Immune Modulation in PrimaryVaccinia virusZoonotic Human Infections

In 2010, the WHO celebrated the 30th anniversary of the smallpox eradication. Ironically, infections caused by viruses related to smallpox are being increasingly reported worldwide, includingMonkeypox,Cowpox,andVaccinia virus(VACV). Little is known about the human immunological responses elicited during acute infections caused by orthopoxviruses. We have followed VACV zoonotic outbreaks taking place in Brazil and analyzed cellular immune responses in patients acutely infected by VACV. Results indicated that these patients show a biased immune modulation when compared to noninfected controls. Amounts of B cells are low and less activated in infected patients. Although present, T CD4+cells are also less activated when compared to noninfected individuals, and so are monocytes/macrophages. Similar results were obtained when Balb/C mice were experimentally infected with a VACV sample isolated during the zoonotic outbreaks. Taking together, the data suggest that zoonotic VACVs modulate specific immune cell compartments during an acute infection in humans.

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Improved Protection of Rhesus Macaques against Intrarectal Simian Immunodeficiency Virus SIVmac251 Challenge by a Replication-Competent Ad5hr-SIVenv/rev and Ad5hr-SIVgag Recombinant Priming/gp120 Boosting Regimen

Journal of Virology ◽

10.1128/jvi.77.15.8354-8365.2003 ◽

2003 ◽

Vol 77 (15) ◽

pp. 8354-8365 ◽

Cited By ~ 41

Author(s):

Jun Zhao ◽

Joel Pinczewski ◽

Victor R. Gómez-Román ◽

David Venzon ◽

V. S. Kalyanaraman ◽

...

Keyword(s):

Immune Responses ◽

Simian Immunodeficiency Virus ◽

Rhesus Macaques ◽

Acute Infection ◽

Neutralizing Antibody ◽

Antibody Activity ◽

Viral Loads ◽

Cellular Immune Responses ◽

Immunodeficiency Virus ◽

Cellular Immune

ABSTRACT In this study we investigated the ability of a replication-competent Ad5hr-SIVenv/rev and Ad5hr-SIVgag recombinant priming/gp120 boosting regimen to induce protective immunity in rhesus macaques against pathogenic simian immunodeficiency virusmac251. Immunization of macaques by two sequential administrations of the same recombinants by the same route resulted in boosting and persistence of SIV-specific cellular immune responses for 42 weeks past the initial immunization. Anti-SIV gp120 immunoglobulin G (IgG) and IgA antibodies were induced in secretory fluids, and all macaques exhibited serum neutralizing antibody activity. After intrarectal SIVmac251 challenge, all of the macaques became infected. However, relative protection, as assessed by statistically significant lower SIV viral loads in plasma at both acute infection and set point, was observed in 8 out of 12 immunized non-Mamu-A∗01 animals. Elevated mean cellular immune responses to Gag and Env, neutralizing antibody activity, and IgG and IgA binding antibody levels were observed in the eight protected macaques. Statistically significant correlations with protective outcome were observed for cellular immune responses to SIV Env and Gag and for SIV gp120-specific IgG antibodies in nasal and vaginal fluids. Two macaques that exhibited the greatest and most persistent viremia control also exhibited strong CD8+ T-cell antiviral activity. The results suggest that a spectrum of immune responses may be necessary for adequate control of viral replication and disease progression and highlight a potential role for nonneutralizing antibodies at mucosal sites.

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Hemocyte-hemocyte adhesion by granulocytes is associated with cellular immunity in the cricket, Gryllus bimaculatus

Scientific Reports ◽

10.1038/s41598-019-54484-5 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Youngwoo Cho ◽

Saeyoull Cho

Keyword(s):

Immune Responses ◽

Cellular Immunity ◽

Post Infection ◽

Plasma Membranes ◽

Immune Cell ◽

Gryllus Bimaculatus ◽

Cellular Immune Responses ◽

Size And Morphology ◽

Cellular Immune ◽

Unique Mechanism

AbstractIn this study, more than 1,000 cricket (Gryllus bimaculatus) hemocytes were classified based on their size and morphology. These hemocytes were classified into six types: granulocytes, plasmatocytes, prohemocytes, spherulocytes, coagulocytes, and oenocytoids. Hemocyte cultures was observed in real time to determine which hemocytes were associated with cellular immune responses against potential pathogens. Granulocytes were identified as the professional immune cell that mediates nodulation, encapsulation, and phagocytosis of pathogens. Granulocytes have been shown to actively produce various sticky nets (amoeba-like hairs and extracellular traps) from their plasma membranes that they use to gather other hemocytes and to implement cellular immune responses. The activation of lysosomes in granulocytes started at 4 h, peaked at 12 h, and returned to baseline by 24 h post-infection. At 48 h post-infection, cells could be found within the cytoplasm of granulocytes and reactivated lysosomes surrounding these cells were visible. This result seems to reflect a phenomenon in which necrotic granulocytes are removed by other healthy granulocytes. This unique mechanism of cellular immunity is therefore a way to efficiently and effectively remove pathogens and simultaneously maintain healthy hemocytes.

