied to prevent the spread of mpox in Japan.Results　A tripartite partnership between academia, community, and government (ACG) was established to promote multisectoral communication between vulnerable communities, medical personnel involved in diagnosis and treatment, public health specialists at public health centers, epidemiologists at the National Institute of Infectious Diseases (NIID), and government and public administration. Through information sharing, this ACG partnership can translate accurate information into effective infection control measures.Conclusion　By developing and maintaining the ACG partnership, an environment will be created that allows an immediate response to future public health crises affecting vulnerable communities. This Practice Report describes the process of establishing an ACG partnership.

Breadth and Durability of SARS-CoV-2-Specific T Cell Responses following Long-Term Recovery from COVID-19.

T cell immunity is crucial for long-term immunological memory, but the profile of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific memory T cells in individuals who recovered from COVID-19 (COVID-19-convalescent individuals) is not sufficiently assessed. In this study, the breadth and magnitude of SARS-CoV-2-specific T cell responses were determined in COVID-19-convalescent individuals in Japan. Memory T cells against SARS-CoV-2 were detected in all convalescent individuals, and those with more severe disease exhibited a broader T cell response relative to cases with mild symptoms. Comprehensive screening of T cell responses at the peptide level was conducted for spike (S) and nucleocapsid (N) proteins, and regions frequently targeted by T cells were identified. Multiple regions in S and N proteins were targeted by memory T cells, with median numbers of target regions of 13 and 4, respectively. A maximum of 47 regions were recognized by memory T cells for an individual. These data indicate that SARS-CoV-2-convalescent individuals maintain a substantial breadth of memory T cells for at least several months following infection. Broader SARS-CoV-2-specific CD4+ T cell responses, relative to CD8+ T cell responses, were observed for the S but not the N protein, suggesting that antigen presentation is different between viral proteins. The binding affinity of predicted CD8+ T cell epitopes to HLA class I molecules in these regions was preserved for the Delta variant and at 94 to 96% for SARS-CoV-2 Omicron subvariants, suggesting that the amino acid changes in these variants do not have a major impact on antigen presentation to SARS-CoV-2-specific CD8+ T cells. IMPORTANCE RNA viruses, including SARS-CoV-2, evade host immune responses through mutations. As broader T cell responses against multiple viral proteins could minimize the impact of each single amino acid mutation, the breadth of memory T cells would be one essential parameter for effective protection. In this study, breadth of memory T cells to S and N proteins was assessed in COVID-19-convalescent individuals. While broad T cell responses were induced against both proteins, the ratio of N to S proteins for breadth of T cell responses was significantly higher in milder cases. The breadth of CD4+ and CD8+ T cell responses was also significantly different between S and N proteins, suggesting different contributions of N and S protein-specific T cells for COVID-19 control. Most CD8+ T cell epitopes in the immunodominant regions maintained their HLA binding to SARS-CoV-2 Omicron subvariants. Our study provides insights into understanding the protective efficacy of SARS-CoV-2-specific memory T cells against reinfection.

Community based multi-disease health screening as an opportunity for early detection of HIV cases and linking them to care.

BACKGROUND: The 95-95-95 UNAIDS global strategy was adapted to end the AIDS epidemic by 2030. The target is based on the premise that early detection of HIV-infected persons and linking them to treatment regardless of their CD4 counts will lead to sustained viral suppression. HIV testing strategies to increase uptake of testing in Western and Central Africa remain inadequate. Hence, a high proportion of people living with HIV in this region do not know their status. This report describes the implementation of a community based multi-disease health screening (also known as "Know Your Status" -KYS), as part of basic science research, in a way that contributed to achieving public health goals. METHODS: A community based multi-disease health screening was conducted in 7 communities within the Eastern region of Ghana between November 2017 and April 2018, to recruit and match HIV seronegative persons to HIV seropositive persons in a case-control HIV gut microbiota study. Health assessments included blood pressure, body mass index, blood sugar, Hepatitis B virus, syphilis, and HIV testing for those who consented. HIV seronegative participants who consented were consecutively enrolled in an ongoing HIV gut microbiota case-control study. Descriptive statistics (percentages) were used to analyze data. RESULTS: Out of 738 people screened during the exercise, 700 consented to HIV testing and 23 (3%) were HIV positive. Hepatitis B virus infection was detected in 4% (33/738) and Syphilis in 2% (17/738). Co-infection of HIV and HBV was detected in 4 persons. The HIV prevalence of 3% found in these communities is higher than both the national prevalence of 1.7% and the Eastern Regional prevalence of 2.7 in 2018. CONCLUSION: Community based multi-disease health screening, such as the one undertaken in our study could be critical for identifying HIV infected persons from the community and linking them to care. In the case of HIV, it will greatly contribute to achieving the first two 95s and working towards ending AIDS by 2030.

