scholarly journals Measles Virus-Specific CD4 T-Cell Activity Does Not Correlate with Protection against Lung Infection or Viral Clearance

2007 ◽  
Vol 81 (16) ◽  
pp. 8571-8578 ◽  
Author(s):  
Karen Pueschel ◽  
Annette Tietz ◽  
Mary Carsillo ◽  
Michael Steward ◽  
Stefan Niewiesk

ABSTRACT Acute measles in children can be prevented by immunization with the live attenuated measles vaccine virus. Although immunization is able to induce CD4 and CD8 T cells as well as neutralizing antibodies, only the latter have been correlated with protective immunity. CD8 T cells, however, have been documented to be important in viral clearance in the respiratory tract, whereas CD4 T cells have been shown to be protective in a mouse encephalitis model. In order to investigate the CD4 T-cell response in infection of the respiratory tract, we have defined a T-cell epitope in the hemagglutinin (H) protein for immunization and developed a monoclonal antibody for depletion of CD4 T cells in the cotton rat model. Although the kinetics of CD4 T-cell development correlated with clearance of virus, the depletion of CD4 T cells during the primary infection did not influence viral titers in lung tissue. Immunization with the H epitope induced a CD4 T-cell response but did not protect against infection. Immunization in the presence of maternal antibodies resulted in the development of a CD4 T-cell response which (in the absence of neutralizing antibodies) did not protect against infection. In summary, CD4 T cells do not seem to protect against infection after immunization and do not participate in clearance of virus infection from lung tissue during measles virus infection. We speculate that the major role of CD4 T cells is to control and clear virus infection from other affected organs like the brain.

2005 ◽  
Vol 201 (10) ◽  
pp. 1555-1565 ◽  
Author(s):  
Reinhard Obst ◽  
Hisse-Martien van Santen ◽  
Diane Mathis ◽  
Christophe Benoist

For CD8+ T cells, a relatively short antigen pulse seems sufficient for antigen-presenting cells to drive clonal expansion and differentiation. It is unknown whether the requirement for antigen is similarly ephemeral for CD4+ T cells. To study the dependence of a CD4+ T cell response on antigen persistence in a quantitatively and temporally controlled manner in vivo, we engineered a mouse line expressing a major histocompatibility complex class II–restricted epitope in dendritic cells under the control of a tetracycline-inducible promoter. Experiments tracking the proliferation of CD4+ T cells exposed to their cognate antigen in various amounts for different time periods revealed that the division of such cells was contingent on the presence of antigen throughout their expansion phase, even in the presence of an inflammatory stimulus. This previously unrecognized feature of a CD4+ T cell response contrasts with the proliferative behavior of CD8+ T cells that has been documented, and it implies that the two T cell subsets might require different strategies for efficient vaccination.


Virology ◽  
2006 ◽  
Vol 347 (1) ◽  
pp. 234-245 ◽  
Author(s):  
Antoinette Tishon ◽  
Hanna Lewicki ◽  
Abegail Andaya ◽  
Dorian McGavern ◽  
Lee Martin ◽  
...  

Blood ◽  
2008 ◽  
Vol 111 (4) ◽  
pp. 2053-2061 ◽  
Author(s):  
Laura Crompton ◽  
Naeem Khan ◽  
Rajiv Khanna ◽  
Laxman Nayak ◽  
Paul A. H. Moss

