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1.
Breast Cancer Res Treat ; 168(1): 29-34, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29230662

RESUMO

PURPOSE: Oncotype Dx (ODx) is a multigene assay that is prognostic and predictive in estrogen receptor (ER) positive early breast cancer. ODx recurrence score (RS) is reported to be histologic grade dependent. Relationship of RS with breast cancer histologic subtypes is unknown. This study was designed to assess the relationship of histologic subtype with RS. Histologic grade dependence of RS was also investigated. METHODS: Results of consecutive ODx tests (1/2007-7/2016) from two institutions were reviewed. Histologic subtypes (in: Lakhani et al., WHO classification, IARC Press, Lyon, 2012), combined Nottingham histologic grade, age and tumor size were recorded from pathology reports. Univariate and multivariate analysis was performed to investigate the relationship between RS and ODx risk categories and histologic subtypes, grade, age and tumor size. RESULTS: RS was grade dependent. RS of grade 1 and grade 2 tumors were significantly lower than grade 3 tumors. There was no high-risk grade 1 tumor. In favorable histologic subtypes there was no high-risk tumor. Mean RS of grade 1 lobular tumors was significantly higher than grade 1 ductal tumors. Using newer ODx cut-offs, 5 grade 1 tumors were reclassified as high risk (RS > 25) and grade 3 lobular tumors showed significantly higher rate of reclassification as high-risk than grade 3 ductal tumors. In a multivariate analysis, only grade showed a significant positive correlation with RS. Adding dichotomous histologic subtyping (favorable vs. non-favorable) to grade further improved correlation with RS. CONCLUSIONS: The Oncotype Dx result is impacted by histologic grade and histologic subtype. Tumors with favorable histologic subtypes and histologic grade 1 tumors do not have high-risk RS. High RS in a grade 1 tumor or in a tumor with favorable histology is unusual that warrants further investigation. Invasive lobular carcinomas rarely show high-risk RS. Histologic grade and histologic subtype should be considered while ordering ODx testing.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/patologia , Carcinoma Lobular/patologia , Recidiva Local de Neoplasia/diagnóstico , Mama/patologia , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Carcinoma Lobular/epidemiologia , Carcinoma Lobular/genética , Feminino , Perfilação da Expressão Gênica/métodos , Testes Genéticos/métodos , Humanos , Gradação de Tumores , Recidiva Local de Neoplasia/epidemiologia , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Prognóstico , Receptores de Estrogênio/metabolismo , Sistema de Registros/estatística & dados numéricos , Estudos Retrospectivos
2.
Am J Obstet Gynecol ; 219(4): 381.e1-381.e10, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30063901

