CD4(+) T-cell depletion in HIV infection: mechanisms of immunological failure

Plasma anti-CD4 IgG levels are associated with poor immune recovery in people with HIV initiating antiretroviral therapy

A segment of people with HIV on effective antiretroviral therapy (ART) continue to experience poor immune recovery, leaving them at heightened risk of non-AIDS-defining events (NAEs). The production of anti-CD4 IgG autoreactive antibodies is suggested as one contributing mechanism to these complications. Here, we found that plasma anti-CD4 levels do not discriminate immunological responders from nonresponders nor predict the occurrence of NAEs, suggesting it is unlikely a contributing immunopathological factor associated with these complications.

Limited restoration of T cell subset distribution and immune function in older people living with HIV-1 receiving HAART

BACKGROUND

Older people living with HIV-1 (PLWH) experience a dual burden from the combined effects of aging and HIV-1 infection, resulting in significant immune dysfunction. Despite receiving HAART, immune reconstitution is not fully optimized. The objective of this study was to investigate the impact of aging and HAART on T cell subsets and function in PLWH across different age groups, thereby providing novel insights into the prognosis of older PLWH.

METHOD

This study was conducted at Yunnan AIDS Care Center, China, to explore the immunological responses of old PLWH to HAART and compared with the middle-age and the younger. Blood samples were collected from 146 PLWH to analyze T cell subsets and their functions, with a particular emphasis on markers related to T cell differentiation, activation, exhaustion, inflammation, and cellular function, using multicolor flow cytometry analysis.

RESULTS

Older age may have a greater effect on long-term CD4+T cell recovery. Compared with young and middle-aged PLWH, older PLWH presented distinct alterations in their immune profile, including a decline in the Naïve CD4+T and CD8+T cell subsets, an expansion of effector memory cells, and other potential immune risk phenotypes, such as activation, exhaustion, and up-regulation of aging markers. In addition, we observed a significant association between the CD4 + EM3 subset and the CD8 + EM2 subset with HIV-1 progression, independent of age, suggesting their potential as reliable markers for assessing immune reconstitution in all PLWH.

CONCLUSION

Our study extends previous findings showing that older participants exhibit a wide range of late differentiation, senescence, or exhaustion phenotypes in cells, including all the CD4+T and CD8+T subsets, consistent with an immunosenescent phenotype. This may accelerate poor immune recovery in older PLWH. Identifying new strategies to improve the immune risk phenotypes of older PLWH may help improve their immune reconstitution outcomes. The CD4 + EM3 subset and the CD8 + EM2 subset should be studied as additional markers of late presentation.

The prognosis for delayed immune recovery in HIV-infected children might be associated with pre-cART CD4+ T cell count irrespective of co-infection with tuberculosis

BACKGROUND

Immune reconstitution following the initiation of combination antiretroviral therapy (cART) significantly impacts the prognosis of individuals infected with human immunodeficiency virus (HIV). Our previous studies have indicated that the baseline CD4+ T cells count and percentage before cART initiation are predictors of immune recovery in TB-negative children infected with HIV, with TB co-infection potentially causing a delay in immune recovery. However, it remains unclear whether these predictors consistently impact immune reconstitution during long-term intensive cART treatment in TB-negative/positive children infected with HIV.

RESULTS

We confirmed that the baseline CD4+ T cell count is a significant predictor of immune recovery following long-term intensive cART treatment among children aged 0 to 13 years. Children with lower CD4+ T cell count prior cART initiation did not show substantial immunological recovery during the follow-up period. Interestingly, children who were co-infected with TB and had higher baseline CD4+ T cell count eventually achieved good immunological recovery comparable to the TB-negative HIV-infected children. Hence, the baseline CD4+ T cell count at the onset of treatment serves as a reliable predictor of immunological reconstitution in HIV-infected children with or without TB co-infection. Taken together, this follow-up study validates our previous findings and further establishes that initiating cART early alongside early HIV testing can help prevent the diminished CD4+ T cell count associated with inadequate immunological reconstitution.

Ocular and Adnexal Diseases in Human Immunodeficiency Virus-Infected Pregnant Women Attending HIV Clinics in Ibadan, Nigeria

Background

Human immunodeficiency virus (HIV) is a lentivirus. It is transmitted through sexual intercourse, shared intravenous drugs, contaminated needle use, blood transfusion, and mother-to-child transmission. Of the patients with HIV, 50%-75% have ocular manifestations and this may be the primary presentation. This study was carried out in two prevention of mother-to-child transmission (PMTCT)/HIV clinics. The aim was to determine the incidence, patterns of presentation, and determinants of ocular and adnexal diseases in HIV-positive pregnant women attending HIV clinics to develop an eye care protocol for them.

Materials and Methods

The study was a cross-sectional study of HIV-positive pregnant women attending the PMTCT/HIV Clinics at University College Hospital and Adeoyo Maternity Teaching Hospital, Ibadan. Patients were interviewed using a structured questionnaire. Blood samples were taken for CD4+ count and viral load. The stage of the disease, type of antiretroviral therapy (ART), and the interval between HIV diagnosis and commencement of ART were recorded. Comprehensive ocular examination, which included visual acuity check unaided and with pinhole, lid, anterior segment examination with slit lamp and posterior segment examination with dilated binocular indirect ophthalmoscopy, was conducted. Statistical Package for Social Sciences version 23 was used to analyse the data.

Results

A total of 153 pregnant women aged 23-42 years (mean, 33.5; standard deviation, ±5.6) were recruited. One hundred and fifteen (75.2%) of them were married in a monogamous setting. Multiple sexual partners (48.4%; n = 74-some women married in monogamous settings at the time of recruitment for this study had multiple sexual partners in the past) and the use of unsterilised objects (46.4%; n = 71) were major high-risk behaviours. Ocular and adnexal diseases were found in 81 (53%) participants. HIV-related ocular and adnexal diseases were found in 16 (10%) participants. Of the 16 HIV-related diseases, optic atrophy was found in seven (43.8%), presumed toxoplasmosis in three (18.7%), presumed cytomegalovirus retinitis in three (18.7%) lid warts in two (12.5%), and conjunctival microangiopathy in one (6.3%) participant. The association between HIV- related ocular and adnexal diseases and gestational age, CD4+ count, viral load and type of ART was not statistically significant.

Conclusion

The few HIV-related findings in this study could be a result of the improved CD+ count/low viral load of most of the recruited participants. Ensuring that patients attending PMTCT/HIV clinic have at least one ocular examination during pregnancy by collaborating with eyecare professionals could ensure prompt detection and treatment of eye diseases, to improve the quality of life of HIV-positive pregnant women.

CD4 Co-Receptor Regulates Sex-Specific NK Cell Responses to Acute Toxoplasma gondii Infection

Immunity to Toxoplasma gondii ( T. gondii ) is sexually dimorphic in humans and mice, with females having higher morbidity and mortality during immune dysfunction and HIV-AIDS. The mechanisms underlying these sex differences are unclear. We investigated how a lack of CD4+ T cells (CD4 co-receptor KO) impacted T. gondii survival in mice. Female CD4 co-receptor KO mice succumbed to T. gondii much faster than males. To dissect why female CD4 co-receptor KO mice died faster, we tested their NK cell responses to acute T. gondii infection compared to males. Although in wild-type (WT) animals, both sexes had similar increases in total NK cells and IFNγ + NK cells, infected CD4 co-receptor KO female mice had 50% fewer IFNγ+ NK cells than infected WT female mice. Infected male CD4 co-receptor KO had a similar increase in IFNγ+ NK cells as WT male mice. Since CD4 co-receptor deficient mice still have functional helper T cells that are CD4-, we next tested survival and NK cell responses in female and male MHCII deficient (MHCIIKO) animals, which completely lack helper CD4+T cells. Surprisingly, survival, NK cell numbers, and IFNγ+ NK cells were not significantly different between WT or MHCIIKO female and male mice. These results suggest CD4 co-receptor expression is required for survival via optimal NK cell responses during acute T. gondii infection only in female mice and not in male mice. Our findings reveal an unappreciated sexual dimorphic role of CD4 co-receptor expression in regulating NK cell responses to acute T. gondii infection.

Criteria air pollutants and HIV-related mortality: Insights from a nationwide case-crossover investigation

The heightened vulnerability of individuals with HIV to environmental stressors is well-recognized, yet the role of air pollution in exacerbating HIV-related mortality remains underexplored. In this nationwide, individual-level case-crossover study conducted from 2013 to 2019, we investigated the association between short-term exposure to criteria air pollutants and HIV-related mortality. Our analysis of 38,510 HIV-related deaths revealed significant associations between exposure to PM2.5, PM10, NO2, and CO and increased mortality risk. The effects of PM2.5 and PM10 persisted for two days, whereas NO2 and CO had immediate, same-day impacts. Vulnerability was heightened in individuals under 65 years, males, those with lower educational attainment, and unmarried individuals. Among causes of death, HIV-related malignant neoplasms exhibited the highest sensitivity to particulate matter. Our findings provide novel insights into the relationship between short-term air pollution exposure and HIV-related mortality, emphasizing the increased susceptibility of this immunocompromised population. The results underscore the need for targeted public health interventions to reduce pollution exposure, particularly for the most at-risk demographic groups. This study contributes to a deeper understanding of environmental health risks faced by individuals living with HIV and informs evidence-based policy recommendations.