Antigen-specific CD8+ cytotoxic T cells often demonstrate extreme conservation of T-cell receptor (TCR) usage between different individuals, but similar characteristics have not been documented for CD4+ T cells. CD4+ T cells predominantly have a helper immune role, but a cytotoxic CD4+ T-cell subset has been characterized, and we have studied the cytotoxic CD4+ T-cell response to a peptide from human cytomegalovirus glycoprotein B presented through HLA-DRB*0701. We show that this peptide elicits a cytotoxic CD4+ T-cell response that averages 3.6% of the total CD4+ T-cell repertoire of cytomegalovirus-seropositive donors. Moreover, CD4+ cytotoxic T-cell clones isolated from different individuals exhibit extensive conservation of TCR usage, which indicates strong T-cell clonal selection for peptide recognition. Remarkably, this TCR sequence was recently reported in more than 50% of cases of CD4+ T-cell large granular lymphocytosis. Immunodominance of cytotoxic CD4+ T cells thus parallels that of CD8+ subsets and suggests that cytotoxic effector function is critical to the development of T-cell clonal selection, possibly from immune competition secondary to lysis of antigen-presenting cells. In addition, these TCR sequences are highly homologous to those observed in HLA-DR7+ patients with CD4+ T-cell large granular lymphocytosis and implicate cytomegalovirus as a likely antigenic stimulus for this disorder.


2008 ◽  
Vol 37 ◽  
pp. 62-68 ◽  
Author(s):  
David A. Hokey ◽  
Jian Yan ◽  
Lauren A. Hirao ◽  
Anlan Dai ◽  
Jean D. Boyer ◽  
...  

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3110-3110
Author(s):  
Erwan R. Piriou ◽  
Christine Jansen ◽  
Karel van Dort ◽  
Iris De Cuyper ◽  
Nening M. Nanlohy ◽  
...  

Abstract Objective: EBV-specific CD8+ T cells have been extensively studied in various settings, and appear to play a major role in the control of EBV-related malignancies. In contrast, it is still unclear whether EBV-specific CD4+ T cells play a role in vivo. To study this question, an assay was developed to measure the CD4+ T-cell response towards two EBV antigens, in both healthy (n=14) and HIV-infected subjects (n=23). In addition, both HAART-treated (n=12) and untreated HIV+ individuals (n=14) - including progressors to EBV-related lymphoma - were studied longitudinally. Methods: EBV-specific CD4+ T cells were stimulated with peptide pools from latent protein EBNA1 and lytic protein BZLF1, and detected by measurement of IFNg-production. Results: After direct ex vivo stimulation, EBNA1 or BZLF1-specific IFNg- (and/or IL2) producing CD4+ T cell numbers were low, and measurable in less than half of the subjects studied (either HIV- and HIV+). Therefore, PBMC were cultured for 12 days in the presence of peptides and IL2 (from day 3), and then restimulated with peptides, allowing specific and reproducible expansion of EBV-specific CD4+ T cells, independent of HLA type and ex vivo antigen processing. Interestingly, numbers of EBV-specific CD4+ T cells inversely correlated with EBV viral load, implying an important role for EBV-specific CD4+ T cells in the control of EBV in vivo. Untreated HIV-infected individuals had a lower CD4+ T cell response to EBNA1 and BZLF1 as compared to healthy EBV carriers and HAART-treated HIV+ subjects. In longitudinal samples, EBNA1-specific, but not BZLF1-specific T-cell numbers increased after HAART, while EBV load was not affected by treatment. In all the progressors to EBV-related lymphoma, EBV-specific CD4+ T cells were lost at least 24 months before lymphoma diagnosis. Conclusions: Both cross-sectional and longitudinal data suggest an important role for EBV-specific CD4+ T cells in the control of EBV-related malignancies. Furthermore, it seems that HAART treatment leads to recovery of EBNA1-specific, but not BZLF1-specific CD4+ T-cell responses, implying changes in the latency pattern of EBV, despite an unaltered cell-associated EBV DNA load. Thus, early HAART treatment might prevent loss of specific CD4+ T-cell help and progression to NHL.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 606-606 ◽  
Author(s):  
Louis J. Picker ◽  
Andrew W. Sylwester ◽  
Bridget L. Mitchell ◽  
Cara Taormina ◽  
Christian Pelte ◽  
...  

