CD8 T Cells Modulate CD4 T-Cell and Eosinophil-Mediated Pulmonary Pathology in Pneumocystis Pneumonia in B-Cell-Deficient Mice

mRNA based vaccines for SARS-CoV-2 have shown exceptional clinical efficacy providing robust protection against severe disease. However, our understanding of transcriptional and repertoire changes following full vaccination remains incomplete. We used single-cell RNA sequencing and functional assays to compare humoral and cellular responses to two doses of mRNA vaccine with responses observed in convalescent individuals with asymptomatic disease. Our analyses revealed enrichment of spike-specific B cells, activated CD4 T cells, and robust antigen-specific polyfunctional CD4 T cell responses in all vaccinees. On the other hand, CD8 T cell responses were both weak and variable. Interestingly, clonally expanded CD8 T cells were observed in every vaccinee, as observed following natural infection. TCR gene usage, however, was variable, reflecting the diversity of repertoires and MHC polymorphism in the human population. Natural infection induced expansion of larger CD8 T cell clones occupied distinct clusters, likely due to the recognition of a broader set of viral epitopes presented by the virus not seen in the mRNA vaccine. Our study highlights a coordinated adaptive immune response where early CD4 T cell responses facilitate the development of the B cell response and substantial expansion of effector CD8 T cells, together capable of contributing to future recall responses.

Download Full-text

Cyclophosphamide Plus Allogeneic CD4+ T Cell Infusion Induces Anti-Lymphoma Immunity Despite Lack of Graft-Versus-Host Disease (GVHD) or Sustained Engraftment.

Blood ◽

10.1182/blood.v104.11.3063.3063 ◽

2004 ◽

Vol 104 (11) ◽

pp. 3063-3063

Author(s):

Sanju Jalla ◽

Jie Wang ◽

Leo Luznik ◽

Ephraim J. Fuchs

Keyword(s):

T Cells ◽

T Cell ◽

B Cell ◽

Tumor Immunity ◽

Cd8 T Cells ◽

Cd4 T Cells ◽

Cd4 T Cell ◽

Cell Leukemia ◽

B Cell Leukemia ◽

T Cell Help

Abstract Recent evidence suggests that tumor-bearing animals contain CD8+ T cells that can respond productively to a tumor vaccine, but that these T cells do not respond because of insufficient help from tumor-specific CD4+ T cells, which have either been inactivated or turned into anti-tumor suppressor T cells. We therefore devised a strategy to augment anti-tumor immunity by administering cyclophosphamide (Cy), to eliminate suppressor CD4+ T cells, followed by combining autologous tumor cell vaccination and infusion of partially MHC-mismatched, or haploidentical, CD4+ T cells as a source of T cell help for endogenous CD8+ T cells. Interestingly, the combination of Cy followed by haploidentical T cell infusion, with or without vaccine, induced potent systemic anti-tumor immunity resulting in cure of 40-50% of BALB/c mice harboring the A20 B cell leukemia/lymphoma. Depletion of CD8+ T cells from the infusate abrogated GVHD but did not compromise anti-tumor immunity. Allogeneic donor spleen cells that contained CD8+ T cells engrafted durably and caused lethal GVHD. In contrast, the combination of Cy plus CD8+ T cell-depleted spleen cell infusion induced only transient engraftment, peaking on day 7 and declining to undetectable levels by day 14. In the absence of Cy conditioning, allogeneic donor spleen cell infusions did not induce detectable chimerism beyond day 3. In summary, Cy plus allogeneic CD4+ T cell infusion induces potent anti-tumor immunity in a mouse model of B cell leukemia/lymphoma. Potential mechanisms of the therapeutic effect include direct tumor cytotoxicity by CD4+ T cells or allogeneic CD4+ T cell help for endogenous, tumor-specific CD8+ T cells.

