CD4: Diferenzas entre revisións

Contido eliminado Contido engadido
Miguelferig (conversa | contribucións)
Sen resumo de edición
Miguelferig (conversa | contribucións)
Sen resumo de edición
Liña 21:
}}
 
En [[bioloxía molecular]], '''CD4''' ([[clúster de diferenciación]] 4) é unha [[glicoproteína]] que se encontra na superficie de células inmunes como o [[linfocito T axudante]], [[monocito]], [[macrófago]], e [[célula dendrítica]]. Descubriuse a finais da década de 1970 e orixinalmente deuselle o nome de leu-3 e T4 (debido aos [[anticorpo monoclonal|anticorpos monoclonais]] OKT4 que reaccionaban con el) antes de ser rebautizado como CD4 en 1984.<ref name="isbn0-387-12056-4">{{cite book | author = Alain Bernard | authorlink = | editor = | others = | title = Leucocyte typing: human leucocyte differentiation antigens detected by monoclonal antibodies: specification, classification, nomenclature: [report on the first international references workshop sponsored by INSERM, WHO and IUIS] | edition = | language = | publisher = Springer | location = Berlin | year = 1984 | origyear = | pages = pages 45–48 | quote = | isbn = 0-387-12056-4 | oclc = | doi = | url = | accessdate = }}</ref> Innos humans,humanos thea proteína CD4 proteinestá iscodificada encodedpolo by the[[xene]] ''CD4'' do [[genecromosoma 12]].<ref name="pmid3086883">{{cite journal | author = Isobe M, Huebner K, Maddon PJ, Littman DR, Axel R, Croce CM | title = The gene encoding the T-cell surface protein T4 is located on human chromosome 12 | journal = Proc. Natl. Acad. Sci. U.S.A. | volume = 83 | issue = 12 | pages = 4399–402 | year = 1986 | month = June | pmid = 3086883 | pmc = 323740 | doi = 10.1073/pnas.83.12.4399| url = http://www.pnas.org/cgi/pmidlookup?view=long&pmid=3086883 }}</ref><ref name="pmid8723724">{{cite journal | author = Ansari-Lari MA, Muzny DM, Lu J, Lu F, Lilley CE, Spanos S, Malley T, Gibbs RA | title = A gene-rich cluster between the CD4 and triosephosphate isomerase genes at human chromosome 12p13 | journal = Genome Res. | volume = 6 | issue = 4 | pages = 314–26 | year = 1996 | month = April | pmid = 8723724 | doi = 10.1101/gr.6.4.314| url = http://www.genome.org/cgi/pmidlookup?view=long&pmid=8723724 }}</ref>
 
Os linfocitos T axudantes CD4+ son [[leucocito]]s que son parte esencial do [[sistema inmunitario]] humano e con frecuencia denomínanse células CD4 cells, T-axudantes ou células T4. Denomínanse células axudantes porque un dos seus principais papeis é enviar sinais a outros tipos de células inmunes, como as células asasinas CD8. As células CD4 envían un sinal ás células CD8 para que destrúan acaben coa infección vírica. Se diminúe a cantidade de células CD4, como por exemplo en casos de infección por VIH, ou despois dun tratamento de inmunosupresión previo a u transplante, o corpo faise vulnerable a un grnan número de infeccións que doutro modo sería combatidas eficazmente.
CD4+ T helper cells are [[leukocytes|white blood cells]] that are an essential part of the human immune system. They are often referred to as CD4 cells, T-helper cells or T4 cells. They are called helper cells because one of their main roles is to send signals to other types of immune cells, included CD8 killer cells. CD4 cells send the signal and CD8 cells destroy and kill the infection or virus. If CD4 cells become depleted, for example in untreated HIV infection, or following immune suppression prior to a transplant, the body is left vulnerable to a wide range of infections that it would otherwise have been able to fight.
 
==Estrutura==
[[FileFicheiro:CD4 receptor.png|leftesquerda|thumbminiatura|SchematicRepresentación representationesquemática ofdo receptor CD4 [[Receptor (biochemistry)|receptor]].]]
Like many cell surface receptors/markers, CD4 is a member of the [[immunoglobulin superfamily]].