Abstract Human Cytomegalovirus (HCMV) is among the largest and most complex of known viruses with 150–200nm virions enclosing a double stranded 230kb DNA genome capable of coding for >200 proteins. HCMV infection is life-long, and for the vast majority of immune competent individuals clinically benign. Disease occurs almost exclusively in the setting of immune deficiency, suggesting that the stable host-parasite relationship that characterizes these infections is the result of an evolutionarily “negotiated” balance between viral mechanisms of pathogenesis and the host immune response. In keeping with, and perhaps because of this balance, the human CD4+ T cell response to whole HCMV viral lysates is enormous, with median peripheral blood frequencies of HCMV-specific cells ~5–10 fold higher than for analogous preparations of other common viruses. Although certain HCMV ORFs have been identified as targets of either the CD4+ or CD8+ T cell response, the specificities comprising the CD4+ T cell response, and both the total frequencies and component parts of the CD8+ T cell response are unknown. Here, we used cytokine flow cytometry and ~14,000 overlapping 15mer peptides comprising all 213 HCMV ORFs encoding proteins >100 amino acids in length to precisely define the total CD4+ and CD8+ HCMV-specific T cell responses and the HCMV ORFs responsible for these responses in 33 HCMV-seropositive, HLA-disparate donors. An additional 9 HCMV seronegative donors were similarly examined to define the extent to which non-HCMV responses cross-react with HCMV-encoded epitopes. We found that when totaled, the median frequencies of HCMV-specific CD4+ and CD8+ T cells in the peripheral blood of the seropositive subjects were 4.0% and 4.5% for the total CD4+ or CD8+ T cell populations, respectively (which corresponds to 9.1% and 10.5% of the memory populations, respectively). The HCMV-specific CD4+ and CD8+ T cell responses included a median 12 and 7 different ORFs, respectively, and all told, 73 HCMV ORFs were identified as targets for both CD4+ and CD8+ T cells, 26 ORFs as targets for CD8+ T cells alone, and 43 ORFS as targets for CD4+ T cells alone. UL55, UL83, UL86, UL99, and UL122 were the HCMV ORFs most commonly recognized by CD4+ T cells; UL123, UL83, UL48, UL122 and UL28 were the HCMV ORFs most commonly recognized by CD8+ T cells. The relationship between immunogenicity and 1) HLA haplotype and 2) ORF expression and function will be discussed. HCMV-seronegative individuals were non-reactive with the vast majority of HCMV peptides. Only 7 potentially cross-reactive responses were identified (all by CD8+ T cells) to 3 ORFs (US32, US29 and UL116) out of a total of almost 4,000 potential responses, suggesting fortuitous cross-reactivity with HCMV epitopes is uncommon. These data provide the first glimpse of the total human T cell response to a complex infectious agent, and will provide insight into the rules governing immunodominance and cross-reactivity in complex viral infections of humans.


Author(s):  
Sophia Schulte ◽  
Janna Heide ◽  
Christin Ackermann ◽  
Sven Peine ◽  
Michael Ramharter ◽  
...  

Abstract Relatively little is known about the ex vivo frequency and phenotype of the P. falciparum-specific CD4+ T cell response in humans. The exported protein 1 (EXP1) is expressed by plasmodia at both, the liver stage and blood stage, of infection making it a potential target for CD4+ and CD8+ effector T cells. Here, a fluorochrome-labelled HLA-DRB1*11:01-restriced MHC class II tetramer derived from the P. falciparum EXP1 (aa62-74) was established for ex vivo tetramer analysis and magnetic bead enrichment in ten patients with acute malaria. EXP1-specific CD4+ T cells were detectable in nine out of ten (90%) malaria patients expressing the HLA-DRB1*11 molecule with an average ex vivo frequency of 0.11% (0-0.22%) of total CD4+ T cells. The phenotype of EXP1-specific CD4+ T cells was further assessed using co-staining with activation (CD38, HLA-DR, CD26), differentiation (CD45RO, CCR7, KLRG1, CD127), senescence (CD57) and co-inhibitory (PD-1, TIGIT, LAG-3, TIM-3) markers as well as the ectonucleotidases CD39 and CD73. EXP1-specific tetramer+ CD4+ T cells had a distinct phenotype compared to bulk CD4+ T cells and displayed a highly activated effector memory phenotype with elevated levels of co-inhibitory receptors and activation markers: EXP1-specific CD4+ T cells universally expressed the co-inhibitory receptors PD-1 and TIGIT as well as the activation marker CD38 and showed elevated frequencies of CD39. These results demonstrate that MHC class II tetramer enrichment is a sensitive approach to investigate ex vivo antigen-specific CD4+ T cells in malaria patients that will aid further analysis of the role of CD4+ T cells during malaria.


