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Updated: Aug 9, 2026
A 3D Human Lung Tissue Model for Functional Studies on Mycobacterium tuberculosis Infection
Published on: October 5, 2015
Lymphocyte subsets in granulomas of human tuberculosis: an in situ immunofluorescence study using monoclonal
1Department of Pathology, Presbyterian-University Hospital, University of Pittsburgh School of Medicine.
Insights
Human tuberculosis lesions show a T cell infiltrate, with fewer CD4 helper cells than normal tissues. This finding impacts understanding of the immune response in tuberculosis.
Area of Science:
- Immunology
- Pathology
- Microbiology
Background:
- Tuberculosis (TB) is a significant global health challenge.
- Understanding the immune cell infiltrate in TB lesions is crucial for developing effective treatments.
Purpose of the Study:
- To investigate the immunophenotypic characteristics of lymphocyte subpopulations in human TB tissue lesions.
- To compare the distribution of T cells, specifically CD4+ and CD8+ T cells, in TB lesions with normal tissues.
Main Methods:
- Analysis of frozen sections from 18 human cervical lymph node TB lesions.
- Staining using a panel of monoclonal antibodies and avidin-biotin immunofluorescence.
- Quantification of lymphocyte subpopulations including CD3, CD4, CD8, HLA-DR, and IgM.
Main Results:
- Lesions showed a predominantly T cell infiltrate (CD3+ cells: 44%).
- The mean CD4/CD8 ratio was 1.3:1.
- A significantly lower proportion of CD4+ (helper/inducer) cells was observed in TB lesions compared to circulation, reactive lymph nodes, and PPD injection sites.
Conclusions:
- Tuberculosis infection is associated with a distinct T cell infiltrate in lesional tissues.
- The reduced presence of CD4+ T cells in TB lesions suggests a complex immune modulation by the infection.
- Further research into the role of specific lymphocyte subpopulations in TB pathogenesis is warranted.
Abstract:
The immunophenotypic characteristics of lymphocyte subpopulations in tissue lesions of human tuberculosis were investigated in 18 cases. Frozen sections of affected cervical lymph nodes were stained with a panel of monoclonal antibodies using avidin-biotin immunofluorescence technique. The mean percentage of cells staining with different antibodies was as follows: CD3 44%; CD4 43%; CD8 36%; HLA-DR 86%; and IgM 29%. The mean CD4/CD8 ratio was 1.3:1. Leu7 and CD1 staining cells were very sparsely distributed in the granulomas. Thus, infection with tuberculosis is associated with a predominantly T cell infiltrate in lesional tissues. The proportion of CD4 positive (helper/inducer) cells at these sites is much lower than that seen (i) in the normal circulation, (ii) in reactive lymph nodes and (iii) at the site of purified protein derivative (PPD) injection in healthy tuberculin-responsive individuals.