HTLV-1 Proliferation after CD8+ Cell Depletion by Monoclonal Anti-CD8 Antibody Administration in Latently HTLV-1-Infected Cynomolgus Macaques.

Human T-cell leukemia virus type 1 (HTLV-1) induces chronic asymptomatic latent infection with a substantial proviral load but without significant viral replication in vivo. Cumulative studies have indicated involvement of CD8-positive (CD8+) cells, including virus-specific CD8+ T cells in the control of HTLV-1 replication. However, whether HTLV-1 expression from latently infected cells in vivo occurs in the absence of CD8+ cells remains unclear. Here, we examined the impact of CD8+ cell depletion by monoclonal anti-CD8 antibody administration on proviral load in HTLV-1-infected cynomolgus macaques. Five cynomolgus macaques were infected with HTLV-1 by inoculation with HTLV-1-producing cells. Administration of monoclonal anti-CD8 antibody in the chronic phase resulted in complete depletion of peripheral CD8+ T cells for approximately 2 months. All five macaques showed an increase in proviral load following CD8+ cell depletion, which peaked just before the reappearance of peripheral CD8+ T cells. Tax-specific CD8+ T-cell responses were detected in these recovered CD8+ T cells. Importantly, anti-HTLV-1 antibodies also increased after CD8+ cell depletion, indicating HTLV-1 antigen expression. These results provide evidence indicating that HTLV-1 can proliferate from the latent phase in the absence of CD8+ cells and suggest that CD8+ cells are responsible for the control of HTLV-1 replication. IMPORTANCE HTLV-1 can cause serious diseases such as adult T-cell leukemia (ATL) in humans after chronic asymptomatic latent infection with substantial proviral load. Proviruses are detectable in peripheral lymphocytes in HTLV-1 carriers, and the association of a higher proviral load with a higher risk of disease progression has been observed. However, neither substantial viral structural protein expression nor viral replication was detectable in vivo. Cumulative studies have indicated involvement of CD8+ cells, including virus-specific CD8+ T cells in the control of HTLV-1 replication. In the present study, we showed that CD8+ cell depletion by monoclonal anti-CD8 antibody administration results in HTLV-1 expression and an increase in proviral load in HTLV-1-infected cynomolgus macaques. Our results indicate that HTLV-1 can proliferate in the absence of CD8+ cells, suggesting that CD8+ cells are responsible for the control of HTLV-1 replication. This study provides insights into the mechanism of virus-host immune interaction in latent HTLV-1 infection.

Association of demographics, HCV co-infection, HIV-1 subtypes and genetic clustering with late HIV diagnosis: a retrospective analysis from the Japanese Drug Resistance HIV-1 Surveillance Network.

INTRODUCTION: Late diagnosis of the human immunodeficiency virus (HIV) is a major concern epidemiologically, socially and for national healthcare systems. Although the association of certain demographics with late HIV diagnosis has been reported in several studies, the association of other factors, including clinical and phylogenetic factors, remains unclear. In the present study, we conducted a nationwide analysis to explore the association of demographics, clinical factors, HIV-1 subtypes/circulating recombinant form (CRFs) and genetic clustering with late HIV diagnosis in Japan, where new infections mainly occur among young men who have sex with men (MSM) in urban areas. METHODS: Anonymized data on demographics, clinical factors and HIV genetic sequences from 39.8% of people newly diagnosed with HIV in Japan were collected by the Japanese Drug Resistance HIV-1 Surveillance Network from 2003 to 2019. Factors associated with late HIV diagnosis (defined as HIV diagnosis with a CD4 count <350 cells/µl) were identified using logistic regression. Clusters were identified by HIV-TRACE with a genetic distance threshold of 1.5%. RESULTS: Of the 9422 people newly diagnosed with HIV enrolled in the surveillance network between 2003 and 2019, 7752 individuals with available CD4 count at diagnosis were included. Late HIV diagnosis was observed in 5522 (71.2%) participants. The overall median CD4 count at diagnosis was 221 (IQR: 62-373) cells/µl. Variables independently associated with late HIV diagnosis included age (adjusted odds ratio [aOR] 2.21, 95% CI 1.88-2.59, ≥45 vs. ≤29 years), heterosexual transmission (aOR 1.34, 95% CI 1.11-1.62, vs. MSM), living outside of Tokyo (aOR 1.18, 95% CI 1.05-1.32), hepatitis C virus (HCV) co-infection (aOR 1.42, 95% CI 1.01-1.98) and not belonging to a cluster (aOR 1.30, 95% CI 1.12-1.51). CRF07_BC (aOR 0.34, 95% CI 0.18-0.65, vs. subtype B) was negatively associated with late HIV diagnosis. CONCLUSIONS: In addition to demographic factors, HCV co-infection, HIV-1 subtypes/CRFs and not belonging to a cluster were independently associated with late HIV diagnosis in Japan. These results imply the need for public health programmes aimed at the general population, including but not limited to key populations, to encourage HIV testing.

