Being opportunistic intracellular pathogens, viruses are dependent on the host for their replication. They hijack host cellular machinery for their replication and survival by targeting crucial cellular physiological pathways, including transcription, translation, immune pathways, and apoptosis. Immediately after translation, the host and viral proteins undergo a process called post-translational modification (PTM). PTMs of proteins involves the attachment of small proteins, carbohydrates/lipids, or chemical groups to the proteins and are crucial for the proteins’ functioning. During viral infection, host proteins utilize PTMs to control the virus replication, using strategies like activating immune response pathways, inhibiting viral protein synthesis, and ultimately eliminating the virus from the host. PTM of viral proteins increases solubility, enhances antigenicity and virulence properties. However, RNA viruses are devoid of enzymes capable of introducing PTMs to their proteins. Hence, they utilize the host PTM machinery to promote their survival. Proteins from viruses belonging to the family: Togaviridae, Flaviviridae, Retroviridae, and Coronaviridae such as chikungunya, dengue, zika, HIV, and coronavirus are a few that are well-known to be modified. This review discusses various host and virus-mediated PTMs that play a role in the outcome during the infection.

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Objective To determine the impact of nutritional status on peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD) in a developing country. Methods 56 patients with end-stage renal disease on CAPD were randomly selected for this study. These patients were assessed for nutritional status and peritonitis episodes. Nutritional parameters were assessed by anthropometry, diet, body mass index (BMI), Nutritional Risk Index (NRI), serum albumin level, and Subjective Global Assessment (SGA). Based on SGA, patients were categorized into either group 1 (malnutrition, n = 31) or group 2 (normal nutritional status, n = 25). Peritonitis was considered the primary outcome and was compared between the two groups. Results Demographic profiles, Kt/V, creatinine clearance, and mean follow-up of the two groups were similar. Number of peritonitis episodes was significantly higher in patients with malnutrition (25/31) compared to patients with normal nutritional status (4/25) ( p = 0.001). Mean peritonitis rate per patient per year was also significantly higher in patients with malnutrition (0.99 ± 1.07) compared to patients with normal nutritional status (0.18 ± 0.42) ( p = 0.007). On univariate analysis, malnutrition based on SGA ( p = 0.009), NRI ( p = 0.02), serum albumin level ( p = 0.005), and calorie intake ( p = 0.006) was a significant predictor of peritonitis. On multivariate Cox regression analysis, only SGA ( p = 0.001, odds ratio 0.08, 95% confidence interval 0.02 – 0.36) was found to be a significant predictor of peritonitis. On general linear model, the observed power of prediction of peritonitis was 0.96 based on SGA. On Kaplan–Meier survival analysis, peritonitis-free survival in patients with normal nutrition (42 months) was significantly higher compared to patients with malnutrition (21 months) based on SGA (log rank p = 0.003). Conclusion We conclude that peritonitis rate is high in patients with malnutrition and that malnutrition indices, especially SGA, can predict the peritonitis rate in CAPD patients.

BANK1, an adaptor protein expressed in B-cells, plays a little understood role in B-cell signaling. Because BANK1 contains an N-terminal putative Toll-interleukin 1 receptor (TIR) domain, we used mouse Bank1−/− splenic B cells to test if BANK1 affects signaling induced by the TLR9 agonist CpG. Following CpG stimulation BANK1 deficiency reduced p38 phosphorylation without affecting that of ERK or JNK and reduced IL-6 secretion. Bank1−/− B cells showed reduced phosphorylation of MNK1/2 and eIF4E, suggesting an effect on translation initiation, while Bank1−/− had no effect on IL6 mRNA stability, thus suggesting that BANK1 has no effect on MK2 signaling. IL-6 secretion observed when CpG stimulation was combined with anti-CD40, was reduced in the absence of BANK1. While in the presence of anti-CD40 stimulation CpG induced a stronger phosphorylation of AKT, mTOR and 4E-BP1, Bank1−/− had no effect on phosphorylation of mTOR and 4E-BP1, and weakly on AKT, implying that BANK1 does not affect the release of eIF4E by phospho-4E-BP1. Together these data establish a previously unrecognized role for BANK1 in CpG-induced responses by splenic B cells on p38 signaling and control of translation initiation of IL-6 via MNK1/2 and eIF4E.