Erin Lalime | Johns Hopkins University (original) (raw)

Papers by Erin Lalime

Research paper thumbnail of Measles Virus Infection of Primary Respiratory Epithelial Cells Derived from Rhesus Macaques

Abstract: Measles remains a leading vaccine-preventable cause of child mortality globally. Althou... more Abstract: Measles remains a leading vaccine-preventable cause of child mortality globally. Although a live-attenuated vaccine against measles virus (MV) is available, measles has been difficult to control. MV is a respiratory infection typically spread by aerosol droplets which target respiratory epithelial cells as initial sites of viral entry and replication.

Research paper thumbnail of The cholesterol recognition/interaction amino acid consensus motif of the influenza A virus M2 protein is not required for virus replication but contributes to virulence.

Influenza A virus particles assemble and bud from plasma membrane domains enriched with the viral... more Influenza A virus particles assemble and bud from plasma membrane domains enriched with the viral glycoproteins but only a small fraction of the total M2 protein is incorporated into virus particles when compared to the other viral glycoproteins. A membrane proximal cholesterol recognition/interaction amino acid consensus (CRAC) motif was previously identified in M2 and suggested to play a role in protein function. We investigated the importance of the CRAC motif on virus replication by generating recombinant proteins and viruses containing amino acid substitutions in this motif. Alteration or completion of the M2 CRAC motif in two different virus strains caused no changes in virus replication in vitro. Viruses lacking an M2 CRAC motif had decreased morbidity and mortality in the mouse model of infection, suggesting that this motif is a virulence determinant which may facilitate virus replication in vivo but is not required for basic virus replication in tissue culture.Copyright 2010 Elsevier Inc. All rights reserved.

Research paper thumbnail of Tyrosines In the Influenza A Virus M2 Protein Cytoplasmic Tail Are Critical for the Production of Infectious Virus Particles.

Journal of …, Jan 1, 2010

Research paper thumbnail of Estrogen and Progesterone Affect Responses to Malaria Infection In Female C57BL/6 Mice

Gender Medicine, Jan 1, 2008

Previous data from our laboratory suggest that gonadally intact C57BL/6 male mice are more likely... more Previous data from our laboratory suggest that gonadally intact C57BL/6 male mice are more likely than their female counterparts to die from Plasmodium chabaudi infection, to recover more slowly from weight loss and hematocrit loss, and to have reduced interferon-gamma (IFN-gamma) and interleukin-10 (IL-10) responses. Removal of the ovaries, and hence, the primary production of sex steroids in females, reverses these differences. We hypothesized that sex differences in response to P chabaudi may be mediated by differential synthesis of IFN-gamma and IL-10 that is influenced by estrogen, progesterone, or both. C57BL/6 female mice (n = 200; n = 10/time point/treatment/experiment) were ovariectomized and implanted with a 21-day controlled-release pellet containing either 0.1 mg of 17beta-estradiol (E(2)), 10 mg of progesterone (P(4)), 0.1 mg of E(2) plus 10 mg of P(4), or cholesterol (placebo). Females were inoculated with 10(6)P chabaudi-infected erythrocytes. Body mass, body temperature, hematocrit, parasitemia, cytokine production, and antibody responses were monitored 0, 3, 5, 7, 10, 14, and 21 days postinoculation. Administration of E(2), either alone or in combination with P(4), mitigated infection-induced weight loss, hematocrit loss, and hypothermia, compared with females receiving placebo pellets (P < 0.05 in each case). Hormone treatment did not affect levels of parasitemia. Females administered E(2) alone or in combination with P(4) produced 4 to 7 times higher IFN-gamma and IL-10 during peak parasitemia than did females implanted with pellets containing either P(4) alone or placebo (P < 0.05 in each case). Exposure to E(2), either alone or in combination with P(4), increased anti-P chabaudi immunoglobulin G (IgG1) responses and the ratio of IgG1 to IgG2c (P < 0.05 in each case). This animal study suggests that physiological levels of estrogen, rather than progesterone, enhance immunity and, possibly, protect females from disease symptoms during malaria infection.