RESUMO

BACKGROUND: Multiple population-level studies have demonstrated an adverse effect of long wait times to surgery on survival for women with endometrial cancer. Other retrospective and nonrandomized prospective studies have shown that preoperative administration of depot medroxyprogesterone acetate decreases tumor glandular cellularity, which may be a surrogate marker for clinically meaningful tumor response. OBJECTIVE: We sought to determine whether preoperative injection with depot medroxyprogesterone acetate decreases tumor glandular cellularity when compared to placebo injection in women awaiting hysterectomy for endometrial intraepithelial neoplasia or type I endometrial cancer, and to determine whether depot medroxyprogesterone acetate injection affects quality of life while waiting for surgery. STUDY DESIGN: This was a double-blind, randomized controlled trial of 400-mg depot medroxyprogesterone acetate injection or 0.9% saline injection at the preoperative visit. Patients with recent use of progesterone analogs were excluded. A sample size of 76 patients (38 per arm) was calculated to detect a 20% difference in decreased glandular cellularity between arms. Pathologic characteristics including the primary outcome, tumor glandular cellularity, from patients' diagnostic biopsies were reviewed by 2 dedicated gynecologic pathologists and compared to posttreatment hysterectomy specimens. On the night prior to surgery, patients completed the Functional Assessment of Cancer Therapy-Endometrial Survey (Version 4) to report quality of life while waiting for surgery. In comparing characteristics between the intervention and control groups, t tests were used for continuous variables, and χ2 or Fisher exact tests were used where appropriate for categorical data. RESULTS: From March 2015 through March 2016, 148 women were screened and 76 patients were enrolled. In all, 38 patients were randomized to and received depot medroxyprogesterone acetate injection and 38 were randomized to and received placebo injection. Demographics were similar between groups. Patients who received depot medroxyprogesterone acetate injection experienced a larger decrease in tumor glandular cellularity (mean change -64 [-31.8%] vs -14 [-5.5%] cells per quarter high-powered field in depot medroxyprogesterone acetate vs placebo groups, P = .002). This effect was most pronounced in women waiting ≥3 weeks for surgery. Several additional histologic and immunohistochemical markers of tumor differentiation and decreased cell proliferation were more pronounced in the depot medroxyprogesterone acetate group than in the placebo group. There were no significant differences in quality of life between groups on the Functional Assessment of Cancer Therapy-Endometrial Survey. Only 5.3% of patients who were approached declined to participate due to concerns regarding an intramuscular injection. CONCLUSION: Administration of depot medroxyprogesterone acetate prior to surgery for type I endometrial cancers caused greater tumor effect than placebo injection. Injection of depot medroxyprogesterone acetate was acceptable to and well tolerated by patients. Depot medroxyprogesterone acetate may represent a meaningful bridge to surgery in women who can expect long wait times.


Assuntos
Adenocarcinoma/terapia , Antineoplásicos Hormonais/uso terapêutico , Neoplasias do Endométrio/terapia , Acetato de Medroxiprogesterona/uso terapêutico , Listas de Espera , Adenocarcinoma/patologia , Antineoplásicos Hormonais/administração & dosagem , Preparações de Ação Retardada , Método Duplo-Cego , Neoplasias do Endométrio/patologia , Feminino , Humanos , Acetato de Medroxiprogesterona/administração & dosagem , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Resultado do Tratamento
3.
Breast J ; 22(6): 637-644, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27540716

RESUMO

To determine the incidence of malignancy for radial scars (RS)/radial sclerosing lesions (RSL) without associated atypia or malignancy identified at needle biopsy. Retrospective review of the pathology data base from January 2004 to July 2013 yielded 100 needle biopsies diagnosed as RS/RSL without associated atypia/malignancy. The RS/RSL was considered "incidental" if the target was calcifications and "targeted" if imaging revealed a mass, architectural distortion, or suspicious magnetic resonance imaging enhancement. The electronic medical record was used to identify surgical pathology, follow-up imaging, and clinical course; all pathology slides and imaging were reviewed by a board-certified pathologist and radiologist, respectively. Patient age, laterality, RS/RSL size, microcalcifications, and associated benign lesions were recorded. Among 100 cases, 54 were "incidental" and 46 were "targeted." In the incidental group, 14 underwent excision, 30 had imaging follow-up, and 10 were lost to follow-up. In the targeted group, 27 underwent excision, 11 had imaging follow-up, and 8 were lost to follow-up. Atypia was identified in four excisions: three from the incidental group and one from the targeted group. Among these, three had negative imaging follow-up (mean 45 months; range 15-60 months); the fourth patient (one of the incidental group) underwent excision alone. One of the 27 "targeted" patients who underwent excision developed ductal carcinoma in situ of the contralateral breast at 96 months. There have been no ipsilateral malignancies. We found no evidence of associated malignancy at excision for either incidental or targeted biopsies of RS/RSL without atypia. Our study suggests that close imaging follow-up is adequate for patients with RS/RSL without associated atypia/malignancy on needle biopsy.


