BoLA-DRB3 exon2 polymorphisms among tuberculous cattle: Nucleotide and functional variability and their association with bovine tuberculosis pathology

EIRIN, M.; CARIGNANO, H.; SHIMIZU, E.; PANDO, M.A.; ZUMÁRRAGA, M.; MAGNANO, G.; MACÍAS, A.; GARBACCIO, S.; HUERTAS, P.; MORSELLA, C.; FERRARA MUÑIZ, X.; CATALDI, A.; PAOLICCHI, F.; POLI, M.

RESEARCH IN VETERINARY SCIENCE

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2020 vol. 130 p. 118 - 125

0034-5288

Bovine tuberculosis (bTB) is caused by Mycobacterium bovis and disseminated worldwide. In Argentina, thehighest prevalence occurs in dairy areas. BoLA DRB3.2 is related to the adaptive immunity in mycobacterialinfections. Genetic polymorphisms of this marker have been associated with resistance or susceptibility to bovinediseases. We evaluated the association between BoLA DRB3.2 polymorphisms and bTB pathology scores in dairyand beef cattle breeds of Argentina. Most bovines exhibited visible lesions compatible with tuberculosis and,furthermore, 150 (85.7%) were also positive by bacteriology. A pathology index showed a variable degree ofdisease, from 3 to 76 (median pathology score=9 (IQR: 7?15)). Thirty-five BoLA DRB3.2 alleles were identifiedwith an associated frequency from 16% to 0.3%, distributed 73% (n = 128) in heterozygosis and 27% (n = 47)in homozygosis, with 12 BoLA DRB3.2 alleles (*0101, *1101, *1501, *0201, *2707 *1001, *1002, *1201,*14011, *0501 *0902 and *0701) representing the 74.7% of the population variability. A functional analysisgrouped them in 4 out of 5 clusters (A-D), suggesting a functional overlapping. Among the 90 identified genotypes,*1101/*1101, *1101/*1501 and *0101/*0101 were the most frequent (10%, 8.9% and 8.9%, respectively).No association was detected between the pathology scores and a specific DRB3.2 allele (p > .05).Animals infected with M. bovis spoligotype SB0153 showed a significantly higher pathology score than thoseaffected by the spoligotype SB0145 (p = .018). Furthermore, the Aberdeen Angus breed exhibited highest pathologicalscores (p < .0001), which were associated with disseminated lesion, thus suggesting that the hostcomponent could be important to the disease progression.