Provided are isolated antibodies or fragments thereof which bind a peptide consisting of residues Leu.sub.63 -Phe.sub.64 -Lys.sub.65 -Gly.sub.66 -Gln.sub.67 -Gly.sub.68 -Cys.sub.69 -Pro.sub.70 -Ser.sub.71 -Thr.sub.72 -His.sub.73 -Val.sub.74 -Leu.sub.75 -Leu.sub.76 -Thr.sub.77 -His.sub.78 -Thr.sub.79 -Ile.sub.80 -Ser.sub.81 -Arg.sub.82 -Ile.sub.83 (peptide 304) of mature human TNF-.alpha.. The antibodies and fragments thereof may be used to identify antibodies capable of binding in the region of mature human TNF-.alpha. of amino acid resides 63-83. Antibodies or fragments thereof which bind particular regions of mature human TNF-.alpha. are shown to elicit particular biological activities dependent upon the particular region wherein binding occurs.

Desde que são os antibodies ou os fragmentos isolados disso que ligam os resíduos consistindo Leu.sub.63 de um peptide - Phe.sub.64 - Lys.sub.65 - Gly.sub.66 - Gln.sub.67 - Gly.sub.68 - Cys.sub.69 - Pro.sub.70 - Ser.sub.71 - Thr.sub.72 - His.sub.73 - Val.sub.74 - Leu.sub.75 - Leu.sub.76 - Thr.sub.77 - His.sub.78 - Thr.sub.79 - Ile.sub.80 - Ser.sub.81 - Arg.sub.82 - Ile.sub.83 (peptide 304) do ser humano maduro TNF-.alpha.. Os antibodies e os fragmentos disso podem ser usados identificar os antibodies capazes de ligar na região do ser humano maduro TNF-.alpha. do amino-ácido residem 63-83. Os antibodies ou os fragmentos que ligam regiões particulares do ser humano maduro TNF-.alpha. são mostrados disso para eliciar as atividades biológicas particulares dependentes da região particular wherein ligar ocorre.