Melanoma in people living with HIV: Immune landscape dynamics and the role of immuno- and antiviral therapies

The intersection of HIV and melanoma presents a complex and unique challenge, marked by distinct patterns in incidence, mortality, and treatment response. Higher mortality rates among people with HIV who develop melanoma underscore an urgent need to identify the factors influencing these outcomes. Investigating immune system dynamics, the effects of anti-retroviral drugs, and the evolving landscape of cancer immunotherapy in this population holds promise for new insights, though significant uncertainties remain. Over the past 25 years, melanoma research has demonstrated that a robust immune response is critical for effective treatment. In the context of chronic HIV infection, viral reservoirs enable the virus to persist despite anti-retroviral therapy and foster dysregulated myeloid and T cell compartments. The resulting chronic inflammation weakens the immune system and damages tissues, potentially creating "cold" tumor microenvironments that are less responsive to therapy. In this challenging context, animal models become invaluable for uncovering underlying biological mechanisms. While these models do not fully replicate human HIV infection, they provide essential insights into critical questions and inform the development of tailored treatments for this patient population. Clinically, increasing trial participation and creating a centralized, accessible repository for HIV and cancer samples and data are vital. Achieving these goals requires institutions to address barriers to research participation among people with HIV, focusing on patient-centered initiatives that leverage biomedical research to improve their outcomes and extend their lives.

Involvement of Human Cellular Proteins and Structures in Realization of the HIV Life Cycle: A Comprehensive Review, 2024

Human immunodeficiency virus (HIV) continues to be a global health challenge, with over 38 million people infected by the end of 2022. HIV-1, the predominant strain, primarily targets and depletes CD4+ T cells, leading to immunodeficiency and subsequent vulnerability to opportunistic infections. Despite the progress made in antiretroviral therapy (ART), drug resistance and treatment-related toxicity necessitate novel therapeutic strategies. This review delves into the intricate interplay between HIV-1 and host cellular proteins throughout the viral life cycle, highlighting key host factors that facilitate viral entry, replication, integration, and immune evasion. A focus is placed on actual findings regarding the preintegration complex, nuclear import, and the role of cellular cofactors such as FEZ1, BICD2, and NPC components in viral transport and genome integration. Additionally, the mechanisms of immune evasion via HIV-1 proteins Nef and Vpu, and their interaction with host MHC molecules and interferon signaling pathways, are explored. By examining these host-virus interactions, this review underscores the importance of host-targeted therapies in complementing ART, with a particular emphasis on the potential of genetic research and host protein stability in developing innovative treatments for HIV/AIDS.

Predictors of CD4 cell count progression over time among adolescents and young adults transitioning to adult-oriented HIV care in Southern Ethiopia from 2017 to 2021: a retrospective cohort study

BACKGROUND

Human immunodeficiency virus (HIV), a viral infection impacting CD4 cells, requires an understanding of factors influencing CD4 cell counts to reduce acquired immunodeficiency syndrome(AIDS)-related morbidity and mortality. Despite its importance, no studies have examined predictors of CD4 cell count progression post-transition to adult-oriented HIV care in Ethiopia. This study aimed to identify predictors affecting CD4 cell count trends among adolescents and young adults transitioning to adult-oriented HIV care. Therefore, this study aimed to identify the predictors that affect the trends of CD4 cell count over time among adolescents and young adults who transitioned to adult-oriented HIV care.

METHODS

A retrospective cohort study was conducted among 206 adolescents and young adults who transitioned to adult-oriented HIV care and had at least two CD4 cell counts in eight selected health facilities in Southern Ethiopia. These facilities were chosen due to their high volume of people living with HIV. A multivariable linear mixed effect model was fitted to identify the predictors of CD4 cell count progression through time. Multi-collinearity between variables was checked using the variance inflation factor. Model comparisons were done using Akaike and Bayesian information criteria. Regression coefficients with 95% confidence intervals (CI) and P-value ≤ 0.05 were used to measure the strength of association and significance level.

RESULTS

The average CD4 cell count was raised by 6.7 cells/mm3 every six months among the study participants. Transitioning at the age of 18 or older (β = 204.71; 95% CI = 81.86347, 327.5574; P < 0.001), being rural residents (β= -119.776; 95% CI = -215.362, -24.189; P < 0.014), having World Health Organization (WHO) stage III & IV HIV (β= -182.161; 95% CI = -318.475, -45.847; P < 0.009), were the predictors for CD4 cell count progression over time.

CONCLUSION

Based on the identified predictors of CD4 cell count progression over time among HIV-positive adolescents and young adults transitioning to adult-oriented HIV care in southern Ethiopia, such as observation time, age at transition, residence, and WHO staging, the study highlights the need for interventions focused on tailored support. Specifically, these interventions should target individuals transitioning with less ART time, those younger than 18, those residing in rural areas, and those with advanced WHO staging, to improve their CD4 cell counts over time.

Iron status, anemia, and birth outcomes among pregnant women in urban Bloemfontein, South Africa: the NuEMI study

BACKGROUND

Despite routine iron supplementation for pregnant women in South Africa, anaemia and iron deficiency (ID) in pregnancy remain a public health concern.

OBJECTIVE

To determine the associations between iron status and birth outcomes of pregnant women attending antenatal clinic at a regional hospital in Bloemfontein.

METHODS

In this cross-sectional study of 427 pregnant women, blood was taken to analyze biomarkers of anaemia (haemoglobin), iron status (ferritin and soluble transferrin receptor) and inflammation (C-reactive protein and α-1-acid glycoprotein). A questionnaire was used to collect information about birth outcomes (birth weight and gestational age at birth), HIV exposure, sociodemographics, iron supplement intake, and maternal dietary iron intake using a validated quantified food frequency questionnaire.

RESULTS

The median (Q1, Q3) weeks of gestation of participants was 32 (26, 36) at enrolment. Anaemia, iron deficiency (ID), ID anaemia (IDA) and ID erythropoiesis (IDE) were present in 42%, 31%, 19% and 9.8% of participants, respectively. Median (Q1, Q3) dietary and supplemental iron intake during pregnancy was 16.8 (12.7, 20.5) mg/d and 65 (65, 65) mg/d, respectively. The median (max-min) total iron intake (diet and supplements) was 81 (8.8-101.8) mg/d, with 88% of participants having a daily intake above the tolerable upper intake level of 45 mg/d. No significant associations of anaemia and iron status with low birth weight and prematurity were observed. However, infants born to participants in the third hemoglobin (Hb) quartile (Hb > 11.3-12.2 g/dL) had a shorter gestation by 1 week than those in the fourth Hb quartile (Hb > 12.2 g/dL) (p = 0.009). Compared to pregnant women without HIV, women with HIV had increased odds of being anaemic (OR:2.14, 95%CI: 1.41, 3.247), having ID (OR:2.19, 95%CI: 1.42, 3.37), IDA (OR:2.23, 95%CI: 1.36, 3.67), IDE (OR:2.22, 95%CI: 1.16, 4.22) and delivering prematurely (OR:2.39, 95%CI: 1.01, 5.64).

CONCLUSION

In conclusion, anaemia, ID, and IDA were prevalent in this sample of pregnant women, despite the reported intake of prescribed iron supplements, with HIV-infected participants more likely to be iron deficient and anaemic. Research focusing on the best formulation and dosage of iron supplementation to enhance iron absorption and status, and compliance to supplementation is recommended, especially for those living with HIV infection.

Role of the CARD8 inflammasome in HIV pathogenesis

Human immunodeficiency virus (HIV) continues to be a significant global health challenge despite decades of research and advances in treatment. Substantial gaps in our understanding of the mechanisms of HIV pathogenesis and the host immune responses still exist. The interaction between HIV and these immune responses is pivotal in the disease progression to acquired immunodeficiency syndrome (AIDS). Recently, the caspase recruitment domain-containing protein 8 (CARD8) inflammasome has emerged as a crucial factor in orchestrating innate immune responses to HIV infection and exerting a substantial impact on viral pathogenesis. CARD8 restricts viral replication by detecting the activity of HIV protease. Conversely, it also contributes to the depletion of CD4+ T cells, a key feature of disease progression towards AIDS. The purpose of this review is to summarize the role of the CARD8 inflammasome in HIV pathogenesis, delving into its mechanisms of action and potential implications for the development of therapeutic strategies.

Entangled Connections: HIV and HPV Interplay in Cervical Cancer-A Comprehensive Review

Cervical cancer (CC) remains a prevalent malignancy and a significant global public health concern, primarily driven by persistent human papillomavirus (HPV) infections. The infectious nature of HPV underscores the preventability of CC through vaccination and screening programs. In addition to HPV, factors such as age, parity, smoking, hormonal contraceptives, and HIV co-infection elevate the risk of CC. HIV-associated immunodeficiency exacerbates susceptibility to infections and cancers, making CC a defining condition for acquired immune deficiency syndrome (AIDS) and one of the most commonly diagnosed cancers among women living with HIV (WLWH). These women face higher risks of HPV exposure due to sexual behavior and often encounter economic, social, and psychological barriers to screening. HIV and HPV co-infection can potentially accelerate CC carcinogenesis, with WLWH typically being diagnosed with CC earlier than their HIV-negative counterparts. Antiretroviral therapy (ART), which reduces AIDS-related mortality, also lowers the risk of invasive CC. The interaction between HIV and HPV is intricate and bidirectional. This summary reviews current evidence on HPV infection and CC in WLWH, highlighting the connections across pathogenesis, prevention, diagnosis, and treatment.