Download Full-text

Spontaneous CD4+ T Cell Activation and Differentiation in Lupus-Prone B6.Nba2 Mice Is IFNAR-Independent

International Journal of Molecular Sciences ◽

10.3390/ijms23020874 ◽

2022 ◽

Vol 23 (2) ◽

pp. 874

Author(s):

Emma J. Keller ◽

Nina Dvorina ◽

Trine N. Jørgensen

Keyword(s):

T Cells ◽

T Cell ◽

B Cell ◽

T Cell Activation ◽

Cd8 T Cells ◽

Lupus Erythematosus ◽

Cell Activation ◽

Cd4 T Cell ◽

Type I ◽

Autoantibody Production

Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by dysregulated T and B lymphocytes. Type I interferons (IFN-I) have been shown to play important pathogenic roles in both SLE patients and mouse models of lupus. Recent studies have shown that B cell intrinsic responses to IFN-I are enough to drive B cell differentiation into autoantibody-secreting memory B cells and plasma cells, although lower levels of residual auto-reactive cells remain present. We speculated that IFN-I stimulation of T cells would similarly drive specific T-cell associated lupus phenotypes including the upregulation of T follicular helper cells and Th17, thereby affecting autoantibody production and the development of glomerulonephritis. Using the B6.Nba2 mouse model of lupus, we evaluated disease parameters in T cell specific IFN-I receptor (IFNAR)-deficient mice (cKO). Surprisingly, all measured CD4+ T cell abnormalities and associated intra-splenic cytokine levels (IFNγ, IL-6, IL-10, IL-17, IL-21) were unchanged and thus independent of IFN-I. In contrast B6.Nba2 cKO mice displayed reduced levels of effector CD8+ T cells and increased levels of Foxp3+ CD8+ regulatory T cells, suggesting that IFN-I induced signaling specifically affecting CD8+ T cells. These data suggest a role for both pathogenic and immunosuppressive CD8+ T cells in Nba2-driven autoimmunity, providing a model to further evaluate the role of these cell subsets during lupus-like disease development in vivo.

Download Full-text

An Optimized CD4 T-Cell Response Can Control Productive and Latent Gammaherpesvirus Infection

Journal of Virology ◽

10.1128/jvi.78.13.6827-6835.2004 ◽

2004 ◽

Vol 78 (13) ◽

pp. 6827-6835 ◽

Cited By ~ 42

Author(s):

Rebecca L. Sparks-Thissen ◽

Douglas C. Braaten ◽

Scott Kreher ◽

Samuel H. Speck ◽

Herbert W. Virgin

Keyword(s):

T Cells ◽

T Cell ◽

B Cells ◽

B Cell ◽

Cd8 T Cells ◽

Cd4 T Cells ◽

Acute Infection ◽

Cd8 T Cell ◽

T Cell Response ◽

Cd4 T Cell

ABSTRACT CD4 T cells are important for control of infection with murine gammaherpesvirus 68 (γHV68), but it is not known whether CD4 T cells function via provision of help to other lymphocyte subsets, such as B cells and CD8 T cells, or have an independent antiviral function. Moreover, under conditions of natural infection, the CD4 T-cell response is not sufficient to eliminate infection. To determine the functional capacities of CD4 T cells under optimal or near-optimal conditions and to determine whether CD4 T cells can control γHV68 infection in the absence of CD8 T cells or B cells, we studied the effect of ovalbumin (OVA)-specific CD4 T cells on infection with a recombinant γHV68 that expresses OVA. OVA-specific CD4 T cells limited acute γHV68 replication and prolonged the life of infected T-cell receptor-transgenic RAG (DO.11.10/RAG) mice, demonstrating CD4 T-cell antiviral activity, independent of CD8 T cells and B cells. Despite CD4 T-cell-mediated control of acute infection, latent infection was established in DO.11.10/RAG mice. However, OVA-specific CD4 T cells reduced the frequency of latently infected cells both early (16 days postinfection) and late (42 days postinfection) after infection of mice containing CD8 T cells and B cells (DO.11.10 mice). These results show that OVA-specific CD4 T cells have B-cell and CD8 T-cell-independent antiviral functions in the control of acute infection and can, in the absence of preexisting CD8 T-cell or B-cell immunity, inhibit the establishment of gammaherpesvirus latency.

