Nadia Anikeeva - Academia.edu (original) (raw)
Papers by Nadia Anikeeva
Our previous data suggest that LFA-1-ICAM-1 interactions in the peripheral supramolecular activat... more Our previous data suggest that LFA-1-ICAM-1 interactions in the peripheral supramolecular activation cluster (pSMAC) of the immunological synapse mediate formation of a tight adhesion junction that might contribute to the sensitivity of target cell lysis by CTL. Herein, we compared more (CD8 ؉ ) and less (CD4 ؉ ) effective CTL to understand the molecular events that promote efficient target cell lysis. We found that abrogation of the pSMAC formation significantly impaired the ability of CD8 ؉ but not CD4 ؉ CTL to lyse target cells despite having no effect of the amount of released granules by both CD8 ؉ and CD4 ؉ CTL. Consistent with this, CD4 ؉ CTL break their synapses more often than do CD8 ؉ CTL, which leads to the escape of the cytolytic molecules from the interface. CD4 ؉ CTL treatment with a protein kinase C inhibitor increases synapse stability and sensitivity of specific target cell lysis. Thus, formation of a stable pSMAC, which is partially controlled by protein kinase C, functions to confine the released lytic molecules at the synaptic interface and to enhance the effectiveness of target cell lysis. Abbreviations used in this paper: pMHC, peptide-MHC; cSMAC, central supramolecular activation cluster; dSMAC, distal supramolecular activation cluster; IS, immunological synapse; PKC, protein kinase C; pSMAC, peripheral supramolecular activation cluster; RU, relative units; TIRF, total internal reflection fluorescence.
Bioorganicheskaia khimiia, 1991
A human interleukin-2 (IL-2) gene was isolated from genomic DNA library. The isolated gene with 5... more A human interleukin-2 (IL-2) gene was isolated from genomic DNA library. The isolated gene with 5'- and 3'-flanking sequences of various lengths was inserted into plasmids derived from the retroviral vector pPSneo. The recombinant plasmids were transfected into myeloma X63Ag8-653 cells. The transfected cells, harbouring the IL-2 gene with the shortened (to position -165) or totally deleted 5'-flanking sequence, constitutively expressed biologically active IL-2. Deletion of 3'-flanking region on did not affect the IL-2 expression.
Journal of Biological Chemistry, 2015
Integrin engagement on lymphocytes initiates &amp... more Integrin engagement on lymphocytes initiates "outside-in" signaling that is required for cytoskeleton remodeling and the formation of the synaptic interface. However, the mechanism by which the "outside-in" signal contributes to receptor-mediated intracellular signaling that regulates the kinetics of granule delivery and efficiency of cytolytic activity is not well understood. We have found that variations in ICAM-1 expression on tumor cells influence killing kinetics of these cells by CD16.NK-92 cytolytic effectors suggesting that changes in integrin ligation on the effector cells regulate the kinetics of cytolytic activity by the effector cells. To understand how variations of the integrin receptor ligation may alter cytolytic activity of CD16.NK-92 cells, we analyzed molecular events at the contact area of these cells exposed to planar lipid bilayers that display integrin ligands at different densities and activating CD16-specific antibodies. Changes in the extent of integrin ligation on CD16.NK-92 cells at the cell/bilayer interface revealed that the integrin signal influences the size and the dynamics of activating receptor microclusters in a Pyk2-dependent manner. Integrin-mediated changes of the intracellular signaling significantly affected the kinetics of degranulation of CD16.NK-92 cells providing evidence that integrins regulate the rate of target cell destruction in antibody dependent cell cytotoxicity (ADCC).
