The molecular pathogenesis of avian influenza infection varies greatly with individual bird species and virus strain. The molecular pathogenesis of the highly pathogenic avian influenza virus (HPAIV) or the low pathogenic avian influenza virus (LPAIV) infection in avian species remains poorly understood. Thus, global immune response of chickens infected with HPAI H5N1 (A/duck/India/02CA10/2011) and LPAI H9N2 (A/duck/India/249800/2010) viruses was studied using microarray to identify crucial host genetic components responsive to these infection. HPAI H5N1 virus induced excessive expression of type I IFNs (IFNA and IFNG), cytokines (IL1B, IL18, IL22, IL13, and IL12B), chemokines (CCL4, CCL19, CCL10, and CX3CL1) and IFN stimulated genes (OASL, MX1, RSAD2, IFITM5, IFIT5, GBP 1, and EIF2AK) in lung tissues. This dysregulation of host innate immune genes may be the critical determinant of the severity and the outcome of the influenza infection in chickens. In contrast, the expression levels of most of these genes was not induced in the lungs of LPAI H9N2 virus infected chickens. This study indicated the relationship between host immune genes and their roles in pathogenesis of HPAIV infection in chickens.

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The differences in the influenza viral pathogenesis observed between different pathogenic strains are associated with distinct properties of virus strains and the host immune responses. In order to determine the differences in the duck immune response against two different pathogenic strains, we studied genome-wide host immune gene response of ducks infected with A/duck/India/02CA10/2011 and A/duck/Tripura/103597/2008 H5N1 viruses using custom-designed microarray. A/duck/India/02CA10/2011 is highly pathogenic virus (HP) to ducks, whereas A/duck/Tripura/103597/2008 is a low pathogenic (LP) virus strain. Comparative lung tissue transcriptome analysis of differentially expressed genes revealed that 686 genes were commonly expressed, 880 and 1556 genes are expressed uniquely to infection with HP and LP virus, respectively. The up-regulation of chemokines (CCL4 and CXCR4) and IFN-stimulated genes (IFITM2, STAT3, TGFB1 and TGFB3) was observed in the lung tissues of ducks infected with HP virus. The up-regulation of other immune genes (IL17, OAS, SOCS3, MHC I and MHC II) was observed in both infection conditions. The expression of important antiviral immune genes MX, IFIT5, IFITM5, ISG12, β-defensins, RSAD2, EIF2AK2, TRIM23 and SLC16A3 was observed in LP virus infection, but not in HP virus infection. Several immune-related gene ontology terms and pathways activated by both the viruses were qualitatively similar but quantitatively different. Based on these findings, the differences in the host immune response might explain a part of the difference observed in the viral pathogenesis of high and low pathogenic influenza strains in ducks.

Background: Dendritic cells (DC) are key regulators of immune response with the ability to affect both the innate and adaptive immune responses and are abundant in the gut mucosa. The severity of shigellosis varies with the serotype involved with S. dysenteriae (SD) producing the severest infections and complications with S. sonnei (SS) being at other end of spectrum usually causing mild self-limiting diarrhea. While shigellae are known to induce the apoptosis of mature DCs, there is no information in cytokine milieu of DCs incubated with different serotypes of Shigellae.

Crimean-Congo hemorrhagic fever (CCHF) is an emerging zoonotic disease in India and requires immediate detection of infection both for preventing further transmission and for controlling the infection. The present study describes development, optimization, and evaluation of a novel molecular beacon-based real-time RT-PCR assay for rapid, sensitive, and specific diagnosis of Crimean-Congo hemorrhagic fever virus (CCHFV). The developed assay was found to be a better alternative to the reported TaqMan assay for routine diagnosis of CCHF.