Research paper thumbnail of Palmitoylation of the Influenza A Virus M2 Protein is Not Required for Virus Replication In Vitro but Contributes to Virus Virulence

Journal of …, Jan 1, 2009

Research paper thumbnail of Measles Virus Infection of Primary Respiratory Epithelial Cells Derived from Rhesus Macaques

Abstract: Measles remains a leading vaccine-preventable cause of child mortality globally. Althou... more Abstract: Measles remains a leading vaccine-preventable cause of child mortality globally. Although a live-attenuated vaccine against measles virus (MV) is available, measles has been difficult to control. MV is a respiratory infection typically spread by aerosol droplets which target respiratory epithelial cells as initial sites of viral entry and replication.

Research paper thumbnail of The cholesterol recognition/interaction amino acid consensus motif of the influenza A virus M2 protein is not required for virus replication but contributes to virulence.

Influenza A virus particles assemble and bud from plasma membrane domains enriched with the viral... more Influenza A virus particles assemble and bud from plasma membrane domains enriched with the viral glycoproteins but only a small fraction of the total M2 protein is incorporated into virus particles when compared to the other viral glycoproteins. A membrane proximal cholesterol recognition/interaction amino acid consensus (CRAC) motif was previously identified in M2 and suggested to play a role in protein function. We investigated the importance of the CRAC motif on virus replication by generating recombinant proteins and viruses containing amino acid substitutions in this motif. Alteration or completion of the M2 CRAC motif in two different virus strains caused no changes in virus replication in vitro. Viruses lacking an M2 CRAC motif had decreased morbidity and mortality in the mouse model of infection, suggesting that this motif is a virulence determinant which may facilitate virus replication in vivo but is not required for basic virus replication in tissue culture.Copyright 2010 Elsevier Inc. All rights reserved.

Research paper thumbnail of Tyrosines In the Influenza A Virus M2 Protein Cytoplasmic Tail Are Critical for the Production of Infectious Virus Particles.

Journal of …, Jan 1, 2010

Research paper thumbnail of Estrogen and Progesterone Affect Responses to Malaria Infection In Female C57BL/6 Mice

Gender Medicine, Jan 1, 2008

Previous data from our laboratory suggest that gonadally intact C57BL/6 male mice are more likely... more Previous data from our laboratory suggest that gonadally intact C57BL/6 male mice are more likely than their female counterparts to die from Plasmodium chabaudi infection, to recover more slowly from weight loss and hematocrit loss, and to have reduced interferon-gamma (IFN-gamma) and interleukin-10 (IL-10) responses. Removal of the ovaries, and hence, the primary production of sex steroids in females, reverses these differences. We hypothesized that sex differences in response to P chabaudi may be mediated by differential synthesis of IFN-gamma and IL-10 that is influenced by estrogen, progesterone, or both. C57BL/6 female mice (n = 200; n = 10/time point/treatment/experiment) were ovariectomized and implanted with a 21-day controlled-release pellet containing either 0.1 mg of 17beta-estradiol (E(2)), 10 mg of progesterone (P(4)), 0.1 mg of E(2) plus 10 mg of P(4), or cholesterol (placebo). Females were inoculated with 10(6)P chabaudi-infected erythrocytes. Body mass, body temperature, hematocrit, parasitemia, cytokine production, and antibody responses were monitored 0, 3, 5, 7, 10, 14, and 21 days postinoculation. Administration of E(2), either alone or in combination with P(4), mitigated infection-induced weight loss, hematocrit loss, and hypothermia, compared with females receiving placebo pellets (P < 0.05 in each case). Hormone treatment did not affect levels of parasitemia. Females administered E(2) alone or in combination with P(4) produced 4 to 7 times higher IFN-gamma and IL-10 during peak parasitemia than did females implanted with pellets containing either P(4) alone or placebo (P < 0.05 in each case). Exposure to E(2), either alone or in combination with P(4), increased anti-P chabaudi immunoglobulin G (IgG1) responses and the ratio of IgG1 to IgG2c (P < 0.05 in each case). This animal study suggests that physiological levels of estrogen, rather than progesterone, enhance immunity and, possibly, protect females from disease symptoms during malaria infection.

Research paper thumbnail of Palmitoylation of the Influenza A Virus M2 Protein is Not Required for Virus Replication In Vitro but Contributes to Virus Virulence

Journal of …, Jan 1, 2009