Plasmacytoid dendritic cells stimulated with Lactococcus lactis strain Plasma produce soluble factors to suppress SARS-CoV-2 replication.

Innate immune responses are important in the control of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication. We have previously found a lactic acid bacteria species, Lactococcus lactis strain Plasma (LC-Plasma), which possesses specific feature to activate plasmacytoid dendritic cells (pDCs) and thus may affect innate immune responses. Here, we investigated the impact of pDC activation by LC-Plasma on SARS-CoV-2 replication in vitro. Addition of the culture supernatant of pDCs stimulated with LC-Plasma resulted in suppression of SARS-CoV-2 replication in Vero and Calu-3 cells. We confirmed interferon-α (IFN-α) secretion in the supernatant of pDCs stimulated with LC-Plasma and induction of IFN-stimulated genes in cells treated with the pDC supernatant. Anti-IFN-α antibody impaired the suppression of SARS-CoV-2 replication by the supernatant of LC-Plasma-stimulated pDCs, suggesting that IFN-α plays an important role in the SARS-CoV-2 suppression. Our results indicate the potential of LC-Plasma to induce inhibitory responses against SARS-CoV-2 replication through pDC stimulation with IFN-α secretion.

Multimodal single-cell analyses of peripheral blood mononuclear cells of COVID-19 patients in Japan.

SARS-CoV-2 continues to spread worldwide. Patients with COVID-19 show distinct clinical symptoms. Although many studies have reported various causes for the diversity of symptoms, the underlying mechanisms are not fully understood. Peripheral blood mononuclear cells from COVID-19 patients were collected longitudinally, and single-cell transcriptome and T cell receptor repertoire analysis was performed. Comparison of molecular features and patients' clinical information revealed that the proportions of cells present, and gene expression profiles differed significantly between mild and severe cases; although even among severe cases, substantial differences were observed among the patients. In one severely-infected elderly patient, an effective antibody response seemed to have failed, which may have caused prolonged viral clearance. Naïve T cell depletion, low T cell receptor repertoire diversity, and aberrant hyperactivation of most immune cell subsets were observed during the acute phase in this patient. Through this study, we provided a better understanding of the diversity of immune landscapes and responses. The information obtained from this study can help medical professionals develop personalized optimal clinical treatment strategies for COVID-19.

Impaired protective role of HLA-B*57:01/58:01 in HIV-1 CRF01_AE infection: a cohort study in Vietnam.

OBJECTIVES: Human Leukocyte Antigen HLA-B*57:01 and B*58:01 are considered anti-HIV-1 protective alleles. HLA-B*57:01/58:01-restricted HIV-1 Gag TW10 (TSTLQEQIGW, Gag residues 240-249) epitope-specific CD8+ T cell responses that frequently select for a Gag escape mutation, T242N, with viral fitness cost are crucial for HIV-1 control. Although this finding has been observed in cohorts where HIV-1 subtype B or C predominates, the protective impact of HLA-B*57:01/58:01 has not been reported in Southeast Asian countries where HIV-1 CRF01_AE is the major circulating strain. Here, the effect of HLA-B*57:01/58:01 on CRF01_AE infection was investigated. METHODS: The correlation of HLA-B*57:01/58:01 with viral load and CD4 counts were analyzed in the CRF01_AE-infected Vietnamese cohort (N = 280). The impact of the T242N mutation on CRF01_AE replication capacity was assessed. RESULTS: HLA-B*57:01/58:01-positive individuals mostly had HIV-1 with T242N (62/63) but showed neither a significant reduction in viral load nor increased CD4 counts relative to B*57:01/58:01-negative participants. In vitro and in vivo analyses revealed a significant reduction in viral fitness of CRF01_AE with T242N. In silico analysis indicated reduced presentation of epitopes in the context of CRF01_AE compared to subtype B or C in 10/16 HLA-B*57:01/58:01-restricted HIV-1 epitopes. CONCLUSION: The protective impact of HLA-B*57:01/58:01 on CRF01_AE infection is impaired despite strong suppressive pressure by TW10-specific CD8+ T cells.

