Characterization of the draining lymph node response in the mouse drug allergy model: A model for drug hypersensitivity reactions

Abstract

The mouse drug allergy model (MDAM) was developed as a tool to predict the potential of systemically administered drugs to produce hypersensitivity reactions (HR). Drugs associated with HR in the clinic produce a marked increase in the cellularity of the draining lymph nodes (DLN) in the MDAM. The objective of this study was to characterize the changes in the DLN following exposure to drugs associated with HR and to investigate whether lymphocyte migration and/or proliferation play a role in the response. These endpoints were also investigated in the local lymph node assay (LLNA) to determine whether responses between the two assays occur via similar mechanisms. Results demonstrated that total numbers of Tand B-cells were proportionally increased in the DLN of mice treated with positive control drugs (i.e. abacavir, amoxicillin, ofloxacin, and sulfamethoxazole) compared to animals administered the vehicle or negative control drugs (metformin and cimetidine). In contrast, a significant increase in the B-cell population of the DLN was observed for 2,4-dinitrofluorobenzene (DNFB) following the LLNA protocol. Down-regulation of CD62L and up-regulation of CCR7 were observed for T-cells from the DLN of the positive control treated mice in the MDAM, but not with DNFB in the LLNA. A mild increase in T-cell proliferation was observed in the MDAM with positive control drugs, while DNFB in the LLNA induced proliferation within the B-cell population only. Anti-CD40L antibody administration inhibited MDAM responses to positive control drugs, but did not affect DNFB-induced increases in total cell number in the LLNA. These results suggest that the increased cellularity of the DLN in the MDAM may be the result of drug-induced alterations in lymphocyte migration and/or effects on lymphocyte proliferation. Moreover, it appears that different mechanisms may be involved in driving the MDAM and LLNA responses.

Enzalutamide and Apalutamide: In Vitro Chemical Reactivity Studies and Activity in a Mouse Drug Allergy Model

“…Molecules associated with T cell-mediated hypersensitivity in humans have been shown to be positive in this model, which is a modification of the lymph node proliferation assay . Following subcutaneous administration of test compounds in C57BL/6 mice, we demonstrated an increase in draining lymph node cellularity with a proportional increase in the number of T cells (CD4+ and CD8+) and B cells …”

“…Studies were conducted as described previously. , Briefly, female C57BL/6 mice (Jackson Laboratories, Bar Harbor, ME, U.S.A.), 5–7-weeks old, were acclimated for at least 7 days prior to use. Groups of five mice received 200 μL of either vehicle (10% DMSO), metformin (100 mg/kg/day; negative control), ofloxacin (100 mg/kg/day; positive control), or test compounds at a dose of 25, 50, or 100 mg/kg/day (via subcutaneous injection in the scruff of the neck) for 3 consecutive days.…”

“…22 Following subcutaneous administration of test compounds in C57BL/6 mice, we demonstrated an increase in draining lymph node cellularity with a proportional increase in the number of T cells (CD4+ and CD8+) and B cells. 23 Because of the difference in the chemical structures between apalutamide and enzalutamide, along with the reported prevalence of skin rash with apalutamide, we hypothesized that the 2-cyanopyridine substituent of apalutamide may be responsible for the development of skin toxicity. The experiments reported herein were designed to test this hypothesis using several methods.…”

New Approaches to Investigate Drug-Induced Hypersensitivity

“…Jessica Whritenour (Pfizer) and her colleagues have developed a mouse allergy model based on lymph node proliferation. 188,189 The assay involves subcutaneous administration of test compounds once daily for 3 days followed by a 2 day rest and then assessment of lymph node cellularity by flow cytometry on day 6. A stimulation index [mean total cell number (treatment group)/ mean total cell number (vehicle group)] ≥ 2.5 is considered a positive response.…”

“…Some of the challenges associated with the development of animal models of drug hypersensitivity include incomplete understanding of the mechanisms driving the reactions, the relative roles of different mechanisms and risk factors, and the rarity of observing these reactions during early toxicity studies. Jessica Whritenour (Pfizer) and her colleagues have developed a mouse allergy model based on lymph node proliferation. , The assay involves subcutaneous administration of test compounds once daily for 3 days followed by a 2 day rest and then assessment of lymph node cellularity by flow cytometry on day 6. A stimulation index [mean total cell number (treatment group)/mean total cell number (vehicle group)] ≥ 2.5 is considered a positive response.…”