http://192.168.1.40:8080/xmlui/handle/123456789/1428 2026-05-31T13:44:02Z http://192.168.1.40:8080/xmlui/handle/123456789/2410 Regulation of impaired protein kinase C signaling by chemokines in murine macrophages during visceral leishmaniasis Dey, R.; Sarkar, A.; Majumder, N.; Bhattacharyya, S. M.; Roychoudhury, K.; Bhattacharyya, S.; Roy, S.; Majumdar, Subrata The protein kinase C (PKC) family regulates macrophage function involved in host defense against infection. In the case of Leishmania donovani infection, the impairment of PKC-mediated signaling is one of the crucial events for the establishment of parasite into the macrophages. Earlier reports established that C-C chemokines mediated protection against leishmaniasis via the generation of nitric oxide after 48 h. In this study, we investigated the role of MIP-1 alpha and MCP-1 in the regulation of impaired PKC activity in the early hours (6 h) of infection. These chemokines restored Ca2+-dependent PKC activity and inhibited Ca2+-independent atypical PKC activity in L. donovani-infected macrophages under both in vivo and in vitro conditions. Pretreatment of macrophages with chemokines induced superoxide anion generation by activating NADPH oxidase components in infected cells. Chemokine administration in vitro induced the migration of infected macrophages and triggered the production of reactive oxygen species. In vivo treatment with chemokines significantly restricted the parasitic burden in livers as well as in spleens. Collectively, these results indicate a novel regulatory role of C-C chemokines in controlling the intracellular growth and multiplication of L. donovani, thereby demonstrating the antileishmanial properties of C-C chemokines in the disease process. DOI: 10.1128/IAI.73.12.8334-8344.2005 2005-12-01T00:00:00Z http://192.168.1.40:8080/xmlui/handle/123456789/2163 Specific and randomly derived immunoactive peptide mimotopes of mycobacterial antigens Sharma, Archna; Saha, Abhik; Bhattacharjee, Surajit; Majumdar, Subrata; Das Gupta, Sujoy K. The mycobacterial cell surface contains complex nonprotein antigens that are highly immunoactive in nature. However, these antigens are chemically heterogeneous and structurally complex, thereby limiting their applications. To identify their peptide mimotopes, phage-displayed peptide libraries Ph.D.-7 and Ph.D.-12 were panned on either defined template, monoclonal antibody (MAb) CS-35 against lipoarabinomannan (LAM), or a polyclonal rabbit immune serum reactive against whole cells of Mycobacterium bovis BCG. Panning on anti-LAM MAb CS-35 yielded two confirmed mimotopes of LAM, a 7-mer and a 12-mer, whereas panning on polyclonal serum yielded a large repertoire of mimotopes reactive against sera from BCG-immunized rabbits, one of which turned out to have the same sequence as the 7-mer LAM mimotope. The dissociation constant of the interaction between MAb CS-35 and a synthetic peptide corresponding to the 7-mer LAM mimotope was determined to be 7.55 mu M. Dot blot assays were performed with peptides corresponding to the two LAM mimotopes to evaluate their diagnostic potential. Both peptides gave discernibly higher signals with a panel of tuberculosis (TB) patient sera than with sera from healthy controls. The peptides were also found to stimulate the release of tumor necrosis factor alpha and interleukin-12 cytokines in the J774A.1 cell line and primary bone marrow-derived macrophages, indicating that they may have immunomodulatory potential. The present study demonstrates that peptide mimotopes of known and unknown mycobacterial antigens could be isolated by using subtractive phage display techniques and that these peptides could have potential applications in areas such as TB diagnostics and immunotherapy. DOI: 10.1128/CVI.00127-06 2006-10-01T00:00:00Z http://192.168.1.40:8080/xmlui/handle/123456789/2155 An unusual pro-inflammatory role of interleukin-10 induced by arabinosylated lipoarabinomannan in murine peritoneal macrophages Majumder, Nivedita; Dey, Ranadhir; Mathur, Ram Kumar; Datta, Sriparna; Maitra, Madhumita; Ghosh, Sanjukta; Saha, Bhaskar; Majumdar, Subrata Various species of Mycobacteria produce a major cell wall-associated lipoglycan, called Lipoarabinomannan (LAM), which is involved in the virulence of Mycobacterial species. In this study, we tried to establish the role of the increased IL-10 secretion under Arabinosylated-LAM (Ara-LAM) treatment, the LAM that induces apoptosis in host macrophages or PBMC. We have studied the survival and apoptotic factors by western blotting, and estimated nitrite generation by Griess reaction, quantified iNOS mRNA by semi-quantitative RT-PCR, and ultimately the fate of the cells were studied by Flow Cytometric Analysis of AnnexinV-FITC binding. As per our observations, neutralization of released IL-10 in C57BL/6 peritoneal macrophages prior to Ara-LAM treatment, as well as macrophages from IL-10 knockout (KO) mice treated with Ara-LAM, showed significant down regulation of pro-apoptotic factors and up regulation of survival factors. These effects were strikingly similar to those when peritoneal macrophages were subjected to TNF-alpha and IL-12 neutralization followed by Ara-LAM-treatment. However, under similar conditions virulent Mannosylated-LAM (from Mycobacterium tuberculosis) treatment of macrophages clearly depicts the importance of IL-10 in the maintenance of pathogenesis, proving its usual immunosuppressive role. Thus, from our detailed investigations we point out an unusual pro-inflammatory action of IL-10 in Ara-LAM treated macrophages, where it behaves in a similar manner as the known Th1 cytokines TNF- alpha and IL-12. DOI: 10.1007/s10719-006-9017-9 2006-12-01T00:00:00Z http://192.168.1.40:8080/xmlui/handle/123456789/2103 Induction of host protective th1 immune response by chemokines in Leishmania donovani-infected BALB/c mice Dey, R; Majumder, N; Majumdar Bhattacharyya, S; Bhattacharjee, Surajit; Banerjee, S.; Roy, S; Majumdar, S The resolution from leishmanial infection is dependent on the coordinated interactions between the components of the cell mediated immune system and the activation of T-cell population into appropriate cytokine production and the activation of macrophages. Earlier reports established that C-C chemokines particularly macrophage inflammatory protein (MIP)-1 alpha and macrophage chemoattractant protein (MCP)-1 restrict the parasitic burden via the regulation of impaired protein kinase C (PKC) signalling and induction of free-radical generation in murine leishmaniasis. This study explored the role of MIP-1 alpha and MCP-1 in the induction of T helper 1 (Th1) immune response and suppression of T helper 2 (Th2) response in Leishmania donovani-infected BALB/c mice. These chemokines induced the known pro-inflammatory cytokine interleukin (IL)-12 secretion and inhibited the secretion of anti-inflammatory cytokines IL-10 and transforming growth factor-beta in infected macrophages. Impaired antigen presentation capability of infected macrophages was also restored by the chemokine treatment. C-C chemokine treatment resulted in reduced levels of mRNA expression of IL-10, but increased levels of mRNA expression of IL-12p40, interferon (IFN)-gamma, tumour necrosis factor-alpha and inducible nitric oxide synthase in both liver mononuclear cells as well as in splenocytes, reflecting a switch of CD4(+) differentiation from Th2 to Th1. Flow cytometric analysis of infected spleen cells suggested that C-C chemokine treatment enhances the CD4(+) T cells to produce increased levels of IFN-gamma. These studies hypothesize a promising immuno-prophylactic effect of chemokines against leishmaniasis by induction of Th1 cytokine release imparting a long-term resistance. DOI: 10.1111/j.1365-3083.2007.02025.x 2007-12-01T00:00:00Z