Peripheral blood bovine lymphocytes and MAP show distinctly different proteome changes and immune pathways in host-pathogen interaction

Abstract

Mycobacterium avium subsp. paratuberculosis (MAP) is a pathogen causing paratuberculosis in cattle and small ruminants. During the long asymptomatic subclinical stage, high numbers of MAP are excreted and can be transmitted to food for human consumption, where they survive many of the standard techniques of food decontamination. Whether MAP is a human pathogen is currently under debate. The aim of this study was a better understanding of the host-pathogen response by analyzing the interaction of peripheral blood lymphocytes (PBL) from cattle with MAP in their exoproteomes/secretomes to gain more information about the pathogenic mechanisms of MAP. Because in other mycobacterial infections, the immune phenotype correlates with susceptibility, we additionally tested the interaction of MAP with recently detected cattle with a different immune capacity referred as immune deviant (ID) cows. In PBL, different biological pathways were enhanced in response to MAP dependent on the immune phenotype of the host. PBL of control cows activated members of cell activation and chemotaxis of leukocytes pathway as well as IL-12 mediated signaling. In contrast, in ID cows CNOT1 was detected as highly abundant protein, pointing to a different immune response, which could be favorable for MAP. Additionally, MAP exoproteomes differed in either GroEL1 or DnaK abundance, depending on the interacting host immune response. These finding point to an interdependent, tightly regulated response of the bovine immune system to MAP and vise versa.

Bovine Peripheral Blood Derived Lymphocyte Proteome and Secretome Show Divergent Reaction of Bovine Immune Phenotypes after Stimulation with Pokeweed Mitogen

“…Analysis of peptides was performed as described [ 5 , 12 ]. Acidified eluted peptides were analyzed in the data-dependent mode on a Q Exactive HF mass spectrometer (Thermo Fisher Scientific, Bremen, Germany) online coupled to an UItimate 3000 RSLC nano-HPLC (Dionex, Sunnyvale, CA, USA).…”

Mycobacterium avium subsp. paratuberculosis Infected Cows Reveal Divergent Immune Response in Bovine Peripheral Blood Derived Lymphocyte Proteome

“…In clinically infected cattle it causes weight loss, diarrhea, and reduced milk yields, and therefore causes major economic losses for the farmer [ 3 , 7 ]. After infection, ruminants usually go through a long, asymptomatic subclinical phase during which MAP cannot reliably be detected by standard diagnostic tests [ 8 , 9 ]. These infected but unrecognized animals are the major spreaders of the disease in livestock and remain difficult to identify because available diagnostic tests are not sensitive enough to detect them [ 10 ].…”

“…On farms where natural MAP infections are detected, there are always differences in the susceptibility of some cattle to the infection. In a previous study, we showed that co-incubation of MAP and peripheral blood mononuclear cells (PBMC) from cows from a MAP-free farm with different immunophenotypes responded to co-incubation with MAP with increased abundance of proteins that can promote MAP infection and persistence [ 18 ], while a classical IL-12-driven immune response was observed in control cows [ 8 ]. On farms with established MAP occurrence, some cows were more susceptible to MAP infection than others [ 10 ].…”

Mycobacterium avium subsp. paratuberculosis Proteome Changes Profoundly in Milk

“…A good example for this environment-dependent variation are cell wall-deficient forms of MAP that were repeatedly isolated from human intestines [ 6 , 28 , 29 , 30 ]. In a previous study, we showed that after incubation of MAP with peripheral blood mononuclear cell (PBMC) of cows with different immunological phenotypes, the exoproteome of MAP changed according to the immunological phenotype of the leukocytes used for coincubation [ 31 ]. For milk, altered properties of MAP were shown by an in vitro experiment, in which incubation of MAP in milk led to faster translocation through a monolayer of Madin–Darby bovine kidney epithelial cells (MDBK) cells [ 32 ].…”