Proceedings of the National Academy of Sciences of the United States of America, Jan 7, 2006
Cytotoxic T lymphocytes (CTL) can respond to a few viral peptide-MHC-I (pMHC-I) complexes among a... more Cytotoxic T lymphocytes (CTL) can respond to a few viral peptide-MHC-I (pMHC-I) complexes among a myriad of virus-unrelated endogenous self pMHC-I complexes displayed on virus-infected cells. To elucidate the molecular recognition events on live CTL, we have utilized a self-assembled biosensor composed of semiconductor nanocrystals, quantum dots, carrying a controlled number of virus-derived (cognate) and other (noncognate) pMHC-I complexes and examined their recognition by antigen-specific T cell receptor (TCR) on anti-virus CD8(+) T cells. The unique architecture of nanoscale quantum dot/pMHC-I conjugates revealed that unexpectedly strong multivalent CD8-MHC-I interactions underlie the cooperative contribution of noncognate pMHC-I to the recognition of cognate pMHC-I by TCR to augment T cell responses. The cooperative, CD8-dependent spread of signal from a few productively engaged TCR to many other TCR can explain the remarkable ability of CTL to respond to virus-infected cells th...
Proceedings of the National Academy of Sciences of the United States of America, Jan 3, 2005
Lymphocyte function-associated antigen-1 (LFA-1) interaction with intercellular adhesion molecule... more Lymphocyte function-associated antigen-1 (LFA-1) interaction with intercellular adhesion molecules (ICAMs) facilitates T cell antigen receptor (TCR)-mediated killing. To dissect TCR and LFA-1 contributions, we evaluated cytolytic activity and granule release by cytotoxic T lymphocytes (CTL) as well as intracellular granule redistribution and morphology of CTL stimulated with natural TCR ligand in the presence or absence of LFA-1 engagement. Although other adhesion mechanisms, e.g., CD2-CD58 interaction, could substitute for LFA-1 to trigger CTL degranulation, productive LFA-1 ligation was indispensable for effective target cell lysis by the released granules. LFA-1-mediated adhesion to glass-supported bilayers containing intercellular adhesion molecule-1 was characterized by a much larger junction area, marked by LFA-1 segregation, and a more compact cell shape compared with those observed for CD2-mediated adhesion to bilayers containing CD58. A larger contact induced by intercellul...
The Journal of biological chemistry, Jan 22, 2004
Antibodies recognizing peptide bound to a major histocompatibility complex (MHC) protein usually ... more Antibodies recognizing peptide bound to a major histocompatibility complex (MHC) protein usually have a higher affinity for the composite peptide.MHC (pMHC) ligand than T cell receptors (TCR) with the same specificity. Because the solvent-accessible peptide area constitutes only a small portion of the contacting pMHC surface, we hypothesized that the contribution of the MHC moiety to the TCR-pMHC complex stability is limited, ensuring a small increment of the binding energy delivered by the peptide to be distinguishable by the TCR or the peptide-specific antibody. This suggests that the gain in affinity of the antibody-pMHC interaction can be achieved through an increase in the on-rate without a significant change in the off-rate of the interaction. To test the hypothesis, we have analyzed the binding of an ovalbumin peptide (pOV8) and its variants associated with soluble H-2Kb protein to the 25-D1.16 monoclonal antibody and compared it with the binding of the same pMHC complexes to...
PLoS ONE, 2012
Noncognate or self peptide-MHC (pMHC) ligands productively interact with T-cell receptor (TCR) an... more Noncognate or self peptide-MHC (pMHC) ligands productively interact with T-cell receptor (TCR) and are always in a large access over the cognate pMHC on the surface of antigen presenting cells. We assembled soluble cognate and noncognate pMHC class I (pMHC-I) ligands at designated ratios on various scaffolds into oligomers that mimic pMHC clustering and examined how multivalency and density of the pMHCs in model clusters influences the binding to live CD8 T cells and the kinetics of TCR signaling. Our data demonstrate that the density of self pMHC-I proteins promotes their interaction with CD8 co-receptor, which plays a critical role in recognition of a small number of cognate pMHC-I ligands. This suggests that MHC clustering on live target cells could be utilized as a sensitive mechanism to regulate T cell responsiveness.
