Biology subjects

Rendahl, A. K.

Publications and source records attributed to Rendahl, A. K..

4 recordsLinked to original sources

bioRxiv2025

NK cell immunotherapy administered at the time of HIV recrudescence is associated with viral control.

One barrier to developing an HIV-1 cure is viral reservoirs persisting within B cell follicles of lymphatic tissues, partly due to failure of HIV-specific cytotoxic cells to express the follicular-homing receptor CXCR5. We evaluated HIV-specific CAR/CXCR5 NK cells armored with IL-15 and a PD-1 knockout for in vitro functionality. The safety and efficacy of these NK cells were assessed in vivo by treating ART-suppressed, HIV-infected-humanized-DRAGA mice following ART interruption. In vitro, CAR and control NK cells proliferated and killed HIV-Envelope-expressing cells. In vivo, there were no adverse health outcomes associated with cell infusions. CAR NK-treated animals had, on average, 1.88 times higher NK cell levels, and cells persisted up to 2 weeks longer than control NK-treated animals. At 56 days post-treatment, 62.5% of CAR NK-treated and 50% of control NK-treated groups had viral loads below the detection limit compared to 0% of the saline control group. Importantly, animals that had undetectable viral loads at 56 days post-treatment had earlier viral rebound post-ART interruption that coincided with high levels of NK cells, suggesting that timing of treatment with viral recrudescence was key to efficacy. This study demonstrates the promise of NK therapies for treating HIV infections.

bioengineering↗

bioRxiv2024

Human-immune-system humanized-DRAGA mice are a valuable model to study novel immunotherapies for HIV-1

Humanized (h)DRAGA mice are a promising in vivo model for investigating immunotherapies for treating HIV infections. These mice are not only susceptible to HIV infection, but they also develop functional human immune cells, including T cells and B cells as well as follicular-like structures that mimic lymphoid B cell follicles, where HIV-producing cells concentrate during infection in a manner similar to that found in humans. This study evaluated the safety, tissue targeting, and efficacy of follicular-targeting HIV-specific chimeric antigen receptor (CAR)-T cells (CAR/CXCR5-T cells) in HIV-infected hDRAGA mice. Intravenously-infused CAR/CXCR5-T cells persisted in hDRAGA mice for the duration of the study, peaking six days post-infusion. This study indicated that CAR/CXCR5-T cell treatment is safe, with 100% survival rate of treated mice and no noticeable changes in pathology. Six days after infusion, CAR/CXCR5-T cells had accumulated in the follicle-like structures, with many appearing in direct contact with HIV-producing cells. However, CAR/CXCR5-T cell treatment did not appear to reduce viral loads compared to controls, perhaps because many of the engineered CAR/CXCR5-T cells were themselves infected with HIV, with some CAR/CXCR5-T cells showing evidence of HIV virion release. Future studies will investigate whether CAR/CXCR5-T cells engineered for resistance against HIV infection are effective in reducing viral loads. This study supports the approach of using the HIV-infected hDRAGA mouse model to test cellular immunotherapies for HIV, as the model recapitulates many aspects of HIV infection in human lymphoid follicles.

immunology↗

bioRxiv2021

CAR/CXCR5-T cell immunotherapy is safe and potentially efficacious in promoting sustained remission of SIV infection

During chronic human immunodeficiency virus (HIV) or simian immunodeficiency virus (SIV) infection prior to AIDS progression, the vast majority of viral replication is concentrated within B cell follicles of secondary lymphoid tissues. We investigated whether infusion of T cells expressing an SIV-specific chimeric antigen receptor (CAR) and the follicular homing receptor, CXCR5, could successfully kill viral-RNA+ cells in targeted lymphoid follicles in SIV-infected rhesus macaques. In this study, CD4 and CD8 T cells from rhesus macaques were genetically modified to express antiviral CAR and CXCR5 moieties (generating CAR/CXCR5-T cells) and autologously infused into a chronically infected animal. At 2 days post-treatment, the CAR/CXCR5-T cells were located primarily in spleen and lymph nodes both inside and outside of lymphoid follicles. Few CAR/CXCR5-T cells were detected in the rectum and lung, and no cells were detected in the bone marrow, liver, brain, or ileum. Within follicles, CAR/CXCR5-T cells were found in direct contact with SIV viral RNA+ cells. We next infused CAR/CXCR5-T cells into ART-suppressed SIV-infected rhesus macaques, in which the animals were released from ART at the time of infusion. These CAR/CXCR5-T cells replicated in vivo within both the extrafollicular and follicular regions of lymph nodes and accumulated within lymphoid follicles. CAR/CXR5-T cell concentrations in follicles peaked during the first week post-infusion but declined to undetectable levels after 2 to 4 weeks. Overall, CAR/CXCR5-T cell-treated animals maintained lower viral loads and follicular viral RNA levels than untreated control animals, and no outstanding adverse reactions were noted. These findings indicate that CAR/CXCR5-T cell treatment is safe and holds promise as a future treatment for the durable remission of HIV. Author summaryA person infected with human immunodeficiency virus (HIV) has replicating virus concentrated within the follicles of lymphoid tissues. The cells needed to clear the infection, cytotoxic T lymphocytes, have limited access to follicles and, thus, the cytotoxic T lymphocytes are never completely able to clear all of the HIV from the body. In this study, we have produced immunotherapeutic T cells that home to follicles and clear infected cells. These T cells express a viral targeting chimeric antigen receptor (CAR) and a molecule called CXCR5, which leads to homing of the cells to follicles. Upon administration of these CAR T-cells to virus-infected primates, we found that the cells localized to the follicle, replicated, and directly interacted with infected cells. While the cells were not maintained in the animals for more than 4 weeks, most of the treated animals maintained lower levels of virus in the blood and follicles than untreated control animals. This study shows that this immunotherapy has potential as a treatment leading to long-term remission of HIV without the need for antiretroviral drugs.

immunology↗

bioRxiv2018

Absence of SIV-specific CD8+ T cells in germinal centers may set the stage for persistent infection

CD8+ T cells play an important role in controlling of HIV and SIV infections. However, these cells are largely excluded from B cell follicles where HIV and SIV producing cells concentrate during chronic infection. It is not known, however, if antigen-specific CD8+ T cells are excluded gradually as pathogenesis progresses from early to chronic phase, or this phenomenon occurs from the beginning infection. In this study we determined that SIV-specific CD8+ T cells were largely excluded from follicles during early infection, we also found that within follicles, they were entirely absent in 60% of the germinal centers (GCs) examined. Furthermore, levels of SIV-specific CD8+ T cells in follicular but not extrafollicular areas significantly correlated inversely with levels of viral RNA+ cells. In addition, subsets of follicular SIV-specific CD8+ T cells were activated and proliferating and expressed the cytolytic protein perforin. These studies suggest that a paucity of SIV-specific CD8+ T cells in follicles and complete absence within GCs during early infection may set the stage for the establishment of persistent chronic infection.\n\nAuthor SummaryA paucity of SIV-specific CD8+ T cells in lymphoid follicles and complete absence within most follicular germinal centers during early infection may set the stage for the establishment of persistent chronic infection.

immunology↗