Exploring the role of topological descriptors to predict physicochemical properties of anti-HIV drugs by using supervised machine learning algorithms

In order to explore the role of topological indices for predicting physio-chemical properties of anti-HIV drugs, this research uses python program-based algorithms to compute topological indices as well as machine learning algorithms. Degree-based topological indices are calculated using Python algorithm, providing important information about the structural behavior of drugs that are essential to their anti-HIV effectiveness. Furthermore, machine learning algorithms analyze the physio-chemical properties that correspond to anti-HIV activities, making use of their ability to identify complex trends in large, convoluted datasets. In addition to improving our comprehension of the links between molecular structure and effectiveness, the collaboration between machine learning and QSPR research further highlights the potential of computational approaches in drug discovery. This work reveals the mechanisms underlying anti-HIV effectiveness, which paves the way for the development of more potent anti-HIV drugs. This work reveals the mechanisms underlying anti-HIV efficiency, which paves the way for the development of more potent anti-HIV drugs which demonstrates the invaluable advantages of machine learning in assessing drug properties by clarifying the biological processes underlying anti-HIV behavior, which paves the way for the design and development of more effective anti-HIV drugs.

T-cell responses to ancestral SARS-CoV-2 and Omicron variant among unvaccinated pregnant and postpartum women living with and without HIV in South Africa

SARS-CoV-2 cell-mediated immunity remains understudied during pregnancy in unvaccinated Black African women living with HIV (WLWH) from low- and middle-income countries. We investigated SARS-CoV-2-specific T-cell responses 1 month following infection in 24 HIV-uninfected women and 15 WLWH at any stage during pregnancy or postpartum. The full-length spike (FLS) glycoprotein and nucleocapsid (N) protein of wild-type (WT) SARS-CoV-2, as well as mutated spike protein regions found in the Omicron variant (B.1.1.529) were targeted by flow cytometry. WT-specific CD4+ and CD8+ T cells elicited similar FLS- and N-specific responses in HIV-uninfected women and WLWH. SARS-CoV-2-specific T-lymphocytes were predominantly TNF-α monofunctional in pregnant and postpartum women living with and without HIV, with fever cells producing either IFN-γ or IL-2. Furthermore, T-cell responses were unaffected by Omicron-specific spike mutations as similar responses between Omicron and the ancestral virus were detected for CD4+ and CD8+ T cells. Our results collectively demonstrate comparable T-cell responses between WLWH on antiretroviral therapy and HIV-uninfected pregnant and postpartum women who were naïve to Covid-19 vaccination. Additionally, we show that T cells from women infected with the ancestral virus, Beta variant (B.1.351), or Delta variant (B.1.617.2) can cross-recognize Omicron, suggesting an overall preservation of T-cell immunity.

HIV vaccination: Navigating the path to a transformative breakthrough-A review of current evidence

Background and Aim

Human immunodeficiency virus (HIV) remains a significant global health challenge, with approximately 39 million people living with HIV worldwide as of 2022. Despite progress in antiretroviral therapy, achieving the UNAIDS "95-95-95" target to end the HIV epidemic by 2025 faces challenges, particularly in sub-Saharan Africa. The pursuit of an HIV vaccine is crucial, offering durable immunity and the potential to end the epidemic. Challenges in vaccine development include the lack of known immune correlates, suitable animal models, and HIV's high mutation rate. This study aims to explore the current state of HIV vaccine development, focusing on the challenges and innovative approaches being investigated.

Methods

In writing this review, we conducted a search of medical databases such as PubMed, ResearchGate, Web of Science, Google Scholar, and Scopus. The exploration of messenger ribonucleic acid vaccines, which have proven successful in the SARS-CoV-2 pandemic, presents a promising avenue for HIV vaccine development. Understanding HIV-1's ability to infiltrate various bodily compartments, establish reservoirs, and manipulate immune responses is critical. Robust cytotoxic T lymphocytes and broadly neutralizing antibodies are identified as key components, though their production faces challenges. Innovative approaches, including computational learning and advanced drug delivery systems, are being investigated to effectively activate the immune system.

Results and Conclusions

Discrepancies between animal models and human responses have hindered the progress of vaccine development. Despite these challenges, ongoing research is focused on overcoming these obstacles through advanced methodologies and technologies. Addressing the challenges in HIV vaccine development is paramount to realizing an effective HIV-1 vaccine and achieving the goal of ending the epidemic. The integration of innovative approaches and a deeper understanding of HIV-1's mechanisms are essential steps toward this transformative breakthrough.

Help or Hinder: Protein Host Factors That Impact HIV-1 Replication

Interactions between human immunodeficiency virus type 1 (HIV-1) and the host factors or restriction factors of its target cells determine the cell's susceptibility to, and outcome of, infection. Factors intrinsic to the cell are involved at every step of the HIV-1 replication cycle, contributing to productive infection and replication, or severely attenuating the chances of success. Furthermore, factors unique to certain cell types contribute to the differences in infection between these cell types. Understanding the involvement of these factors in HIV-1 infection is a key requirement for the development of anti-HIV-1 therapies. As the list of factors grows, and the dynamic interactions between these factors and the virus are elucidated, comprehensive and up-to-date summaries that recount the knowledge gathered after decades of research are beneficial to the field, displaying what is known so that researchers can build off the groundwork of others to investigate what is unknown. Herein, we aim to provide a review focusing on protein host factors, both well-known and relatively new, that impact HIV-1 replication in a positive or negative manner at each stage of the replication cycle, highlighting factors unique to the various HIV-1 target cell types where appropriate.

T Cell Responses during Human Immunodeficiency Virus/Mycobacterium tuberculosis Coinfection

Coinfection with Mycobacterium tuberculosis (Mtb) and the human immunodeficiency virus (HIV) is a significant public health concern. Individuals infected with Mtb who acquire HIV are approximately 16 times more likely to develop active tuberculosis. T cells play an important role as both targets for HIV infection and mediators of the immune response against both pathogens. This review aims to synthesize the current literature and provide insights into the effects of HIV/Mtb coinfection on T cell populations and their contributions to immunity. Evidence from multiple in vitro and in vivo studies demonstrates that T helper responses are severely compromised during coinfection, leading to impaired cytotoxic responses. Moreover, HIV's targeting of Mtb-specific cells, including those within granulomas, offers an explanation for the severe progression of the disease. Herein, we discuss the patterns of differentiation, exhaustion, and transcriptomic changes in T cells during coinfection, as well as the metabolic adaptations that are necessary for T cell maintenance and functionality. This review highlights the interconnectedness of the immune response and the pathogenesis of HIV/Mtb coinfection.

Anti-HIV activity in traditional Chinese medicine: clinical implications of monomeric herbal remedies and compound decoctions

With the global spread of human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS), the pursuit of potent treatments has ascended as a paramount concern in global healthcare. Traditional Chinese medicine (TCM) has been used for thousands of years in China and other East Asian countries and it offers remedies for an extensive array of ailments, including HIV and AIDS. This review focuses on the clinical significance of single herbs and composite tonics in TCM with antiviral activity against HIV. Initially, the anti-HIV activity of single herbs was analyzed in detail. Many herbs have been shown to have significant anti-HIV activity. The active ingredients of these herbs exhibit their anti-HIV effects through various mechanisms, such as inhibiting viral replication, preventing viral binding to host cells, and interfering with the viral lifecycle. Furthermore, we delved into the clinical significance of HIV-associated formulations provided as a result of Chinese compound prescription. These combinations of herbal ingredients are designed to amplify therapeutic efficacy and minimize adverse effects. Clinical trials have demonstrated the therapeutic benefits of these prescriptions for individuals infected with HIV. The intricate composition of these prescriptions potentially augments their anti-HIV activity through synergistic effects. Additionally, this review underscores the clinical importance of TCM in the context of HIV treatment. While numerous herbs and prescriptions exhibit anti-HIV activity, their safety and efficacy in clinical applications warrant further investigation. When combined with contemporary antiretroviral drugs, TCM may serve as an adjunctive therapy, assisting in reducing side effects, and enhancing patients' quality of life. To optimally harness these natural resources, further exploration is imperative to ascertain their efficacy, safety, and optimal utilization, thereby offering a broader spectrum of therapeutic options for HIV-afflicted individuals.