Development of a novel Macaque-Tropic HIV-1 adapted to cynomolgus macaques.

Macaque-tropic HIV-1 (HIV-1mt) variants have been developed to establish preferable primate models that are advantageous in understanding HIV-1 infection pathogenesis and in assessing the preclinical efficacy of novel prevention/treatment strategies. We previously reported that a CXCR4-tropic HIV-1mt, MN4Rh-3, efficiently replicates in peripheral blood mononuclear cells (PBMCs) of cynomolgus macaques homozygous for TRIMCyp (CMsTC). However, the CMsTC challenged with MN4Rh-3 displayed low viral loads during the acute infection phase and subsequently exhibited short-term viremia. These virological phenotypes in vivo differed from those observed in most HIV-1-infected people. Therefore, further development of the HIV-1mt variant was needed. In this study, we first reconstructed the MN4Rh-3 clone to produce a CCR5-tropic HIV-1mt, AS38. In addition, serial in vivo passages allowed us to produce a highly adapted AS38-derived virus that exhibits high viral loads (up to approximately 106 copies ml-1) during the acute infection phase and prolonged periods of persistent viremia (lasting approximately 16 weeks postinfection) upon infection of CMsTC. Whole-genome sequencing of the viral genomes demonstrated that the emergence of a unique 15-nt deletion within the vif gene was associated with in vivo adaptation. The deletion resulted in a significant increase in Vpr protein expression but did not affect Vif-mediated antagonism of antiretroviral APOBEC3s, suggesting that Vpr is important for HIV-1mt adaptation to CMsTC. In summary, we developed a novel CCR5-tropic HIV-1mt that can induce high peak viral loads and long-term viremia and exhibits increased Vpr expression in CMsTC.

Strengthening surveillance in Ghana against public health emergencies of international concern.

Among western African countries, the Republic of Ghana has maintained an economic growth rate of 5% since the 1980s and is now categorized as a middle-income country. However, as with other developing countries, Ghana still has challenges in the effective implementation of surveillance for infectious diseases. Facing public health emergencies of international concern (PHEIC), it is crucial to establish a reliable sample transportation system to the referral laboratory. Previously, surveillance capacity in Ghana was limited based on Integrated Disease Surveillance and Response, and therefore the "Surveillance and Laboratory Support for Emerging Pathogens of Public Health Importance in Ghana (SLEP)" was introduced to strengthen diarrhea surveillance. The SLEP project started with a sentinel diarrhea survey supported by SATREPS/JICA in collaboration with National Public Health Reference Laboratory (NHPRL) and Noguchi Memorial Institute of Medicine (NMIMR). The base-line survey revealed the limited capacity to detect diarrhea pathogens and to transfer samples from health centers to NHPRL. The involvement of private clinic/hospital facilities into the surveillance network is also crucial to strengthen surveillance in Ghana. The strong and interactive relationship between the two top referral laboratories, NHPRL under the Ministry of Health NMIMR and under the Ministry of Education, enables Ghana Health Services and is critical for the rapid response against PHEIC. In future, we hope that the outcome of the SLEP surveillance project could contribute to building a surveillance network with more timely investigation and transfer of samples to referral labs.

High-level resistance to non-nucleos(t)ide reverse transcriptase inhibitor based first-line antiretroviral therapy in Ghana; A 2017 study.

