Sex differences in hippocampal cytokine networks after systemic immune challenge (preprint)

Increased production of cytokines in the in the brain during illness or injury modulates physiological processes, behavior, and cognitive function. It is likely that the pattern of cytokines, rather than the activation of any individual cytokine, determines the functional outcome of neuroimmune signaling. Cytokine networks may thus be particularly useful for understanding sex differences in immune and neuroimmune activation and outcomes. In this project, we aimed to determine the activation and resolution of hippocampal cytokine networks in both male and female mice. We measured 32 cytokines in the hippocampus and periphery of male and female mice at rest, 2, 6, 24, 48, and 168 hours after an acute systemic injection of lipopolysaccharide (LPS; 250g/kg). We hypothesized that males and females would exhibit both differences in individual cytokine levels and differences in network dynamics of hippocampal cytokines. Cytokines with sex-specific activation by LPS included male-specific elevations of IFN{gamma}, CSF1, CSF2, and IL-10; and female-specific activation of the IL-2 family and IL-4. We also observed differences in time course, where females showed more rapid elevations, and faster resolution of cytokine activity compared with males. Network analysis using ARACNE and Cytoscape demonstrated markedly different hippocampal cytokine networks across sex even at baseline, and sex differences in cytokine network activation states in response to LPS. Analysis of global shifts in cytokine concentrations further identified a period of cytokine and chemokine downregulation at 48 hours that was more pronounced in females compared with males. Together, these findings demonstrate that sex differences in neuroimmune responses include both differences in intensity of the cytokine response, and importantly differences in cytokine networks activated. Such sex differences in cytokine networks in the brain are likely critical for short and long-term functional outcomes associated with neuroimmune activation.

Intranasal Administration of ACIS KEPTIDE™ Prevents SARS-CoV2-Induced Acute Toxicity in K18-hACE2 Humanized Mouse Model of COVID-19: A Mechanistic Insight for the Prophylactic Role of KEPTIDE™ in COVID-19 (preprint)

Abstract: Previously, we have demonstrated that ACIS KEPTIDE, a chemically modified peptide, selectively binds to ACE-2 receptor and prevents the entry of SARS-CoV2 virions in vitro in primate kidney Cells. However, it is not known if ACIS KEPTIDE attenuates the entry of SARS-CoV2 virus in vivo in lung and kidney tissues, protects health, and prevent death once applied through intranasal route. In our current manuscript, we demonstrated that the intranasal administration of SARS-CoV2 (1*106) strongly induced the expression of ACE-2, promoted the entry of virions into the lung and kidney cells, caused acute histopathological toxicities, and mortality (28%). Interestingly, thirty-minutes of pre-treatment with 50 g/Kg Body weight ACIS normalized the expression of ACE-2 via receptor internalization, strongly mitigated that viral entry, and prevented mortality suggesting its prospect as a prophylactic therapy in the treatment of COVID-19. On the contrary, the peptide backbone of ACIS was unable to normalize the expression of ACE-2, failed to improve the health vital signs and histopathological abnormalities. In summary, our results suggest that ACIS is a potential vaccine-alternative, prophylactic agent that prevents entry of SARS-CoV2 in vivo, significantly improves respiratory health and also dramatically prevents acute mortality in K18-hACE2 humanized mice.

ACIS, A Novel KepTide™, Binds to ACE-2 Receptor and Inhibits the Infection of SARS-CoV2 Virus in vitro in Primate Kidney Cells: Therapeutic Implications for COVID-19 (preprint)

Coronavirus disease 2019 (COVID-19) is a severe acute respiratory syndrome (SARS) caused by a virus known as SARS-Coronavirus 2 (SARS-CoV2). Without a targeted-medicine, this disease has been causing a massive humanitarian crisis not only in terms of mortality, but also imposing a lasting damage to social life and economic progress of humankind. Therefore, an immediate therapeutic strategy needs to be intervened to mitigate this global crisis. Here, we report a novel KepTide(TM) (Knock-End Peptide) therapy that nullifies SARS-CoV2 infection. SARS-CoV2 employs its surface glycoprotein spike (S-glycoprotein) to interact with angiotensin converting enzyme-2 (ACE-2) receptor for its infection in host cells. Based on our in-silico-based homology modeling study validated with a recent X-ray crystallographic structure (PDB ID:6M0J), we have identified that a conserved motif of S-glycoprotein that intimately engages multiple hydrogen-bond (H-bond) interactions with ACE-2 enzyme. Accordingly, we designed a peptide, termed as ACIS (ACE-2 Inhibitory motif of Spike), that displayed significant affinity towards ACE-2 enzyme as confirmed by biochemical assays such as BLItz and fluorescence polarization assays. Interestingly, more than one biochemical modifications were adopted in ACIS in order to enhance the inhibitory action of ACIS and hence called as KEpTide(TM). Consequently, a monolayer invasion assay, plaque assay and dual immunofluorescence analysis further revealed that KEpTide(TM) efficiently mitigated the infection of SARS-CoV2 in vitro in VERO E6 cells. Finally, evaluating the relative abundance of ACIS in lungs and the potential side-effects in vivo in mice, our current study discovers a novel KepTideTM therapy that is safe, stable, and robust to attenuate the infection of SARS-CoV2 virus if administered intranasally.