Exploring the interplay between Kaposi's sarcoma and SARS-CoV-2 infection: A case series and systematic review

Kaposi's sarcoma (KS) is an angio-proliferative disease with a viral etiology and a multifactorial pathogenesis that results from immune dysfunction. In patients affected by latent viral infections such as herpesviruses, SARS-CoV-2 infection may result in lytic cycle reactivation in host cells. A robust immune system response is crucial for eliminating pathogens and resolving both latent and non-latent viral infections. We report a case series of KS characterized by tumor progression after SARS-CoV-2 infection. We performed a systematic literature review of the PubMed/MEDLINE and EMBASE databases. The keyword terms included "SARS-CoV-2," "HHV-8," "Kaposi's sarcoma," "IL-6," and "COVID-19." English language restriction was applied. Items not covered by our study were excluded. KS is a complex disease linked to an impaired immune system. Conditions that result in temporary or permanent immunodeficiency can trigger viral reactivation or exacerbate an existing disease. It is feasible that the increase in cytokine levels in COVID-19 patients, coupled with lymphocyte downregulation and treatment that induces herpesvirus lytic reactivation, may contribute to the progression of KS after SARS-CoV-2 infection. These observations suggest that patients with KS should be clinically monitored both during and after SARS-CoV-2 infection. Nevertheless, prospective data should be collected to validate this hypothesis and enhance our understanding of the mechanisms implicated in the onset or progression of KS.

Exosomal microRNAs associated with tuberculosis among people living with human immunodeficiency virus

Objective

To investigate the diagnostic value of selected exosomal miRNAs for Tuberculosis (TB) among people living with human immunodeficiency virus (PLHIV).

Methods

A total of 43 adult HIV patients, including 20 diagnosed with TB and 23 controls, were enrolled. The levels of six exosomal miRNAs (miR-20a, miR-20b, miR-26a, miR-106a, miR-191, and miR-486) were measured using qRT-PCR.

Results

The levels of these six exosomal miRNAs (miR-20a, miR-20b, miR-26a, miR-106a, miR-191, and miR-486) were significantly higher in the plasma of TB patients compared to controls among PLHIV. The Receiver Operating Characteristic (ROC) curve of these six miRNAs showed a fair performance in distinguishing TB patients from controls, with Area Under Curve (AUC) values of 0.78 (95 %CI 0.63-0.93), 0.81 (95 %CI 0.67-0.95), 0.77 (95 %CI 0.61-0.93), 0.84 (95 %CI 0.70-0.98), 0.82 (95 %CI 0.68-0.95) and 0.79 (95 %CI 0.65-0.93), respectively. These miRNAs showed higher AUC values for extrapulmonary tuberculosis compared to pulmonary tuberculosis. An analysis of subgroups was performed based on CD4 + T cell count (＜200 and ≥ 200 cells·µL-1). In the high CD4 count group, all these six exosomal miRNAs appeared to have higher AUC values compared to the low CD4 count group.

Conclusions

These six exosomal miRNAs could serve as potential biomarkers for diagnosing TB among PLHIV.

Safety and Efficacy of Antiviral Drugs and Vaccines in Pregnant Women: Insights from Physiologically Based Pharmacokinetic Modeling and Integration of Viral Infection Dynamics

Addressing the complexities of managing viral infections during pregnancy is essential for informed medical decision-making. This comprehensive review delves into the management of key viral infections impacting pregnant women, namely Human Immunodeficiency Virus (HIV), Hepatitis B Virus/Hepatitis C Virus (HBV/HCV), Influenza, Cytomegalovirus (CMV), and SARS-CoV-2 (COVID-19). We evaluate the safety and efficacy profiles of antiviral treatments for each infection, while also exploring innovative avenues such as gene vaccines and their potential in mitigating viral threats during pregnancy. Additionally, the review examines strategies to overcome challenges, encompassing prophylactic and therapeutic vaccine research, regulatory considerations, and safety protocols. Utilizing advanced methodologies, including PBPK modeling, machine learning, artificial intelligence, and causal inference, we can amplify our comprehension and decision-making capabilities in this intricate domain. This narrative review aims to shed light on diverse approaches and ongoing advancements, this review aims to foster progress in antiviral therapy for pregnant women, improving maternal and fetal health outcomes.

Association between obesity and cancer risk in adults with HIV in Korea

INTRODUCTION

This study aimed to investigate the association between obesity and cancer risk as well as site-specific cancer risks in adults with HIV using a nationwide health screening database in Korea.

METHODS

Of the 16,671 adults with a new diagnosis of HIV from 2004 to 2020, 456 incident cancer cases and 1814 individually matched controls by sex, year of birth, year of HIV diagnosis, and follow-up duration (1 : 4 ratio) were included in this nested case-control study. The association between obesity (BMI ≥25 kg/m 2 ) and cancer risks was estimated and presented as odds ratios (ORs) and 95% confidence intervals (95% CIs).

RESULTS

Of the 456 cancer incident cases, there were 146 AIDS-defining cancer cases and 310 non-AIDS-defining cancer cases. Compared with nonobese adults with HIV, obese adults with HIV were at higher risk of non-AIDS-defining cancer (OR = 1.478, 95% CI = 1.118-1.955). Otherwise, the overall risk of AIDS-defining cancer (OR = 0.816, 95% CI = 0.520-1.279) and each type of AIDS-defining cancer (Kaposi sarcoma and non-Hodgkin's lymphoma) were not high in obese adults with HIV. Of the specific types of non-AIDS-defining cancers, obesity was associated with an increased risk of colorectal cancer (OR = 3.090, 95% CI = 1.110-8.604) and liver, bile duct, and pancreatic cancers (OR = 2.532, 95% CI = 1.141-5.617).

CONCLUSION

Obesity, which is one of the important health concerns in HIV management, was associated with an increased risk of non-AIDS-defining cancer but not AIDS-defining cancer.

Incidence and predictors of tuberculosis among HIV-infected children after initiation of antiretroviral therapy in Ethiopia: A systematic review and meta-analysis

BACKGROUND

Globally, Tuberculosis (TB) is the main cause of morbidity and mortality among infectious disease. TB and Human Immune Virus (HIV) are the two deadly pandemics which interconnected each other tragically, and jeopardize the lives of children; particularly in Sub-Saharan Africa. Therefore, this review was aimed to determine the aggregated national pooled incidence of tuberculosis among HIV- infected children and its predictors in Ethiopia.

METHODS

An electronic search engine (HINARI, PubMed, Scopus, web of science), Google scholar and free Google databases were searched to find eligible studies. Quality of the studies was checked using the Joanna Briggs Institute (JBI) quality assessment checklists for cohort studies. Heterogeneity between studies was evaluated using Cochrane Q-test and the I2 statistics.

RESULT

This review revealed that the pooled national incidence of tuberculosis among children with HIV after initiation of ART was 3.63% (95% CI: 2.726-4.532) per 100-person-years observations. Being Anemic, poor and fair ART adherence, advanced WHO clinical staging, missing of cotrimoxazole and isoniazid preventing therapy, low CD4 cell count, and undernutrition were significant predictors of tuberculosis incidence.

CONCLUSION

The study result indicated that the incidence of TB among HIV- infected children is still high. Therefore, parents/guardians should strictly follow and adjust nutritional status of their children to boost immunity, prevent undernutrition and opportunistic infections. Cotrimoxazole and isoniazid preventive therapy need to continually provide for HIV- infected children for the sake of enhancing CD4/immune cells, reduce viral load, and prevent from advanced disease stages. Furthermore, clinicians and parents strictly follow ART adherence.

Flow cytometry-based method using diversity of cytokine production differentiates between Mycobacterium tuberculosis infection and disease

Authors present a pilot study of the development of innovative flow cytometry-based assay with a potential for use in tuberculosis diagnostics. Currently available tests do not provide robust discrimination between latent tuberculosis infection (TBI) and tuberculosis disease (TB). The desired application is to distinguish between the two conditions by evaluating the production of a combination of three cytokines: IL-2 (interleukin-2), IFNɣ (interferon gamma) and TNFɑ (tumor necrosis factor alpha) in CD4+ and CD8+ T cells. The study was conducted on 68 participants, divided into two arms according to age (paediatric and adults). Each arm was further split into three categories (non-infection (NI), TBI, TB) based on the immune reaction to Mycobacterium tuberculosis (M.tb) after a close contact with pulmonary TB. Each blood sample was stimulated with specific M.tb antigens present in QuantiFERON tubes (TB1 and TB2). We inferred TBI or TB based on the predominant cytokine response of the CD4+ and/or CD8+ T cells. Significant differences were detected between the NI, TBI and the TB groups in TB1 in the CD4+TNFɑ+parameter in children. Along with IL-2, TNFɑ seems to be the most promising diagnostic marker in both CD4+and CD8+ T cells. However, more detailed analyses on larger cohorts are needed to confirm the observed tendencies.