Assuntos
Biópsia/métodos , Doenças Mamárias/patologia , Neoplasias da Mama/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Mamárias/diagnóstico por imagem , Neoplasias da Mama/diagnóstico por imagem , Calcinose/patologia , Carcinoma Intraductal não Infiltrante/diagnóstico por imagem , Carcinoma Intraductal não Infiltrante/patologia , Feminino , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Técnicas Estereotáxicas
4.
J Surg Oncol ; 112(6): 658-61, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26430853

RESUMO

Radiation associated sarcoma is a significant consequence of cancer therapy. Incidence of radiation associated sarcoma correlates with overall radiotherapy exposure. Prognosis is generally poor with 5 year survival rates lower than that for spontaneously occurring sarcomas. Surgical management presents many challenges including having to work in irradiated tissue planes while trying to achieve negative margins. We present a patient with a rare radiation associated pelvic sarcoma whose course illustrates the complexity of this problem.


Assuntos
Adenocarcinoma/radioterapia , Recidiva Local de Neoplasia/radioterapia , Neoplasias Induzidas por Radiação/etiologia , Neoplasias Pélvicas/etiologia , Radioterapia/efeitos adversos , Neoplasias Retais/radioterapia , Sarcoma/etiologia , Adenocarcinoma/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Neoplasias Induzidas por Radiação/patologia , Neoplasias Pélvicas/patologia , Prognóstico , Neoplasias Retais/patologia , Sarcoma/patologia
6.
Hum Pathol ; 78: 163-170, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29753007

RESUMO

Morphological variants of lobular carcinoma in situ (LCIS) include classical (CLCIS), pleomorphic (PLCIS) and florid type (FLCIS). Treatment guidelines suggest managing PLCIS and FLCIS like ductal carcinoma in situ (DCIS); therefore accurate identification of LCIS subtypes is critical. However, the significance of separating PLCIS from FLCIS is not clear. Also, interobserver agreement in identifying LCIS subtypes, using contemporary criteria, is not known. We aimed to evaluate interobserver agreement amongst breast pathologists in diagnosing LCIS subtypes and use the agreement data to justify LCIS classification for management purposes. Six breast pathologists independently reviewed 50 hematoxylin and eosin-stained slides comprised of a mix of LCIS subtypes. After reviewing published criteria, participants diagnosed PLCIS, CLCIS and apocrine change in a marked region of interest and FLCIS based on entire section. PLCIS was identified in 8 to 37 slides with overall moderate agreement (Fleiss' κ = 0.565) and pairwise κ (Cohen's) ranging from -.008 to 0.492. FLCIS was diagnosed in 15-26 slides with overall substantial agreement (Fleiss' κ = 0.687) and pairwise κ ranging from -.068 to 0.706. Both FLCIS and PLCIS coexisted in 45% of slides with consensus on non-classical LCIS. Comedo-type necrosis (odds ratio = 5.5) and apoptosis (odds ratio = 1.8) predicted FLCIS. We found moderate and substantial agreement in diagnosing PLCIS and FLCIS respectively. Objective histological features linked with aggressive behavior were more frequent with FLCIS. PLCIS and FLCIS patterns frequently coexist, contain similar molecular aberrations, and are managed similarly (like DCIS); therefore, combining FLCIS and PLCIS into one category (non-classical LCIS) should be considered.


Assuntos
Carcinoma de Mama in situ/patologia , Neoplasias da Mama/patologia , Carcinoma Intraductal não Infiltrante/patologia , Carcinoma Lobular/patologia , Adulto , Idoso , Biomarcadores Tumorais/análise , Mama/patologia , Carcinoma de Mama in situ/diagnóstico , Neoplasias da Mama/diagnóstico , Carcinoma Intraductal não Infiltrante/diagnóstico , Carcinoma Lobular/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
7.
Hum Pathol ; 65: 123-132, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28457730