European Journal of Immunology, 2014
[1, 2]. The cytolytic activity of NK cells is regulated by the balance between positive and negat... more [1, 2]. The cytolytic activity of NK cells is regulated by the balance between positive and negative signals induced by various activating and inhibitory receptors . The specificity of NK cell responses is partially mediated by IgG antibodies that recognize cell surface cancer-associated epitopes and induce antibodydependent cell-mediated cytotoxicity (ADCC) through antibody Fc binding to FcγRIIIa (CD16).
Proceedings of the National Academy of Sciences, 2005
Lymphocyte function-associated antigen-1 (LFA-1) interaction with intercellular adhesion molecule... more Lymphocyte function-associated antigen-1 (LFA-1) interaction with intercellular adhesion molecules (ICAMs) facilitates T cell antigen receptor (TCR)-mediated killing. To dissect TCR and LFA-1 contributions, we evaluated cytolytic activity and granule release by cytotoxic T lymphocytes (CTL) as well as intracellular granule redistribution and morphology of CTL stimulated with natural TCR ligand in the presence or absence of LFA-1 engagement. Although other adhesion mechanisms, e.g., CD2-CD58 interaction, could substitute for LFA-1 to trigger CTL degranulation, productive LFA-1 ligation was indispensable for effective target cell lysis by the released granules. LFA-1-mediated adhesion to glass-supported bilayers containing intercellular adhesion molecule-1 was characterized by a much larger junction area, marked by LFA-1 segregation, and a more compact cell shape compared with those observed for CD2-mediated adhesion to bilayers containing CD58. A larger contact induced by intercellular adhesion molecule 1 determined a unique positioning of granules near the interface. These data provide evidence that LFA-1 delivers a distinct signal essential for directing released cytolytic granules to the surface of antigenbearing target cells to mediate the effective destruction of these cells by CTL.
Proceedings of the National Academy of Sciences, 2006
CD8 coreceptor ͉ peptide-MHC clustering ͉ sensitivity of T cell responses ͉ antivirus immunity § ... more CD8 coreceptor ͉ peptide-MHC clustering ͉ sensitivity of T cell responses ͉ antivirus immunity § To whom correspondence may be addressed.
Our previous data suggest that LFA-1-ICAM-1 interactions in the peripheral supramolecular activat... more Our previous data suggest that LFA-1-ICAM-1 interactions in the peripheral supramolecular activation cluster (pSMAC) of the immunological synapse mediate formation of a tight adhesion junction that might contribute to the sensitivity of target cell lysis by CTL. Herein, we compared more (CD8 ؉ ) and less (CD4 ؉ ) effective CTL to understand the molecular events that promote efficient target cell lysis. We found that abrogation of the pSMAC formation significantly impaired the ability of CD8 ؉ but not CD4 ؉ CTL to lyse target cells despite having no effect of the amount of released granules by both CD8 ؉ and CD4 ؉ CTL. Consistent with this, CD4 ؉ CTL break their synapses more often than do CD8 ؉ CTL, which leads to the escape of the cytolytic molecules from the interface. CD4 ؉ CTL treatment with a protein kinase C inhibitor increases synapse stability and sensitivity of specific target cell lysis. Thus, formation of a stable pSMAC, which is partially controlled by protein kinase C, functions to confine the released lytic molecules at the synaptic interface and to enhance the effectiveness of target cell lysis. Abbreviations used in this paper: pMHC, peptide-MHC; cSMAC, central supramolecular activation cluster; dSMAC, distal supramolecular activation cluster; IS, immunological synapse; PKC, protein kinase C; pSMAC, peripheral supramolecular activation cluster; RU, relative units; TIRF, total internal reflection fluorescence.
Bioorganicheskaia khimiia, 1991
A human interleukin-2 (IL-2) gene was isolated from genomic DNA library. The isolated gene with 5... more A human interleukin-2 (IL-2) gene was isolated from genomic DNA library. The isolated gene with 5'- and 3'-flanking sequences of various lengths was inserted into plasmids derived from the retroviral vector pPSneo. The recombinant plasmids were transfected into myeloma X63Ag8-653 cells. The transfected cells, harbouring the IL-2 gene with the shortened (to position -165) or totally deleted 5'-flanking sequence, constitutively expressed biologically active IL-2. Deletion of 3'-flanking region on did not affect the IL-2 expression.