Elevated Inflammation Associated with Markers of Neutrophil Function and Gastrointestinal Disruption in Pilot Study of Plasmodium fragile Co-Infection of ART-Treated SIVmac239+ Rhesus Macaques

Human immunodeficiency virus (HIV) and malaria, caused by infection with Plasmodium spp., are endemic in similar geographical locations. As a result, there is high potential for HIV/Plasmodium co-infection, which increases the pathology of both diseases. However, the immunological mechanisms underlying the exacerbated disease pathology observed in co-infected individuals are poorly understood. Moreover, there is limited data available on the impact of Plasmodium co-infection on antiretroviral (ART)-treated HIV infection. Here, we used the rhesus macaque (RM) model to conduct a pilot study to establish a model of Plasmodium fragile co-infection during ART-treated simian immunodeficiency virus (SIV) infection, and to begin to characterize the immunopathogenic effect of co-infection in the context of ART. We observed that P. fragile co-infection resulted in parasitemia and anemia, as well as persistently detectable viral loads (VLs) and decreased absolute CD4+ T-cell counts despite daily ART treatment. Notably, P. fragile co-infection was associated with increased levels of inflammatory cytokines, including monocyte chemoattractant protein 1 (MCP-1). P. fragile co-infection was also associated with increased levels of neutrophil elastase, a plasma marker of neutrophil extracellular trap (NET) formation, but significant decreases in markers of neutrophil degranulation, potentially indicating a shift in the neutrophil functionality during co-infection. Finally, we characterized the levels of plasma markers of gastrointestinal (GI) barrier permeability and microbial translocation and observed significant correlations between indicators of GI dysfunction, clinical markers of SIV and Plasmodium infection, and neutrophil frequency and function. Taken together, these pilot data verify the utility of using the RM model to examine ART-treated SIV/P. fragile co-infection, and indicate that neutrophil-driven inflammation and GI dysfunction may underlie heightened SIV/P. fragile co-infection pathogenesis.

A novel web-based risk calculator for predicting surgical site infection in HIV-positive facture patients: a multicenter cohort study in China

Background

Surgical site infection (SSI) is a common complication in HIV-positive fracture patients undergoing surgery, leading to increased morbidity, mortality, and healthcare costs. Accurate prediction of SSI risk can help guide clinical decision-making and improve patient outcomes. However, there is a lack of user-friendly, Web-based calculator for predicting SSI risk in this patient population.

Objective

This study aimed to develop and validate a novel web-based risk calculator for predicting SSI in HIV-positive fracture patients undergoing surgery in China.

Method

A multicenter retrospective cohort study was conducted using data from HIV-positive fracture patients who underwent surgery in three tertiary hospitals in China between May 2011 and September 2023. We used patients from Beijing Ditan Hospital as the training cohort and patients from Chengdu Public Health and Changsha First Hospital as the external validation cohort. Univariate, multivariate logistic regression analyses and SVM-RFE were performed to identify independent risk factors for SSIs. A web-based calculator was developed using the identified risk factors and validated using an external validation cohort. The performance of the nomogram was evaluated using the area under the receiver operating characteristic (AUC) curves, calibration plots, and decision curve analysis (DCA).

Results

A total of 338 HIV-positive patients were included in the study, with 216 patients in the training cohort and 122 patients in the validation cohort. The overall SSI incidence was 10.7%. The web-based risk calculator (https://sydtliubo.shinyapps.io/DynNom_for_SSI/) incorporated six risk factors: HBV/HCV co-infection, HIV RNA load, CD4+ T-cell count, Neu and Lym level. The nomogram demonstrated good discrimination, with an AUC of 0.890 in the training cohort and 0.853 in the validation cohort. The calibration plot showed good agreement between predicted and observed SSI probabilities. The DCA indicated that the nomogram had clinical utility across a wide range of threshold probabilities.

Conclusion

Our study developed and validated a novel web-based risk calculator for predicting SSI risk in HIV-positive fracture patients undergoing surgery in China. The nomogram demonstrated good discrimination, calibration, and clinical utility, and can serve as a valuable tool for risk stratification and clinical decision-making in this patient population. Future studies should focus on integrating this nomogram into hospital information systems for real-time risk assessment and management.

Non-Coding RNAs in HIV Infection, NeuroHIV, and Related Comorbidities

NeuroHIV affects approximately 30-60% of people living with HIV-1 (PLWH) and is characterized by varying degrees of cognitive impairments, presenting a multifaceted challenge, the underlying cause of which is chronic, low-level neuroinflammation. Such smoldering neuroinflammation is likely an outcome of lifelong reliance on antiretrovirals coupled with residual virus replication in the brains of PLWH. Despite advancements in antiretroviral therapeutics, our understanding of the molecular mechanism(s) driving inflammatory processes in the brain remains limited. Recent times have seen the emergence of non-coding RNAs (ncRNAs) as critical regulators of gene expression, underlying the neuroinflammatory processes in HIV infection, NeuroHIV, and their associated comorbidities. This review explores the role of various classes of ncRNAs and their regulatory functions implicated in HIV infection, neuropathogenesis, and related conditions. The dysregulated expression of ncRNAs is known to exacerbate the neuroinflammatory responses, thus contributing to neurocognitive impairments in PLWH. This review also discusses the diagnostic and therapeutic potential of ncRNAs in HIV infection and its comorbidities, suggesting their utility as non-invasive biomarkers and targets for modulating neuroinflammatory pathways. Understanding these regulatory roles could pave the way for novel diagnostic strategies and therapeutic interventions in the context of HIV and its comorbidities.

Single domain antibodies from camelids in the treatment of microbial infections

Infectious diseases continue to pose significant global health challenges. In addition to the enduring burdens of ailments like malaria and HIV, the emergence of nosocomial outbreaks driven by antibiotic-resistant pathogens underscores the ongoing threats. Furthermore, recent infectious disease crises, exemplified by the Ebola and SARS-CoV-2 outbreaks, have intensified the pursuit of more effective and efficient diagnostic and therapeutic solutions. Among the promising options, antibodies have garnered significant attention due to their favorable structural characteristics and versatile applications. Notably, nanobodies (Nbs), the smallest functional single-domain antibodies of heavy-chain only antibodies produced by camelids, exhibit remarkable capabilities in stable antigen binding. They offer unique advantages such as ease of expression and modification and enhanced stability, as well as improved hydrophilicity compared to conventional antibody fragments (antigen-binding fragments (Fab) or single-chain variable fragments (scFv)) that can aggregate due to their low solubility. Nanobodies directly target antigen epitopes or can be engineered into multivalent Nbs and Nb-fusion proteins, expanding their therapeutic potential. This review is dedicated to charting the progress in Nb research, particularly those derived from camelids, and highlighting their diverse applications in treating infectious diseases, spanning both human and animal contexts.

Pre-existing cell populations with cytotoxic activity against SARS-CoV-2 in people with HIV and normal CD4/CD8 ratio previously unexposed to the virus

Introduction

HIV-1 infection may produce a detrimental effect on the immune response. Early start of antiretroviral therapy (ART) is recommended to preserve the integrity of the immune system. In fact, people with HIV (PWH) and normal CD4/CD8 ratio appear not to be more susceptible to severe forms of COVID-19 than the general population and they usually present a good seroconversion rate in response to vaccination against SARS-CoV-2. However, few studies have fully characterized the development of cytotoxic immune populations in response to COVID-19 vaccination in these individuals.

Methods

In this study, we recruited PWH with median time of HIV-1 infection of 6 years, median CD4/CD8 ratio of 1.0, good adherence to ART, persistently undetectable viral load, and negative serology against SARS-CoV-2, who then received the complete vaccination schedule against COVID-19. Blood samples were taken before vaccination against COVID-19 and one month after receiving the complete vaccination schedule.

Results

PWH produced high levels of IgG against SARS-CoV-2 in response to vaccination that were comparable to healthy donors, with a significantly higher neutralization capacity. Interestingly, the cytotoxic activity of PBMCs from PWH against SARS-CoV-2-infected cells was higher than healthy donors before receiving the vaccination schedule, pointing out the pre-existence of activated cell populations with likely unspecific antiviral activity. The characterization of these cytotoxic cell populations revealed high levels of Tgd cells with degranulation capacity against SARS-CoV-2-infected cells. In response to vaccination, the degranulation capacity of CD8+ T cells also increased in PWH but not in healthy donors.

Discussion

The full vaccination schedule against COVID-19 did not modify the ability to respond against HIV-1-infected cells in PWH and these individuals did not show more susceptibility to breakthrough infection with SARS-CoV-2 than healthy donors after 12 months of follow-up. These results revealed the development of protective cell populations with broad-spectrum antiviral activity in PWH with normal CD4/CD8 ratio and confirmed the importance of early ART and treatment adherence to avoid immune dysfunctions.

A novel humanized mouse model for HIV and tuberculosis co-infection studies

Background

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), continues to be a major public health problem worldwide. The human immunodeficiency virus (HIV) is another equally important life-threatening pathogen. HIV infection decreases CD4+ T cell levels markedly increasing Mtb co-infections. An appropriate animal model for HIV/Mtb co-infection that can recapitulate the diversity of the immune response in humans during co-infection would facilitate basic and translational research in HIV/Mtb infections. Herein, we describe a novel humanized mouse model.

Methods

The irradiated NSG-SGM3 mice were transplanted with human CD34+ hematopoietic stem cells, and the humanization was monitored by staining various immune cell markers for flow cytometry. They were challenged with HIV and/or Mtb, and the CD4+ T cell depletion and HIV viral load were monitored over time. Before necropsy, the live mice were subjected to pulmonary function test and CT scan, and after sacrifice, the lung and spleen homogenates were used to determine Mtb load (CFU) and cytokine/chemokine levels by multiplex assay, and lung sections were analyzed for histopathology. The mouse sera were subjected to metabolomics analysis.