RESUMO

There is no consensus regarding biomarker testing on the ipsilateral breast carcinomas present in separate biopsies, irrespective of whether the biopsies are performed concurrently or consecutively. We aimed to investigate estrogen receptor (ER), progesterone receptor (PR) and HER2 concordance in ipsilateral concurrent biopsies with invasive breast tumors. Consecutive ipsilateral concurrent biopsies with invasive breast tumors were identified retrospectively. Biomarker results, histologic grade and histologic subtype among the tumors in concurrent samples were compared. ER, PR, and HER2 expression was different in 3 (2.5%), 11 (9.2%) and 7 (5.9%) cases, respectively. All ER-discordant cases were sets of ER-negative (ER-) and weak-low ER-positive (ER+), ductal subtype and histologic grade 2 or 3 tumors. All PR-discordant cases were ER+, and comprised of histologic grades 1 to 3 ductal as well as lobular tumors. All HER2 discordant cases were histologic grade 2 to 3 ductal tumors. Biomarker discordance was independent of grade and subtype discordance. We found very low biomarker discordance among tumors in concurrent samples from ipsilateral breast. Our results suggest that ER and HER2 discordance in concurrent samples is predictable. ER discordance is present only in a setting of low ER+ tumors. Low-grade ductal and/or lobular tumors are ER and HER2 concordant. HER2 discordance is noted in grade 2 to 3 ductal tumors only. Histologic subtype and grade may guide extent of biomarker testing in concurrent ipsilateral breast biopsies.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias da Mama/química , Carcinoma Ductal de Mama/química , Receptor ErbB-2/análise , Receptores de Estrogênio/análise , Receptores de Progesterona/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/patologia , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Gradação de Tumores , Invasividade Neoplásica , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Adulto Jovem
8.
J Pediatr Adolesc Gynecol ; 30(6): 652-654, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28578185

RESUMO

BACKGROUND: Müllerian adenosarcomas of the cervix are composed of benign epithelial and malignant stromal components. The purpose of this report is to describe the clinical and histologic difficulties in diagnosis and to propose fertility-preserving management of low-grade lesions. CASE: A 14-year-old girl presented with a friable lesion found to originate from the anterior cervical lip. Initially, clinical suspicion was for sarcoma botryoides, however, pathologic evaluation revealed a low-grade cervical Müllerian adenosarcoma. Cold knife conization was performed, and the mass was resected with clear margins. SUMMARY AND CONCLUSION: Müllerian adenosarcoma of the cervix is difficult to diagnose in adolescents because of features more commonly associated with alternative diagnoses. For patients with low-grade lesions desiring future fertility, local excision with close follow-up is reasonable.


Assuntos
Adenossarcoma/diagnóstico , Neoplasias do Colo do Útero/diagnóstico , Neoplasias Uterinas/diagnóstico , Adenossarcoma/terapia , Adolescente , Conização/métodos , Feminino , Humanos , Neoplasias do Colo do Útero/terapia , Neoplasias Uterinas/terapia
9.
PLoS Med ; 3(10): e403, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17076553

RESUMO

BACKGROUND: Very little is known about the immunodominance patterns of HIV-1-specific T cell responses during primary HIV-1 infection and the reasons for human lymphocyte antigen (HLA) modulation of disease progression. METHODS AND FINDINGS: In a cohort of 104 individuals with primary HIV-1 infection, we demonstrate that a subset of CD8(+) T cell epitopes within HIV-1 are consistently targeted early after infection, while other epitopes subsequently targeted through the same HLA class I alleles are rarely recognized. Certain HLA alleles consistently contributed more than others to the total virus-specific CD8(+) T cell response during primary infection, and also reduced the absolute magnitude of responses restricted by other alleles if coexpressed in the same individual, consistent with immunodomination. Furthermore, individual HLA class I alleles that have been associated with slower HIV-1 disease progression contributed strongly to the total HIV-1-specific CD8(+) T cell response during primary infection. CONCLUSIONS: These data demonstrate consistent immunodominance patterns of HIV-1-specific CD8(+) T cell responses during primary infection and provide a mechanistic explanation for the protective effect of specific HLA class I alleles on HIV-1 disease progression.