Journal of Biological Chemistry, 2015
Integrin engagement on lymphocytes initiates &amp... more Integrin engagement on lymphocytes initiates "outside-in" signaling that is required for cytoskeleton remodeling and the formation of the synaptic interface. However, the mechanism by which the "outside-in" signal contributes to receptor-mediated intracellular signaling that regulates the kinetics of granule delivery and efficiency of cytolytic activity is not well understood. We have found that variations in ICAM-1 expression on tumor cells influence killing kinetics of these cells by CD16.NK-92 cytolytic effectors suggesting that changes in integrin ligation on the effector cells regulate the kinetics of cytolytic activity by the effector cells. To understand how variations of the integrin receptor ligation may alter cytolytic activity of CD16.NK-92 cells, we analyzed molecular events at the contact area of these cells exposed to planar lipid bilayers that display integrin ligands at different densities and activating CD16-specific antibodies. Changes in the extent of integrin ligation on CD16.NK-92 cells at the cell/bilayer interface revealed that the integrin signal influences the size and the dynamics of activating receptor microclusters in a Pyk2-dependent manner. Integrin-mediated changes of the intracellular signaling significantly affected the kinetics of degranulation of CD16.NK-92 cells providing evidence that integrins regulate the rate of target cell destruction in antibody dependent cell cytotoxicity (ADCC).
Proceedings of the National Academy of Sciences of the United States of America, Jan 7, 2006
Cytotoxic T lymphocytes (CTL) can respond to a few viral peptide-MHC-I (pMHC-I) complexes among a... more Cytotoxic T lymphocytes (CTL) can respond to a few viral peptide-MHC-I (pMHC-I) complexes among a myriad of virus-unrelated endogenous self pMHC-I complexes displayed on virus-infected cells. To elucidate the molecular recognition events on live CTL, we have utilized a self-assembled biosensor composed of semiconductor nanocrystals, quantum dots, carrying a controlled number of virus-derived (cognate) and other (noncognate) pMHC-I complexes and examined their recognition by antigen-specific T cell receptor (TCR) on anti-virus CD8(+) T cells. The unique architecture of nanoscale quantum dot/pMHC-I conjugates revealed that unexpectedly strong multivalent CD8-MHC-I interactions underlie the cooperative contribution of noncognate pMHC-I to the recognition of cognate pMHC-I by TCR to augment T cell responses. The cooperative, CD8-dependent spread of signal from a few productively engaged TCR to many other TCR can explain the remarkable ability of CTL to respond to virus-infected cells th...
Proceedings of the National Academy of Sciences of the United States of America, Jan 3, 2005
Lymphocyte function-associated antigen-1 (LFA-1) interaction with intercellular adhesion molecule... more Lymphocyte function-associated antigen-1 (LFA-1) interaction with intercellular adhesion molecules (ICAMs) facilitates T cell antigen receptor (TCR)-mediated killing. To dissect TCR and LFA-1 contributions, we evaluated cytolytic activity and granule release by cytotoxic T lymphocytes (CTL) as well as intracellular granule redistribution and morphology of CTL stimulated with natural TCR ligand in the presence or absence of LFA-1 engagement. Although other adhesion mechanisms, e.g., CD2-CD58 interaction, could substitute for LFA-1 to trigger CTL degranulation, productive LFA-1 ligation was indispensable for effective target cell lysis by the released granules. LFA-1-mediated adhesion to glass-supported bilayers containing intercellular adhesion molecule-1 was characterized by a much larger junction area, marked by LFA-1 segregation, and a more compact cell shape compared with those observed for CD2-mediated adhesion to bilayers containing CD58. A larger contact induced by intercellul...
