PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 12370388

Differences between T cell epitopes recognized after immunization and after infection.

Thorsten U Vogel·Helen Horton·Deborah H Fuller·Donald K Carter·Kathy Vielhuber·David H O'Connor·Tim Shipley·Jim Fuller·Gerd Sutter·Volker Erfle·Nancy Wilson·Louis J Picker·David I Watkins
View original source ↗Export metadata ↓

Abstract

Evidence suggests that cellular immune responses play a crucial role in the control of HIV and SIV replication in infected individuals. Several vaccine strategies have therefore targeted these CD8(+) and CD4(+) responses. Whether vaccination induces the same repertoire of responses seen after infection is, however, a key unanswered question in HIV vaccine development. We therefore compared the epitope specificity induced by vaccination to that present postchallenge in the peripheral blood. Intracellular cytokine staining of PBMC stimulated with overlapping 15/20-mer peptides spanning the proteins of SIV were measured after DNA/modified vaccinia Ankara vaccination of eight rhesus macaques. Lymphocytes from 8 animals recognized a total of 39 CD8 epitopes and 41 CD4 epitopes encoded by the vaccine. T cell responses were again monitored after challenge with SIVmac239 to investigate the evolution of these responses. Only 57% of all CD8(+) T cell responses and 19% of all CD4(+) T cell responses present after vaccination were recalled after infection as measured in the peripheral blood. Interestingly, 29 new CD8 epitopes and 5 new CD4 epitopes were recognized by PBMC in the acute phase. These new epitopes were not detected after vaccination, and only some of them were maintained in the chronic phase (33% of CD8 and no CD4 responses). Additionally, 24 new CD8 epitopes and 7 new CD4 epitopes were recognized by PBMC in the chronic phase of infection. The repertoire of the immune response detected in the peripheral blood after immunization substantially differed from the immune response detected in the peripheral blood after infection.

Explore related subjects

Administration, RectalAmino Acid SequenceAnimalsBase SequenceCD4-Positive T-LymphocytesCD8-Positive T-LymphocytesCell Line, TransformedEpitopes, T-LymphocyteImmunity, CellularImmunization, SecondaryInjections, IntradermalLeukocytes, MononuclearLymphoid TissueMacaca mulattaMolecular Sequence DataPeptide FragmentsPeptide MappingSAIDS VaccinesSimian Acquired Immunodeficiency SyndromeSimian Immunodeficiency VirusVaccines, SyntheticVaccinia virusViral ProteinsComparative StudyJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Thorsten U Vogel, Helen Horton, Deborah H Fuller, Donald K Carter, Kathy Vielhuber, David H O'Connor, Tim Shipley, Jim Fuller, Gerd Sutter, Volker Erfle, Nancy Wilson, Louis J Picker, David I Watkins. 2002-10-15. Differences between T cell epitopes recognized after immunization and after infection.. https://doi.org/10.4049/jimmunol.169.8.4511

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Recognition, perceptions and treatment practices for severe malaria in rural Tanzania: implications for accessing rectal artesunate as a pre-referral.

OBJECTIVES: Preparatory to a community trial investigating how best to deliver rectal artesunate as pre-referral treatment for severe malaria; local understanding, perceptions of signs/symptoms of severe malaria and treatment-seeking patterns for and barriers to seeking biomedical treatment were investigated. METHODOLOGY/PRINCIPAL FINDINGS: 19 key informant interviews, 12 in-depth interviews and 14 focus group discussions targeting care-givers, opinion leaders, and formal and informal health care providers were conducted. Monthly fever episodes and danger signs or symptoms associated with severe malaria among under-fives were recorded. Respondents recognized convulsions, altered consciousness and coma, and were aware of their risks if not treated. But, these symptoms were perceived to be caused by supernatural forces, and traditional healers were identified as primary care providers. With some delay, mothers eventually visited a health facility when convulsions were part of the illness, despite pressures against this. Although vomiting and failure to eat/suck/drink were associated with malaria, they were not considered as indicators of danger signs unless combined with another more severe symptom. Study communities were familiar with rectal application of medicines. CONCLUSIONS/SIGNIFICANCE: Communities' recognition and awareness of major symptoms of severe malaria could encourage action, but perceptions of their causes and poor discrimination of other danger signs - vomiting and failure to feed - might impede early treatment. An effective health education targeting parents/guardians, decision-makers/advisors, and formal and informal care providers might be a prerequisite for successful introduction of rectal artemisinins as an emergency treatment. Role of traditional healers in delivering such medication to the community should be explored.

Administration, Rectal↗
PubMed2007

Application of 10 percent formalin for the treatment of radiation-induced hemorrhagic proctitis.

PURPOSE: Rectal instillation of 4 percent formalin solution has been described as a successful treatment for hemorrhagic radiation proctitis recalcitrant to medical treatment. We present our experience with a new method of treatment involving the topical application of 10 percent buffered formalin, which is well tolerated and suitable for office use. METHODS: Patients with marked or refractory rectal bleeding and clinical features consistent with radiation proctitis were reviewed. Treatment involved direct application of a 10 percent buffered formalin solution to the affected mucosa using a 16-inch cotton tip applicator applied through a proctoscope in the office setting. RESULTS: A total of 100 patients with a mean age of 75 (range, 49-91) years were followed for 18 (range, 1-79) months. The interval from radiation exposure to formalin treatment was 21 months. Overall, 93 percent of patients had cessation of bleeding after an average of 3.5 formalin applications at two-week to four-week intervals. Patients with severe (Grade 3) proctitis and those taking aspirin required an average of 1.5 additional treatments. A total of eight patients rebled at a mean of 24 months from treatment; however, all responded to further applications of formalin. Three patients complained of anal pain and one experienced dizziness postprocedure for a complication rate of 1.1 percent. CONCLUSIONS: We present a simple, cost-effective, and well-tolerated method of controlling hemorrhagic radiation proctitis. It is performed by using materials readily available in the office of a colon and rectal surgeon, eliminating the need for bowel preparation, anesthesia, or a surgical suite.

Administration, Rectal↗
PubMed2007

Rectal microbicide acceptability: results of a volume escalation trial.

OBJECTIVES: The objectives of this study were to determine what volume of a microbicide placebo gel is acceptable when applied intrarectally before receptive anal intercourse (RAI); and to evaluate responses to properties of the gel, its application, and its use. STUDY DESIGN: HIV-uninfected men who reported unprotected RAI with serodiscordant or unknown-status partners were enrolled in a volume escalation trial. RESULTS: Up to 35 mL of gel with the physical properties of Femglide (transparent and odorless) was acceptable to the majority of participants. Choice of different levels of viscosity may be needed. For some men, volumes judged acceptable when tried without intercourse were not acceptable when used during sex. Overall, participants reported high intentions to use microbicides when available. Condom use was inconsistent despite advice to use condoms. CONCLUSIONS: Microbicides that would require up to 35 mL of volume to be effective would be acceptable to men who engage in high-risk RAI.

Administration, Rectal↗