Results

Our humanized NSG-SGM3 mice were able to engraft human CD34+ stem cells, which then differentiated into a full-lineage of human immune cell subsets. After co-infection with HIV and Mtb, these mice showed decrease in CD4+ T cell counts overtime and elevated HIV load in the sera, similar to the infection pattern of humans. Additionally, Mtb caused infections in both lungs and spleen, and induced granulomatous lesions in the lungs. Distinct metabolomic profiles were also observed in the tissues from different mouse groups after co-infections.

Conclusion

The humanized NSG-SGM3 mice are able to recapitulate the pathogenic effects of HIV and Mtb infections and co-infection at the pathological, immunological and metabolism levels and are therefore a reproducible small animal model for studying HIV/Mtb co-infection.

Detectable Virological Load and Associated Factors among People Living with HIV on Antiretroviral Treatment: A Retrospective Study

The complete and prolonged suppression of viral load is the primary objective of HAART in people living with HIV. Some people may experience therapeutic failure, while others may achieve virological suppression but are unable to maintain it, developing persistent or single detection of low-level viremia. This study aims to evaluate the determinants of a detectable viral load among patients on HAART to identify and address them promptly. In this retrospective study, all patients referring to the Infectious Disease Operative Unit of the Vito Fazzi Hospital in Lecce, Puglia, older than 18 years, receiving HAART for at least 12 months as of 30 June 2022, were included. For each patient, demographic characteristics such as age, sex, educational level, stable relationship, cohabitation, employment status, and information relating to habits and lifestyles such as physical activity, use of drugs, and substances or supplements for sport, abuse of alcohol, and smoking were collected. Degree of comorbidity was quantified according to the Charlson Comorbidity Index, and the presence of obesity and the COVID-19 infection was also considered. Univariable and multivariable logistic regression models were used to assess the association between patients' characteristics and the outcome. In the multivariable logistic regression model, the odds were lower for the duration of therapy (OR: 0.96; p = 0.0397), prescriber's perception of adherence to therapy (OR: 0.50; p < 0.0001), and Nadir CD4+ T-cell count (OR: 0.85; p = 0.0329), and higher for the presence of AIDS (OR: 1.89; p = 0.0423) and COVID-19 (OR: 2.31; p = 0.0182). Our findings support the early initiation of HAART to achieve virological suppression. Additionally, measures to improve adherence to therapy should be adopted to ensure better outcomes for patients.

The Prognosis for Delayed Immune Recovery in HIV-Infected Children might be Associated with Pre-cART CD4 + T cell Count Irrespective of Co-Infection with Tuberculosis

Background

Immune reconstitution following the initiation of combination antiretroviral therapy (cART) significantly impacts the prognosis of individuals infected with human immunodeficiency virus (HIV). Our previous studies have indicated that the baseline CD4+ T cells count and percentage before cART initiation are predictors of immune recovery in TB-negative children infected with HIV, with TB co-infection potentially causing a delay in immune recovery. However, it remains unclear whether these predictors consistently impact immune reconstitution during long-term intensive cART treatment in TB-negative/positive children infected with HIV.

Results

We confirmed that the baseline CD4+ T cell count is a significant predictor of immune recovery following long-term intensive cART treatment among children aged 5 to 18 years. Children with lower CD4+ T cell count prior cART initiation did not show substantial immunological recovery during the follow-up period. Interestingly, children who were co-infected with TB and had higher baseline CD4+ T cell count eventually achieved good immunological recovery comparable to the TB-negative HIV-infected children. Hence, the baseline CD4+ T cell count at the onset of treatment serves as a reliable predictor of immunological reconstitution in HIV-infected children with or without TB co-infection. Taken together, this follow-up study validates our previous findings and further establishes that initiating cART early alongside early HIV testing can help prevent the diminished CD4+ T cell count associated with inadequate immunological reconstitution.

High-parameter phenotypic characterization reveals a subset of human Th17 cells that preferentially produce IL-17 against M. tuberculosis antigen

Background

Interleukin-17-producing CD4 T cells contribute to the control of Mycobacterium tuberculosis (Mtb) infection in humans; whether infection with human immunodeficiency virus (HIV) disproportionately affects distinct Th17-cell subsets that respond to Mtb is incompletely defined.

Methods

We performed high-definition characterization of circulating Mtb-specific Th17 cells by spectral flow cytometry in people with latent TB and treated HIV (HIV-ART). We also measured kynurenine pathway activity by liquid chromatography-mass spectrometry (LC/MS) on plasma and tested the hypothesis that tryptophan catabolism influences Th17-cell frequencies in this context.

Results

We identified two subsets of Th17 cells: subset 1 defined as CD4+Vα7.2-CD161+CD26+and subset 2 defined as CD4+Vα7.2-CCR6+CXCR3-cells of which subset 1 was significantly reduced in latent tuberculosis infection (LTBI) with HIV-ART, yet Mtb-responsive IL-17-producing CD4 T cells were preserved; we found that IL-17-producing CD4 T cells dominate the response to Mtb antigen but not cytomegalovirus (CMV) antigen or staphylococcal enterotoxin B (SEB), and tryptophan catabolism negatively correlates with both subset 1 and subset 2 Th17-cell frequencies.

Conclusions

We found differential effects of ART-suppressed HIV on distinct subsets of Th17 cells, that IL-17-producing CD4 T cells dominate responses to Mtb but not CMV antigen or SEB, and that kynurenine pathway activity is associated with decreases of circulating Th17 cells that may contribute to tuberculosis immunity.

Plasma Virome of HIV-infected Subjects on Suppressive Antiretroviral Therapy Reveals Association of Differentially Abundant Viruses with Distinct T-cell Phenotypes and Inflammation

Background

The plasma virome represents the overall composition of viral sequences present in it. Alteration in plasma virome has been reported in treatment naïve and immunocompromised (CD4 count < 200) people with HIV (PWH). However, the effect of ART on virome composition in PWH on ART with preserved CD4 counts is poorly understood.

Objectives

We aimed to assess the alterations in plasma virome in PWH on ART in comparison to HIV-negative uninfected controls and to further investigate possible associations of plasma viruses with inflammation and immune dysfunction, namely, immunosenescence and immune exhaustion.

Methods

Plasma viral DNA from PWH on ART and controls was used for sequencing on the Illumina Nextseq500 platform, followed by the identification of viral sequences using an automated pipeline, VIROMATCH. Multiplex cytokine assay was performed to measure the concentrations of various cytokines in plasma. Immunophenotyping was performed on PBMCs to identify T cell markers of immunosenescence and immune exhaustion.

Results

In our observational, cross-sectional pilot study, chronically infected PWH on ART had significantly different viral species compositions compared to controls. The plasma virome of PWH showed a significantly high relative abundance of species Human gammaherpesvirus 4, also known as Epstein-Barr virus (EBV). Moreover, EBV emerged as a significant viral taxon differentially enriched in PWH on ART, which further correlated positively with the exhaustion phenotype of T cells and significantly increased TNF-α in PWH on ART. Additionally, a significantly increased proportion of senescent T cells and IL-8 cytokine was detected in PWH on ART.

Conclusion

Altered plasma virome influenced the inflammatory response and T-cell phenotype in PWH on ART.

CD4+ T cell count and HIV-1 viral load dynamics positively impacted by H. pylori infection in HIV-positive patients regardless of ART status in a high-burden setting

BACKGROUND

There is a widespread co-infection of HIV and Helicobacter pylori (H. pylori) globally, particularly in developing countries, and it has been suggested that this co-infection may affect the course of HIV disease. However, the interplay between H. pylori infection and HIV disease progression is not fully elucidated. In this study, we investigated the effect of H. pylori co-infection on CD4+ T cell count and HIV viral load dynamics in HIV-positive individuals in a high co-endemic setting.

METHODS

A comparative cross-sectional study was conducted among 288 HIV-positive and 175 HIV-negative individuals, both with and without H. pylori infection. Among HIV-positive participants, 195 were on antiretroviral therapy (ART) and 93 were ART-naïve. CD4+ T cell count and HIV-1 viral load were measured and compared between H. pylori-infected and -uninfected individuals, taking into account different HIV and ART status.

RESULT

Our study demonstrated that individuals infected with H. pylori had a significantly higher CD4+ T cell count compared to uninfected controls among both HIV-negative and HIV-positive participants, regardless of ART therapy. Conversely, HIV/H. pylori co-infected participants had lower HIV-1 viral load than those without H. pylori infection. Linear regression analysis further confirmed a positive association between H. pylori infection, along with other clinical factors such as BMI, ART, and duration of therapy, with CD4+ T cell count while indicating an inverse relationship with HIV-1 viral load in HIV-positive patients. Additionally, factors such as khat chewing, age and WHO clinical stage of HIV were associated with reduced CD4+ T cell count and increased HIV-1 viral load.

CONCLUSION

Our study demonstrates that H. pylori co-infection was associated with higher CD4+ T cell count and lower HIV-1 viral load in HIV-positive patients, regardless of ART status. These findings show a positive effect of H. pylori co-infection on the dynamics of HIV-related immunological and virological parameters. Further studies are needed to elucidate the underlying mechanisms of the observed effects.