The Journal of biological chemistry, Jan 22, 2004
Antibodies recognizing peptide bound to a major histocompatibility complex (MHC) protein usually ... more Antibodies recognizing peptide bound to a major histocompatibility complex (MHC) protein usually have a higher affinity for the composite peptide.MHC (pMHC) ligand than T cell receptors (TCR) with the same specificity. Because the solvent-accessible peptide area constitutes only a small portion of the contacting pMHC surface, we hypothesized that the contribution of the MHC moiety to the TCR-pMHC complex stability is limited, ensuring a small increment of the binding energy delivered by the peptide to be distinguishable by the TCR or the peptide-specific antibody. This suggests that the gain in affinity of the antibody-pMHC interaction can be achieved through an increase in the on-rate without a significant change in the off-rate of the interaction. To test the hypothesis, we have analyzed the binding of an ovalbumin peptide (pOV8) and its variants associated with soluble H-2Kb protein to the 25-D1.16 monoclonal antibody and compared it with the binding of the same pMHC complexes to...
PLoS ONE, 2012
Noncognate or self peptide-MHC (pMHC) ligands productively interact with T-cell receptor (TCR) an... more Noncognate or self peptide-MHC (pMHC) ligands productively interact with T-cell receptor (TCR) and are always in a large access over the cognate pMHC on the surface of antigen presenting cells. We assembled soluble cognate and noncognate pMHC class I (pMHC-I) ligands at designated ratios on various scaffolds into oligomers that mimic pMHC clustering and examined how multivalency and density of the pMHCs in model clusters influences the binding to live CD8 T cells and the kinetics of TCR signaling. Our data demonstrate that the density of self pMHC-I proteins promotes their interaction with CD8 co-receptor, which plays a critical role in recognition of a small number of cognate pMHC-I ligands. This suggests that MHC clustering on live target cells could be utilized as a sensitive mechanism to regulate T cell responsiveness.
European Journal of Immunology, 2014
[1, 2]. The cytolytic activity of NK cells is regulated by the balance between positive and negat... more [1, 2]. The cytolytic activity of NK cells is regulated by the balance between positive and negative signals induced by various activating and inhibitory receptors . The specificity of NK cell responses is partially mediated by IgG antibodies that recognize cell surface cancer-associated epitopes and induce antibodydependent cell-mediated cytotoxicity (ADCC) through antibody Fc binding to FcγRIIIa (CD16).
Proceedings of the National Academy of Sciences, 2005
Lymphocyte function-associated antigen-1 (LFA-1) interaction with intercellular adhesion molecule... more Lymphocyte function-associated antigen-1 (LFA-1) interaction with intercellular adhesion molecules (ICAMs) facilitates T cell antigen receptor (TCR)-mediated killing. To dissect TCR and LFA-1 contributions, we evaluated cytolytic activity and granule release by cytotoxic T lymphocytes (CTL) as well as intracellular granule redistribution and morphology of CTL stimulated with natural TCR ligand in the presence or absence of LFA-1 engagement. Although other adhesion mechanisms, e.g., CD2-CD58 interaction, could substitute for LFA-1 to trigger CTL degranulation, productive LFA-1 ligation was indispensable for effective target cell lysis by the released granules. LFA-1-mediated adhesion to glass-supported bilayers containing intercellular adhesion molecule-1 was characterized by a much larger junction area, marked by LFA-1 segregation, and a more compact cell shape compared with those observed for CD2-mediated adhesion to bilayers containing CD58. A larger contact induced by intercellular adhesion molecule 1 determined a unique positioning of granules near the interface. These data provide evidence that LFA-1 delivers a distinct signal essential for directing released cytolytic granules to the surface of antigenbearing target cells to mediate the effective destruction of these cells by CTL.
Proceedings of the National Academy of Sciences, 2006
CD8 coreceptor ͉ peptide-MHC clustering ͉ sensitivity of T cell responses ͉ antivirus immunity § ... more CD8 coreceptor ͉ peptide-MHC clustering ͉ sensitivity of T cell responses ͉ antivirus immunity § To whom correspondence may be addressed.