Comparative study of IgA V_H3 gene usage in healthy TST⁻ and TST⁺ population exposed to tuberculosis: deep sequencing analysis

Abstract

SummaryThe acquired immune response against tuberculosis is commonly associated with T-cell responses with little known about the role of B cells or antibodies. There have been suggestions that B cells and humoral immunity can modulate the immune response to Mycobacterium tuberculosis. However, the mechanisms involving B-cell responses in M. tuberculosis are not fully understood, in particular the antibody gene preferences. We hypothesized that a preferential use of V genes can be seen associated with resistance to infection mainly in the IgA isotype, which is of prominent importance for infection by pathogens via the mucosal route. We studied healthy individuals with long-term exposure to tuberculosis, infected (TST + ) and uninfected TST À ) with M. tuberculosis. From a total of 22 V genes analysed, the TST À population preferred the V H 3-23 and Vj1 genes. The V H 3-23 genes were subsequently subjected to 454 amplicon sequencing. The TST À population showed a higher frequency of the D3-10 segment compared with the D3-22 segment for the TST + population. The J segment usage pattern was similar for both populations with J4 segment being used the most. A preferential pairing of J4 segments to D3-3 was seen for the TST À population.The antibodyome difference between both populations suggests a preference for antibodies with V H 3-23, D3-3, J H 4 gene usage by the TST À population that could be associated with resistance to infection with M. tuberculosis.

Antibodies and tuberculosis

“…Genome-wide linkage survey performed on these patients revealed two loci potentially responsible for this phenotype on chromosomes 11p14 and 5p15 linked to a TNF-α response element [42]. A similar cohort of nurses in a TB ward that remained TST-negative despite years of exposure underwent antibody repertoire sequencing with next-generation sequencing [43]. Here an IgA gene rearrangement of VH3-23-D3-3-J4 was predominant amongst those nurses who remained TST-negative and did not develop active disease compared to their TST reactive colleagues [43].…”

“…A similar cohort of nurses in a TB ward that remained TST-negative despite years of exposure underwent antibody repertoire sequencing with next-generation sequencing [43]. Here an IgA gene rearrangement of VH3-23-D3-3-J4 was predominant amongst those nurses who remained TST-negative and did not develop active disease compared to their TST reactive colleagues [43]. An earlier study of nurses exposed to TB revealed a strong antibody response against a non-immunodominant epitope of Acr [44].…”

Human T‐cell receptor V gene segment of alpha and beta families: A revised primer design strategy

“…The absence of amplicons after amplification might be due to the absence of a specific gene in an individual due to the variation in TCR gene repertoire in individuals . The repertoire variation of individuals resulting in different TCR V gene frequency in every individual is most likely due to genetic variation, different medical history, and immune responses . Annealing temperature optimization is required due to the high melting temperature difference of the primer pair and the degeneracy content , which can result in nonspecific amplification by the primer set .…”

Pulmonary non-tuberculous mycobacterial infections: current state and future management

“…The growing consensus about the protective role of antibodies in mycobacterial infections [294][295][296][297][298] suggests the potential use of antibody formulations for the treatment of PNTM. Previous studies have demonstrated the role of humoral immune responses in the defence against mycobacteria in humans [299][300][301].…”