Probiotic Therapy During Vaccination Alters Antibody Response to Simian-Human Immunodeficiency Virus Infection But Not to Commensals
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Strategies to boost vaccine-induced mucosal humoral responses are critical to developing an HIV-1 vaccine, and probiotic supplementation could help boost antibody responses. Researchers analyzed antibody titers to explore this topic in rhesus macaques (sex not specified) infected with simian–human immunodeficiency virus (SHIV). They reported that probiotic treatment during vaccination led to delayed kinetics in the circulating HIV-specific IgA response after breakthrough SHIV infection.
CD8+ T Cells Promote HIV Latency by Remodeling CD4+ T Cell Metabolism to Enhance Their Survival, Quiescence, and Stemness
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An HIV reservoir persists following antiretroviral therapy, representing the main barrier to an HIV cure. Using a validated in vitro model, investigators explored the mechanism by which CD8+ T cells promote HIV latency and inhibit latency reversal in HIV-infected CD4+ T cells. They reported that CD8+ T cells favor the establishment of HIV latency by modulating metabolic, stemness, and survival pathways that correlate with the downregulation of HIV expression and promote HIV latency.
Cannabinoid Enhancement of lncRNA MMP25-AS1/MMP25 Interaction Reduces Neutrophil Infiltration and Intestinal Epithelial Injury in HIV/SIV Infection
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Gastrointestinal CD4+ T cell depletion during acute simian immunodeficiency virus (SIV) and HIV infection causes significant structural and functional damage, disrupting intestinal immune homeostasis and leading to intestinal epithelial barrier dysfunction. Oral phytocannabinoids are safe and well tolerated in people with HIV, but more information is needed regarding the effects of long-term tetrahydrocannabinol (THC) use on the intestinal epithelial compartment.
Effect of Passive Administration of Monoclonal Antibodies Recognizing Simian Immunodeficiency Virus (SIV) V2 in CH59-Like Coil/Helical or β-Sheet Conformations on Time of SIVmac251 Acquisition
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Research suggests that the SIV variable region 2 (V2) is a region of virus vulnerability, likely because of its exposure on the apex of virions and on the surfaces of SIV-infected cells. Researchers examined the effects of two monoclonal antibodies, NCI05 and NCI09, on the acquisition of SIV using rhesus macaques (sex not specified). They found that NCI05, but not NCI09, delays SIV acquisition, highlighting the complexity of antibody responses to V2. Both antibodies were unable to decrease the risk of viral acquisition.
In Vivo MRI Is Sensitive to Remyelination in a Nonhuman Primate Model of Multiple Sclerosis
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Experimental autoimmune encephalomyelitis (EAE) in the common marmoset is a model for studying inflammatory demyelination in multiple sclerosis (MS). Researchers investigated the feasibility and sensitivity of magnetic resonance imaging (MRI) in characterizing remyelination, a crucial step to recover from MS. Investigators demonstrated that multisequence 7T MRI could detect spontaneous remyelination in marmoset EAE at high statistical sensitivity and specificity in vivo.
Effect of the Snake Venom Component Crotamine on Lymphatic Endothelial Cell Responses and Lymph Transport
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The pathology of snake envenomation is closely tied to the severity of edema in the tissue surrounding the area of the bite. This study focused on one of the most abundant venom components in North American viper venom, crotamine, and the effects it has on the cells and function of the lymphatic system. The authors found that genes that encode targets of crotamine are highly present in lymphatic tissues and cells and that there is a differential distribution of those genes that correlates with phasic contractile activity.
Pembrolizumab and Cabozantinib in Recurrent Metastatic Head and Neck Squamous Cell Carcinoma: A Phase 2 Trial
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A multicenter clinical trial was conducted in 33 evaluable (36 enrolled) patients with recurrent metastatic head and neck squamous cell carcinoma (RMHNSCC) on a regimen combining cabozantinib, a tyrosine kinase inhibitor, with the standard of care of anti–programmed cell death protein 1 agent pembrolizumab. Results showed that 17 patients (52%) exhibited partial response and 13 (39%) exhibited stable disease, with an overall clinical benefit rate of 91%. Median progression-free survival (PFS) was 14.6 months, and the 1-year PFS was 54%.
Structural Insights Into the Broad Protection Against H1 Influenza Viruses by a Computationally Optimized Hemagglutinin Vaccine
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Influenza is an ongoing public health concern, and computationally optimized broadly reactive antigen (COBRA) hemagglutinin proteins represent a potential strategy for formulating broadly effective influenza vaccines. Researchers determined the crystal structure of COBRA P1, as well as its binding to 1F8, a broadly neutralizing antibody. This work provides valuable insights into the underlying molecular basis for the broad effectiveness of P1, and these insights can be applied to future vaccine designs. Supported by ORIP (K01OD026569), NIAID, and NIGMS.
Longitudinal Characterization of Circulating Extracellular Vesicles and Small RNA During Simian Immunodeficiency Virus Infection and Antiretroviral Therapy
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Antiretroviral therapy is effective for controlling HIV infection but does not fully prevent early aging disorders or serious non-AIDS events among people with HIV. Using pigtail and rhesus macaques (sex not specified), researchers profiled extracellular vesicle small RNAs during different phases of simian immunodeficiency virus infection to explore the potential relationship between extracellular vesicle–associated small RNAs and the infection process. They reported that average particle counts correlated with infection, but the trend could not be explained fully by virions.
Infant Rhesus Macaques Immunized Against SARS-CoV-2 Are Protected Against Heterologous Virus Challenge 1 Year Later
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The Moderna and Pfizer–BioNTech mRNA vaccines received emergency use authorization for infants 6 months and older in June 2022, but questions remain regarding the durability of vaccine efficacy against emerging variants in this age group. Using a two-dose vaccine regimen consisting of stabilized prefusion Washington-strain spike protein encoded by mRNA and encapsulated in lipid nanoparticles, the investigators immunized 2-month-old rhesus macaques of both sexes.