Discordance between antibody and T cell responses in recipients of trivalent inactivated influenza vaccine☆
Introduction
Human influenza is a highly contagious acute respiratory illness that is responsible for significant morbidity and excess mortality in the elderly and the very young worldwide. Though effective antiviral medications targeting the neuraminidase (NA) glycoprotein are available, prevention of influenza morbidity and mortality is primarily through the immunization of target groups at high risk for mortality or hospitalization [1]. Annual worldwide epidemics of influenza A and the recent emergence of zoonotic infections with highly pathogenic H5N1 and H9N2 avian influenza strains have heightened efforts to understand the role of both humoral and cell-mediated immunity in the control of influenza virus infection [2].
Current vaccine approaches depend on the induction of antibodies to the viral surface proteins hemagglutinin and neuraminidase that neutralize the infectivity of the virus and interfere with the release of newly replicated virus from the host cell [2], [3]. When the vaccine virus closely matches the challenge infecting virus, the vaccines are effective. The virus however undergoes frequent mutations at antibody combining sites and the vaccine is less effective. This is a much bigger problem when a new subtype of influenza virus emerges, e.g. the H5N1 avian derived viruses, and there are no cross-reactive antibody sites on the vaccine virus hemagglutinin (HA) and the new subtype of virus. Ideally, influenza vaccines would also be expected to induce influenza specific CD8 T cell-mediated responses that may contribute to protective immunity. Studies in murine models of influenza demonstrated that CD8 T cells were effective in reducing viral titers and aided in recovery [4], [5], [6], [7], [8], [9]. These models have also demonstrated that delayed influenza virus clearance occurs in CD8 T cell deficient mice [10] and that memory T lymphocytes can act independently of a humoral immune response in order to confer resistance to influenza infection [11], [12]. Influenza virus-specific cytotoxic T lymphocytes (CTL) have also been shown to limit influenza A virus replication and protect against lethal viral challenge [7], [8], [13]. The role of CD4 T cells in influenza infection is less defined. CD4 virus-specific T cells may help compensate for the absence of CD8 CTL because the virus can be cleared in CD8-deficient mice; however, mice lacking both CD4 and CD8 T cells do not clear virus or survive [14], [15]. Belz et al. demonstrated that responses in the secondary lymphoid organs of CD4 T cell deficient mice infected with influenza were defective while responses in bronchoalveolar lavage were similar in CD4 T cell deficient mice and wild type mice. This suggested that CD4 T cells may not be required for the primary response to influenza but may be important in the generation of memory CD8 T cells [16].
In contrast, there have been few studies on cellular immunity to influenza in humans. Knowledge about human CD8 T cell immune responses has been more well developed than human CD4 T cell responses [17], [18]. Studies on the cytotoxic T lymphocyte repertoire to influenza A viruses indicate that influenza memory T cell responses are directed to a number of epitopes on a variety of proteins including the nucleoprotein, nonstructural protein 1 (NS1), and the matrix protein 1 (M1) [19], [20]. Most of these highly conserved cross-reactive epitopes have been found to be conserved in H5N1 viruses from recent outbreaks [17]. Therefore, cell-mediated immunity appears to be important in both restricting influenza A virus replication and reducing disease severity, and appears to offer a more potentially cross-reactive vaccine approach for the prevention of pandemic or epidemic influenza.
In this study, we evaluated the human memory T cell and the serum antibody responses of healthy subjects following immunization with the licensed 2005–2006 trivalent inactivated influenza vaccine in order to better understand the role that both T and B cells may play in the protection afforded by the vaccine. Using carboxyfluoroscein succinimidyl ester (CFSE), enzyme-linked immunosorbent spot (ELISPOT) and neutralization assays to examine responses to the individual influenza A H1 and H3 viral strains, we were particularly interested in the following questions: (1) the effect of prevaccination levels of T cell immunity to both influenza A virus strains on the cellular immune responses generated by subsequent vaccination, (2) the phenotype(s) of the T cells responding to vaccine and (3) the relationships between the antibody and T cell components of the host immune response to influenza vaccine.