Assuntos
Síndrome da Imunodeficiência Adquirida/genética , Síndrome da Imunodeficiência Adquirida/imunologia , Linfócitos T CD8-Positivos/imunologia , HIV-1/imunologia , Antígenos HLA/genética , Alelos , Variação Antigênica , Estudos de Coortes , Progressão da Doença , Epitopos de Linfócito T/imunologia , Feminino , Genes MHC Classe I/imunologia , Infecções por HIV/imunologia , Humanos , Epitopos Imunodominantes/imunologia , Masculino , Modelos de Riscos Proporcionais
10.
AIDS ; 19(14): 1449-56, 2005 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-16135897

RESUMO

OBJECTIVES: To determine HIV-1-specific T cell responses in clade B infected individuals recognizing the clade A, B and C consensus sequences in order to assess the degree of inter-clade cross-reactivity of these immune responses at the single epitope level. METHODS: HIV-1-specific T cell responses were assessed cross-sectionally in 27 chronically HIV-1-infected individuals from a population infected mainly with clade B viral strains, using an interferon-gamma Elispot assay with a total of 1230 overlapping peptides spanning the entire amino acid sequence of the clade A, B and C 2001 consensus sequences. RESULTS: No significant difference was observed between the total magnitude or breadth of T cell responses recognizing either the clade A, B or C consensus sequences. However, at the single peptide level, 194 T cell responses were identified that recognized only one of the three different clade-specific peptide variants (A: B: C, 34: 105: 55), 125 T cell responses recognized two of the three peptide variants (AB: AC: BC, 71: 15: 39) and 166 T cell responses (34%) were cross-reactive with all three different peptide variants. Peptides recognized in all three consensus sequence variants had a significantly lower entropy (P < 0.0001) and a significantly higher inter-clade homology (P < 0.0001). CONCLUSIONS: Viral epitopes within regions of low HIV-1 clade B diversity and high inter-clade homology can be recognized in the clade A, B and C variants and indicate a wide degree of cross-isolate and cross-clade recognition by HIV-1-specific T cells. These regions may therefore be of particular relevance for the design of HIV-1 vaccines.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Adulto , Sequência Consenso/imunologia , Epitopos de Linfócito T/imunologia , Humanos , Imunidade Celular , Pessoa de Meia-Idade
11.
PLoS Med ; 1(2): e36, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15526059

RESUMO

BACKGROUND: Early treatment of acute HIV infection with highly active antiretroviral therapy, followed by supervised treatment interruption (STI), has been associated with at least transient control of viremia. However, the durability of such control remains unclear. Here we present longitudinal follow-up of a single-arm, open-label study assessing the impact of STI in the setting of acute HIV-1 infection. METHODS AND FINDINGS: Fourteen patients were treated during acute HIV-1 infection and subsequently subjected to an STI protocol that required retreatment if viral load exceeded 50,000 RNA copies/ml plasma or remained above 5,000 copies/ml for more than three consecutive weeks. Eleven of 14 (79%) patients were able to achieve viral loads of less than 5,000 RNA copies/ml for at least 90 d following one, two, or three interruptions of treatment. However, a gradual increase in viremia and decline in CD4+ T cell counts was observed in most individuals. By an intention-to-treat analysis, eight (57%), six (43%), and three (21%) of 14 patients achieved a maximal period of control of 180, 360, and 720 d, respectively, despite augmentation of HIV-specific CD4+ and CD8+ T cell responses. The magnitude of HIV-1-specific cellular immune responses before treatment interruption did not predict duration of viremia control. The small sample size and lack of concurrent untreated controls preclude assessment of possible clinical benefit despite failure to control viremia by study criteria. CONCLUSIONS: These data indicate that despite initial control of viremia, durable viral control to less than 5,000 RNA copies/ml plasma in patients following treated acute HIV-1 infection occurs infrequently. Determination of whether early treatment leads to overall clinical benefit will require a larger and randomized clinical trial. These data may be relevant to current efforts to develop an HIV-1 vaccine designed to retard disease progression rather than prevent infection since they indicate that durable maintenance of low-level viremia may be difficult to achieve.