The spleen is the graveyard of CD4+ cells in patients with immunological failure of visceral leishmaniasis and AIDS

BACKGROUND

Visceral leishmaniasis (VL), or kala-azar, is a common comorbidity in patients with AIDS in endemic areas. Many patients continue to experiences relapses of VL despite virological control, but with immunological failure. These patients remain chronically symptomatic with hypersplenism, for example with anemia, leukopenia, and thrombocytopenia, and are at risk of severe co-infection due to low CD4+ count. Therefore, in this study, splenectomized patients with VL and HIV infection were investigated to understand why the CD4+ count fails to recover in these patients, evaluating the importance of spleen mass for hypersplenism and immunological failure.

METHODS

From a retrospective open cohort of 13 patients who had previously undergone splenectomy as salvage therapy for relapsing VL, 11 patients with HIV infection were investigated. This study compared the patients' complete blood cell count (CBC) and CD4+ and CD8+ cell counts before and after splenectomy with respect to spleen weight.

RESULTS

CBC was substantially improved after splenectomy, indicating hypersplenism. However, to the best of our knowledge, this is the first study to show that spleen mass is strongly and negatively correlated with CD4+ cell count (ρ = -0.71, P = 0.015).

CONCLUSIONS

This finding was unexpected, as the spleen is the most extensive lymphoid tissue and T-lymphocyte source. After reviewing the literature and reasoning, we hypothesized that the immunological failure was secondary to CD4+ loss initially by apoptosis in the spleen induced by productive HIV infection and, subsequently, by pyroptosis sustained by parasitic infection in spleen macrophages.

Early Initiation of Antiretroviral Therapy Preserves the Metabolic Function of CD4+ T Cells in Subtype C Human Immunodeficiency Virus 1 Infection

BACKGROUND

Immune dysfunction often persists in people living with human immunodeficiency virus (HIV) who are on antiretroviral therapy (ART), clinically manifesting as HIV-1-associated comorbid conditions. Early ART initiation may reduce incidence of HIV-1-associated immune dysfunction and comorbid conditions. Immunometabolism is a critical determinant of functional immunity. We investigated the effect of HIV-1 infection and timing of ART initiation on CD4+ T cell metabolism and function.

METHODS

Longitudinal blood samples from people living with HIV who initiated ART during hyperacute HIV-1 infection (HHI; before peak viremia) or chronic HIV-1 infection (CHI) were assessed for the metabolic and immune functions of CD4+ T cells. Metabolite uptake and mitochondrial mass were measured using fluorescent analogues and MitoTracker Green accumulation, respectively, and were correlated with CD4+ T cell effector functions.

RESULTS

Initiation of ART during HHI prevented dysregulation of glucose uptake by CD4+ T cells, but glucose uptake was reduced before and after ART initiation in CHI. Glucose uptake positively correlated with interleukin-2 and tumor necrosis factor-α production by CD4+ T cells. CHI was associated with elevated mitochondrial mass in effector memory CD4+ T cells that persisted after ART and correlated with PD-1 expression.

CONCLUSIONS

ART initiation in HHI largely prevented metabolic impairment of CD4+ T cells. ART initiation in CHI was associated with persistently dysregulated immunometabolism of CD4+ T cells, which was associated with impaired cellular functions and exhaustion.

Oxidative phosphorylation in HIV-1 infection: impacts on cellular metabolism and immune function

Human Immunodeficiency Virus Type 1 (HIV-1) presents significant challenges to the immune system, predominantly characterized by CD4+ T cell depletion, leading to Acquired Immunodeficiency Syndrome (AIDS). Antiretroviral therapy (ART) effectively suppresses the viral load in people with HIV (PWH), leading to a state of chronic infection that is associated with inflammation. This review explores the complex relationship between oxidative phosphorylation, a crucial metabolic pathway for cellular energy production, and HIV-1, emphasizing the dual impact of HIV-1 infection and the metabolic and mitochondrial effects of ART. The review highlights how HIV-1 infection disrupts oxidative phosphorylation, promoting glycolysis and fatty acid synthesis to facilitate viral replication. ART can exacerbate metabolic dysregulation despite controlling viral replication, impacting mitochondrial DNA synthesis and enhancing reactive oxygen species production. These effects collectively contribute to significant changes in oxidative phosphorylation, influencing immune cell metabolism and function. Adenosine triphosphate (ATP) generated through oxidative phosphorylation can influence the metabolic landscape of infected cells through ATP-detected purinergic signaling and contributes to immunometabolic dysfunction. Future research should focus on identifying specific targets within this pathway and exploring the role of purinergic signaling in HIV-1 pathogenesis to enhance HIV-1 treatment modalities, addressing both viral infection and its metabolic consequences.

A Novel Humanized Mouse Model for HIV and Tuberculosis Co-infection Studies

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), continues to be a major public health problem worldwide. The human immunodeficiency virus (HIV) is another equally important life-threatening pathogen. Further, co-infections with HIV and Mtb have severe effects in the host, with people infected with HIV being fifteen to twenty-one times more likely to develop active TB. The use of an appropriate animal model for HIV/Mtb co-infection that can recapitulate the diversity of the immune response in humans would be a useful tool for conducting basic and translational research in HIV/Mtb infections. The present study was focused on developing a humanized mouse model for investigations on HIV-Mtb co-infection. Using NSG-SGM3 mice that can engraft human stem cells, our studies showed that they were able to engraft human CD34+ stem cells which then differentiate into a full-lineage of human immune cell subsets. After co-infection with HIV and Mtb, these mice showed decrease in CD4+ T cell counts overtime and elevated HIV load in the sera, similar to the infection pattern of humans. Additionally, Mtb caused infections in both lungs and spleen, and induced the development of granulomatous lesions in the lungs, detected by CT scan and histopathology. Distinct metabolomic profiles were also observed in the tissues from different mouse groups after co-infections. Our results suggest that the humanized NSG-SGM3 mice are able to recapitulate the effects of HIV and Mtb infections and co-infection in the human host at pathological, immunological and metabolism levels, providing a dependable small animal model for studying HIV/Mtb co-infection.

A combined biochemical and cellular approach reveals Zn2+-dependent hetero- and homodimeric CD4 and Lck assemblies in T cells

The CD4 or CD8 co-receptors' interaction with the protein-tyrosine kinase Lck initiates the tyrosine phosphorylation cascade leading to T cell activation. A critical question is: to what extent are co-receptors and Lck coupled? Our contribution concerns Zn2+, indispensable for CD4- and CD8-Lck formation. We combined biochemical and cellular approaches to show that dynamic fluctuations of free Zn2+ in physiological ranges influence Zn(CD4)2 and Zn(CD4)(Lck) species formation and their ratio, although the same Zn(Cys)2(Cys)2 cores. Moreover, we demonstrated that the affinity of Zn2+ to CD4 and CD4-Lck species differs significantly. Increased intracellular free Zn2+ concentration in T cells causes higher CD4 partitioning in the plasma membrane. We additionally found that CD4 palmitoylation decreases the specificity of CD4-Lck formation in the reconstituted membrane model. Our findings help elucidate co-receptor-Lck coupling stoichiometry and demonstrate that intracellular free Zn2+ has a major role in the interplay between CD4 dimers and CD4-Lck assembly.

The Role of Glutathione in the Management of Cell-Mediated Immune Responses in Individuals with HIV

Human immunodeficiency virus (HIV) is a major cause of death worldwide. Without appropriate antiretroviral therapy, the infection can develop into acquired immunodeficiency syndrome (AIDS). AIDS leads to the dysregulation of cell-mediated immunity resulting in increased susceptibility to opportunistic infections and excessive amounts of inflammatory cytokines. HIV-positive individuals also demonstrate diminished glutathione (GSH) levels which allows for increased viral replication and increased pro-inflammatory cytokine release, further contributing to the high rates of mortality seen in patients with HIV. Adequate GSH supplementation has reduced inflammation and slowed the decline of CD4+ T cell counts in HIV-positive individuals. We aim to review the current literature regarding the role of GSH in cell-mediated immune responses in individuals with HIV- and AIDS-defining illnesses.

Epigenetic modulation of myeloid cell functions in HIV and SARS-CoV-2 infection

Myeloid cells play a vital role in innate immune responses as they recognize and phagocytose pathogens like viruses, present antigens, produce cytokines, recruit other immune cells to combat infections, and contribute to the attenuation of immune responses to restore homeostasis. Signal integration by pathogen recognition receptors enables myeloid cells to adapt their functions by a network of transcription factors and chromatin remodelers. This review provides a brief overview of the subtypes of myeloid cells and the main epigenetic regulation mechanisms. Special focus is placed on the epigenomic alterations in viral nucleic acids of HIV and SARS-CoV-2 along with the epigenetic changes in the host's myeloid cell compartment. These changes are important as they lead to immune suppression and promote the progression of the disease. Finally, we highlight some promising examples of 'epidrugs' that modulate the epigenome of immune cells and could be used as therapeutics for viral infections.