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Genotype Considerations for Virus-Like Particle-Based Bivalent Norovirus Vaccine Composition

Clinical and Vaccine Immunology ◽

10.1128/cvi.00015-15 ◽

2015 ◽

Vol 22 (6) ◽

pp. 656-663 ◽

Cited By ~ 24

Author(s):

Maria Malm ◽

Kirsi Tamminen ◽

Suvi Lappalainen ◽

Hanni Uusi-Kerttula ◽

Timo Vesikari ◽

...

Keyword(s):

Immune Responses ◽

Natural Infection ◽

Effective Vaccine ◽

Blocking Antibody ◽

Minimum Requirement ◽

Cellular Immune Responses ◽

Virus Like Particle ◽

Human Infections ◽

Cellular Immune ◽

Blocking Antibodies

ABSTRACTNorovirus (NoV) genogroup I (GI) and GII are responsible for most human infections with NoV. Because of the high genetic variability of NoV, natural infection does not induce sufficient protective immunity to different genotypes or to variants of the same genotype and there is little or no cross-protection against different genogroups. NoV-derived virus-like particles (VLPs) are promising vaccine candidates that induce high levels of NoV-specific humoral and cellular immune responses. It is believed that a bivalent NoV vaccine consisting of a representative VLP from GI and GII is a minimum requirement for an effective vaccine. Here, we compared the abilities of monovalent immunizations with NoV GI.1-2001, GI.3-2002, GII.4-1999, and GII.4-2010 New Orleans VLPs to induce NoV type-specific and cross-reactive immune responses and protective blocking antibody responses in BALB/c mice. All of the VLPs induced comparable levels of type-specific serum IgG antibodies, as well as blocking antibodies to the VLPs used for immunization. However, the abilities of different VLP genotypes to induce cross-reactive IgG and cross-blocking antibodies varied remarkably. Our results confirm previous findings of a lack of cross-protective immune responses between GI and GII NoVs. These data support the rationale for including NoV GI.3 and GII.4-1999 VLPs in the bivalent vaccine formulation, which could be sufficient to induce protective immune responses across NoV genotypes in the two common genogroups in humans.

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Immune response in mice immunized with acidic antigenic fractions from Trypanosoma cruzi cytosol

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46651992000500003 ◽

1992 ◽

Vol 34 (5) ◽

pp. 389-394 ◽

Cited By ~ 11

Author(s):

Susana Gea ◽

Adriana Gruppi ◽

Fabio Cerban ◽

Maria C. Pistoresi Palencia ◽

Elsa Vottero-Cima

Keyword(s):

Skeletal Muscle ◽

Immune Response ◽

Immune Responses ◽

Acute Infection ◽

Specific Ige ◽

Partial Protection ◽

Histological Studies ◽

Cellular Immune Responses ◽

Resistance To Infection ◽

Cellular Immune

The humoral and cellular immune responses as well as the resistance to infection with bloodstream forms of T. cruzi were studied in mice immunized with acidic antigenic fractions from parasite cytosol, F III and F IV, plus Bordetella pertussis as adjuvant. The immunization with F III induced positive ITH and DTH responses to homologous antigens. In mice immunized with F IV, the ITH was negative and four out of six animals presented positive DTH reactions. In both groups of mice the analysis of IgG aginst T. cruzi showed that the major isotype elicited was IgG1. Specific IgE was also detected in sera from F III immunized mice, thus confirming the presence of homocytothropic antibodies. The parasitemias reached by F III and F IV immunized mice after challenge were lower than those of the controls showing in this way a partial protection against the acute infection. The histological studies of heart and skeletal muscle performed two months after the infection revealed variable mononuclear infiltration in all infected mice despite immunization.

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Cellular Immune Responses in Seronegative Sexual Contacts of Acute Hepatitis C Patients

Journal of Virology ◽

10.1128/jvi.78.22.12252-12258.2004 ◽

2004 ◽

Vol 78 (22) ◽

pp. 12252-12258 ◽

Cited By ~ 63

Author(s):

Sanaa M. Kamal ◽

Ashraf Amin ◽

Mohamed Madwar ◽

Camilla S. Graham ◽

Qi He ◽

...

Keyword(s):

Hepatitis C ◽

Immune Responses ◽

Acute Hepatitis ◽

Acute Infection ◽

Spontaneous Clearance ◽

Acute Hepatitis C ◽

Cellular Immune Responses ◽

Acute Hcv ◽

Sexual Contacts ◽

Cellular Immune

ABSTRACT Acute hepatitis C virus (HCV) is typically defined as new viremia and antibody seroconversion. Rates and immunologic correlates of hepatitis C clearance have therefore been based on clearance of viremia only in individuals who initially had an antibody response. We sought to characterize the immunological correlates of clearance in patients with acute hepatitis C and their sexual contacts. We prospectively determined CD4+ and CD8+ cytotoxic T-lymphocyte responses in index patients with acute HCV and their sexual contacts who developed acute infection, either with or without spontaneous clearance, as well as those contacts who never developed viremia. Responses were measured using proliferation and ELISpot assays for CD4+ and CD8+ responses. We demonstrate in this prospective study that cellular immune responses can develop in exposed but persistently aviremic and antibody-negative individuals as well as those individuals with spontaneous clearance of acute HCV. These findings lend further credence to the importance of cellular immune responses in recovery from HCV and suggest that low exposure to HCV may lead to development of HCV-specific immune responses without ongoing HCV replication. This finding has important implications for HCV vaccine and therapeutic development.

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