Download Full-text

Faculty Opinions recommendation of Chemokines enhance immunity by guiding naive CD8+ T cells to sites of CD4+ T cell-dendritic cell interaction.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1029236.374061 ◽

2006 ◽

Author(s):

Allan Zajac

Keyword(s):

T Cells ◽

T Cell ◽

Dendritic Cell ◽

Cd8 T Cells ◽

Cell Interaction ◽

Cd4 T Cell

Download Full-text

Faculty Opinions recommendation of CD40-CD40 ligand interaction between dendritic cells and CD8+ T cells is needed to stimulate maximal T cell responses in the absence of CD4+ T cell help.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1071829.524753 ◽

2007 ◽

Author(s):

Marcia Blackman

Keyword(s):

T Cells ◽

Dendritic Cells ◽

T Cell ◽

Cd8 T Cells ◽

T Cell Responses ◽

Cd40 Ligand ◽

Cd4 T Cell ◽

Ligand Interaction ◽

Cell Responses ◽

T Cell Help

Download Full-text

Longitudinal Changes in Cd4+, Cd8+ T Cell Phenotype and Activation Marker Expression Following Antiretroviral Therapy Initiation among Patients with Cryptococcal Meningitis

Journal of Fungi ◽

10.3390/jof5030063 ◽

2019 ◽

Vol 5 (3) ◽

pp. 63

Author(s):

Alice Bayiyana ◽

Samuel Okurut ◽

Rose Nabatanzi ◽

Godfrey Zziwa ◽

David R. Boulware ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Antiretroviral Therapy ◽

Cell Surface ◽

Cd8 T Cells ◽

Cryptococcal Meningitis ◽

Cd8 T Cell ◽

Cd4 T Cell ◽

Effector Memory ◽

Memory Subset

Despite improvement in the prognosis of HIV/AIDS (human immunodeficiency virus/acquired immune deficiency syndrome) patients on antiretroviral therapy (ART), cryptococcal meningitis (CM) still causes 10–15% mortality among HIV-infected patients. The immunological impact of ART on the CD4+ and CD8+ T cell repertoire during cryptococcal co-infection is unclear. We determined longitudinal phenotypic changes in T cell subsets among patients with CM after they initiated ART. We hypothesized that ART alters the clonotypic phenotype and structural composition of CD4+ and CD8+ T cells during CM co-infection. For this substudy, peripheral blood mononuclear cells (PBMC) were isolated at four time points from CM patients following ART initiation during the parent study (ClinicalTrials.gov number, NCT01075152). Phenotypic characterization of CD4+ and CD8+ T cells was done using T cell surface marker monoclonal antibodies by flow cytometry. There was variation in the expression of immunophenotypic markers defining central memory (CD27+CD45R0+), effector memory (CD45R0+CD27–), immune activation (CD38+ and Human Leucocyte Antigen DR (HLA-DR+), and exhaustion (Programmed cell death protein one (PD-1) in the CD4+ T cell subset. In comparison to the CD4+ T cell population, the CD8+ central memory subset declined gradually with minimal increase in the effector memory subset. Both CD4+ and CD8+ T cell immune exhaustion and activation markers remained elevated over 12 weeks. The relative surge and decline in the expression of T cell surface markers outlines a variation in the differentiation of CD4+ T cells during ART treatment during CM co-infection.

Download Full-text

Reduced immune-regulatory molecule expression on human colonic memory CD4 T cells in older adults

Immunity & Ageing ◽

10.1186/s12979-021-00217-0 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Stephanie M. Dillon ◽