Expanding access to effective antiretroviral therapy (ART) is a major tool for management of Human Immunodeficiency Virus (HIV) infection. However, rising levels of HIV drug-resistance have significantly hampered the anticipated success of ART in persons living with HIV (PLWH), particularly those from Africa. Though great strides have been made in Ghana toward achieving the UNAIDS "95-95-95" target, a substantial number of PLWH receiving ART have not attained viral suppression. This study investigated patterns of drug resistance mutations in ART naïve as well as ART-experienced PLWH receiving first-line regimen drugs from Ghana. In a cross-sectional study, blood samples were collected from HIV-1 infected adults (≥18 years) attending HIV/AIDS clinic at the Eastern Regional Hospital, Koforidua, Ghana from September to October 2017. Viral RNA isolated from plasma were subjected to genotypic drug resistance testing for Protease Inhibitors (PI), Reverse Transcriptase Inhibitors (RTI), and Integrase Strand Transfer Inhibitors (INSTI). A total of 95 (84 ART experienced, 11 ART naïve) HIV-1 infected participants were sampled in this study. Sixty percent (50/84) of the ART-experienced participants were controlling viremia (viral load < 1,000 copies/ml). Of the 95 patient samples, 32, 34, and 33 were successfully sequenced for protease, reverse-transcriptase, and integrase regions, respectively. The dominant HIV-1 subtypes detected were CRF02_AG (70%), and A3 (10%). Major drug resistance associated mutations were only detected for reverse transcriptase inhibitors. The predominant drug resistance mutations were against nucleos(t)ide reverse transcriptase inhibitors (NRTI)-M184V/I and non-nucleos(t)ide reverse transcriptase inhibitors (NNRTI)-K103N. In the ART-experienced group, M184V/I and K103N were detected in 54% (15/28) and 46% (13/28) of individuals, respectively. Both mutations were each detected in 33% (2/6) of ART naïve individuals. Multiclass resistance to NRTI and NNRTI was detected in 57% of ART-experienced individuals and two ART naïve individuals. This study reports high-level resistance to NNRTI-based antiretroviral therapy in PLWH in Ghana. However, the absence of major PI and INSTI associated-mutations is a good signal that the current WHO recommendation of Dolutegravir in combination with an NRTI backbone will yield maximum benefits as first-line regimen for PLWH in Ghana.

SARS-CoV-2-specific CD4+ T cell longevity correlates with Th17-like phenotype.

Determinants of memory T cell longevity following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remain unknown. In addition, phenotypes associated with memory T cell longevity, antibody titers, and disease severity are incompletely understood. Here, we longitudinally analyzed SARS-CoV-2-specific T cell and antibody responses of a unique cohort with similar numbers of mild, moderate, and severe coronavirus disease 2019 cases. The half-lives of CD4+ and CD8+ T cells were longer than those of antibody titers and showed no clear correlation with disease severity. When CD4+ T cells were divided into Th1-, Th2-, Th17-, and Tfh-like subsets, the Th17-like subset showed a longer half-life than other subsets, indicating that Th17-like cells are most closely correlated with T cell longevity. In contrast, Th2- and Tfh-like T cells were more closely correlated with antibody titers than other subsets. These results suggest that distinct CD4+ T cell subsets are associated with longevity and antibody responses.

Association of envelope-specific B-cell differentiation and viral selective pressure signatures in HIV-1 CRF01_AE infection.

OBJECTIVE: In HIV type 1 (HIV-1) infection, virus-specific B-cell and neutralizing antibody (NAb) responses are impaired but exert selective pressure on target viral Envelope (Env) resulting in prominent sequence diversification among geographical areas. The basal induction patterns of HIV Env-specific B cells and their interaction with HIV Env awaits clarification. DESIGN: We investigated the relationship of Env polymorphisms and Env-specific B-cell responses in treatment-naive HIV-1 CRF01_AE-infected Vietnamese. METHODS: Samples of 43 HIV-1 CRF01_AE infection-identified individuals were divided into acute-phase ( n  = 12) and chronic-phase ( n  = 31) by combined criteria of serological recent-infection assay and clinical parameters. We quantified subcloning-based polymorphic residue site numbers in plasma-derived Env variable region 1-5 (V1-V5)-coding regions within each individual, designating their summation within each region as variant index. Peripheral blood Env gp 140-specific B-cell responses and plasma neutralizing activity of Env pseudoviruses were examined to analyze their relationship with variant index. RESULTS: HIV-1 CRF01_AE Env gp140-specific total B-cell and plasma cell (CD19 + IgD - CD27 + CD38 + CD138 + ) responses were determined. In chronic-phase samples, significant correlation of variant index in all Env V1-V5 regions with Env-specific plasma cell responses was shown, and V1-V5 total variant index correlated stronger with Env-specific plasma cell as compared with total Env-specific B-cell responses. Env V5 variant index was significantly higher in chronic-phase cross-neutralizers of V5-polymorphic/VRC01-insensitive CRF01_AE Env. CONCLUSION: Results revealed the association between circulating Env-specific plasma cell responses and Env polymorphisms, implicating selective pressure on Env by plasma cell-derived antibodies and conversely suggests that Env-specific B-cell induction alone is insufficient for exerting Env selective pressure in HIV infection.