Anti-cytokine antibodies as carrier proteins. Prolongation of in vivo effects of exogenous cytokines by injection of cytokine-anti-cytokine antibody complexes.

Abstract

Anti-cytokine antibodies that block interactions between cytokines and cytokine receptors have been used to inhibit endogenous cytokine function. However, injection of mice with mixtures of IL-4 and either of two neutralizing anti-IL-4 mAb, at a cytokine/anti-cytokine mAb molar ratio of approximately 2:1, enhances and prolongs in vivo IL-4 activity, as measured by induction of increased spleen cell Ia expression. Although splenocyte Ia expression returns to baseline two days after mice are injected with free IL-4, soluble IL-4-anti-IL-4 mAb complexes still induce several-fold increases in Ia expression 3 days after injection. Complexes that contain as little as 400 ng of IL-4 have considerable in vivo stimulatory activity, and a maximal effect on splenocyte Ia expression is induced by injection of 2 micrograms of complexed IL-4. The stimulatory effect of IL-4-containing complexes on splenocyte Ia expression can be blocked by increasing the ratio of anti-IL-4 mAb to IL-4, by injection of anti-IL-4R mAb, and by in vivo aggregation of the complexes. Complexes of IL-4 with a non-neutralizing anti-IL-4 mAb do not have increased IL-4 agonist activity in vivo. These observations are most consistent with the possibility that neutralizing anti-IL-4 mAb act as carrier proteins that increase the in vivo half-life of IL-4 by preventing its excretion, and possibly, by preventing modification of its active site. The enhanced agonist effect of IL-4-anti-IL-4 mAb complexes is not unique; complexes of IL-3 with a neutralizing anti-IL-3 mAb have a greatly increased ability, compared with free IL-3, to stimulate mucosal mastocytosis, and complexes of IL-7 with a neutralizing anti-IL-7 mAb have a greatly increased ability, compared with free IL-7 or IL-7 complexed with a non-neutralizing anti-IL-7 mAb, to stimulate an increase in pre-B cell number. These observations suggest that complexes of cytokines and neutralizing anti-cytokine mAb may provide a generally useful way to increase the magnitude and duration of cytokine effects in vivo.

Inactive disease in patients with lupus is linked to autoantibodies to type I interferons that normalize blood IFNα and B cell subsets

“…These results suggest that non-neutralizing anti-IFN-Abs may stabilize circulating IFNα levels as previously suggested for other cytokines. 34 , 35 , 36 Patients lacking anti-IFN-Abs present active disease over time ( Figure 2 D). Neither the titers of anti-IFN-Abs nor IFNα serum levels were affected by treatment regime ( Figures S3 F–S3H).…”

Eosinophil‐derived IL ‐4 is necessary to establish the inflammatory structure in innate inflammation

“…In support of this hypothesis, eosinophil depletion decreased the total IL‐4 levels in the inflamed paws 8 and 24 h after zymosan injection (Fig 6A ). To determine whether the altered resolution of inflammation induced by eosinophil depletion can be rescued by IL‐4 application, we administered a stabilized form of IL‐4 (IL‐4c) (Finkelman et al , 1993 ; Milner et al , 2010 ; Jenkins et al , 2011 ). Administration of IL‐4c did neither affect recruitment of eosinophils (Fig 6B ) nor the number of resident (Ly6C − /CD45 + /F4‐80 + ) or monocyte‐derived macrophages (Ly6C + /CD45 + /F4‐80 + ) (Fig 6C ).…”

“…As control purified rat IgG2a (Biolegend, San Diego, USA) was used. IL‐4c was prepared using IL‐4 (Peprotech, Hamburg, Germany) and anti‐IL4 antibody (Biolegend, San Diego, USA) (Finkelman et al , 1993 ; Milner et al , 2010 ; Jenkins et al , 2011 ) and administered i.p. (0.166 mg/kg IL‐4 and 0.883 mg/kg anti‐IL4 antibody) 24 h prior zymosan injection.…”

Treg Therapy for the Induction of Immune Tolerance in Transplantation—Not Lost in Translation?

“…Another problem with low-dose IL-2 therapy is that the half life of IL-2 is very short, hence IL-2 has to be administered by repeated infusion. However, the half life of IL-2 and other related cytokines in vivo can be greatly extended by complexing the cytokines with specific antibodies before injection [ 61 ]. Moreover, in addition to increasing the duration and magnitude of T-cell responses in vivo, cytokine/antibody complexes can be used to selectively stimulate particular T-cell subsets.…”