2005 ◽  
Vol 35 (3) ◽  
pp. 796-805 ◽  
Author(s):  
Erwan?R. Piriou ◽  
Karel van Dort ◽  
Nening?M. Nanlohy ◽  
Marinus?H. van Oers ◽  
Frank Miedema ◽  
...  

2006 ◽  
Vol 203 (12) ◽  
pp. 2661-2672 ◽  
Author(s):  
Marie-Claire Gauduin ◽  
Yi Yu ◽  
Amy Barabasz ◽  
Angela Carville ◽  
Mike Piatak ◽  
...  

We investigated simian immunodeficiency virus (SIV)-specific CD4+ T cell responses in rhesus macaques chronically infected with attenuated or pathogenic SIV strains. Analysis of SIVΔnef-infected animals revealed a relatively high frequency of SIV-specific CD4+ T cells representing 4–10% of all CD4+ T lymphocytes directed against multiple SIV proteins. Gag-specific CD4+ T cells in wild-type SIV-infected animals were 5–10-fold lower in frequency and inversely correlated with the level of plasma viremia. SIV-specific CD4+ cells from SIVΔnef animals were predominantly CD27−CD28−CD45RAlowCCR7−CCR5−, consistent with an effector–memory subset, and included a fully differentiated CD45RA+CCR7− subpopulation. In contrast, SIV-specific CD4+ T cells from SIV-infected animals were mostly CD27+CD28+CD45RA−CCR7+CCR5+, consistent with an early central memory phenotype. The CD45RA+CCR7−CD4+ subset from SIVΔnef animals was highly enriched for effector CD4+ T cells, as indicated by the perforin expression and up-regulation of the lysosomal membrane protein CD107a after SIV Gag stimulation. SIV-specific CD4+ T cells in attenuated SIV-infected animals were increased in frequency in bronchioalveolar lavage and decreased in lymph nodes, consistent with an effector–memory T cell population. The ability of SIVΔnef to induce a high frequency virus-specific CD4+ T cell response with direct effector function may play a key role in protective immunity produced by vaccination with attenuated SIV strains.


Blood ◽  
2003 ◽  
Vol 101 (7) ◽  
pp. 2686-2692 ◽  
Author(s):  
Laila E. Gamadia ◽  
Ester B. M. Remmerswaal ◽  
Jan F. Weel ◽  
Frederieke Bemelman ◽  
René A. W. van Lier ◽  
...  

The correlates of protective immunity to disease-inducing viruses in humans remain to be elucidated. We determined the kinetics and characteristics of cytomegalovirus (CMV)–specific CD4+ and CD8+ T cells in the course of primary CMV infection in asymptomatic and symptomatic recipients of renal transplants. Specific CD8+ cytotoxic T lymphocyte (CTL) and antibody responses developed regardless of clinical signs. CD45RA−CD27+CCR7− CTLs, although classified as immature effector cells in HIV infection, were the predominant CD8 effector population in the acute phase of protective immune reactions to CMV and were functionally competent. Whereas in asymptomatic individuals the CMV-specific CD4+ T-cell response preceded CMV-specific CD8+T-cell responses, in symptomatic individuals the CMV-specific effector-memory CD4+ T-cell response was delayed and only detectable after antiviral therapy. The appearance of disease symptoms in these patients suggests that functional CD8+ T-cell and antibody responses are insufficient to control viral replication and that formation of effector-memory CD4+ T cells is necessary for recovery of infection.


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