Section snippets
Viruses
Influenza A viruses H1N1 A/New Caledonia/20/99 (Lot # 3XANA060818B) and H3N2 A/Wisconsin/67/05 (Lot # 3XAWN060818B) were purchased from Charles River Laboratories (North Franklin, Connecticut) for use in CFSE, ELISPOT, and proliferation assays. These viruses were propagated in the allantoic cavity in Specific Pathogen Free (SPF) eggs with the final hemagglutinin titers for the A/New Caledonia strain and the A/Wisconsin strains 1:512 per 0.05 ml and 1:16 per 0.05 ml, respectively. The following
IFNγ-producing cell responses to influenza vaccination
We used ELISPOT assays to quantitate the number of IFNγ-producing cells in PBMC specific for the influenza A H1N1 subtype strain A/New Caledonia/20/99 and the H3N2 subtype strain A/Wisconsin/67/05. The H3N2 A/Wisconsin/67/05 virus is a very closely related antigenic variant of the 2005–06 vaccine strain H3N2A/California/07/04. There was an overall moderate but not a statistically significant increase in the number of IFN-γ-producing cells post-vaccination after stimulation with either of the
Discussion
Our study examined the pattern of cellular responses in influenza vaccinated individuals using three different T cell assays, ELISPOT to quantitate the numbers of specific IFNγ-producing cells and 3H thymidine and CFSE assays to quantitate the number of proliferating T cells, in relation to B cell responses examined using microneutralization assays. We studied the responses to two influenza A subtype viruses—H1N1 A/New Caledonia/20/99 and H3N2 A/Wisconsin/67/05 which contain the HA and NA
Acknowledgements
We thank Dr. Jeffrey S. Kennedy, Karen Longtine, Melissa O’Neill, and Jaclyn Longtine for their help in obtaining the human PBMC samples that were used in this study. We thank Christine Turcotte for assistance with HLA typing and Ping Liu for preliminary experiments using plaque assays as a readout for the neutralization assay.
References (40)
Realities and enigmas of human viral influenza: pathogenesis, epidemiology and control
Vaccine
(2002)- et al.
Cross-reactive protection against influenza A virus infections by an NS1-specific CTL clone
Virology
(1990) - et al.
HLA restricted virus-specific cytotoxic T-lymphocyte responses to live and inactivated influenza vaccines
Lancet
(1981) - et al.
A panel of MHC class I restricted viral peptides for use as a quality control for vaccine trial ELISPOT assays
J Immunol Methods
(2002) - et al.
Humoral and cell-mediated immune responses of humans to inactivated influenza vaccine with or without QS21 adjuvant
Vaccine
(2007) - et al.
Comparison of single versus booster dose of influenza vaccination on humoral and cellular immune responses in older adults
Vaccine
(2005) - et al.
Responses to influenza vaccination in different T-cell subsets: a comparison of healthy young and older adults
Vaccine
(1998) - et al.
Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP)
MMWR Recomm Rep
(2004) - et al.
Safety efficacy and effectiveness of cold-adapted, live, attenuated, trivalent, intranasal influenza vaccine in adults and children
Philos Trans R Soc Lond B Biol Sci
(2001) - et al.
Influenza virus subtype-specific cytotoxic T lymphocytes lyse target cells coated with a protein produced in E. coli
J Exp Med
(1985)
Human interferon alpha and gamma production by lymphocytes during the generation of influenza virus-specific cytotoxic T lymphocytes
J Gen Virol
An influenza specific T-killer clone is restricted to H-2Ld and cross-reacts with Dk region
Immunogenetics
HA2 subunit of influenza A H1 and H2 subtype viruses induces a protective cross-reactive cytotoxic T lymphocyte response
J Immunol
Cytotoxic T lymphocytes recognize a cross-reactive epitope on the transmembrane region of influenza H1 and H2 hemagglutinins
Viral Immunol
Transgenic mice lacking class I major histocompatibility complex-restricted T cells have delayed viral clearance and increased mortality after influenza virus challenge
J Exp Med
Resistance to and recovery from lethal influenza virus infection in B lymphocyte-deficient mice
J Exp Med
Mechanism of protective immunity against influenza virus infection in mice without antibodies
J Immunol
Rapid recovery of lung histology correlates with clearance of influenza virus by specific CD8+ cytotoxic T cells
Immunology
Recovery from a viral respiratory infection. I. Influenza pneumonia in normal and T-deficient mice
J Immunol
Clearance of influenza virus respiratory infection in mice lacking class I major histocompatibility complex-restricted CD8+ T cells
J Exp Med
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Financial support: This work was supported by Funding from the National Institute of Allergy and Infectious Diseases/National Institutes of Health Grant U19 AI-057319.