Assuntos
Terapia Antirretroviral de Alta Atividade , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Doença Aguda , Adulto , Esquema de Medicação , Feminino , HIV-1/patogenicidade , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Viremia
13.
J Virol ; 79(8): 5000-5, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15795285

RESUMO

Human immunodeficiency virus type 1 (HIV-1) mutates to escape immune selection pressure, but there is little evidence of selection mediated through HLA-A2, the dominant class I allele in persons infected with clade B virus. Moreover, HLA-A2-restricted responses are largely absent in the acute phase of infection as the viral load is being reduced, suggesting that circulating viruses may lack immunodominant epitopes targeted through HLA-A2. Here we demonstrate an A2-restricted epitope within Vpr (Vpr59-67) that is targeted by acute-phase HIV-1-specific CD8+ T cells, but only in a subset of persons expressing HLA-A2. Individuals in the acute stage of infection with viruses containing the most common current sequence within this epitope (consensus sequence) were unable to mount epitope-specific T-cell responses, whereas subjects infected with the less frequent I60L variant all developed these responses. The I60L variant epitope was a stronger binder to HLA-A2 and was recognized by epitope-specific T cells at lower peptide concentrations than the consensus sequence epitope. These data demonstrate that HLA-A2 is capable of contributing to the acute-phase cytotoxic T-lymphocyte response in infected subjects, but that most currently circulating viruses lack a dominant immunogenic epitope presented by this allele, and suggest that immunodominant epitopes restricted by common HLA alleles may be lost as the epidemic matures.


Assuntos
Vacinas contra a AIDS , Desenho de Fármacos , HIV-1/imunologia , Antígeno HLA-A2/imunologia , Linfócitos T Citotóxicos/imunologia , Síndrome da Imunodeficiência Adquirida/imunologia , Síndrome da Imunodeficiência Adquirida/virologia , Sequência de Aminoácidos , Sequência Conservada , Epitopos/imunologia , Produtos do Gene vpr/química , Produtos do Gene vpr/imunologia , HIV-1/classificação , HIV-1/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Interferon gama/imunologia , Linfócitos T Citotóxicos/virologia , Produtos do Gene vpr do Vírus da Imunodeficiência Humana
14.
J Virol ; 79(21): 13239-49, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16227247

RESUMO

The sequence diversity of human immunodeficiency virus type 1 (HIV-1) represents a major obstacle to the development of an effective vaccine, yet the forces impacting the evolution of this pathogen remain unclear. To address this issue we assessed the relationship between genome-wide viral evolution and adaptive CD8+ T-cell responses in four clade B virus-infected patients studied longitudinally for as long as 5 years after acute infection. Of the 98 amino acid mutations identified in nonenvelope antigens, 53% were associated with detectable CD8+ T-cell responses, indicative of positive selective immune pressures. An additional 18% of amino acid mutations represented substitutions toward common clade B consensus sequence residues, nine of which were strongly associated with HLA class I alleles not expressed by the subjects and thus indicative of reversions of transmitted CD8 escape mutations. Thus, nearly two-thirds of all mutations were attributable to CD8+ T-cell selective pressures. A closer examination of CD8 escape mutations in additional persons with chronic disease indicated that not only did immune pressures frequently result in selection of identical amino acid substitutions in mutating epitopes, but mutating residues also correlated with highly polymorphic sites in both clade B and C viruses. These data indicate a dominant role for cellular immune selective pressures in driving both individual and global HIV-1 evolution. The stereotypic nature of acquired mutations provides support for biochemical constraints limiting HIV-1 evolution and for the impact of CD8 escape mutations on viral fitness.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Evolução Molecular , Infecções por HIV/imunologia , HIV-1/genética , HIV-1/imunologia , Mutação/imunologia , Polimorfismo Genético , Seleção Genética , Doença Aguda , Alelos , Sequência de Aminoácidos , Substituição de Aminoácidos , Doença Crônica , Estudos de Coortes , Epitopos de Linfócito T/genética , Genes MHC Classe I/genética , Alemanha , Infecções por HIV/virologia , Humanos , Contagem de Linfócitos , Dados de Sequência Molecular , Alinhamento de Sequência , Estados Unidos
15.
J Virol ; 79(20): 12952-60, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16188997