Crosstalk between gut microbiome and neuroinflammation in pathogenesis of HIV-associated neurocognitive disorder

HIV-associated neurocognitive disorder (HAND) has become a chronic neurodegenerative disease affecting the quality of life in people living with HIV (PLWH). Despite an established association between HAND and neuroinflammation induced by HIV proteins (gp120, Tat, Rev., Nef, and Vpr), the pathogenesis of HAND remains to be fully elucidated. Accumulating evidence demonstrated that the gut microbiome is emerging as a critical regulator of various neurodegenerative diseases (e.g., Parkinson's disease, Alzheimer's disease), suggesting that the crosstalk between the gut microbiome and neuroinflammation may contribute to the development of these diseases, for example, gut dysbiosis and microbiota-derived metabolites can trigger inflammation in the brain. However, the potential role of the gut microbiome in the pathogenesis of HAND remains largely unexplored. In this review, we aim to discuss and elucidate the HAND pathogenesis correlated with gut microbiome and neuroinflammation, and intend to explore the probable intervention strategies for HAND.

HIV-Related Oral Mucosa Lesions: A Cross-Sectional Study on a Cohort of Italian Patients

BACKGROUND

Human immunodeficiency virus (HIV) infection can be associated with oral mucosal diseases, including oral candidiasis and HPV infection, which are putative indicators of the immune status.

AIM AND METHODS

This retrospective cross-sectional study was aimed at assessing the prevalence of HIV-related oral mucosal lesions in a cohort of Italian HIV+ patients regularly attending the Clinics of Infectious Diseases.

RESULTS

One hundred seventy-seven (n = 177) patients were enrolled and 30 (16.9%) of them showed HIV-related diseases of the oral mucosa. They were mainly found in male patients over 35 years old, undergoing Combination Antiretroviral Therapy (cART), and with CD4+ count < 500/µL. Oral candidiasis was the most common HIV-related oral lesion. No significant correlations could be detected between the prevalence of HPV infection and other clinical parameters (lymphocyte count, cART treatment and viral load).

CONCLUSIONS

HIV-related oral mucosal diseases can correlate with immunosuppression. Early diagnosis and management of oral lesions in HIV+ patients should be part of the regular follow-up, from a multidisciplinary perspective of collaboration between oral medicine and infectious disease specialists, in an attempt to reduce morbidity due to oral lesions and modulate antiretroviral therapy according to the patient's immune status.

Gut Microbiota and Other Factors Associated With Increased Regulatory T Cells in Hiv-exposed Uninfected Infants

HIV-exposed uninfected infants (HEU) have higher infectious morbidity than HIV-unexposed infants (HUU). HEU have multiple immune defects of unknown origin. We hypothesized that HEU have higher regulatory T cells (Treg) than HUU, which may dampen their immune defenses against pathogens. We compared 25 Treg subsets between HEU and HUU and sought the factors that may affect Treg frequencies. At birth, 3 Treg subsets, including CD4 + FOXP3 + and CD4 + FOXP3 + CD25+, had higher frequencies in 123 HEU than 117 HUU and 3 subsets were higher in HUU. At 28 and 62 weeks of life, 5 Treg subsets were higher in HEU, and none were higher in HUU. The frequencies of the discrepant Treg subsets correlated at birth with differential abundances of bacterial taxas in maternal gut microbiome and at subsequent visits in infant gut microbiomes. In vitro, bacterial taxa most abundant in HEU expanded Treg subsets with higher frequencies in HEU, recapitulating the in vivo observations. Other factors that correlated with increased Treg were low maternal CD4 + T cells in HEU at birth and male sex in HUU at 28 weeks. We conclude that maternal and infant gut dysbiosis are central to the Treg increase in HEU and may be targeted by mitigating interventions.

Next-generation bNAbs for HIV-1 cure strategies

Despite the ability to suppress viral replication using anti-retroviral therapy (ART), HIV-1 remains a global public health problem. Curative strategies for HIV-1 have to target and eradicate latently infected cells across the body, i.e. the viral reservoir. Broadly neutralizing antibodies (bNAbs) targeting the HIV-1 envelope glycoprotein (Env) have the capacity to neutralize virions and bind to infected cells to initiate elimination of these cells. To improve the efficacy of bNAbs in terms of viral suppression and viral reservoir eradication, next generation antibodies (Abs) are being developed that address the current limitations of Ab treatment efficacy; (1) low antigen (Env) density on (reactivated) HIV-1 infected cells, (2) high viral genetic diversity, (3) exhaustion of immune cells and (4) short half-life of Abs. In this review we summarize and discuss preclinical and clinical studies in which anti-HIV-1 Abs demonstrated potent viral control, and describe the development of engineered Abs that could address the limitations described above. Next generation Abs with optimized effector function, avidity, effector cell recruitment and immune cell activation have the potential to contribute to an HIV-1 cure or durable control.

The immune response to SARS-CoV-2 in people with HIV

This review examines the intersection of the HIV and SARS-CoV-2 pandemics. People with HIV (PWH) are a heterogeneous group that differ in their degree of immune suppression, immune reconstitution, and viral control. While COVID-19 in those with well-controlled HIV infection poses no greater risk than that for HIV-uninfected individuals, people with advanced HIV disease are more vulnerable to poor COVID-19 outcomes. COVID-19 vaccines are effective and well tolerated in the majority of PWH, though reduced vaccine efficacy, breakthrough infections and faster waning of vaccine effectiveness have been demonstrated in PWH. This is likely a result of suboptimal humoral and cellular immune responses after vaccination. People with advanced HIV may also experience prolonged infection that may give rise to new epidemiologically significant variants, but initiation or resumption of antiretroviral therapy (ART) can effectively clear persistent infection. COVID-19 vaccine guidelines reflect these increased risks and recommend prioritization for vaccination and additional booster doses for PWH who are moderately to severely immunocompromised. We recommend continued research and monitoring of PWH with SARS-CoV-2 infection, especially in areas with a high HIV burden.

Advancing towards HIV-1 remission: Insights and innovations in stem cell therapies

Human immunodeficiency virus type 1 (HIV-1) continues to pose a significant global health challenge despite advances in combined antiretroviral therapy (cART), which has transformed HIV-1 infection from a fatal disease to a manageable chronic condition. However, cART is not curative, and its long-term use is associated with challenges such as pill burden, drug toxicities, and the emergence of drug-resistant viral strains. The persistence of active viral reservoirs necessitates lifelong treatment, highlighting the need for alternative therapeutic strategies capable of achieving HIV-1 remission or cure. Stem cell therapy has emerged as a promising approach to address these challenges by targeting latent viral reservoirs, restoring host immune function, and potentially achieving sustained viral suppression in the absence of cART. This review critically evaluates current scientific literature on stem cell therapies for HIV-1, focusing on three major approaches: 1) hematopoietic stem cell transplantation (HSCT), 2) gene therapy, and 3) cell-based immunotherapies. Each approach is examined in terms of its underlying mechanisms, clinical feasibility, recent advancements, and associated challenges. Furthermore, future research directions are discussed, emphasizing the optimization of the current treatment protocols, enhancement of safety and efficacy, and the importance of large-scale clinical trials with different cohorts (different HIV clades, different genders of participants, and pediatric HIV) to evaluate long-term outcomes that include effective and scalable HIV cure challenges. Collaborative efforts across multidisciplinary fields are needed to overcome existing barriers so to realize the full therapeutic potential of stem cell-based approaches for developing an effective and scalable remission or cure strategies.

Infectious Diseases

Microglia, brain-resident innate immune cells, have been extensively studied in neurodegenerative contexts like Alzheimer's disease. The Coronavirus disease 2019 (COVID-19) pandemic highlighted how peripheral infection and inflammation can be detrimental to the neuroimmune milieu and initiate microgliosis driven by peripheral inflammation. Microglia can remain deleterious to brain health by sustaining inflammation in the central nervous system even after the clearance of the original immunogenic agents. In this chapter, we discuss how pulmonary infection with Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) can lead to neurovascular and neuroimmune inflammation causing the neurological syndrome of post-acute sequelae of COVID-19 (PASC). Further, we incorporate lessons from the Human Immunodeficiency Virus' (HIV's) effects on microglial functioning in the era of combined antiretroviral therapies (cART) that contribute to HIV-1 associated neurocognitive disorders (HAND). Finally, we describe roles for mixed lineage kinase 3 (MLK3) and leucine-rich repeat kinase (LRRK2) as key regulators of multiple inflammatory and apoptotic pathways important to the pathogenesis of PASC and HAND. Inhibition of these pathways provides a therapeutically synergistic method of treating both PASC and HAND.

Performance Evaluation of Microscanner Plus, an Automated Image-Based Cell Counter, for Counting CD4+ T Lymphocytes in HIV Patients

Counting CD4+ T lymphocytes using flow cytometry is a standard method for monitoring patients with HIV infections. Simpler and cheaper alternatives to flow cytometry are in high demand because getting access to flow cytometers is difficult or impossible in resource-limited settings. We evaluated the performance of the Microscanner Plus, a simple and automated image-based cell counter, in determining CD4 counts against a flow cytometer. CD4 count results of the Microscanner Plus and flow cytometer were compared using samples from 47 HIV-infected patients and 87 healthy individuals. All CV% for precision and reproducibility tests were less than 10%. The Microscanner Plus's lowest detectable CD4 count was determined to be 15.27 cells/µL of whole blood samples. The correlation coefficient (R) between Microscanner Plus and flow cytometry for CD4 counting in 134 clinical samples was very high, at 0.9906 (p < 0.0001). The automated Microscanner Plus showed acceptable analytical performance for counting CD4+ T lymphocytes and may be particularly useful for monitoring HIV patients in resource-limited settings.