This review discusses the roles of B- and T-cells in SARS-CoV-2 infections and experimental validations for the selection of B-, CD4+ and CD8+ T-cell epitopes which could lead to the construction of a multi-epitope peptide vaccine. Peptide-based vaccines are known for their low immunogenicity which could be overcome by incorporating immunostimulatory adjuvants and nanoparticles such as Poly Lactic-co-Glycolic Acid (PLGA) or chitosan.Coronavirus disease 2019 (COVID-19) caused by novel Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV2), is typically associated with severe respiratory distress and has claimed more than 525,000 lives already. The most fearful aspect is the unavailability of any concrete guidelines and treatment or protective strategies for reducing mortality or morbidity caused by this virus. Repurposing of drugs, antivirals, convalescent plasma and neutralizing antibodies are being considered for treatment but are still questionable in lieu of the conflicting data, study design and induction of secondary infections. Stem cell therapy has seen substantial advancements over the past decade for the treatment of various diseases including pulmonary disorders with severe complications similar to COVID-19. Recently, mesenchymal stem cells (MSCs) have received particular attention as a potential therapeutic modality for SARS-CoV2 infection due to their ability to inhibit cytokine storm, a hallmark of severe COVID-19. MSCs secretion of trophic factors and extracellular vesicles mediated intercellular signaling are considered as principal contributing factors for tissue recovery. Although, recent preliminary studies have established the safety and efficacy of these cells without any severe secondary complications in the treatment of SARS-CoV2 infection, the rational use of MSCs on a large scale would still require additional relevant clinical investigations and validation of postulated mechanisms of these cells. This review presents the current clinical findings and update on the potential use of stem cell therapy and its secretome in combating the symptoms associated with COVID-19.In this study, apical dendritic spine density of neurons in hippocampal, amygdalar and prefrontal cortical areas was compared in rats that were repeatedly winning or losing social conflicts. Territorial male wild-type Groningen (WTG) rats were allowed multiple daily attacks (>20 times) on intruder males in the resident-intruder paradigm. Frequent winning experiences are known to facilitate uncontrolled aggressive behavior reflected in aggressive attacks on anesthetized males which was also observed in the winners in this study. Both winners and losers were socially housed during the experiments; winners with females to stimulate territorial behavior, and losers with two other losing male rats. Twenty-four hours after the last social encounter, brains from experienced residential winners and repeatedly defeated intruder rats were collected and neuronal morphology in selected brain regions was studied via Golgi-Cox staining. Results indicate that spine density in the apical dendrites of the hippocampal CA1 reduced similarly in both winners and losers. In addition, winners showed increased spine densities at the proximal segments (20-30 μm) of the basolateral amygdala neurons and losers tended to show a decreased spine density at the more proximal segments of the infralimbic region of prefrontal cortex neurons. No effect of winning and losing was observed in the medial amygdala. The atrophic effect of repeated defeats in hippocampal and prefrontal regions was anticipated despite the fact that social housing of the repeatedly losing intruder males may have played a protective role. The reduction of hippocampal spine density in the winners seems surprising but supports previous findings in hierarchical dominant males in rat colonies. The dominants showed even greater shrinkage of the apical dendritic arbors of hippocampal CA3 pyramidal neurons compared to the stressed subordinates.Delay discounting involves choosing between a small, immediate reward, and a larger but delayed one. see more As the delay between choice and large reward gets longer, people with ADHD tend to become impulsive faster than controls, indicated by a switch in preference from the large to the smaller reward. Choosing the smaller reward when the larger is considered reward maximizing is labeled impulsive behaviour. It is well documented that increased delays between choice and reward affects choice preference in both humans and other animals. Other variables such as the inter-trial interval or trial length are observed to have an effect on human discounting, but their effect on discounting in other animals is largely assumed rather than tested. In the current experiment, we tested this assumption. One group of rats was exposed to increasing delays between choosing the large reward and receiving it, while another group experienced longer inter-trial intervals that were equal in length to the delays in the other group. This ensured that trial length was controlled for in delay discounting, but that the delay function and inter-trial intervals could be manipulated and measured separately. Results showed that while the delay between choice and reward caused impulsive behaviour in rats, the length of the inter-trial interval (and by extension trial length) had no impact on choice behaviour. A follow-up experiment found this to be the case even if the length of the inter-trial interval was signaled with audio cues. These results suggest that rats, and possibly animals in general, are insensitive to time between trials, and therefore cannot easily represent human counterparts on the task.Early life stress can induce lifelong emotional and social behavioral deficits that may in some cases be alleviated by drugs or alcohol. A model for early life stress, rodent maternal separation, recapitulates these behavioral sequelae, which are not limited to potentiated anxiety-like behavior, attenuated social motivation, and altered reward-seeking. Here we employed mouse maternal separation with early weaning (MSEW), consisting of pup-dam separation lasting 4-8 hours on postnatal days (PD) 2-16, with early weaning on PD 17. Prior MSEW studies have limited subjects by age or sex, so we more comprehensively investigated MSEW effects in both sexes, during adolescence and adulthood. We found universal effects of MSEW to include lifelong enhancement of anxiety-like and despair behavior, as well as deficits in social motivation. We also observed some sex-dependent effects of MSEW, namely that female MSEW mice exhibited social habituation to a greater degree than their male counterparts. Low dose ethanol administration had no major effects on the social behavior of non-stressed mice.