Tezha A. Thompson ◽

Allison J. Christians ◽

Martin D. McCarter ◽

Cara C. Wilson

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cd4 T Cells ◽

Older Persons ◽

Age Groups ◽

T Cell Immunity ◽

Cd4 T Cell ◽

Cell Immunity ◽

Memory Cd4 T Cells

Abstract Background The etiology of the low-level chronic inflammatory state associated with aging is likely multifactorial, but a number of animal and human studies have implicated a functional decline of the gastrointestinal immune system as a potential driver. Gut tissue-resident memory T cells play critical roles in mediating protective immunity and in maintaining gut homeostasis, yet few studies have investigated the effect of aging on human gut T cell immunity. To determine if aging impacted CD4 T cell immunity in the human large intestine, we utilized multi-color flow cytometry to measure colonic lamina propria (LP) CD4 T cell frequencies and immune-modulatory marker expression in younger (mean ± SEM: 38 ± 1.5 yrs) and older (77 ± 1.6 yrs) adults. To determine cellular specificity, we evaluated colon LP CD8 T cell frequency and phenotype in the same donors. To probe tissue specificity, we evaluated the same panel of markers in peripheral blood (PB) CD4 T cells in a separate cohort of similarly aged persons. Results Frequencies of colonic CD4 T cells as a fraction of total LP mononuclear cells were higher in older persons whereas absolute numbers of colonic LP CD4 T cells per gram of tissue were similar in both age groups. LP CD4 T cells from older versus younger persons exhibited reduced CTLA-4, PD-1 and Ki67 expression. Levels of Bcl-2, CD57, CD25 and percentages of activated CD38+HLA-DR+ CD4 T cells were similar in both age groups. In memory PB CD4 T cells, older age was only associated with increased CD57 expression. Significant age effects for LP CD8 T cells were only observed for CTLA-4 expression, with lower levels of expression observed on cells from older adults. Conclusions Greater age was associated with reduced expression of the co-inhibitory receptors CTLA-4 and PD-1 on LP CD4 T cells. Colonic LP CD8 T cells from older persons also displayed reduced CTLA-4 expression. These age-associated profiles were not observed in older PB memory CD4 T cells. The decline in co-inhibitory receptor expression on colonic LP T cells may contribute to local and systemic inflammation via a reduced ability to limit ongoing T cell responses to enteric microbial challenge.

Download Full-text

HIV-Related Arterial Stiffness in Malawian Adults Is Associated With the Proportion of PD-1–Expressing CD8+ T Cells and Reverses With Antiretroviral Therapy

The Journal of Infectious Diseases ◽

10.1093/infdis/jiz015 ◽

2019 ◽

Vol 219 (12) ◽

pp. 1948-1958 ◽

Cited By ~ 1

Author(s):

Christine Kelly ◽

Henry C Mwandumba ◽

Robert S Heyderman ◽

Kondwani Jambo ◽

Raphael Kamng’ona ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Antiretroviral Therapy ◽

Arterial Stiffness ◽

Cell Count ◽

Cd8 T Cells ◽

Sub Saharan Africa ◽

Cd4 T Cell ◽

Sub Saharan ◽

Cd4 T Cell Count

Abstract Background The contribution of immune activation to arterial stiffness and its reversibility in human immunodeficiency virus (HIV)–infected adults in sub-Saharan Africa is unknown. Methods HIV-uninfected and HIV-infected Malawian adults initiating antiretroviral therapy (ART) with a CD4+ T-cell count of <100 cells/μL were enrolled and followed for 44 weeks; enrollment of infected adults occurred 2 weeks after ART initiation. We evaluated the relationship between carotid femoral pulse wave velocity (cfPWV) and T-cell activation (defined as HLA-DR+CD38+ T cells), exhaustion (define as PD-1+ T cells), and senescence (defined as CD57+ T cells) and monocyte subsets, using normal regression. Results In 279 HIV-infected and 110 HIV-uninfected adults, 142 (37%) had hypertension. HIV was independently associated with a 12% higher cfPWV (P = .02) at baseline and a 14% higher cfPWV at week 10 (P = .02), but the increases resolved by week 22. CD4+ and CD8+ T-cell exhaustion were independently associated with a higher cfPWV at baseline (P = .02). At 44 weeks, arterial stiffness improved more in those with greater decreases in the percentage of CD8+ T cells and the percentage of PD-1+CD8+ T cells (P = .01 and P = .03, respectively). When considering HIV-infected participants alone, the adjusted arterial stiffness at week 44 tended to be lower in those with higher baseline percentage of PD-1+CD8+ T cells (P = .054). Conclusions PD-1+CD8+ T-cells are associated with HIV-related arterial stiffness, which remains elevated during the first 3 months of ART. Resources to prevent cardiovascular disease in sub-Saharan Africa should focus on blood pressure reduction and individuals with a low CD4+ T-cell count during early ART.

Download Full-text