Innate immunity is the first line of the host immune system to fight against infections. Natural killer cells are the innate immunity lymphocytes responsible for fighting against virus-infected and cancerous cells. They have various mechanisms to suppress viral infections. On the other hand, viruses have evolved to utilize different ways to evade NK cell-mediated responses. Viruses can balance the response by regulating the cytokine release pattern and changing the proportion of activating and inhibitory receptors on the surface of NK cells. Exosomes are a subtype of extracellular vesicles that are involved in intercellular communication. Most cell populations can release these nano-sized vesicles, and it was shown that these vesicles produce identical outcomes to the originating cell from which they are released. In recent years, the role of NK cell-derived exosomes in various diseases including viral infections has been highlighted, drawing attention to utilizing the therapeutic potential of these nanoparticles. In this article, the role of NK cells in various viral infections and the mechanisms used by viruses to evade these important immune system cells are initially examined. Subsequently, the role of NK cell exosomes in controlling various viral infections is discussed. Finally, the current position of these cells in the treatment of viral infections and the therapeutic potential of their exosomes are reviewed.

The human papillomavirus (HPV) is the main cause of cervical cancer in developing countries. Rapid diagnosis and initiation of treatment of the HPV infection are critical. Various methods have been employed to reduce the immunogenicity of antibodies targeting HPV serotypes. Nanobodies are the smallest fragments of naturally occurring single-domain antibodies with their antigenbinding site compromised into a single domain. Nanobodies have remarkable properties such as high stability, solubility, and high homology to the human VH3 domain. In this study, a phagemid library was employed to enrich for nanobodies against the L1 protein of the human papilloma virus. Binding reactivity of the selected clones was evaluated using phage enzyme-linked immunosorbent assay (phage-ELISA). Finally, two nanobodies (sm5 and sm8) with the best reactivity against the Gardasil vaccine and the purified HPV-16 L1 protein were expressed and purified using a Ni(+)-NTA column. The accuracy of expression and purification of the nanobodies was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting assays. In vitro studies demonstrated that neutralization was achieved by the selected nanobodies. The ease of generation and unique features of these molecules make nanobodies promising molecules for the new generation of HPV diagnosis and therapy.

The purpose of this study was to compare the effectiveness of Atazanavir/Ritonavir/Dolutegravir/Hydroxychloroquine and Lopinavir/Ritonavir/Hydroxychloroquine treatment regimens in COVID‐19 patients based on clinical and laboratory parameters. We prospectively evaluated the clinical and laboratory outcomes of 62 moderate to severe COVID‐19 patients during a 10‐day treatment plan. Patients were randomly assigned to either KH (receiving Lopinavir/Ritonavir [Kaletra] plus Hydroxychloroquine) or ADH (receiving Atazanavir/Ritonavir, Dolutegravir, and Hydroxychloroquine) groups. During this period, clinical and laboratory parameters and outcomes such as intensive care unit (ICU) admission or mortality rate were recorded. Compared to the KH group, after the treatment period, patients in the ADH group had higher activated partial thromboplastin time (aPTT) (12, [95% confidence interval [CI]: 6.97, 17.06), p = <0.01), international normalized ratio (INR) (0.17, [95% CI: 0.07, 0.27), p = <0.01) and lower C‐reactive protein (CRP) (−14.29, (95% CI: −26.87, −1.71), p = 0.03) and potassium (−0.53, (95% CI: −1.03, −0.03), p = 0.04) values. Moreover, a higher number of patients in the KH group needed invasive ventilation (6 (20%) vs. 1 (3.1%), p = 0.05) and antibiotic administration (27 (90%) vs. 21(65.6), p = 0.02) during hospitalization while patients in the ADH group needed more corticosteroid administration (9 (28.1%) vs. 2 (6.7%), p = 0.03). There was no difference in mortality rate, ICU admission rate, and hospitalization period between the study groups. Our results suggest that the Atazanavir/Dolutegravir treatment regimen may result in a less severe disease course compared to the Lopinavir/Ritonavir treatment regimen and can be considered as an alternative treatment option beside standard care. However, to confirm our results, larger‐scale studies are recommended.

Introduction: Today, one of the most important challenges of the therapeutic system is the resistance of bacteria against different antibiotics especially in intensive care units which lead to an increase in hospitalization time and the patients’ expenses. Acinetobacter baumannii is one of the most significant contaminating bacteria in intensive care units which has exhibited resistance against different antibiotics in recent years. The aim of this study was to investigate the synergism effect of the silver nanoparticles with the shallot and nettle alcoholic extracts against the standard and multidrug resistant A. baumannii isolates. Materials and Methods: Samples were collected from intensive care units and the A. baumannii isolates were identified using biochemical tests. Then, the antibiogram test was carried out for each isolate. The antibacterial effect of nanoparticles, shallot and nettle extracts was evaluated singularly and in combination with each other against standard and resistant A. baumannii isolates. Measuring the diameter of inhibited growth zone, MIC, MBC and checkerboard tests were conducted for each isolate. Results: The results showed that the silver nanoparticles, shallot and nettle alcoholic extracts each had antibacterial property against the standard and resistant A. baumannii isolates. The mixture of the nettle extract with silver nanoparticles had a synergism effect against the standard and resistant isolates and the mixture of the shallot extract with silver nanoparticles had an additive effect against A. baumannii isolates. Conclusions: Due to the increase of antibiotics resistance and the resistance to the pathogenic bacteria especially in intensive care units, it is necessary to find effective and accessible substances to destroy the resistant bacteria and reduce the mortality rate of patients. The results of the present study revealed that the antibacterial property of the shallot and the nettle alcoholic extracts could increase the antibacterial property of the silver nanoparticles. As a result, these can be used for disinfecting different wards of a hospital, in particular, the intensive care units.