RESUMO

Human immunodeficiency virus type 1 (HIV-1) evades CD8(+) T-cell responses through mutations within targeted epitopes, but little is known regarding its ability to generate de novo CD8(+) T-cell responses to such mutants. Here we examined gamma interferon-positive, HIV-1-specific CD8(+) T-cell responses and autologous viral sequences in an HIV-1-infected individual for more than 6 years following acute infection. Fourteen optimal HIV-1 T-cell epitopes were targeted by CD8(+) T cells, four of which underwent mutation associated with dramatic loss of the original CD8(+) response. However, following the G(357)S escape in the HLA-A11-restricted Gag(349-359) epitope and the decline of wild-type-specific CD8(+) T-cell responses, a novel CD8(+) T-cell response equal in magnitude to the original response was generated against the variant epitope. CD8(+) T cells targeting the variant epitope did not exhibit cross-reactivity against the wild-type epitope but rather utilized a distinct T-cell receptor Vbeta repertoire. Additional studies of chronically HIV-1-infected individuals expressing HLA-A11 demonstrated that the majority of the subjects targeted the G(357)S escape variant of the Gag(349-359) epitope, while the wild-type consensus sequence was significantly less frequently recognized. These data demonstrate that de novo responses against escape variants of CD8(+) T-cell epitopes can be generated in chronic HIV-1 infection and provide the rationale for developing vaccines to induce CD8(+) T-cell responses directed against both the wild-type and variant forms of CD8 epitopes to prevent the emergence of cytotoxic T-lymphocyte escape variants.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Linfócitos T Citotóxicos/imunologia , Doença Crônica , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Proteína do Núcleo p24 do HIV/genética , Proteína do Núcleo p24 do HIV/imunologia , HIV-1/genética , Antígenos HLA-A/metabolismo , Antígeno HLA-A11 , Humanos , Dados de Sequência Molecular , Mutação , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Especificidade da Espécie
16.
J Virol ; 78(13): 7069-78, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15194783

RESUMO

Numerous studies now support that human immunodeficiency virus type 1 (HIV-1) evolution is influenced by immune selection pressure, with population studies showing an association between specific HLA alleles and mutations within defined cytotoxic T-lymphocyte epitopes. Here we combine sequence data and functional studies of CD8 T-cell responses to demonstrate that allele-specific immune pressures also select for mutations flanking CD8 epitopes that impair antigen processing. In persons expressing HLA-A3, we demonstrate consistent selection for a mutation in a C-terminal flanking residue of the normally immunodominant Gag KK9 epitope that prevents its processing and presentation, resulting in a rapid decline in the CD8 T-cell response. This single amino acid substitution also lies within a second HLA-A3-restricted epitope, with the mutation directly impairing recognition by CD8 T cells. Transmission of the mutation to subjects expressing HLA-A3 was shown to prevent the induction of normally immunodominant acute-phase responses to both epitopes. However, subsequent in vivo reversion of the mutation was coincident with delayed induction of new CD8 T-cell responses to both epitopes. These data demonstrate that mutations within the flanking region of an HIV-1 epitope can impair recognition by an established CD8 T-cell response and that transmission of these mutations alters the acute-phase CD8(+) T-cell response. Moreover, reversion of these mutations in the absence of the original immune pressure reveals the potential plasticity of immunologically selected evolutionary changes.


Assuntos
Substituição de Aminoácidos , Apresentação de Antígeno , Evolução Molecular , Produtos do Gene gag/genética , Antígenos HIV/genética , HIV-1/imunologia , Linfócitos T Citotóxicos/imunologia , Proteínas Virais/genética , Sequência de Aminoácidos , Epitopos de Linfócito T/imunologia , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/genética , Antígeno HLA-A3/metabolismo , Humanos , Epitopos Imunodominantes/imunologia , Dados de Sequência Molecular , Seleção Genética , Produtos do Gene gag do Vírus da Imunodeficiência Humana
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