Late-emerging strains of HIV induce T-cell homeostasis failure by promoting bystander cell death and immune exhaustion in naïve CD4 and all CD8 T-cells

Hematological parameters abnormalities and associated factors in HIV-positive adults before and after highly active antiretroviral treatment in Goba Referral Hospital, southeast Ethiopia: A cross-sectional study

Objectives

Hematological abnormalities of the major blood cell lines are frequently reported in patients with HIV-1 infection, in patients without antiretroviral therapy, and during the advanced stages of the disease. Chronic immune activation and inflammation results in the progressive depletion of CD4+ T-cells play a significant role in the clinical progression and pathogenesis of this infection. This study was aimed at assessing the prevalence of hematological abnormalities and their associated factors before and after the initiation of antiretroviral therapy in adults with HIV-1 infection in a referral hospital.

Methods

The study was conducted from 1 April to 30 June 2018, at Goba Referral Hospital. A total of 308 HIV-positive adults on treatment were enrolled during the study period. Socio-demographic and clinical data were collected using a structured questionnaire, with pre-highly active antiretroviral therapy data were extracted from medical records while post-treatment immuno-hematological measurements were done on blood samples collected at the time of enrollment.

Results

The prevalence of anemia, leukopenia, and thrombocytopenia before initiation of antiretroviral treatment was higher, although anemia and thrombocytopenia decreased correspondingly after initiation of treatment leukopenia increased by 4%. Mean values of immuno-hematological parameters before and after treatment initiation were significant (p < 0.05). CD4+ T-cell count <200 cells/µL was the only independent risk factor for anemia and leukopenia before highly active antiretroviral therapy, while stage IV disease, female sex, zidovudine, lamivudine, and nevirapine treatment, and intestinal parasite infection were predictors of anemia after treatment initiation.

Conclusion

The study revealed that hematological abnormalities are common in HIV infection, while the occurrence of abnormalities after highly active antiretroviral therapy initiation. Different risk factors are associated with hematological abnormalities at pre- and post-highly active antiretroviral therapy with regular monitoring of risk factors, adherence to the early initiation of highly active antiretroviral therapy, and conduct of further longitudinal studies are recommended.

Multilineage polyclonal engraftment of Cal-1 gene-modified cells and in vivo selection after SHIV infection in a nonhuman primate model of AIDS

We have focused on gene therapy approaches to induce functional cure/remission of HIV-1 infection. Here, we evaluated the safety and efficacy of the clinical grade anti-HIV lentiviral vector, Cal-1, in pigtailed macaques (Macaca nemestrina). Cal-1 animals exhibit robust levels of gene marking in myeloid and lymphoid lineages without measurable adverse events, suggesting that Cal-1 transduction and autologous transplantation of hematopoietic stem cells are safe, and lead to long-term, multilineage engraftment following myeloablative conditioning. Ex vivo, CD4+ cells from transplanted animals undergo positive selection in the presence of simian/human immunodeficiency virus (SHIV). In vivo, Cal-1 gene-marked cells are evident in the peripheral blood and in HIV-relevant tissue sites such as the gastrointestinal tract. Positive selection for gene-marked cells is observed in blood and tissues following SHIV challenge, leading to maintenance of peripheral blood CD4+ T-cell counts in a normal range. Analysis of Cal-1 lentivirus integration sites confirms polyclonal engraftment of gene-marked cells. Following infection, a polyclonal, SHIV-resistant clonal repertoire is established. These findings offer strong preclinical evidence for safety and efficacy of Cal-1, present a new method for tracking protected cells over the course of virus-mediated selective pressure in vivo, and reveal previously unobserved dynamics of virus-dependent T-cell selection.

Current understanding of HIV-1 and T-cell adaptive immunity: progress to date

The cellular immune response to human immunodeficiency virus (HIV) has different components originating from both the adaptive and innate immune systems. HIV cleverly utilizes the host machinery to survive by its intricate nature of interaction with the host immune system. HIV evades the host immune system at innate ad adaptive, allows the pathogen to replicate and transmit from one host to another. Researchers have shown that HIV has multipronged effects especially on the adaptive immunity, with CD4(+) cells being the worst effect T-cell populations. Various analyses have revealed that, the exposure to HIV results in clonal expansion and excessive activation of the immune system. Also, an abnormal process of differentiation has been observed suggestive of an alteration and blocks in the maturation of various T-cell subsets. Additionally, HIV has shown to accelerate immunosenescence and exhaustion of the overtly activated T-cells. Apart from causing phenotypic changes, HIV has adverse effects on the functional aspect of the immune system, with evidences implicating it in the loss of the capacity of T-cells to secrete various antiviral cytokines and chemokines. However, there continues to be many aspects of the immune- pathogenesis of HIV that are still unknown and thus required further research in order to convert the malaise of HIV into a manageable epidemic.