RESUMO
In an effort to identify novel therapeutic targets for autoimmunity and transplant rejection, we developed and performed a large-scale retroviral-based functional screen to select for proteins that inhibit antigen receptor-mediated activation of lymphocytes. In addition to known regulators of antigen receptor signaling, we identified a novel adaptor protein, SLAP-2 which shares 36% sequence similarity with the known Src-like adaptor protein, SLAP. Similar to SLAP, SLAP-2 is predominantly expressed in hematopoietic cells. Overexpression of SLAP-2 in B and T cell lines specifically impaired antigen receptor-mediated signaling events, including CD69 surface marker upregulation, nuclear factor of activated T cells (NFAT) promoter activation and calcium influx. Signaling induced by phorbol myristate acetate (PMA) and ionomycin was not significantly reduced, suggesting SLAP-2 functions proximally in the antigen receptor signaling cascade. The SLAP-2 protein contains an NH2-terminal myristoylation consensus sequence and SH3 and SH2 Src homology domains, but lacks a tyrosine kinase domain. In antigen receptor-stimulated cells, SLAP-2 associated with several tyrosine phosphorylated proteins, including the ubiquitin ligase Cbl. Deletion of the COOH terminus of SLAP-2 blocked function and abrogated its association with Cbl. Mutation of the putative myristoylation site of SLAP-2 compromised its inhibitory activity and impaired its localization to the membrane compartment. Our identification of the negative regulator SLAP-2 demonstrates that a retroviral-based screening strategy may be an efficient way to identify and characterize the function of key components of many signal transduction systems.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas Nucleares , Proteínas Proto-Oncogênicas pp60(c-src)/genética , Proteínas Proto-Oncogênicas pp60(c-src)/imunologia , Receptores de Antígenos de Linfócitos B/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Transdução de Sinais/imunologia , Domínios de Homologia de src , Sequência de Aminoácidos , Antígenos CD/biossíntese , Antígenos CD/genética , Antígenos CD/imunologia , Antígenos de Diferenciação de Linfócitos T/biossíntese , Antígenos de Diferenciação de Linfócitos T/genética , Antígenos de Diferenciação de Linfócitos T/imunologia , Linfócitos B/citologia , Linfócitos B/imunologia , Sequência de Bases , Cálcio/metabolismo , Linhagem Celular , Clonagem Molecular , DNA Complementar , Proteínas de Ligação a DNA/genética , Humanos , Células Jurkat , Lectinas Tipo C , Dados de Sequência Molecular , Ácido Mirístico/metabolismo , Fatores de Transcrição NFATC , Fosforilação , Regiões Promotoras Genéticas , Receptores Proteína Tirosina Quinases/biossíntese , Receptores Proteína Tirosina Quinases/imunologia , Homologia de Sequência de Aminoácidos , Tetraciclina/farmacologia , Transativadores , Fatores de Transcrição/genética , Ativação Transcricional , Tirosina/metabolismoAssuntos
Infecções por Mycobacterium/veterinária , Mycobacterium avium/patogenicidade , Mycobacterium/patogenicidade , Reação em Cadeia da Polimerase/veterinária , Tuberculose Aviária/diagnóstico , Animais , Aves , DNA Bacteriano/análise , Mycobacterium/genética , Infecções por Mycobacterium/diagnóstico , Mycobacterium avium/genética , Polimorfismo de Fragmento de Restrição , Sensibilidade e EspecificidadeRESUMO
Aging is an all-encompassing, multifactorial process involving a decreased capacity for adaptation and a gradual decrease in functional reserve of all the body's systems. Aging itself is not truly a disease process but is instead an index of the probability of many disease states. Underlying disease is not always clinically evident in the elderly. Increased operative risk, when present, is attributable to identifiable disease, not simply to the aging process. A thorough understanding of the expected physiologic deviations from the norm must be the benchmark for the anesthesiologist, surgeon, and consultant in formulating a treatment plan. Deviations exceeding those expected must be dealt with cogently by this health care team. It is, therefore, extremely important to establish and maintain communication and understanding among the care team, the patient, and the family. With this approach, we can minimize the risks of anesthesia in the elderly.
Assuntos
Anestesia Geral/métodos , Geriatria , Idoso , Sistema Cardiovascular/fisiopatologia , Humanos , Rim/fisiopatologia , Cinética , Preparações Farmacêuticas/metabolismo , Sistema Respiratório/fisiopatologiaAssuntos
Pneumopatias/cirurgia , Pulmão/cirurgia , Pneumonectomia , Anestesia Geral , Bronquiectasia/cirurgia , Humanos , Pulmão/fisiopatologia , Pneumopatias/fisiopatologia , Pneumopatias/terapia , Neoplasias Pulmonares/cirurgia , Cuidados Pós-Operatórios , Complicações Pós-Operatórias/prevenção & controle , Testes de Função Respiratória , Terapia Respiratória , Risco , Tuberculose Pulmonar/cirurgiaRESUMO
We have attempted to present a brief overview of current considerations in anesthesia for surgery of gastrointestinal disease as practiced at our institution. Many considerations remain unexplored owing to limitations of space. We have deliberately concentrated upon antecedent and concurrent therapy encountered in the treatment of the surgical patient. The potent drugs introduced in the past decade have produced infinite potential for drug interactions--some serious, some not so serious, and some which are desirable. We hope we have generated further reader interest in this mushrooming problem of modern medicine confronting the anesthesiologist and surgeon in the perioperative period.
